fix(tui): prevent session picker crash

Track footer focus by stable command and initialize option state before action bindings can evaluate selection-dependent availability.

Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>

.changeset/calm-services-start.md

@@ -0,0 +1,5 @@
+---
+"@opencode-ai/client": patch
+---
+
+Reuse a same-version background service when a repeated health probe succeeds instead of replacing an endpoint another client may already be using.

CONTEXT.md

@@ -1,245 +0,0 @@
-# OpenCode Session Runtime
-
-OpenCode sessions preserve durable conversational history while assembling the runtime context an agent needs to act correctly in its current environment.
-
-## Language
-
-**Model Context**:
-The complete model-visible input assembled for one **Step**, including system instructions, **Session History**, tool definitions, and step-local additions. **Instructions** are one component of Model Context, not a synonym for it.
-_Avoid_: System Context
-
-**Instructions**:
-The opaque algebra of independently refreshable typed instruction sources that render the durable instruction baseline and chronological updates shown to the model.
-_Avoid_: Model Context, System Context
-
-**Session History**:
-The projected chronological conversation selected for a **Step** after applying the active compaction boundary and interleaving derived **Instruction Updates** from the current **Instruction Epoch**.
-_Avoid_: Session Context
-
-**Instruction Source**:
-One independently read typed value within **Instructions**, represented by a stable namespaced key, canonical JSON codec, pure first/changed renderers, and an optional removal renderer.
-_Avoid_: Prompt fragment
-
-**InstructionEntry**:
-One API-managed, durable, per-Session instruction value. Its slash-free client key maps to the `api/<key>` **Instruction Source** key. Entries deliberately render to the model as mechanism-neutral `<context>` blocks: the model sees session context, not how it was attached.
-
-**InstructionDiscovery**:
-The Location-scoped service that observes ambient global and upward-project `AGENTS.md` files as one ordered aggregate **Instruction Source**.
-
-**Instruction State**:
-The Session-owned projection cache of one instruction log fold: epoch start, values at that start, current values, and the last folded sequence. It is rebuilt from durable events and never authors model-visible facts.
-
-**Instruction Update**:
-A durable `session.instructions.updated` value delta admitted at a **Safe Step Boundary**. Its model-visible System text is rendered from stored values at request assembly and is never persisted verbatim.
-_Avoid_: Correction, stored prose, raw text diff
-
-**Initial Instructions**:
-The deterministic instruction text rendered from values at the current **Instruction Epoch** start and sent as provider-cache prefix state until completed compaction moves the epoch or Session movement or committed revert resets it.
-_Avoid_: Live system prompt
-
-**Instruction Epoch**:
-The span between completed compactions. Its start is the last `session.compaction.ended` sequence, or the initial complete instruction delta when no prior epoch exists.
-
-**Instruction Values**:
-The key-to-hash map produced by folding instruction deltas in durable sequence order. Hash bodies live once in the content-addressed instruction blob store.
-
-**Unavailable Instruction Source**:
-An expected temporary inability to read an **Instruction Source** value; the runtime retains its prior effective value and emits no update, while an unavailable source blocks the initial complete delta.
-
-**Safe Step Boundary**:
-The point during Step preparation, after prior tool settlement and before durable input promotion, where instruction changes may be admitted chronologically.
-
-**Admitted Prompt**:
-A durable user input accepted into the Session inbox but not yet included in **Session History**.
-
-**Prompt Promotion**:
-The durable transition that removes an **Admitted Prompt** from pending input and appends its user message to **Session History**.
-
-**Step**:
-One logical LLM call spanning pre-flight instruction synchronization, input promotion, request build, and compaction check; the provider stream; and tool settlement.
-_Avoid_: provider turn, turn (unqualified)
-
-**Physical Attempt**:
-One actual provider request on the wire in service of a **Step**; most Steps have one Physical Attempt, while overflow-triggered compaction recovery may give one Step two.
-
-**Assistant Turn**:
-A reserved name for the not-yet-modeled unit containing all **Steps** from prompt promotion until the assistant yields the floor; do not reify it until something durable needs it.
-
-**Settlement**:
-The terminal transition for a unit of work: Step and tool settlement are durable, while drain and execution settlement are coordinator-observed.
-
-**Execution**:
-One session-scoped coordinator busy period from first wake until idle. An Execution is process-local coordination rather than a durable domain entity.
-
-**Session Drain**:
-One process-local execution span that promotes eligible input and runs required **Steps** until no immediate continuation remains. A Session Drain has no durable identity or transcript boundary.
-
-**Model Tool Output**:
-The bounded projection of a Core-executed tool result persisted in Session history and replayed to the model. A tool may shape this projection semantically, but the Tool Registry enforces the final size limit.
-
-**Managed Tool Output File**:
-A temporary file created under OpenCode's shared tool-output directory to retain complete output that was too large for Session history.
-
-**Model Request Options**:
-Provider-semantic model settings selected from the Catalog and active Session variant before the LLM protocol adapter encodes them for a provider request.
-_Avoid_: Request body, wire options
-
-**Generation Controls**:
-Provider-neutral sampling and output controls, partitioned from provider semantics and compatibility wire fields when model metadata enters the Catalog.
-
-**Native Continuation Metadata**:
-Opaque protocol-shaped data attached to assistant content and required to continue that content natively with a compatible model, such as a reasoning signature or provider-hosted item identifier.
-
-**PTY Environment**:
-The host-supplied environment overlay applied by the server when creating a PTY, observed for the request Location and resolved PTY working directory.
-
-**OpenCode Client**:
-The generated Promise and Effect APIs derived from the public `HttpApi`; **Embedded OpenCode** shares the Effect API through an in-memory `HttpClient` against the same router and handlers.
-_Avoid_: Remote client
-
-**SDK Contract IR**:
-The runtime-neutral compiled representation of the authoritative `HttpApi`, preserving encoded and decoded type projections plus transport metadata so independent SDK emitters can choose their public value model and runtime interpreter.
-
-**Embedded OpenCode**:
-A scoped in-process host that structurally extends the **OpenCode Client**, supplies an in-memory HTTP transport, and exposes additional same-process capabilities directly.
-_Avoid_: Local implementation
-
-**Page**:
-A bounded ordered result containing `items` and opaque `previous` and `next` cursor links for navigating the same query in either direction.
-_Avoid_: Response envelope
-
-## Relationships
-
-- **Instructions** is an opaque carrier composed from zero or more **Instruction Sources**.
-- **Model Context** is broader than **Instructions**. For each **Step**, the runner assembles the selected agent or provider system text, **Initial Instructions**, **Session History**, available tools, and step-local additions into one model request.
-- **Session History** persists conversational messages. The runner derives model-facing **Instruction Update** messages from value deltas and interleaves them by durable sequence; **Initial Instructions** remain separate provider-request state.
-- The runner explicitly loads and combines instruction built-ins, **InstructionDiscovery**, selected-agent skill guidance, reference guidance, MCP guidance, and **InstructionEntry** values. There is no instruction registry.
-- `Instructions.combine(...)` preserves caller order and rejects duplicate stable namespaced source keys. The runner loads its producers concurrently, then combines them in its fixed declared order.
-- Each **Instruction Source** read returns one coherent typed value, explicit removal, or temporary unavailability. `Instructions.make(...)` hides the value type so differently typed sources compose uniformly; its canonical codec defines storage and hash equivalence, while pure renderers produce first, changed, and optional removal text.
-- `Instructions.read(...)` reads every composed source concurrently and exactly once at the boundary. `Instructions.diff(...)` compares encoded-value hashes with current **Instruction Values** and returns one delta plus new blob bodies.
-- `Instructions.renderInitial(...)` renders values at the **Instruction Epoch** start. `Instructions.renderUpdate(...)` renders one hydrated delta against the values immediately before it.
-- A changed **Instruction Source** contributes its hash to one **Instruction Update**; explicit removal contributes the `"removed"` sentinel.
-- An **Instruction Update** persists only its value delta. Rendered text is derived during request assembly and excluded from compaction summaries.
-- The instruction blob insert, durable delta, and **Instruction State** advance commit atomically.
-- Changes from multiple **Instruction Sources** admitted at one safe boundary combine into one **Instruction Update**.
-- Instruction changes are sampled and admitted lazily at a **Safe Step Boundary**, never pushed asynchronously when their source changes.
-- At a **Safe Step Boundary**, prior tool results are already settled; instruction preparation completes before newly admitted user input promotes.
-- An **Admitted Prompt** is replayable pending input, not yet model-visible **Session History**.
-- **Prompt Promotion** atomically consumes the pending inbox entry and appends its model-visible user message.
-- Steering prompts promote at the next **Safe Step Boundary** while the current **Session Drain** still requires continuation. Promoting any newly admitted user input resets the selected agent's step allowance; multiple prompts promoted at one boundary reset it once.
-- A queued prompt does not promote while the current **Session Drain** requires continuation. The runner promotes one queued prompt when the Session would otherwise become idle, then reevaluates continuation before promoting another.
-- A **Session Drain** is process-local coordination rather than a durable domain entity. Durable recovery must reason from prompts, projected history, physical attempts, and tool state rather than inventing an enclosing execution identity.
-- An **Execution** contains one or more **Session Drains**; a **Session Drain** contains one reserved assistant-turn span at a time; that span contains **Steps**; and each **Step** contains one or more **Physical Attempts** plus any tool calls it requires.
-- A **Step** record covers only the model-visible span from first assistant output through tool settlement; pre-flight leaves no record, and one Step settles at most one record.
-- The first **Step** admits one complete delta and renders **Initial Instructions** without narrating that delta in history; an unavailable initial source blocks the Step instead of persisting incomplete values.
-- Instruction preparation precedes durable input promotion on every Step so an unavailable first baseline leaves pending input untouched and later updates enter history before newly promoted input.
-- Completed compaction moves the **Instruction Epoch** to the exact `session.compaction.ended` sequence and copies current hashes to the epoch's initial values. Earlier updates leave active model history while durable deltas remain.
-- A newly composed **Instruction Source** absent from current **Instruction Values** emits its first rendering once at the next **Safe Step Boundary**.
-- **Unavailable Instruction Source** uses stale-while-revalidate semantics and is distinct from a successfully loaded absence, which may emit removal text.
-- **InstructionDiscovery** observes ambient instructions as one ordered aggregate **Instruction Source**.
-- Ambient discovery reads global and upward-project `AGENTS.md` files and honors `OPENCODE_DISABLE_PROJECT_CONFIG` for project files.
-- After a successful internal file or directory read, nearby `AGENTS.md` files toward the Location root are injected once per Session as durable synthetic instruction messages.
-- **InstructionEntry** stores API-managed per-Session JSON values. Each entry contributes one `api/<key>` **Instruction Source**, so adding, replacing, or removing an entry is reconciled at the next **Safe Step Boundary**.
-- Location-scoped instruction producers naturally re-resolve when a moved Session next runs in its destination Location.
-- Moving a Session clears its **Instruction State**, so the destination must admit a complete delta before another prompt can promote. Committed revert does the same; replay derives both resets from their durable events.
-- Selected-agent available-skill guidance is an **Instruction Source** composed explicitly by the runner. It lists only names and descriptions permitted for that agent; skill bodies and locations are exposed only through the permission-checked `skill` tool.
-- The selected agent and model are sampled when a **Step** starts. Changes admitted after that boundary apply to the next Step and do not restart the current Step.
-- An agent switch that changes selected-agent guidance produces an **Instruction Update** while preserving the current baseline.
-- Local tool authorization and pending permission requests retain the effective agent of the **Step** that issued the call; a later agent switch cannot change that call's policy.
-- Instruction source changes never wake idle Sessions; the next naturally scheduled **Safe Step Boundary** loads and compares current values lazily.
-- Once admitted, an **Instruction Update** remains durable even if the following **Physical Attempt** fails and is replayed unchanged on retry.
-- **Instruction Updates** remain durable value history but are not `session_message` rows. Clients display changed keys rather than model-facing prose.
-- The date **Instruction Source** initially preserves host-local calendar-date behavior; a configured user timezone may replace that default later.
-- **Initial Instructions** are recomputed deterministically from durable values for every request; rendered bytes are not stored.
-- A model/provider switch preserves current **Instruction Values**, the **Instruction Epoch**, and chronological conversation history; the new selection applies to the next **Step**.
-- **Native Continuation Metadata** remains in durable history. Step projection includes it only for a successful exact originating provider/model match; failed Steps and incompatible models omit opaque metadata, while non-empty visible reasoning lowers to ordinary assistant text after a model switch. This conservative relation may widen only when recorded provider tests establish compatibility.
-- **Model Request Options** remain provider-semantic through Catalog resolution. The Session runner maps them into the LLM package's provider-option namespace; the selected protocol adapter alone owns provider wire encoding.
-- **Generation Controls**, protocol-semantic **Model Request Options**, and compatibility request body fields are separate Catalog domains. A shared ingestion adapter partitions legacy and models.dev AI-SDK-shaped options before routing.
-- The **PTY Environment** is a server concern rather than a Core PTY concern. PTY creation merges caller values, then the host overlay, then Core-forced terminal invariants such as `TERM` and `OPENCODE_TERMINAL`.
-- Networked and **Embedded OpenCode** use the same **OpenCode Client** and preserve the full HTTP encoding, routing, middleware, and decoding boundary; only the `HttpClient` transport differs.
-- The Effect-native network constructor obtains `HttpClient.HttpClient` from its environment so callers own transport selection, recording, tracing, retries, and tests. Convenience runtimes may provide a fetch transport separately.
-- Creating **Embedded OpenCode** is scoped. Closing its owning Scope releases the in-process server resources, database resources, registrations, and fibers.
-- **Embedded OpenCode** exposes shared client capabilities and embedded-only capabilities on one object; consumers do not navigate through a nested `.client` property.
-- The beta **OpenCode Client** currently uses plural consumer-facing capability groups such as `sessions`; whether the stable Session namespace should instead be singular `session` must be settled before stabilization. Internal server identifiers do not implicitly define public client names.
-- Server's concrete `HttpApi` is authoritative for shared **OpenCode Client** capabilities. Codegen compiles its Session group directly; the Effect runtime uses an equivalent Protocol-only projection so generated artifacts remain independent of Core and Server.
-- SDK generation reflects the public `HttpApi` once into an **SDK Contract IR**. Promise and Effect emitters share endpoint structure and transport metadata without being required to expose identical public values: an emitter may select encoded wire types, decoded domain types, compile-time brands, runtime validation, and its own execution abstraction independently.
-- The first Effect emitter is the rich projection: it exposes decoded Effect-native values, preserves brands and schema transformations, performs runtime schema decoding, and delegates transport interpretation to `HttpApiClient`. Lighter wire-shaped Effect output remains possible through another emitter policy rather than constraining the shared IR.
-- The rich Effect emitter regenerates private executable schemas when the **SDK Contract IR** proves that their transport semantics can be reproduced exactly. Contracts with authoritative custom transformations use the import-based Effect emitter against a Protocol-only client projection whose generated transport output is tested against Server's concrete API; the Promise emitter still derives zero-Effect structural wire types from the same IR.
-- `@opencode-ai/protocol` owns Session endpoint construction and middleware placement. Server supplies concrete middleware keys to produce the authoritative build-time API; the client projection supplies transport-only keys without importing Core or Server at runtime.
-- The first Promise emitter targets the same clean domain-oriented method organization rather than Hey API source compatibility. It returns unwrapped values directly, rejects declared and infrastructure failures, and begins with minimal client-level transport configuration; result wrappers, interceptors, and legacy generated signatures are outside the initial surface.
-- The first Promise emitter parses response syntax and trusts its generated structural types; it does not perform runtime structural validation. Malformed payload syntax fails, while a syntactically valid shape mismatch is not detected at the SDK boundary. Standalone validator generation remains an optional future emitter policy.
-- Declared Promise-client failures retain their tagged structural wire values and have generated type guards. Consumers do not depend on generated `Error` subclass identity, preserving discrimination across package copies and realms while remaining structurally aligned with Effect domain errors.
-- Promise-client infrastructure failures use one generated `ClientError` class with a structured reason such as transport failure, unexpected status, unsupported content type, or malformed response. Promise methods reject with either a tagged declared domain failure or `ClientError`, matching the Effect client's conceptual domain/infrastructure error division.
-- Promise methods accept a separate optional per-call transport-options argument containing `AbortSignal` and header overrides. Cancellation and transport metadata do not enter the domain input object; broader interceptor and response-mode APIs remain deferred.
-- Promise streaming methods return a lazy `AsyncIterable` directly rather than a Promise-wrapped stream object. Iteration opens the connection, `AbortSignal` cancels it, and ending iteration closes the underlying request; the Effect emitter analogously returns `Stream` directly.
-- Promise SSE connection establishment, declared HTTP failures, and infrastructure failures occur during `AsyncIterable` iteration, beginning with its first `next()` call, rather than during synchronous method construction.
-- Neither generated streaming runtime automatically reconnects after disconnection. Promise `AsyncIterable` and Effect `Stream` fail explicitly; live consumers refresh and resubscribe, while durable sequence-based resume remains explicit composition above the generated client.
-- Promise client construction is synchronous and network-free. It requires `baseUrl`, defaults to `globalThis.fetch`, accepts client-level headers, and merges them with per-call header overrides.
-- Effect client construction accepts an explicit `baseUrl` and obtains `HttpClient.HttpClient` from the Effect environment. It does not install fetch or duplicate per-call transport policy; callers transform/provide the client for headers, tracing, retries, recording, and tests, while fiber interruption owns cancellation.
-- Promise and Effect emitters each own their generated public type modules. The **SDK Contract IR**, not a physically shared generated type package, is the common source; this permits zero-Effect wire types and rich decoded Effect types to evolve independently.
-- Promise and Effect network clients ship from `@opencode-ai/client` behind isolated root and `/effect` exports. The root has no runtime path to Effect; `/effect` imports only Effect, Schema, and Protocol.
-- The Effect-native scoped host belongs to `@opencode-ai/sdk-next`, which will assume the existing `@opencode-ai/sdk` name after legacy consumers migrate. Client remains network-only and SDK depends one-way on Client.
-- SDK executes Server's assembled `HttpRouter` in memory. It opens no listener and performs no network I/O, while preserving Server routing, middleware, codecs, handlers, and errors.
-- The Effect Client and SDK re-export their decoded datatype facade from Schema so callers do not depend on internal package locations or Core's versioned names.
-- A capability intended for both networked and **Embedded OpenCode** belongs in the authoritative public `HttpApi`; embedded-only same-process capabilities extend **Embedded OpenCode** separately.
-- `sessions.log({ sessionID, after, follow })` is the public durable Session event stream. It verifies the Session, replays durable events after the optional aggregate sequence, optionally continues with newly committed durable events, excludes live-only fragments, and is transported as SSE in both networked and embedded modes.
-- `events.subscribe()` is a distinct public instance-wide live stream for Session and non-Session activity. It has no replay guarantee and includes connection, heartbeat, and instance-disposal lifecycle events; consumers recover from disconnection by refreshing authoritative state.
-- A Session ID is not an optional filter on `events.subscribe()`: instance-wide live events and durable Session events have different schemas, replay guarantees, cursors, lifecycle events, and failure behavior.
-- The initial common OpenCode Client does not expose server-global event aggregation. `events.subscribe()` is bounded to the connected OpenCode instance or workspace; any future cross-instance administrative stream requires a separately designed API.
-- `events.subscribe()` does not automatically reconnect after transport loss. The live-only stream fails with `ClientError`; consumers refresh authoritative state before explicitly opening a new subscription because events missed during disconnection cannot be replayed.
-- `sessions.log({ sessionID, after, follow })` returns the generated HTTP client's cold durable event stream and does not build reconnection policy into the endpoint or client constructor. Transport loss fails the stream with `ClientError`. Callers may compose an explicit resuming stream above it by retaining the last observed durable sequence and opening a new subscription with `after`; any reusable resume helper remains a separate API design question.
-- The stable `sessions.list(...)` design returns a **Page** in both networked and **Embedded OpenCode**; embedded execution does not define a separate unbounded array-returning list operation. The beta client currently preserves the existing HTTP `{ data, cursor }` envelope until emitter-level Page projection is implemented.
-- Session list cursors are opaque branded values carrying continuation query and ordering state. Consumers pass them back unchanged and do not inspect storage anchors or encoded filter fields.
-- A Session list continuation accepts only its opaque cursor. Scope, filters, ordering, and page size are fixed by the initial query and carried by that cursor.
-- `sessions.messages(...)` returns a **Page** and uses the same cursor discipline as `sessions.list(...)`: the initial request supplies `sessionID`, ordering, and page size; continuation supplies `sessionID` plus only an opaque branded message cursor carrying ordering, page size, direction, and message anchor. Using a cursor with another Session is invalid.
-- `sessions.message({ sessionID, messageID })` is a required resource lookup. An unknown Session fails with `SessionNotFoundError`; a known Session with an absent or differently owned message fails with `MessageNotFoundError` without disclosing cross-Session ownership. Absence is not represented as `undefined` across the public HTTP boundary.
-- `sessions.interrupt({ sessionID })` first verifies that the durable Session exists, failing with `SessionNotFoundError` otherwise. For a known Session, interruption is idempotent: idle, already-settled, or locally unowned execution is a no-op.
-- `sessions.active()` snapshots the current process's foreground Session drain registry as a record of Session IDs to `{ type: "running" }`. Missing IDs are inactive; background subagents and tasks do not make their parent Session active, and process restart clears the registry.
-- `sessions.context({ sessionID })` preserves the existing message-only operation. It returns projected **Session History**; it does not include or represent the complete **Model Context**, whose agent system text, **Initial Instructions**, tools, and step-local additions remain separate.
-- **Open question**: Should a future, separately named operation expose complete **Model Context**, including the instruction baseline, applied instruction metadata, tools, and step-local additions?
-- `sessions.prompt(...)` exposes `resume?: boolean`. Omitting it preserves durable admission followed by an advisory execution wake; `resume: false` requests durable admit-only behavior.
-- The public operation remains `sessions.prompt(...)`; `SessionPending.admit` is the internal primitive, while the public `Admission` result and `resume` option express its durable admission semantics.
-- `sessions.create(...)` accepts an optional `location`. Omission resolves through the connected OpenCode instance's default or current location; an explicit value selects a known location. Networked and embedded transports use the same handler semantics.
-- `sessions.switchAgent({ sessionID, agent })` is part of the common client alongside `sessions.switchModel(...)`. It affects subsequent Session activity and fails with `SessionNotFoundError` for an unknown Session.
-- The **Embedded OpenCode** Layer delegates to the same scoped creation path; it does not define a second implementation.
-- A **PTY Environment** adapter observes plugins in the request Location while passing the resolved PTY working directory to the hook; standalone servers use an empty adapter.
-- An **Instruction Update** lowers to the provider's native chronological instruction role when supported and to a wrapped chronological fallback otherwise.
-- When the aggregate discovered instruction set changes, its **Instruction Update** includes the complete current ordered set and supersedes the prior aggregate value; when no discovered instructions remain, the message states that previously loaded instructions no longer apply.
-- Ambient project instruction discovery honors `OPENCODE_DISABLE_PROJECT_CONFIG`; global instructions remain eligible.
-- Oversized textual **Model Tool Output** retains a bounded preview in Session history while its complete text moves to managed tool-output storage. Arbitrary structured-result size is a separate concern.
-- One tool settlement receives one aggregate textual limit, using the configured maximum lines or UTF-8 bytes, whichever is reached first. The limit is provider-independent; token pressure belongs to context assembly and compaction.
-- Generic truncation preserves the beginning and end of textual output. Tools may apply a more meaningful strategy before the Tool Registry enforces the final limit.
-- A truncated **Model Tool Output** identifies its complete text in the bounded model-visible preview. The Tool Registry also supplies managed paths as internal metadata to tool hooks; Session events do not expose a typed `outputPaths` field.
-- A **Managed Tool Output File** is temporary and may expire after its retention period. The bounded **Model Tool Output**, not the file, is the durable replayable record.
-- Failure to retain a **Managed Tool Output File** fails settlement operationally. The Session never publishes a successful result whose complete output was lost during generic bounding.
-- Once a tool operation succeeds, bounding its **Model Tool Output** and publishing its one durable settlement form an interruption-safe completion region. Raw oversized success is never published before a later correction.
-- When a structured-only result would exceed the **Model Tool Output** limit, its validated structured value remains unchanged for Session consumers while model replay uses a bounded textual JSON preview and optional managed output path.
-- Existing tool-managed output paths survive generic bounding. A fallback file retains exactly the complete projected text received by the Tool Registry and never claims to reconstruct output already discarded by tool-specific shaping.
-- **Managed Tool Output Files** use globally unique names in one shared flat directory. They receive no special filesystem authority; each tool applies its ordinary external-path policy.
-- Provider-executed tool results remain provider-native transcript facts outside generic Tool Registry bounding. Their context control requires provider-aware pruning or compaction because some providers require exact structured round-trip payloads.
-
-## Client contract architecture
-
-Semantic values that mean the same thing internally and publicly live in the lightweight Schema leaf. Core consumes Schema for domain behavior; Protocol composes Schema values into paths, payloads, envelopes, errors, cursors, and streams; Server imports both, hosts Protocol's exact groups, and owns protocol/domain adaptation. The root Promise client remains zero-Effect, `/effect` depends on Effect plus Schema and Protocol, and `@opencode-ai/sdk-next` composes the scoped in-process host above Client, Core, and Server.
-
-Shared public records are plain objects declared with `Schema.Struct`. A same-name inferred interface gives object records readable TypeScript signatures without constructors, prototypes, or nominal identity; unions retain explicit type aliases.
-
-Before stabilizing the client API:
-
-- Keep additional public schemas in Schema and additional network groups in Protocol; neither package may transitively load databases, Drizzle, Session execution, providers, watchers, native modules, or WASM.
-- Keep concrete Location middleware keys in Server while Protocol owns their placement. Client projections may supply transport-only keys, but must prove generated equivalence with Server's concrete API.
-- Project the existing list response envelope to the stable client **Page** shape and enforce separate initial-query and cursor-continuation inputs without changing the hosted V2 wire contract.
-- Settle the stable consumer namespace (`session` versus the current beta `sessions`) and use an explicit codegen annotation if the consumer name should differ from the server group identifier.
-- Preserve V2 route paths, operation IDs, codecs, errors, middleware behavior, and OpenAPI output while making this change.
-- Preserve browser-safe `@opencode-ai/client` and `@opencode-ai/client/effect` bundles through import-boundary tests.
-- Define embedded-host placement before supporting multiple hosts over one database. Hosts that share durable Session storage must also share process-local Session execution coordination, or each host must receive isolated storage explicitly.
-- Keep an embedded request scope alive until any streamed response body finishes. The initial non-streaming Session surface does not exercise this lifetime boundary; Session and instance event streams must do so before joining the embedded client.
-
-## Example dialogue
-
-> **Dev:** "The date changed while the session was active. Should the **Instruction Update** say what the old date was?"
-> **Domain expert:** "No. Emit the newly effective date so the agent can act on the current instructions."
-
-## Flagged ambiguities
-
-- Legacy `experimental.chat.system.transform` can mutate assembled system text arbitrarily, but V2 plugins do not yet expose an equivalent hook. Decide separately whether to port it, model dynamic uses as explicit **Instruction Sources**, or narrow its semantics.

package.json

@@ -12,6 +12,7 @@
     "dev:web": "bun --cwd packages/app dev",
     "dev:console": "ulimit -n 10240 2>/dev/null; bun run --cwd packages/console/app dev",
     "dev:stats": "bun sst shell --stage=production -- bun run --cwd packages/stats/app dev",
+    "dev:www": "bun run --cwd packages/www dev",
     "dev:storybook": "bun --cwd packages/storybook storybook",
     "lint": "oxlint",
     "lint:effect-patterns": "ast-grep scan -c script/ast-grep/sgconfig.yml packages/core/src packages/server/src packages/protocol/src packages/cli/src",
@@ -102,6 +103,8 @@
   "devDependencies": {
     "@actions/artifact": "5.0.1",
     "@ast-grep/cli": "0.44.0",
+    "@types/react": "19.2.17",
+    "@types/react-dom": "19.2.3",
     "@tsconfig/bun": "catalog:",
     "@types/mime-types": "3.0.1",
     "@typescript/native-preview": "catalog:",

packages/app/src/i18n/en.ts

@@ -65,8 +65,8 @@ export const dict = {
   "command.message.next.description": "Go to the next user message",
   "command.model.choose": "Choose model",
   "command.model.choose.description": "Select a different model",
-  "command.mcp.toggle": "Toggle MCPs",
-  "command.mcp.toggle.description": "Toggle MCPs",
+  "command.mcp.toggle": "Manage MCP servers",
+  "command.mcp.toggle.description": "Enable or disable MCP servers",
   "command.agent.cycle": "Cycle agent",
   "command.agent.cycle.description": "Switch to the next agent",
   "command.agent.cycle.reverse": "Cycle agent backwards",
@@ -307,9 +307,9 @@ export const dict = {
   "prompt.toast.promptSendFailed.title": "Failed to send prompt",
   "prompt.toast.promptSendFailed.description": "Unable to retrieve session",
 
-  "dialog.mcp.title": "MCPs",
+  "dialog.mcp.title": "MCP servers",
   "dialog.mcp.description": "{{enabled}} of {{total}} enabled",
-  "dialog.mcp.empty": "No MCPs configured",
+  "dialog.mcp.empty": "No MCP servers configured",
 
   "dialog.lsp.empty": "LSPs auto-detected from file types",
   "dialog.plugins.empty": "Plugins configured in opencode.json",

packages/cli/package.json

@@ -36,7 +36,6 @@
     "@opencode-ai/core": "workspace:*",
     "@opencode-ai/plugin": "workspace:*",
     "@opencode-ai/schema": "workspace:*",
-    "@opencode-ai/sdk": "workspace:*",
     "@opencode-ai/server": "workspace:*",
     "@opencode-ai/tui": "workspace:*",
     "@opentui/core": "catalog:",
@@ -45,6 +44,7 @@
     "@parcel/watcher": "2.5.1",
     "effect": "catalog:",
     "fuzzysort": "catalog:",
+    "immer": "11.1.4",
     "jsonc-parser": "3.3.1",
     "open": "10.1.2",
     "opentui-spinner": "catalog:",

packages/cli/src/commands/handlers/debug/agents.ts

@@ -1,6 +1,6 @@
 import { EOL } from "os"
 import { Effect } from "effect"
-import { createOpencodeClient } from "@opencode-ai/sdk/v2/client"
+import { OpenCode } from "@opencode-ai/client"
 import { Commands } from "../../commands"
 import { Runtime } from "../../../framework/runtime"
 import { Service } from "@opencode-ai/client/effect"
@@ -12,11 +12,11 @@ export default Runtime.handler(
     const options = yield* ServiceConfig.options()
     const found = yield* Service.discover(options)
     const endpoint = found ?? (yield* Service.start(options))
-    const client = createOpencodeClient({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
-    const response = yield* Effect.promise(() => client.v2.agent.list({ location: { directory: process.cwd() } }))
+    const client = OpenCode.make({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
+    const response = yield* Effect.promise(() => client.agent.list({ location: { directory: process.cwd() } }))
     process.stdout.write(
       JSON.stringify(
-        response.data?.data.toSorted((a, b) => a.id.localeCompare(b.id)),
+        response.data.toSorted((a, b) => a.id.localeCompare(b.id)),
         null,
         2,
       ) + EOL,

packages/cli/src/commands/handlers/default.ts

@@ -4,7 +4,7 @@ import { run } from "@opencode-ai/tui"
 import { loadBuiltinPlugins } from "@opencode-ai/tui/builtins"
 import { Commands } from "../commands"
 import { Runtime } from "../../framework/runtime"
-import { TuiConfig } from "../../tui-config"
+import { Config } from "../../config"
 import { Effect, Option } from "effect"
 import { Server } from "../../services/server"
 import { Updater } from "../../services/updater"
@@ -35,13 +35,18 @@ export default Runtime.handler(Commands, (input) =>
       ),
     )
     preflight.loading()
-    const config = yield* TuiConfig.load()
+    const config = yield* Config.Service
     let disposeSlots: (() => void) | undefined
-    const runFork = Effect.runForkWith(yield* Effect.context())
+    const context = yield* Effect.context()
+    const runFork = Effect.runForkWith(context)
+    const runPromise = Effect.runPromiseWith(context)
     yield* run({
       server,
       args: { continue: input.continue, sessionID: Option.getOrUndefined(input.session) },
-      config,
+      config: {
+        get: () => runPromise(config.get()),
+        update: (update) => runPromise(config.update(update)),
+      },
       terminalHandoff: () => preflight.finish(),
       log: (level, message, tags) => {
         const effect =

packages/cli/src/commands/handlers/mcp/auth.ts

@@ -1,11 +1,11 @@
 import { EOL } from "node:os"
 import { Effect } from "effect"
 import {
-  createOpencodeClient,
+  OpenCode,
   type IntegrationAttemptStatus,
   type IntegrationOAuthMethod,
-  type OpencodeClient,
-} from "@opencode-ai/sdk/v2/client"
+  type OpenCodeClient,
+} from "@opencode-ai/client"
 import { Commands } from "../../commands"
 import { Runtime } from "../../../framework/runtime"
 import { Service } from "@opencode-ai/client/effect"
@@ -20,7 +20,7 @@ export default Runtime.handler(
     const options = yield* ServiceConfig.options()
     const found = yield* Service.discover(options)
     const endpoint = found ?? (yield* Service.start(options))
-    const client = createOpencodeClient({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
+    const client = OpenCode.make({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
 
     const integration = yield* resolveIntegration(client, input.name, location)
     if (!integration)
@@ -32,10 +32,9 @@ export default Runtime.handler(
       return yield* Effect.fail(new Error(`MCP server "${input.name}" is not an OAuth-capable remote server`))
 
     const started = yield* Effect.promise(() =>
-      client.v2.integration.connect.oauth({ integrationID: integration.id, methodID: method.id, inputs: {}, location }),
+      client.integration.connect.oauth({ integrationID: integration.id, methodID: method.id, inputs: {}, location }),
     )
-    const attempt = started.data?.data
-    if (!attempt) return yield* Effect.fail(new Error(started.error?.message ?? "Failed to start OAuth attempt"))
+    const attempt = started.data
     if (attempt.mode === "code")
       return yield* Effect.fail(new Error("This server requires manual code entry, which the CLI does not support"))
 
@@ -52,13 +51,14 @@ export default Runtime.handler(
 )
 
 const poll = (
-  client: OpencodeClient,
+  client: OpenCodeClient,
   attemptID: string,
 ): Effect.Effect<Exclude<IntegrationAttemptStatus, { status: "pending" }>> =>
   Effect.gen(function* () {
-    const response = yield* Effect.promise(() => client.v2.integration.attempt.status({ attemptID, location }))
-    const status = response.data?.data
-    if (!status || status.status === "pending") {
+    const status = yield* Effect.promise(() => client.integration.attempt.status({ attemptID, location })).pipe(
+      Effect.map((result) => result.data),
+    )
+    if (status.status === "pending") {
       yield* Effect.sleep("1 second")
       return yield* poll(client, attemptID)
     }

packages/cli/src/commands/handlers/mcp/list.ts

@@ -1,6 +1,6 @@
 import { EOL } from "node:os"
 import { Effect } from "effect"
-import { createOpencodeClient, type McpServer } from "@opencode-ai/sdk/v2/client"
+import { OpenCode, type McpServer } from "@opencode-ai/client"
 import { Commands } from "../../commands"
 import { Runtime } from "../../../framework/runtime"
 import { Service } from "@opencode-ai/client/effect"
@@ -12,9 +12,9 @@ export default Runtime.handler(
     const options = yield* ServiceConfig.options()
     const found = yield* Service.discover(options)
     const endpoint = found ?? (yield* Service.start(options))
-    const client = createOpencodeClient({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
-    const response = yield* Effect.promise(() => client.v2.mcp.list({ location: { directory: process.cwd() } }))
-    const servers = (response.data?.data ?? []).toSorted((a, b) => a.name.localeCompare(b.name))
+    const client = OpenCode.make({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
+    const response = yield* Effect.promise(() => client.mcp.list({ location: { directory: process.cwd() } }))
+    const servers = response.data.toSorted((a, b) => a.name.localeCompare(b.name))
     if (servers.length === 0) {
       process.stdout.write("No MCP servers configured" + EOL)
       return

packages/cli/src/commands/handlers/mcp/logout.ts

@@ -1,6 +1,6 @@
 import { EOL } from "node:os"
 import { Effect } from "effect"
-import { createOpencodeClient } from "@opencode-ai/sdk/v2/client"
+import { OpenCode } from "@opencode-ai/client"
 import { Commands } from "../../commands"
 import { Runtime } from "../../../framework/runtime"
 import { Service } from "@opencode-ai/client/effect"
@@ -15,7 +15,7 @@ export default Runtime.handler(
     const options = yield* ServiceConfig.options()
     const found = yield* Service.discover(options)
     const endpoint = found ?? (yield* Service.start(options))
-    const client = createOpencodeClient({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
+    const client = OpenCode.make({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
 
     const integration = yield* resolveIntegration(client, input.name, location)
     if (!integration) {
@@ -31,7 +31,7 @@ export default Runtime.handler(
 
     yield* Effect.forEach(
       credentials,
-      (connection) => Effect.promise(() => client.v2.credential.remove({ credentialID: connection.id, location })),
+      (connection) => Effect.promise(() => client.credential.remove({ credentialID: connection.id, location })),
       { discard: true },
     )
     process.stdout.write(`Removed OAuth credentials for ${input.name}` + EOL)

packages/cli/src/commands/handlers/mcp/resolve.ts

@@ -1,17 +1,18 @@
 import { Effect } from "effect"
-import type { OpencodeClient } from "@opencode-ai/sdk/v2/client"
+import type { OpenCodeClient } from "@opencode-ai/client"
 
 // Resolve through the MCP-owned integrationID rather than matching integration names: the shared
 // integration registry also holds provider/plugin integrations, whose names could collide with a server.
 // Fails when the server is unknown; returns undefined when the server has no integration (e.g. a local
 // or anonymous server), leaving that case for the caller to interpret.
-export const resolveIntegration = (client: OpencodeClient, name: string, location: { directory: string }) =>
+export const resolveIntegration = (client: OpenCodeClient, name: string, location: { directory: string }) =>
   Effect.gen(function* () {
-    const servers = yield* Effect.promise(() => client.v2.mcp.list({ location }))
-    const server = (servers.data?.data ?? []).find((entry) => entry.name === name)
+    const servers = yield* Effect.promise(() => client.mcp.list({ location }))
+    const server = servers.data.find((entry) => entry.name === name)
     if (!server) return yield* Effect.fail(new Error(`MCP server not found: ${name}`))
     const integrationID = server.integrationID
     if (!integrationID) return undefined
-    const found = yield* Effect.promise(() => client.v2.integration.get({ integrationID, location }))
-    return found.data?.data
+    return yield* Effect.promise(() => client.integration.get({ integrationID, location })).pipe(
+      Effect.map((result) => result.data ?? undefined),
+    )
   })

packages/cli/src/config/config.ts

@@ -0,0 +1,109 @@
+export * as Config from "./config"
+
+import { Global } from "@opencode-ai/core/global"
+import { Context, Effect, FileSystem, Layer, Option, Schema, Semaphore } from "effect"
+import { produce, type Draft } from "immer"
+import { applyEdits, modify, parse, type ParseError } from "jsonc-parser"
+import path from "path"
+import { ConfigMigration } from "./migrate"
+import { Info } from "./schema"
+
+export * from "./schema"
+
+export interface Interface {
+  readonly path: string
+  readonly get: () => Effect.Effect<Info>
+  readonly update: (update: (draft: Draft<Info>) => void) => Effect.Effect<Info, Error>
+}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/cli/config/Config") {}
+
+const decode = Schema.decodeUnknownOption(Info)
+const decodeRecord = Schema.decodeUnknownOption(Schema.Record(Schema.String, Schema.Any))
+const empty: Info = {}
+
+export const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    const fs = yield* FileSystem.FileSystem
+    const global = yield* Global.Service
+    const file = path.join(global.config, "cli.json")
+    const lock = yield* Semaphore.make(1)
+
+    const readJson = Effect.fnUntraced(function* () {
+      const text = yield* fs.readFileString(file).pipe(Effect.catch(() => Effect.succeed(undefined)))
+      if (text === undefined) return undefined
+      const errors: ParseError[] = []
+      const value: any = parse(text, errors, { allowTrailingComma: true })
+      if (errors.length) return undefined
+      return Option.getOrUndefined(decodeRecord(value))
+    })
+
+    const write = Effect.fnUntraced(function* (text: string) {
+      const temp = file + ".tmp"
+      yield* fs.makeDirectory(path.dirname(file), { recursive: true })
+      yield* fs.writeFileString(temp, text, { mode: 0o600 })
+      yield* fs.rename(temp, file)
+    })
+
+    const migrate = ConfigMigration.run({ file, config: global.config, state: global.state }).pipe(
+      Effect.provideService(FileSystem.FileSystem, fs),
+    )
+
+    const get = Effect.fn("cli.config.get")(function* () {
+      yield* migrate.pipe(Effect.catchCause((cause) => Effect.logWarning("failed to migrate cli config", { cause })))
+      return Option.getOrElse(decode(yield* readJson()), () => empty)
+    })
+
+    const update = Effect.fn("cli.config.update")((update: (draft: Draft<Info>) => void) =>
+      lock
+        .withPermits(1)(
+          Effect.gen(function* () {
+            yield* migrate
+            const current = Option.getOrElse(decode(yield* readJson()), () => empty)
+            const next = produce(current, update)
+            const edits = changes(current, next)
+            if (!edits.length) return current
+            const text = yield* fs.readFileString(file).pipe(Effect.catch(() => Effect.succeed("{}")))
+            const updated = edits.reduce(
+              (text, edit) =>
+                applyEdits(
+                  text,
+                  modify(text, edit.path, edit.value, { formattingOptions: { tabSize: 2, insertSpaces: true } }),
+                ),
+              text,
+            )
+            const errors: ParseError[] = []
+            const config = Option.getOrUndefined(decode(parse(updated, errors, { allowTrailingComma: true })))
+            if (errors.length || config === undefined) return yield* Effect.fail(new Error("Invalid CLI config update"))
+            yield* write(updated.endsWith("\n") ? updated : updated + "\n")
+            return config
+          }),
+        )
+        .pipe(Effect.mapError((cause) => new Error("Failed to update CLI config", { cause }))),
+    )
+
+    return Service.of({ path: file, get, update })
+  }),
+)
+
+type Edit = { readonly path: (string | number)[]; readonly value: any }
+
+function changes(before: any, after: any, path: (string | number)[] = []): Edit[] {
+  if (Object.is(before, after)) return []
+  if (
+    before !== null &&
+    after !== null &&
+    typeof before === "object" &&
+    typeof after === "object" &&
+    !Array.isArray(before) &&
+    !Array.isArray(after)
+  ) {
+    return [...new Set([...Object.keys(before), ...Object.keys(after)])].flatMap((key) => {
+      if (!(key in after)) return [{ path: [...path, key], value: undefined }]
+      if (!(key in before)) return [{ path: [...path, key], value: after[key] }]
+      return changes(before[key], after[key], [...path, key])
+    })
+  }
+  return [{ path, value: after }]
+}

packages/cli/src/config/index.ts

@@ -0,0 +1 @@
+export * as Config from "./config"

packages/cli/src/config/migrate.ts

@@ -0,0 +1,142 @@
+export * as ConfigMigration from "./migrate"
+
+import { TuiConfigV1 } from "@opencode-ai/tui/config/v1"
+import { Effect, FileSystem, Option, Schema } from "effect"
+import { parse, type ParseError } from "jsonc-parser"
+import path from "path"
+import type { Info } from "./schema"
+
+const decodeV1 = Schema.decodeUnknownOption(TuiConfigV1.Info)
+const decodeRecord = Schema.decodeUnknownOption(Schema.Record(Schema.String, Schema.Any))
+
+export const run = Effect.fn("cli.config.migrate")(function* (input: {
+  readonly file: string
+  readonly config: string
+  readonly state: string
+}) {
+  const fs = yield* FileSystem.FileSystem
+  if (yield* fs.exists(input.file).pipe(Effect.orElseSucceed(() => false))) return
+
+  const legacyValue = yield* readJson(path.join(input.config, "tui.json"))
+  const legacy = Option.getOrUndefined(decodeV1(legacyValue))
+  const kv = yield* readJson(path.join(input.state, "kv.json"))
+  const migrated = migrateV1(legacy, kv ?? {})
+  if (!Object.keys(migrated).length) return
+
+  const temp = input.file + ".tmp"
+  yield* fs.makeDirectory(path.dirname(input.file), { recursive: true })
+  yield* fs.writeFileString(temp, JSON.stringify(migrated, null, 2) + "\n", { mode: 0o600 })
+  yield* fs.rename(temp, input.file)
+  yield* Effect.logInfo("migrated cli config", {
+    from: [
+      legacyValue === undefined ? undefined : path.join(input.config, "tui.json"),
+      kv === undefined ? undefined : path.join(input.state, "kv.json"),
+    ].filter(Boolean),
+    to: input.file,
+  })
+})
+
+export function migrateV1(legacy: TuiConfigV1.Info | undefined, kv: Record<string, any>): Info {
+  const plugins = [
+    ...(legacy?.plugin?.map((plugin) =>
+      typeof plugin === "string" ? plugin : { package: plugin[0], options: plugin[1] },
+    ) ?? []),
+    ...Object.entries(legacy?.plugin_enabled ?? {}).map(([id, enabled]) => (enabled ? id : `-${id}`)),
+  ]
+  const themeName = legacy?.theme ?? kv.theme
+  const themeMode = kv.theme_mode_lock
+  const attentionSoundPack = kv.attention_sound_pack
+  const diffView = kv.diff_viewer_view ?? (legacy?.diff_style === "stacked" ? "unified" : undefined)
+  const thinking =
+    kv.thinking_mode ??
+    (kv.thinking_visibility === undefined ? undefined : kv.thinking_visibility ? "show" : "hide")
+
+  return {
+    ...(themeName !== undefined || themeMode !== undefined
+      ? { theme: { ...(themeName === undefined ? {} : { name: themeName }), ...(themeMode === undefined ? {} : { mode: themeMode }) } }
+      : {}),
+    ...(legacy?.keybinds === undefined ? {} : { keybinds: legacy.keybinds }),
+    ...(plugins.length ? { plugins } : {}),
+    ...(legacy?.leader_timeout === undefined ? {} : { leader: { timeout: legacy.leader_timeout } }),
+    ...(legacy?.scroll_speed === undefined && legacy?.scroll_acceleration?.enabled === undefined
+      ? {}
+      : {
+          scroll: {
+            ...(legacy.scroll_speed === undefined ? {} : { speed: legacy.scroll_speed }),
+            ...(legacy.scroll_acceleration?.enabled === undefined
+              ? {}
+              : { acceleration: legacy.scroll_acceleration.enabled }),
+          },
+        }),
+    ...(legacy?.attention === undefined && attentionSoundPack === undefined
+      ? {}
+      : {
+          attention: {
+            ...legacy?.attention,
+            ...(attentionSoundPack === undefined ? {} : { sound_pack: attentionSoundPack }),
+          },
+        }),
+    ...(legacy?.diff_style === undefined &&
+    kv.diff_wrap_mode === undefined &&
+    kv.diff_viewer_show_file_tree === undefined &&
+    kv.diff_viewer_single_patch === undefined &&
+    diffView === undefined
+      ? {}
+      : {
+          diffs: {
+            ...(kv.diff_wrap_mode === undefined ? {} : { wrap: kv.diff_wrap_mode }),
+            ...(kv.diff_viewer_show_file_tree === undefined ? {} : { tree: kv.diff_viewer_show_file_tree }),
+            ...(kv.diff_viewer_single_patch === undefined ? {} : { single: kv.diff_viewer_single_patch }),
+            ...(diffView === undefined ? {} : { view: diffView }),
+          },
+        }),
+    ...(kv.terminal_title_enabled === undefined ? {} : { terminal: { title: kv.terminal_title_enabled } }),
+    ...(kv.file_context_enabled === undefined && kv.paste_summary_enabled === undefined
+      ? {}
+      : {
+          prompt: {
+            ...(kv.file_context_enabled === undefined ? {} : { editor: kv.file_context_enabled }),
+            ...(kv.paste_summary_enabled === undefined
+              ? {}
+              : { paste: kv.paste_summary_enabled ? ("compact" as const) : ("full" as const) }),
+          },
+        }),
+    ...(kv.sidebar === undefined &&
+    kv.scrollbar_visible === undefined &&
+    thinking === undefined &&
+    kv.exploration_grouping === undefined
+      ? {}
+      : {
+          session: {
+            ...(kv.sidebar === undefined ? {} : { sidebar: kv.sidebar }),
+            ...(kv.scrollbar_visible === undefined ? {} : { scrollbar: kv.scrollbar_visible }),
+            ...(thinking === undefined ? {} : { thinking }),
+            ...(kv.exploration_grouping === undefined
+              ? {}
+              : { grouping: kv.exploration_grouping ? ("auto" as const) : ("none" as const) }),
+          },
+        }),
+    ...(kv.tips_hidden === undefined && kv.dismissed_getting_started === undefined
+      ? {}
+      : {
+          hints: {
+            ...(kv.tips_hidden === undefined ? {} : { tips: !kv.tips_hidden }),
+            ...(kv.dismissed_getting_started === undefined
+              ? {}
+              : { onboarding: !kv.dismissed_getting_started }),
+          },
+        }),
+    ...(kv.animations_enabled === undefined ? {} : { animations: kv.animations_enabled }),
+    ...(legacy?.mouse === undefined ? {} : { mouse: legacy.mouse }),
+  }
+}
+
+const readJson = Effect.fnUntraced(function* (target: string) {
+  const fs = yield* FileSystem.FileSystem
+  const text = yield* fs.readFileString(target).pipe(Effect.catch(() => Effect.succeed(undefined)))
+  if (text === undefined) return undefined
+  const errors: ParseError[] = []
+  const value: any = parse(text, errors, { allowTrailingComma: true })
+  if (errors.length) return undefined
+  return Option.getOrUndefined(decodeRecord(value))
+})

packages/cli/src/config/schema.ts

@@ -0,0 +1,5 @@
+import { Config } from "@opencode-ai/tui/config"
+import { Schema } from "effect"
+
+export const Info = Schema.Struct({ ...Config.Info.fields })
+export type Info = Schema.Schema.Type<typeof Info>

packages/cli/src/framework/runtime.ts

@@ -3,6 +3,7 @@ import { Command } from "effect/unstable/cli"
 import { Spec } from "./spec"
 import { Global } from "@opencode-ai/core/global"
 import { Updater } from "../services/updater"
+import { Config } from "../config"
 
 export type Input<Value> =
   Value extends Spec.Node<infer _Name, infer Command, infer _Commands>
@@ -13,18 +14,26 @@ export type Input<Value> =
 
 type RuntimeHandler = (
   input: unknown,
-) => Effect.Effect<void, unknown, FileSystem.FileSystem | Global.Service | Updater.Service | Scope.Scope>
+) => Effect.Effect<
+  void,
+  unknown,
+  FileSystem.FileSystem | Global.Service | Updater.Service | Config.Service | Scope.Scope
+>
 type Loader<Node extends Spec.Any> = () => Promise<{
   default: (
     input: Input<Node>,
-  ) => Effect.Effect<void, any, FileSystem.FileSystem | Global.Service | Updater.Service | Scope.Scope>
+  ) => Effect.Effect<
+    void,
+    any,
+    FileSystem.FileSystem | Global.Service | Updater.Service | Config.Service | Scope.Scope
+  >
 }>
 type ProvidedCommand = Command.Command<
   string,
   unknown,
   unknown,
   unknown,
-  FileSystem.FileSystem | Global.Service | Updater.Service | Scope.Scope
+  FileSystem.FileSystem | Global.Service | Updater.Service | Config.Service | Scope.Scope
 >
 
 export type Handlers<Node extends Spec.Any> = keyof Node["commands"] extends never

packages/cli/src/index.ts

@@ -11,6 +11,7 @@ import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { Global } from "@opencode-ai/core/global"
 import { AppProcess } from "@opencode-ai/core/process"
+import { Config } from "./config"
 
 const Handlers = Runtime.handlers(Commands, {
   $: () => import("./commands/handlers/default"),
@@ -51,6 +52,7 @@ Effect.logInfo("cli starting", {
 }).pipe(
   Effect.flatMap(() => Runtime.run(Commands, Handlers, { version: InstallationVersion })),
   Effect.annotateLogs({ role: "cli" }),
+  Effect.provide(Config.layer),
   Effect.provide(Updater.layer),
   Effect.provide(AppNodeBuilder.build(LayerNode.group([Global.node, AppProcess.node]))),
   Effect.provide(Observability.layer),

packages/cli/src/mini/demo.ts

@@ -1,7 +1,7 @@
 // Demo mode for testing direct interactive mode without a real SDK.
 //
-// Enabled with `--demo`. Intercepts prompt submissions and generates synthetic
-// SDK events that feed through the real reducer and footer pipeline. This
+// Enabled with `--demo`. Intercepts prompt submissions and drives the same
+// presentation commits and footer actions as the live transport. This
 // lets you test scrollback formatting, permission UI, question UI, and tool
 // snapshots without making actual model calls. Pass a demo slash command as
 // the initial interactive message to trigger a preview immediately.
@@ -15,10 +15,18 @@
 // Demo mode also handles permission and question replies locally, completing
 // or failing the synthetic tool parts as appropriate.
 import path from "path"
-import type { Event, ToolPart } from "@opencode-ai/sdk/v2"
-import { createSessionData, reduceSessionData, type SessionData } from "./session-data"
+import type { PermissionV2Request, QuestionV2Request } from "@opencode-ai/client/promise"
 import { writeSessionOutput } from "./stream"
-import type { FooterApi, PermissionReply, QuestionReject, QuestionReply, RunPrompt, StreamCommit } from "./types"
+import { toolCommit } from "./stream-v2.subagent"
+import type {
+  FooterApi,
+  MiniToolPart,
+  PermissionReply,
+  QuestionReject,
+  QuestionReply,
+  RunPrompt,
+  StreamCommit,
+} from "./types"
 
 const KINDS = [
   "markdown",
@@ -124,7 +132,7 @@ type Permit = {
   ref: Ref
   permission: string
   patterns: string[]
-  metadata?: Record<string, unknown>
+  metadata?: PermissionV2Request["metadata"]
   always: string[]
   done: Perm["done"]
 }
@@ -132,9 +140,7 @@ type Permit = {
 type State = {
   id: string
   thinking: boolean
-  data: SessionData
   footer: FooterApi
-  limits: () => Record<string, number>
   msg: number
   part: number
   call: number
@@ -142,12 +148,12 @@ type State = {
   ask: number
   perms: Map<string, Perm>
   asks: Map<string, Ask>
+  started: Set<string>
 }
 
 type Input = {
   sessionID: string
   thinking: boolean
-  limits: () => Record<string, number>
   footer: FooterApi
 }
 
@@ -255,185 +261,69 @@ function take(state: State, key: "msg" | "part" | "call" | "perm" | "ask", prefi
   return `demo_${prefix}_${state[key]}`
 }
 
-function feed(state: State, event: Event): void {
-  const out = reduceSessionData({
-    data: state.data,
-    event,
-    sessionID: state.id,
-    thinking: state.thinking,
-    limits: state.limits(),
-  })
-  state.data = out.data
+function present(state: State, commits: StreamCommit[], view?: QuestionV2Request | PermissionV2Request): void {
   writeSessionOutput(
+    { footer: state.footer },
     {
-      footer: state.footer,
+      commits,
+      footer: view
+        ? {
+            view: "action" in view ? { type: "permission", request: view } : { type: "question", request: view },
+            patch: { status: "action" in view ? "awaiting permission" : "awaiting answer" },
+          }
+        : undefined,
     },
-    out,
+  )
+}
+
+function clearBlocker(state: State): void {
+  writeSessionOutput(
+    { footer: state.footer },
+    { commits: [], footer: { view: { type: "prompt" }, patch: { status: "" } } },
   )
 }
 
 function open(state: State): string {
-  const id = take(state, "msg", "msg")
-  feed(state, {
-    type: "message.updated",
-    properties: {
-      sessionID: state.id,
-      info: {
-        id,
-        sessionID: state.id,
-        role: "assistant",
-        time: {
-          created: Date.now(),
-        },
-        parentID: `user_${id}`,
-        modelID: "demo",
-        providerID: "demo",
-        mode: "demo",
-        agent: "demo",
-        path: {
-          cwd: process.cwd(),
-          root: process.cwd(),
-        },
-        cost: 0.001,
-        tokens: {
-          input: 120,
-          output: 320,
-          reasoning: 80,
-          cache: {
-            read: 0,
-            write: 0,
-          },
-        },
-      },
-    },
-  } as Event)
-  return id
+  return take(state, "msg", "msg")
 }
 
 async function emitText(state: State, body: string, signal?: AbortSignal): Promise<void> {
   const msg = open(state)
   const part = take(state, "part", "part")
-  const start = Date.now()
-
-  feed(state, {
-    type: "message.part.updated",
-    properties: {
-      sessionID: state.id,
-      time: Date.now(),
-      part: {
-        id: part,
-        sessionID: state.id,
-        messageID: msg,
-        type: "text",
-        text: "",
-        time: {
-          start,
-        },
-      },
-    },
-  } as Event)
-
-  let next = ""
   for (const item of split(body)) {
     if (signal?.aborted) {
       return
     }
 
-    next += item
-    feed(state, {
-      type: "message.part.delta",
-      properties: {
-        sessionID: state.id,
-        messageID: msg,
-        partID: part,
-        field: "text",
-        delta: item,
-      },
-    } as Event)
+    present(state, [{ kind: "assistant", source: "assistant", text: item, phase: "progress", messageID: msg, partID: part }])
     await wait(45, signal)
   }
-
-  feed(state, {
-    type: "message.part.updated",
-    properties: {
-      sessionID: state.id,
-      time: Date.now(),
-      part: {
-        id: part,
-        sessionID: state.id,
-        messageID: msg,
-        type: "text",
-        text: next,
-        time: {
-          start,
-          end: Date.now(),
-        },
-      },
-    },
-  } as Event)
 }
 
 async function emitReasoning(state: State, body: string, signal?: AbortSignal): Promise<void> {
   const msg = open(state)
   const part = take(state, "part", "part")
-  const start = Date.now()
-
-  feed(state, {
-    type: "message.part.updated",
-    properties: {
-      sessionID: state.id,
-      time: Date.now(),
-      part: {
-        id: part,
-        sessionID: state.id,
-        messageID: msg,
-        type: "reasoning",
-        text: "",
-        time: {
-          start,
-        },
-      },
-    },
-  } as Event)
-
-  let next = ""
+  let first = true
   for (const item of split(body)) {
     if (signal?.aborted) {
       return
     }
 
-    next += item
-    feed(state, {
-      type: "message.part.delta",
-      properties: {
-        sessionID: state.id,
-        messageID: msg,
-        partID: part,
-        field: "text",
-        delta: item,
-      },
-    } as Event)
+    if (state.thinking) {
+      present(state, [
+        {
+          kind: "reasoning",
+          source: "reasoning",
+          text: first ? `Thinking: ${item.replace(/\[REDACTED\]/g, "")}` : item.replace(/\[REDACTED\]/g, ""),
+          phase: "progress",
+          messageID: msg,
+          partID: part,
+        },
+      ])
+      first = false
+    }
     await wait(45, signal)
   }
-
-  feed(state, {
-    type: "message.part.updated",
-    properties: {
-      sessionID: state.id,
-      time: Date.now(),
-      part: {
-        id: part,
-        sessionID: state.id,
-        messageID: msg,
-        type: "reasoning",
-        text: next,
-        time: {
-          start,
-          end: Date.now(),
-        },
-      },
-    },
-  } as Event)
 }
 
 function make(state: State, tool: string, input: Record<string, unknown>): Ref {
@@ -448,29 +338,23 @@ function make(state: State, tool: string, input: Record<string, unknown>): Ref {
 }
 
 function startTool(state: State, ref: Ref, metadata: Record<string, unknown> = {}): void {
-  feed(state, {
-    type: "message.part.updated",
-    properties: {
-      sessionID: state.id,
-      time: Date.now(),
-      part: {
-        id: ref.part,
-        sessionID: state.id,
-        messageID: ref.msg,
-        type: "tool",
-        callID: ref.call,
-        tool: ref.tool,
-        state: {
-          status: "running",
-          input: ref.input,
-          metadata,
-          time: {
-            start: ref.start,
-          },
+  state.started.add(ref.part)
+  present(
+    state,
+    [
+      toolCommit(
+        {
+          id: ref.part,
+          sessionID: state.id,
+          messageID: ref.msg,
+          callID: ref.call,
+          tool: ref.tool,
+          state: { status: "running", input: ref.input, metadata, time: { start: ref.start } },
         },
-      },
-    },
-  } as Event)
+        "start",
+      ),
+    ],
+  )
 }
 
 function askPermission(state: State, item: Permit): void {
@@ -482,21 +366,15 @@ function askPermission(state: State, item: Permit): void {
     done: item.done,
   })
 
-  feed(state, {
-    type: "permission.asked",
-    properties: {
-      id,
-      sessionID: state.id,
-      permission: item.permission,
-      patterns: item.patterns,
-      metadata: item.metadata ?? {},
-      always: item.always,
-      tool: {
-        messageID: item.ref.msg,
-        callID: item.ref.call,
-      },
-    },
-  } as Event)
+  present(state, [], {
+    id,
+    sessionID: state.id,
+    action: item.permission,
+    resources: item.patterns,
+    metadata: item.metadata ?? {},
+    save: item.always,
+    source: { type: "tool", messageID: item.ref.msg, callID: item.ref.call },
+  })
 }
 
 function doneTool(
@@ -508,77 +386,53 @@ function doneTool(
     metadata?: Record<string, unknown>
   },
 ): void {
-  feed(state, {
-    type: "message.part.updated",
-    properties: {
-      sessionID: state.id,
-      time: Date.now(),
-      part: {
-        id: ref.part,
-        sessionID: state.id,
-        messageID: ref.msg,
-        type: "tool",
-        callID: ref.call,
-        tool: ref.tool,
-        state: {
-          status: "completed",
-          input: ref.input,
-          output: output.output,
-          title: output.title,
-          metadata: output.metadata ?? {},
-          time: {
-            start: ref.start,
-            end: Date.now(),
-          },
-        },
-      },
+  if (!state.started.has(ref.part)) startTool(state, ref)
+  const part: MiniToolPart = {
+    id: ref.part,
+    sessionID: state.id,
+    messageID: ref.msg,
+    callID: ref.call,
+    tool: ref.tool,
+    state: {
+      status: "completed",
+      input: ref.input,
+      output: output.output,
+      title: output.title,
+      metadata: output.metadata ?? {},
+      time: { start: ref.start, end: Date.now() },
     },
-  } as Event)
+  }
+  present(state, [toolCommit(part, output.output ? "progress" : "final")])
 }
 
 function failTool(state: State, ref: Ref, error: string): void {
-  feed(state, {
-    type: "message.part.updated",
-    properties: {
-      sessionID: state.id,
-      time: Date.now(),
-      part: {
-        id: ref.part,
-        sessionID: state.id,
-        messageID: ref.msg,
-        type: "tool",
-        callID: ref.call,
-        tool: ref.tool,
-        state: {
-          status: "error",
-          input: ref.input,
-          error,
-          metadata: {},
-          time: {
-            start: ref.start,
-            end: Date.now(),
+  if (!state.started.has(ref.part)) startTool(state, ref)
+  present(
+    state,
+    [
+      toolCommit(
+        {
+          id: ref.part,
+          sessionID: state.id,
+          messageID: ref.msg,
+          callID: ref.call,
+          tool: ref.tool,
+          state: {
+            status: "error",
+            input: ref.input,
+            error,
+            metadata: {},
+            time: { start: ref.start, end: Date.now() },
           },
         },
-      },
-    },
-  } as Event)
+        "final",
+      ),
+    ],
+  )
 }
 
 function emitError(state: State, text: string): void {
-  const event = {
-    id: `session.error:${state.id}:${Date.now()}`,
-    type: "session.error",
-    properties: {
-      sessionID: state.id,
-      error: {
-        name: "UnknownError",
-        data: {
-          message: text,
-        },
-      },
-    },
-  } satisfies Event
-  feed(state, event)
+  present(state, [{ kind: "error", source: "system", text, phase: "start" }])
 }
 
 async function emitBash(state: State, signal?: AbortSignal): Promise<void> {
@@ -685,7 +539,7 @@ function emitTask(state: State): void {
         start: Date.now(),
       },
     },
-  } satisfies ToolPart
+  } satisfies MiniToolPart
   showSubagent(state, {
     sessionID: "sub_demo_1",
     partID: ref.part,
@@ -979,18 +833,12 @@ function emitQuestion(state: State, kind: QuestionKind = "multi"): void {
   const id = take(state, "ask", "ask")
   state.asks.set(id, { ref })
 
-  feed(state, {
-    type: "question.asked",
-    properties: {
-      id,
-      sessionID: state.id,
-      questions,
-      tool: {
-        messageID: ref.msg,
-        callID: ref.call,
-      },
-    },
-  } as Event)
+  present(state, [], {
+    id,
+    sessionID: state.id,
+    questions,
+    tool: { messageID: ref.msg, callID: ref.call },
+  })
 }
 
 async function emitFmt(state: State, kind: string, body: string, signal?: AbortSignal): Promise<boolean> {
@@ -1089,9 +937,7 @@ export function createRunDemo(input: Input) {
   const state: State = {
     id: input.sessionID,
     thinking: input.thinking,
-    data: createSessionData(),
     footer: input.footer,
-    limits: input.limits,
     msg: 0,
     part: 0,
     call: 0,
@@ -1099,6 +945,7 @@ export function createRunDemo(input: Input) {
     ask: 0,
     perms: new Map(),
     asks: new Map(),
+    started: new Set(),
   }
 
   const start = async (): Promise<void> => {
@@ -1166,16 +1013,7 @@ export function createRunDemo(input: Input) {
     }
 
     state.perms.delete(input.requestID)
-    const event = {
-      id: `permission.replied:${input.requestID}:${Date.now()}`,
-      type: "permission.replied",
-      properties: {
-        sessionID: state.id,
-        requestID: input.requestID,
-        reply: input.reply,
-      },
-    } satisfies Event
-    feed(state, event)
+    clearBlocker(state)
 
     if (input.reply === "reject") {
       failTool(state, item.ref, input.message || "permission rejected")
@@ -1193,16 +1031,7 @@ export function createRunDemo(input: Input) {
     }
 
     state.asks.delete(input.requestID)
-    const event = {
-      id: `question.replied:${input.requestID}:${Date.now()}`,
-      type: "question.replied",
-      properties: {
-        sessionID: state.id,
-        requestID: input.requestID,
-        answers: input.answers,
-      },
-    } satisfies Event
-    feed(state, event)
+    clearBlocker(state)
     doneTool(state, ask.ref, {
       title: "question",
       output: "",
@@ -1220,13 +1049,7 @@ export function createRunDemo(input: Input) {
     }
 
     state.asks.delete(input.requestID)
-    feed(state, {
-      type: "question.rejected",
-      properties: {
-        sessionID: state.id,
-        requestID: input.requestID,
-      },
-    } as Event)
+    clearBlocker(state)
     failTool(state, ask.ref, "question rejected")
     return true
   }

packages/cli/src/mini/footer.permission.tsx

@@ -14,7 +14,7 @@
 import type { TextareaRenderable } from "@opentui/core"
 import { useKeyboard, useTerminalDimensions } from "@opentui/solid"
 import { For, Match, Show, Switch, createEffect, createMemo, createSignal } from "solid-js"
-import type { PermissionRequest } from "@opencode-ai/sdk/v2"
+import type { PermissionV2Request } from "@opencode-ai/client/promise"
 import {
   createPermissionBodyState,
   permissionAlwaysLines,
@@ -130,7 +130,7 @@ export function RejectField(props: {
 }
 
 export function RunPermissionBody(props: {
-  request: PermissionRequest
+  request: PermissionV2Request
   theme: RunFooterTheme
   block: RunBlockTheme
   diffStyle?: RunDiffStyle
@@ -142,7 +142,7 @@ export function RunPermissionBody(props: {
   const ft = createMemo(() => toolFiletype(info().file))
   const narrow = createMemo(() => footerWidthPolicy(dims().width).dialog.narrow)
   const opts = createMemo(() =>
-    permissionOptions(state().stage).filter((option) => option !== "always" || props.request.always.length > 0),
+    permissionOptions(state().stage).filter((option) => option !== "always" || (props.request.save?.length ?? 0) > 0),
   )
   const busy = createMemo(() => state().submitting)
   const title = createMemo(() => {

packages/cli/src/mini/footer.question.tsx

@@ -16,7 +16,7 @@
 import type { TextareaRenderable } from "@opentui/core"
 import { useKeyboard, useTerminalDimensions } from "@opentui/solid"
 import { For, Show, createEffect, createMemo, createSignal } from "solid-js"
-import type { QuestionRequest } from "@opencode-ai/sdk/v2"
+import type { QuestionV2Request } from "@opencode-ai/client/promise"
 import {
   createQuestionBodyState,
   questionConfirm,
@@ -45,7 +45,7 @@ import type { RunFooterTheme } from "./theme"
 import type { QuestionReject, QuestionReply } from "./types"
 
 export function RunQuestionBody(props: {
-  request: QuestionRequest
+  request: QuestionV2Request
   theme: RunFooterTheme
   onReply: (input: QuestionReply) => void | Promise<void>
   onReject: (input: QuestionReject) => void | Promise<void>

packages/cli/src/mini/footer.ts

@@ -627,7 +627,6 @@ export class RunFooter implements FooterApi {
 
     this.themes.splice(index, 1)
     theme.block.syntax?.destroy()
-    theme.block.subtleSyntax?.destroy()
   }
 
   public close(): void {
@@ -1023,7 +1022,6 @@ export class RunFooter implements FooterApi {
     void resolveRunTheme(this.renderer).then((theme) => {
       if (this.isGone) {
         theme.block.syntax?.destroy()
-        theme.block.subtleSyntax?.destroy()
         return
       }
 

packages/cli/src/mini/noninteractive.ts

@@ -1,8 +1,8 @@
 import type { EventSubscribeOutput, OpenCodeClient } from "@opencode-ai/client/promise"
-import type { ReasoningPart, StepFinishPart, StepStartPart, TextPart, ToolPart } from "@opencode-ai/sdk/v2"
 import { SessionMessage } from "@opencode-ai/schema/session-message"
 import { EOL } from "node:os"
 import { UI } from "./ui"
+import type { MiniToolPart } from "./types"
 
 type Model = {
   providerID: string
@@ -28,8 +28,8 @@ type Input = {
   auto: boolean
   /** True when the client is attached to a shared server rather than an exclusive in-process one. */
   attached: boolean
-  renderTool: (part: ToolPart) => Promise<void>
-  renderToolError: (part: ToolPart) => Promise<void>
+  renderTool: (part: MiniToolPart) => Promise<void>
+  renderToolError: (part: MiniToolPart) => Promise<void>
 }
 
 type StartedPart = {
@@ -77,7 +77,7 @@ export async function runNonInteractivePrompt(input: Input) {
     return true
   }
 
-  const writeText = (part: TextPart, timestamp: number) => {
+  const writeText = (part: { text: string; [key: string]: unknown }, timestamp: number) => {
     if (emit("text", timestamp, { part })) return
     const text = part.text.trim()
     if (!text) return
@@ -169,7 +169,7 @@ export async function runNonInteractivePrompt(input: Input) {
       if (!promoted) continue
 
       if (event.type === "session.step.started") {
-        const part: StepStartPart = {
+        const part = {
           id: partID(event.id),
           sessionID: input.sessionID,
           messageID: event.data.assistantMessageID,
@@ -191,7 +191,7 @@ export async function runNonInteractivePrompt(input: Input) {
       if (event.type === "session.text.ended") {
         const started = starts.get("text")
         starts.delete("text")
-        const part: TextPart = {
+        const part = {
           id: started?.id ?? partID(event.id),
           sessionID: input.sessionID,
           messageID: event.data.assistantMessageID,
@@ -210,7 +210,7 @@ export async function runNonInteractivePrompt(input: Input) {
       if (event.type === "session.reasoning.ended" && input.thinking) {
         const started = starts.get("reasoning")
         starts.delete("reasoning")
-        const part: ReasoningPart = {
+        const part = {
           id: started?.id ?? partID(event.id),
           sessionID: input.sessionID,
           messageID: event.data.assistantMessageID,
@@ -263,7 +263,7 @@ export async function runNonInteractivePrompt(input: Input) {
       }
       if (event.type === "session.tool.success") {
         const current = tools.get(event.data.callID) ?? fallbackTool(event)
-        const part: ToolPart = {
+        const part: MiniToolPart = {
           id: current.id,
           sessionID: input.sessionID,
           messageID: event.data.assistantMessageID,
@@ -296,7 +296,7 @@ export async function runNonInteractivePrompt(input: Input) {
       if (event.type === "session.tool.failed") {
         const current = tools.get(event.data.callID) ?? fallbackTool(event)
         const error = event.data.error.message
-        const part: ToolPart = {
+        const part: MiniToolPart = {
           id: current.id,
           sessionID: input.sessionID,
           messageID: event.data.assistantMessageID,
@@ -325,7 +325,7 @@ export async function runNonInteractivePrompt(input: Input) {
       }
 
       if (event.type === "session.step.ended") {
-        const part: StepFinishPart = {
+        const part = {
           id: partID(event.id),
           sessionID: input.sessionID,
           messageID: event.data.assistantMessageID,

packages/cli/src/mini/permission.shared.ts

@@ -13,7 +13,7 @@
 //
 // permissionInfo() extracts display info (icon, title, lines, diff) from
 // the request, delegating to tool.ts for tool-specific formatting.
-import type { PermissionRequest } from "@opencode-ai/sdk/v2"
+import type { PermissionV2Request } from "@opencode-ai/client/promise"
 import type { PermissionReply } from "./types"
 import { toolPath, toolPermissionInfo } from "./tool"
 
@@ -55,7 +55,7 @@ function text(v: unknown): string {
   return typeof v === "string" ? v : ""
 }
 
-function data(request: PermissionRequest): Dict {
+function data(request: PermissionV2Request): Dict {
   const meta = dict(request.metadata)
   return {
     ...meta,
@@ -63,8 +63,8 @@ function data(request: PermissionRequest): Dict {
   }
 }
 
-function patterns(request: PermissionRequest): string[] {
-  return request.patterns.filter((item): item is string => typeof item === "string")
+function patterns(request: PermissionV2Request): string[] {
+  return request.resources.filter((item): item is string => typeof item === "string")
 }
 
 export function createPermissionBodyState(requestID: string): PermissionBodyState {
@@ -89,15 +89,15 @@ export function permissionOptions(stage: PermissionStage): PermissionOption[] {
   return []
 }
 
-export function permissionInfo(request: PermissionRequest): PermissionInfo {
+export function permissionInfo(request: PermissionV2Request): PermissionInfo {
   const pats = patterns(request)
   const input = data(request)
-  const info = toolPermissionInfo(request.permission, input, dict(request.metadata), pats)
+  const info = toolPermissionInfo(request.action, input, dict(request.metadata), pats)
   if (info) {
     return info
   }
 
-  if (request.permission === "external_directory") {
+  if (request.action === "external_directory") {
     const meta = dict(request.metadata)
     const raw = text(meta.parentDir) || text(meta.filepath) || pats[0] || ""
     const dir = raw.includes("*") ? raw.slice(0, raw.indexOf("*")).replace(/[\\/]+$/, "") : raw
@@ -108,7 +108,7 @@ export function permissionInfo(request: PermissionRequest): PermissionInfo {
     }
   }
 
-  if (request.permission === "doom_loop") {
+  if (request.action === "doom_loop") {
     return {
       icon: "⟳",
       title: "Continue after repeated failures",
@@ -118,19 +118,20 @@ export function permissionInfo(request: PermissionRequest): PermissionInfo {
 
   return {
     icon: "⚙",
-    title: `Call tool ${request.permission}`,
-    lines: [`Tool: ${request.permission}`],
+    title: `Call tool ${request.action}`,
+    lines: [`Tool: ${request.action}`],
   }
 }
 
-export function permissionAlwaysLines(request: PermissionRequest): string[] {
-  if (request.always.length === 1 && request.always[0] === "*") {
-    return [`This will allow ${request.permission} until OpenCode is restarted.`]
+export function permissionAlwaysLines(request: PermissionV2Request): string[] {
+  const save = request.save ?? []
+  if (save.length === 1 && save[0] === "*") {
+    return [`This will allow ${request.action} until OpenCode is restarted.`]
   }
 
   return [
     "This will allow the following patterns until OpenCode is restarted.",
-    ...request.always.map((item) => `- ${item}`),
+    ...save.map((item) => `- ${item}`),
   ]
 }
 

packages/cli/src/mini/question.shared.ts

@@ -13,7 +13,7 @@
 //
 // Custom answers: if a question has custom=true, an extra "Type your own
 // answer" option appears. Selecting it enters editing mode with a text field.
-import type { QuestionInfo, QuestionRequest } from "@opencode-ai/sdk/v2"
+import type { QuestionV2Info, QuestionV2Request } from "@opencode-ai/client/promise"
 import type { QuestionReject, QuestionReply } from "./types"
 
 export type QuestionBodyState = {
@@ -51,23 +51,23 @@ export function questionSync(state: QuestionBodyState, requestID: string): Quest
   return createQuestionBodyState(requestID)
 }
 
-export function questionSingle(request: QuestionRequest): boolean {
+export function questionSingle(request: QuestionV2Request): boolean {
   return request.questions.length === 1 && request.questions[0]?.multiple !== true
 }
 
-export function questionTabs(request: QuestionRequest): number {
+export function questionTabs(request: QuestionV2Request): number {
   return questionSingle(request) ? 1 : request.questions.length + 1
 }
 
-export function questionConfirm(request: QuestionRequest, state: QuestionBodyState): boolean {
+export function questionConfirm(request: QuestionV2Request, state: QuestionBodyState): boolean {
   return !questionSingle(request) && state.tab === request.questions.length
 }
 
-export function questionInfo(request: QuestionRequest, state: QuestionBodyState): QuestionInfo | undefined {
+export function questionInfo(request: QuestionV2Request, state: QuestionBodyState): QuestionV2Info | undefined {
   return request.questions[state.tab]
 }
 
-export function questionCustom(request: QuestionRequest, state: QuestionBodyState): boolean {
+export function questionCustom(request: QuestionV2Request, state: QuestionBodyState): boolean {
   return questionInfo(request, state)?.custom !== false
 }
 
@@ -84,7 +84,7 @@ export function questionPicked(state: QuestionBodyState): boolean {
   return state.answers[state.tab]?.includes(value) ?? false
 }
 
-export function questionOther(request: QuestionRequest, state: QuestionBodyState): boolean {
+export function questionOther(request: QuestionV2Request, state: QuestionBodyState): boolean {
   const info = questionInfo(request, state)
   if (!info || info.custom === false) {
     return false
@@ -93,7 +93,7 @@ export function questionOther(request: QuestionRequest, state: QuestionBodyState
   return state.selected === info.options.length
 }
 
-export function questionTotal(request: QuestionRequest, state: QuestionBodyState): number {
+export function questionTotal(request: QuestionV2Request, state: QuestionBodyState): number {
   const info = questionInfo(request, state)
   if (!info) {
     return 0
@@ -156,7 +156,7 @@ export function questionStoreCustom(state: QuestionBodyState, tab: number, text:
 
 function questionPick(
   state: QuestionBodyState,
-  request: QuestionRequest,
+  request: QuestionV2Request,
   answer: string,
   custom = false,
 ): QuestionStep {
@@ -204,7 +204,7 @@ function questionToggle(state: QuestionBodyState, answer: string): QuestionBodyS
   return storeAnswers(state, state.tab, list)
 }
 
-export function questionMove(state: QuestionBodyState, request: QuestionRequest, dir: -1 | 1): QuestionBodyState {
+export function questionMove(state: QuestionBodyState, request: QuestionV2Request, dir: -1 | 1): QuestionBodyState {
   const total = questionTotal(request, state)
   if (total === 0) {
     return state
@@ -216,7 +216,7 @@ export function questionMove(state: QuestionBodyState, request: QuestionRequest,
   }
 }
 
-export function questionSelect(state: QuestionBodyState, request: QuestionRequest): QuestionStep {
+export function questionSelect(state: QuestionBodyState, request: QuestionV2Request): QuestionStep {
   const info = questionInfo(request, state)
   if (!info) {
     return { state }
@@ -255,7 +255,7 @@ export function questionSelect(state: QuestionBodyState, request: QuestionReques
   return questionPick(state, request, option.label)
 }
 
-export function questionSave(state: QuestionBodyState, request: QuestionRequest): QuestionStep {
+export function questionSave(state: QuestionBodyState, request: QuestionV2Request): QuestionStep {
   const info = questionInfo(request, state)
   if (!info) {
     return { state }
@@ -305,20 +305,20 @@ export function questionSave(state: QuestionBodyState, request: QuestionRequest)
   return questionPick(state, request, value, true)
 }
 
-export function questionSubmit(request: QuestionRequest, state: QuestionBodyState): QuestionReply {
+export function questionSubmit(request: QuestionV2Request, state: QuestionBodyState): QuestionReply {
   return {
     requestID: request.id,
     answers: questionAnswers(state, request.questions.length),
   }
 }
 
-export function questionReject(request: QuestionRequest): QuestionReject {
+export function questionReject(request: QuestionV2Request): QuestionReject {
   return {
     requestID: request.id,
   }
 }
 
-export function questionHint(request: QuestionRequest, state: QuestionBodyState): string {
+export function questionHint(request: QuestionV2Request, state: QuestionBodyState): string {
   if (state.submitting) {
     return "Waiting for question event..."
   }

packages/cli/src/mini/run.ts

@@ -2,13 +2,13 @@ import { Service } from "@opencode-ai/client/effect"
 import { OpenCode, type OpenCodeClient } from "@opencode-ai/client/promise"
 import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Model } from "@opencode-ai/schema/model"
-import type { ToolPart } from "@opencode-ai/sdk/v2"
 import { open } from "node:fs/promises"
 import path from "node:path"
 import { Server } from "../services/server"
 import { loadRunAgents, waitForCatalogReady } from "./catalog.shared"
 import { runNonInteractivePrompt } from "./noninteractive"
 import { toolInlineInfo } from "./tool"
+import type { MiniToolPart } from "./types"
 import { UI } from "./ui"
 
 export type RunCommandInput = {
@@ -224,7 +224,7 @@ function isBinaryContent(bytes: Uint8Array) {
   return bytes.reduce((count, byte) => count + Number(byte < 9 || (byte > 13 && byte < 32)), 0) / bytes.length > 0.3
 }
 
-async function renderTool(part: ToolPart) {
+async function renderTool(part: MiniToolPart) {
   const info = toolInlineInfo(part)
   if (info.mode === "block") {
     UI.empty()
@@ -240,7 +240,7 @@ async function renderTool(part: ToolPart) {
   )
 }
 
-async function renderToolError(part: ToolPart) {
+async function renderToolError(part: MiniToolPart) {
   const info = toolInlineInfo(part)
   UI.println(UI.Style.TEXT_NORMAL + "✗", UI.Style.TEXT_NORMAL + `${info.title} failed`)
 }

packages/cli/src/mini/runtime.ts

@@ -547,7 +547,6 @@ async function runInteractiveRuntime(input: RunRuntimeInput, deps: RunRuntimeDep
       footer,
       sessionID: state.sessionID,
       thinking: input.thinking,
-      limits: () => state.limits,
     })
   }
 

packages/cli/src/mini/scrollback.shared.ts

@@ -6,11 +6,7 @@ function syntax(style?: SyntaxStyle): SyntaxStyle {
   return style ?? SyntaxStyle.fromTheme([])
 }
 
-export function entrySyntax(commit: StreamCommit, theme: RunTheme): SyntaxStyle {
-  if (commit.kind === "reasoning") {
-    return syntax(theme.block.subtleSyntax ?? theme.block.syntax)
-  }
-
+export function entrySyntax(theme: RunTheme): SyntaxStyle {
   return syntax(theme.block.syntax)
 }
 

packages/cli/src/mini/scrollback.surface.ts

@@ -143,7 +143,7 @@ export class RunScrollbackStream {
     }
 
     active.renderable.fg = entryColor(active.commit, theme)
-    active.renderable.syntaxStyle = entrySyntax(active.commit, theme)
+    active.renderable.syntaxStyle = entrySyntax(theme)
   }
 
   private createEntry(commit: StreamCommit, body: ActiveBody): ActiveEntry {
@@ -165,7 +165,7 @@ export class RunScrollbackStream {
           ? new CodeRenderable(surface.renderContext, {
               content: "",
               filetype: body.filetype,
-              syntaxStyle: entrySyntax(commit, this.theme),
+              syntaxStyle: entrySyntax(this.theme),
               width: "100%",
               wrapMode: "word",
               drawUnstyledText: false,
@@ -175,7 +175,7 @@ export class RunScrollbackStream {
             })
           : new MarkdownRenderable(surface.renderContext, {
               content: "",
-              syntaxStyle: entrySyntax(commit, this.theme),
+              syntaxStyle: entrySyntax(this.theme),
               width: "100%",
               streaming: true,
               internalBlockMode: "top-level",

packages/cli/src/mini/scrollback.writer.tsx

@@ -84,7 +84,7 @@ export function RunEntryContent(props: {
   const theme = createMemo(() => props.theme ?? RUN_THEME_FALLBACK)
   const body = createMemo(() => props.body ?? entryBody(props.commit))
   const style = createMemo(() => entryLook(props.commit, theme().entry))
-  const syntax = createMemo(() => entrySyntax(props.commit, theme()))
+  const syntax = createMemo(() => entrySyntax(theme()))
   const color = createMemo(() => entryColor(props.commit, theme()))
   const suppressBackgrounds = createMemo(() => props.opts?.suppressBackgrounds === true)
   const diffBg = (color: ColorInput) => (suppressBackgrounds() ? transparent : color)

packages/cli/src/mini/session.shared.ts

@@ -1,15 +1,10 @@
-// Session message extraction and prompt history.
-//
-// Fetches session messages from the SDK and extracts user turn text for
-// the prompt history ring. Also finds the most recently used variant for
-// the current model so the footer can pre-select it.
+import type { SessionMessageInfo, SessionMessageUser } from "@opencode-ai/client/promise"
 import { promptCopy, promptSame } from "./prompt.shared"
-import type { Message, Part } from "@opencode-ai/sdk/v2"
 import type { RunInput, RunPrompt } from "./types"
 
 const LIMIT = 200
 
-export type SessionMessages = Array<{ info: Message; parts: Part[] }>
+export type SessionMessages = SessionMessageInfo[]
 
 type Turn = {
   prompt: RunPrompt
@@ -25,133 +20,42 @@ export type RunSession = {
   variant?: string
 }
 
-function fileName(url: string, filename?: string) {
-  if (filename) {
-    return filename
-  }
-
-  try {
-    const next = new URL(url)
-    if (next.protocol !== "file:") {
-      return url
-    }
-
-    const name = next.pathname.split("/").at(-1)
-    if (name) {
-      return decodeURIComponent(name)
-    }
-  } catch {}
-
-  return url
-}
-
-function fileSource(
-  part: Extract<SessionMessages[number]["parts"][number], { type: "file" }>,
-  text: { start: number; end: number; value: string },
-) {
-  if (part.source) {
-    return {
-      ...structuredClone(part.source),
-      text,
-    }
-  }
-
+function messagePrompt(message: SessionMessageUser): RunPrompt {
   return {
-    type: "file" as const,
-    path: part.filename ?? part.url,
-    text,
-  }
-}
-
-export function messagePrompt(msg: SessionMessages[number]): RunPrompt {
-  const parts: RunPrompt["parts"] = []
-  let text = msg.parts
-    .filter((part): part is Extract<SessionMessages[number]["parts"][number], { type: "text" }> => {
-      return part.type === "text" && !part.synthetic
-    })
-    .map((part) => part.text)
-    .join("")
-  let cursor = Bun.stringWidth(text)
-  const used: Array<{ start: number; end: number }> = []
-
-  const take = (value: string): { start: number; end: number; value: string } | undefined => {
-    let from = 0
-    while (true) {
-      const idx = text.indexOf(value, from)
-      if (idx === -1) {
-        return undefined
-      }
-
-      const start = Bun.stringWidth(text.slice(0, idx))
-      const end = start + Bun.stringWidth(value)
-      if (!used.some((item) => item.start < end && start < item.end)) {
-        return { start, end, value }
-      }
-
-      from = idx + value.length
-    }
-  }
-
-  const add = (value: string) => {
-    const gap = text ? " " : ""
-    const start = cursor + Bun.stringWidth(gap)
-    text += gap + value
-    const end = start + Bun.stringWidth(value)
-    cursor = end
-    return { start, end, value }
-  }
-
-  for (const part of msg.parts) {
-    if (part.type === "file") {
-      const next = part.source?.text ? structuredClone(part.source.text) : take("@" + fileName(part.url, part.filename))
-      const span = next ?? add("@" + fileName(part.url, part.filename))
-      used.push({ start: span.start, end: span.end })
-      parts.push({
-        type: "file",
-        mime: part.mime,
-        filename: part.filename,
-        url: part.url,
-        source: fileSource(part, span),
-      })
-      continue
-    }
-
-    if (part.type !== "agent") {
-      continue
-    }
-
-    const span = part.source ? structuredClone(part.source) : (take("@" + part.name) ?? add("@" + part.name))
-    used.push({ start: span.start, end: span.end })
-    parts.push({
-      type: "agent",
-      name: part.name,
-      source: span,
-    })
-  }
-
-  return { text, parts }
-}
-
-function turn(msg: SessionMessages[number]): Turn | undefined {
-  if (msg.info.role !== "user") {
-    return undefined
-  }
-
-  return {
-    prompt: messagePrompt(msg),
-    provider: msg.info.model.providerID,
-    model: msg.info.model.modelID,
-    variant: msg.info.model.variant,
+    text: message.text,
+    parts: [
+      ...(message.files ?? []).map((file) => ({
+        type: "file" as const,
+        url: file.source.type === "uri" ? file.source.uri : `data:${file.mime};base64,${file.data}`,
+        mime: file.mime,
+        filename: file.name,
+        source: file.mention
+          ? {
+              type: "file",
+              path: file.name ?? (file.source.type === "uri" ? file.source.uri : "inline attachment"),
+              text: { start: file.mention.start, end: file.mention.end, value: file.mention.text },
+            }
+          : undefined,
+      })),
+      ...(message.agents ?? []).map((agent) => ({
+        type: "agent" as const,
+        name: agent.name,
+        source: agent.mention
+          ? { start: agent.mention.start, end: agent.mention.end, value: agent.mention.text }
+          : undefined,
+      })),
+    ],
   }
 }
 
 export function createSession(messages: SessionMessages): RunSession {
   return {
     first: messages.length === 0,
-    turns: messages.flatMap((msg) => {
-      const item = turn(msg)
-      return item ? [item] : []
-    }),
+    turns: messages.flatMap((message) =>
+      message.type === "user"
+        ? [{ prompt: messagePrompt(message), provider: undefined, model: undefined, variant: undefined }]
+        : [],
+    ),
   }
 }
 
@@ -164,89 +68,34 @@ export async function resolveCurrentSession(
     sdk.message.list({ sessionID, limit, order: "desc" }),
     sdk.session.get({ sessionID }),
   ])
-  const messages = response.data.toReversed()
+  const current = createSession(response.data.toReversed())
   return {
-    first: messages.length === 0,
-    turns: messages.flatMap((message) => {
-      if (message.type !== "user") return []
-      return [
-        {
-          prompt: {
-            text: message.text,
-            parts: [
-              ...(message.files ?? []).map((file) => ({
-                type: "file" as const,
-                url: file.source.type === "uri" ? file.source.uri : `data:${file.mime};base64,${file.data}`,
-                mime: file.mime,
-                filename: file.name,
-                source: file.mention
-                  ? {
-                      type: "file" as const,
-                      path: file.name ?? (file.source.type === "uri" ? file.source.uri : "inline attachment"),
-                      text: { start: file.mention.start, end: file.mention.end, value: file.mention.text },
-                    }
-                  : undefined,
-              })),
-              ...(message.agents ?? []).map((agent) => ({
-                type: "agent" as const,
-                name: agent.name,
-                source: agent.mention
-                  ? { start: agent.mention.start, end: agent.mention.end, value: agent.mention.text }
-                  : undefined,
-              })),
-            ],
-          },
-          provider: session.model?.providerID,
-          model: session.model?.id,
-          variant: session.model?.variant,
-        },
-      ]
-    }),
+    ...current,
+    turns: current.turns.map((turn) => ({
+      ...turn,
+      provider: session.model?.providerID,
+      model: session.model?.id,
+      variant: session.model?.variant,
+    })),
     ...(session.model && {
-      model: {
-        providerID: session.model.providerID,
-        modelID: session.model.id,
-      },
+      model: { providerID: session.model.providerID, modelID: session.model.id },
       variant: session.model.variant,
     }),
   }
 }
 
 export function sessionHistory(session: RunSession, limit = LIMIT): RunPrompt[] {
-  const out: RunPrompt[] = []
-
-  for (const turn of session.turns) {
-    if (!turn.prompt.text.trim()) {
-      continue
-    }
-
-    if (out[out.length - 1] && promptSame(out[out.length - 1], turn.prompt)) {
-      continue
-    }
-
-    out.push(promptCopy(turn.prompt))
-  }
-
-  return out.slice(-limit)
+  return session.turns
+    .map((turn) => turn.prompt)
+    .filter((prompt) => prompt.text.trim())
+    .filter((prompt, index, prompts) => index === 0 || !promptSame(prompts[index - 1], prompt))
+    .map(promptCopy)
+    .slice(-limit)
 }
 
 export function sessionVariant(session: RunSession, model: RunInput["model"]): string | undefined {
-  if (!model) {
-    return undefined
-  }
+  if (!model) return
+  if (session.model?.providerID === model.providerID && session.model.modelID === model.modelID) return session.variant
 
-  if (session.model?.providerID === model.providerID && session.model.modelID === model.modelID) {
-    return session.variant
-  }
-
-  for (let idx = session.turns.length - 1; idx >= 0; idx -= 1) {
-    const turn = session.turns[idx]
-    if (turn.provider !== model.providerID || turn.model !== model.modelID) {
-      continue
-    }
-
-    return turn.variant
-  }
-
-  return undefined
+  return session.turns.findLast((turn) => turn.provider === model.providerID && turn.model === model.modelID)?.variant
 }

packages/cli/src/mini/stream-v2.subagent.ts

@@ -15,10 +15,14 @@
 // Per-child interruption uses `v2.session.interrupt(childID)`. Per-child
 // backgrounding is intentionally absent: subagent jobs block the parent
 // session, so only whole-session `v2.session.background(parentID)` exists.
-import type { EventSubscribeOutput, OpenCodeClient } from "@opencode-ai/client/promise"
-import type { SessionMessageAssistantTool, SessionMessageInfo, ToolPart } from "@opencode-ai/sdk/v2"
+import type {
+  EventSubscribeOutput,
+  OpenCodeClient,
+  SessionMessageAssistantTool,
+  SessionMessageInfo,
+} from "@opencode-ai/client/promise"
 import { Locale } from "@opencode-ai/tui/util/locale"
-import type { FooterSubagentDetail, FooterSubagentState, FooterSubagentTab, StreamCommit } from "./types"
+import type { FooterSubagentDetail, FooterSubagentState, FooterSubagentTab, MiniToolPart, StreamCommit } from "./types"
 
 const CHILD_MESSAGE_LIMIT = 80
 const CHILD_FRAME_LIMIT = 80
@@ -32,11 +36,11 @@ export function outputText(content: ReadonlyArray<{ type: string; text?: string
   return content.flatMap((item) => (item.type === "text" && item.text ? [item.text] : [])).join("\n")
 }
 
-export function legacyTool(input: {
+export function miniTool(input: {
   sessionID: string
   messageID: string
   tool: SessionMessageAssistantTool
-}): ToolPart {
+}): MiniToolPart {
   const tool = input.tool
   const providerCall =
     tool.executed === undefined && tool.providerState === undefined
@@ -109,7 +113,7 @@ export function legacyTool(input: {
   }
 }
 
-export function toolCommit(part: ToolPart, phase: "start" | "progress" | "final"): StreamCommit {
+export function toolCommit(part: MiniToolPart, phase: "start" | "progress" | "final"): StreamCommit {
   const status = part.state.status
   const text =
     status === "running"
@@ -310,7 +314,7 @@ export function createSubagentTracker(input: SubagentTrackerInput): SubagentTrac
   }
 
   const childTool = (child: ChildState, item: SessionMessageAssistantTool, messageID: string) => {
-    const part = legacyTool({
+    const part = miniTool({
       sessionID: child.sessionID,
       messageID,
       tool: item,

packages/cli/src/mini/stream-v2.transport.ts

@@ -1,14 +1,15 @@
-import type { EventSubscribeOutput, OpenCodeClient } from "@opencode-ai/client/promise"
 import type {
-  PermissionRequest,
-  QuestionRequest,
-  SessionMessageInfo,
+  EventSubscribeOutput,
+  OpenCodeClient,
+  PermissionV2Request,
+  QuestionV2Request,
   SessionMessageAssistantTool,
-} from "@opencode-ai/sdk/v2"
+  SessionMessageInfo,
+} from "@opencode-ai/client/promise"
 import { Event } from "@opencode-ai/schema/event"
 import { blockerStatus, pickBlockerView } from "./session-data"
 import { writeSessionOutput } from "./stream"
-import { createSubagentTracker, legacyTool, toolCommit } from "./stream-v2.subagent"
+import { createSubagentTracker, miniTool, toolCommit } from "./stream-v2.subagent"
 import type {
   FooterApi,
   FooterView,
@@ -87,8 +88,6 @@ type ShellWait = {
 }
 
 type RunV2Event = EventSubscribeOutput
-type PermissionV2Request = Extract<RunV2Event, { type: "permission.v2.asked" }>["data"]
-type QuestionV2Request = Extract<RunV2Event, { type: "question.v2.asked" }>["data"]
 type PromptFilePart = Extract<RunPromptPart, { type: "file" }>
 
 type ToolState = {
@@ -101,8 +100,8 @@ type ToolState = {
 }
 
 type State = {
-  permissions: PermissionRequest[]
-  questions: QuestionRequest[]
+  permissions: PermissionV2Request[]
+  questions: QuestionV2Request[]
   view: FooterView
   messageIDs: Set<string>
   text: Map<string, string>
@@ -138,27 +137,6 @@ export function formatUnknownError(error: unknown): string {
   return "unknown error"
 }
 
-function permission(request: PermissionV2Request): PermissionRequest {
-  return {
-    id: request.id,
-    sessionID: request.sessionID,
-    permission: request.action,
-    patterns: [...request.resources],
-    metadata: request.metadata ?? {},
-    always: [...(request.save ?? [])],
-    tool: request.source?.type === "tool" ? request.source : undefined,
-  }
-}
-
-function question(request: QuestionV2Request): QuestionRequest {
-  return {
-    id: request.id,
-    sessionID: request.sessionID,
-    questions: request.questions.map((item) => ({ ...item, options: item.options.map((option) => ({ ...option })) })),
-    tool: request.tool,
-  }
-}
-
 function sessionID(event: RunV2Event) {
   return "sessionID" in event.data && typeof event.data.sessionID === "string" ? event.data.sessionID : undefined
 }
@@ -229,8 +207,7 @@ function streamPartKey(messageID: string, partID: string) {
   return `${messageID}\u0000${partID}`
 }
 
-// Matches the commit shapes the legacy session-data reducer produced for direct
-// shell calls: one "start" commit rendering `$ command` and one "progress"
+// Direct shell calls use one "start" commit rendering `$ command` and one "progress"
 // commit rendering the merged output (see toolEntryBody in tool.ts).
 function shellCommit(
   callID: string,
@@ -384,7 +361,7 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
   }
 
   const renderTool = (messageID: string, item: SessionMessageAssistantTool) => {
-    const part = legacyTool({
+    const part = miniTool({
       sessionID: input.sessionID,
       messageID,
       tool: item,
@@ -536,8 +513,8 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
     ])
     const projected = structuredClone(messages.data).toReversed() as SessionMessageInfo[]
     for (const message of projected) renderMessage(message, next.render, next.reuseVisibleWait)
-    state.permissions = permissions.map(permission)
-    state.questions = questions.map(question)
+    state.permissions = permissions
+    state.questions = questions
     syncBlockers()
     await subagents.hydrate({ messages: [...projected], active })
     const running = input.sessionID in active
@@ -770,7 +747,7 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
       return
     }
     if (event.type === "permission.v2.asked") {
-      if (!state.permissions.some((item) => item.id === event.data.id)) state.permissions.push(permission(event.data))
+      if (!state.permissions.some((item) => item.id === event.data.id)) state.permissions.push(event.data)
       syncBlockers()
       return
     }
@@ -780,7 +757,7 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
       return
     }
     if (event.type === "question.v2.asked") {
-      if (!state.questions.some((item) => item.id === event.data.id)) state.questions.push(question(event.data))
+      if (!state.questions.some((item) => item.id === event.data.id)) state.questions.push(event.data)
       syncBlockers()
       return
     }

packages/cli/src/mini/stream.ts

@@ -1,10 +1,10 @@
-// Thin bridge between reducer output and the footer API.
+// Thin bridge between transport output and the footer API.
 //
-// The reducers produce StreamCommit[] and an optional FooterOutput (patch +
+// Transports produce StreamCommit[] and an optional FooterOutput (patch +
 // view + subagent state). This module forwards them to footer.append() and
 // footer.event() respectively, adding trace writes along the way. It also
 // defaults status updates to phase "running" if the caller didn't set a
-// phase -- a convenience so reducer code doesn't have to repeat that.
+// phase -- a convenience so transport code doesn't have to repeat that.
 import type { FooterApi, FooterOutput, FooterPatch, FooterSubagentState, StreamCommit } from "./types"
 
 type Trace = {
@@ -103,9 +103,9 @@ export function traceSubagentState(state: FooterSubagentState) {
     permissions: state.permissions.map((item) => ({
       id: item.id,
       sessionID: item.sessionID,
-      permission: item.permission,
-      patterns: item.patterns,
-      tool: item.tool,
+      action: item.action,
+      resources: item.resources,
+      source: item.source,
       metadata: item.metadata
         ? {
             keys: Object.keys(item.metadata),
@@ -137,7 +137,7 @@ export function traceFooterOutput(footer?: FooterOutput) {
   }
 }
 
-// Forwards reducer output to the footer: commits go to scrollback, patches update the status bar.
+// Forwards transport output to the footer: commits go to scrollback, patches update the status bar.
 export function writeSessionOutput(input: OutputInput, out: StreamOutput): void {
   for (const commit of out.commits) {
     input.trace?.write("ui.commit", commit)

packages/cli/src/mini/theme.ts

@@ -47,7 +47,6 @@ export type RunBlockTheme = {
   text: ColorInput
   muted: ColorInput
   syntax?: SyntaxStyle
-  subtleSyntax?: SyntaxStyle
   diffAdded: ColorInput
   diffRemoved: ColorInput
   diffAddedBg: ColorInput
@@ -172,42 +171,10 @@ function tint(base: RGBA, overlay: RGBA, value: number): RGBA {
   )
 }
 
-function blend(color: RGBA, bg: RGBA): RGBA {
-  if (color.a >= 1) {
-    return color
-  }
-
-  return RGBA.fromValues(
-    bg.r + (color.r - bg.r) * color.a,
-    bg.g + (color.g - bg.g) * color.a,
-    bg.b + (color.b - bg.b) * color.a,
-    1,
-  )
-}
-
 function chroma(color: RGBA) {
   return Math.max(color.r, color.g, color.b) - Math.min(color.r, color.g, color.b)
 }
 
-function opaqueSyntaxStyle(style: SyntaxStyle | undefined, bg: RGBA): SyntaxStyle | undefined {
-  if (!style) {
-    return undefined
-  }
-
-  return SyntaxStyle.fromStyles(
-    Object.fromEntries(
-      [...style.getAllStyles()].map(([name, value]) => [
-        name,
-        {
-          ...value,
-          fg: value.fg ? blend(value.fg, bg) : value.fg,
-          bg: value.bg ? blend(value.bg, bg) : value.bg,
-        },
-      ]),
-    ),
-  )
-}
-
 function indexedPalette(colors: TerminalColors, size: number = Math.max(colors.palette.length, 16)): RGBA[] {
   return Array.from({ length: size }, (_, index) => {
     const value = colors.palette[index]
@@ -502,10 +469,7 @@ function map(
   scrollbackTheme: TuiThemeCurrent,
   splash: RunSplashTheme,
   syntax?: SyntaxStyle,
-  subtleSyntax?: SyntaxStyle,
 ): RunTheme {
-  const opaqueSubtleSyntax = opaqueSyntaxStyle(subtleSyntax, scrollbackTheme.background)
-  subtleSyntax?.destroy()
   const footerBackground = alpha(footerTheme.background, 1)
   const footerMode = mode(footerBackground)
   const shade = fade(footerTheme.backgroundMenu, footerTheme.background, 0.12, 0.56, 0.72)
@@ -566,7 +530,6 @@ function map(
       text: scrollbackTheme.text,
       muted: scrollbackTheme.textMuted,
       syntax,
-      subtleSyntax: opaqueSubtleSyntax,
       diffAdded: scrollbackTheme.diffAdded,
       diffRemoved: scrollbackTheme.diffRemoved,
       diffAddedBg: transparent,
@@ -677,13 +640,7 @@ export async function resolveRunTheme(renderer: CliRenderer): Promise<RunTheme>
       _hasSelectedListItemText: true,
     }
     const syntax = shared.generateSyntax(syntaxTheme)
-    return map(
-      footerTheme,
-      scrollbackTheme,
-      splashTheme(scrollbackTheme, indexed),
-      syntax,
-      shared.generateSubtleSyntax(syntaxTheme),
-    )
+    return map(footerTheme, scrollbackTheme, splashTheme(scrollbackTheme, indexed), syntax)
   } catch {
     return RUN_THEME_FALLBACK
   }

packages/cli/src/mini/tool.ts

@@ -15,10 +15,9 @@
 import os from "os"
 import path from "path"
 import stripAnsi from "strip-ansi"
-import type { ToolPart } from "@opencode-ai/sdk/v2"
 import { LANGUAGE_EXTENSIONS } from "@opencode-ai/tui/util/filetype"
 import { Locale } from "@opencode-ai/tui/util/locale"
-import type { RunEntryBody, StreamCommit, ToolSnapshot } from "./types"
+import type { MiniToolPart, RunEntryBody, StreamCommit, ToolSnapshot } from "./types"
 
 export type ToolView = {
   output: boolean
@@ -1177,7 +1176,7 @@ function rule(name?: string): AnyToolRule | undefined {
   return TOOL_RULES[name]
 }
 
-function frame(part: ToolPart): ToolFrame {
+function frame(part: MiniToolPart): ToolFrame {
   const state = dict(part.state)
   return {
     raw: "",
@@ -1231,7 +1230,7 @@ export function toolStructuredFinal(commit: StreamCommit): boolean {
   )
 }
 
-export function toolInlineInfo(part: ToolPart): ToolInline {
+export function toolInlineInfo(part: MiniToolPart): ToolInline {
   const ctx = frame(part)
   const draw = rule(ctx.name)?.run
   try {

packages/cli/src/mini/types.ts

@@ -7,12 +7,16 @@
 //
 // Data flow through the system:
 //
-//   SDK events → session-data reducer → StreamCommit[] + FooterOutput
+//   V2 events / demo actions → StreamCommit[] + FooterOutput
 //     → stream.ts bridges to footer API
 //       → footer.ts queues commits and patches the footer view
 //         → OpenTUI split-footer renderer writes to terminal
-import type { OpenCodeClient, ReferenceListOutput } from "@opencode-ai/client/promise"
-import type { FilePart, PermissionRequest, QuestionRequest, ToolPart } from "@opencode-ai/sdk/v2"
+import type {
+  OpenCodeClient,
+  PermissionV2Request,
+  QuestionV2Request,
+  ReferenceListOutput,
+} from "@opencode-ai/client/promise"
 import type { TuiConfig } from "@opencode-ai/tui/config/v1"
 
 export type RunFilePart = {
@@ -30,7 +34,11 @@ export type RunPromptPart =
       url: string
       filename?: string
       mime?: string
-      source?: FilePart["source"]
+      source?: {
+        type: string
+        text: { start: number; end: number; value: string }
+        [key: string]: unknown
+      }
     }
   | { type: "agent"; name: string; source?: { start: number; end: number; value: string } }
 
@@ -210,6 +218,41 @@ export type ToolQuestionSnapshot = {
 
 export type ToolSnapshot = ToolCodeSnapshot | ToolDiffSnapshot | ToolTaskSnapshot | ToolQuestionSnapshot
 
+export type MiniToolState =
+  | { status: "pending"; input: Record<string, unknown>; raw?: string }
+  | {
+      status: "running"
+      input: Record<string, unknown>
+      title?: string
+      metadata?: Record<string, unknown>
+      time: { start: number }
+    }
+  | {
+      status: "completed"
+      input: Record<string, unknown>
+      output: string
+      title?: string
+      metadata?: Record<string, unknown>
+      time: { start: number; end: number }
+    }
+  | {
+      status: "error"
+      input: Record<string, unknown>
+      error: string
+      metadata?: Record<string, unknown>
+      time: { start: number; end: number }
+    }
+
+export type MiniToolPart = {
+  id: string
+  sessionID: string
+  messageID: string
+  type?: "tool"
+  callID: string
+  tool: string
+  state: MiniToolState
+}
+
 export type EntryLayout = "inline" | "block"
 
 export type RunEntryBody =
@@ -220,13 +263,13 @@ export type RunEntryBody =
   | { type: "structured"; snapshot: ToolSnapshot }
 
 // Which interactive surface the footer is showing. Only one view is active at
-// a time. The reducer drives transitions: when a permission arrives the view
+// a time. The transport drives transitions: when a permission arrives the view
 // switches to "permission", and when the permission resolves it falls back to
 // "prompt".
 export type FooterView =
   | { type: "prompt" }
-  | { type: "permission"; request: PermissionRequest }
-  | { type: "question"; request: QuestionRequest }
+  | { type: "permission"; request: PermissionV2Request }
+  | { type: "question"; request: QuestionV2Request }
 
 export type FooterPromptRoute =
   | { type: "composer" }
@@ -259,11 +302,11 @@ export type FooterSubagentDetail = {
 export type FooterSubagentState = {
   tabs: FooterSubagentTab[]
   details: Record<string, FooterSubagentDetail>
-  permissions: PermissionRequest[]
-  questions: QuestionRequest[]
+  permissions: PermissionV2Request[]
+  questions: QuestionV2Request[]
 }
 
-// The reducer emits this alongside scrollback commits so the footer can update in the same frame.
+// The transport emits this alongside scrollback commits so the footer can update in the same frame.
 export type FooterOutput = {
   patch?: FooterPatch
   view?: FooterView
@@ -357,8 +400,8 @@ export type StreamSource = "assistant" | "reasoning" | "tool" | "system"
 
 export type StreamToolState = "running" | "completed" | "error"
 
-// A single append-only commit to scrollback. The session-data reducer produces
-// these from SDK events, and RunFooter.append() queues them for the next
+// A single append-only commit to scrollback. The transport produces these from
+// V2 events, and RunFooter.append() queues them for the next
 // microtask flush. Once flushed, they become immutable terminal scrollback
 // rows -- they cannot be rewritten.
 export type StreamCommit = {
@@ -370,7 +413,7 @@ export type StreamCommit = {
   messageID?: string
   partID?: string
   tool?: string
-  part?: ToolPart
+  part?: MiniToolPart
   interrupted?: boolean
   toolState?: StreamToolState
   toolError?: string

packages/cli/src/tui-config.ts

@@ -1,24 +0,0 @@
-export * as TuiConfig from "./tui-config"
-
-import { Global } from "@opencode-ai/core/global"
-import { TuiConfig } from "@opencode-ai/tui/config/v1"
-import { Effect, FileSystem, Option, Schema } from "effect"
-import { parse, type ParseError } from "jsonc-parser"
-import path from "path"
-
-export const load = Effect.fn("TuiConfig.load")(function* () {
-  const fs = yield* FileSystem.FileSystem
-  const global = yield* Global.Service
-  const filepath = path.join(global.config, "tui.json")
-  const text = yield* fs.readFileString(filepath).pipe(Effect.catch(() => Effect.succeed(undefined)))
-  if (!text) return TuiConfig.resolve({}, { terminalSuspend: process.platform !== "win32" })
-
-  const errors: ParseError[] = []
-  const input: unknown = parse(text, errors, { allowTrailingComma: true })
-  if (errors.length) return TuiConfig.resolve({}, { terminalSuspend: process.platform !== "win32" })
-
-  return TuiConfig.resolve(
-    Option.getOrElse(Schema.decodeUnknownOption(TuiConfig.Info)(input), () => ({})),
-    { terminalSuspend: process.platform !== "win32" },
-  )
-})

packages/cli/test/config.test.ts

@@ -0,0 +1,144 @@
+import { NodeFileSystem } from "@effect/platform-node"
+import { Global } from "@opencode-ai/core/global"
+import { Effect } from "effect"
+import { expect, test } from "bun:test"
+import path from "path"
+import { Config } from "../src/config"
+
+function run<A, E>(directory: string, effect: Effect.Effect<A, E, Config.Service>) {
+  return Effect.runPromise(
+    effect.pipe(
+      Effect.provide(Config.layer),
+      Effect.provide(Global.layerWith({ config: directory, state: directory })),
+      Effect.provide(NodeFileSystem.layer),
+    ),
+  )
+}
+
+test("migrates tui and kv config into cli.json", async () => {
+  const directory = await Bun.$`mktemp -d`.text().then((value) => value.trim())
+  await Bun.write(
+    path.join(directory, "tui.json"),
+    JSON.stringify({
+      theme: "legacy",
+      keybinds: { leader: "ctrl+o" },
+      plugin: [["example", { mode: "safe" }]],
+      plugin_enabled: { disabled: false },
+      leader_timeout: 500,
+      scroll_speed: 2,
+      scroll_acceleration: { enabled: true },
+      diff_style: "stacked",
+      mouse: false,
+    }),
+  )
+  await Bun.write(
+    path.join(directory, "kv.json"),
+    JSON.stringify({
+      theme_mode_lock: "light",
+      attention_sound_pack: "custom.pack",
+      diff_wrap_mode: "none",
+      diff_viewer_show_file_tree: false,
+      diff_viewer_single_patch: true,
+      diff_viewer_view: "split",
+      terminal_title_enabled: false,
+      file_context_enabled: false,
+      paste_summary_enabled: false,
+      sidebar: "hide",
+      scrollbar_visible: true,
+      thinking_mode: "show",
+      exploration_grouping: false,
+      tips_hidden: true,
+      dismissed_getting_started: true,
+      animations_enabled: false,
+      skipped_version: "9.9.9",
+      which_key_layout: "overlay",
+    }),
+  )
+
+  try {
+    const config = await run(
+      directory,
+      Effect.gen(function* () {
+        const service = yield* Config.Service
+        return yield* service.get()
+      }),
+    )
+
+    expect(config).toMatchObject({
+      theme: { name: "legacy", mode: "light" },
+      keybinds: { leader: "ctrl+o" },
+      plugins: [{ package: "example", options: { mode: "safe" } }, "-disabled"],
+      leader: { timeout: 500 },
+      scroll: { speed: 2, acceleration: true },
+      attention: { sound_pack: "custom.pack" },
+      diffs: { wrap: "none", tree: false, single: true, view: "split" },
+      terminal: { title: false },
+      prompt: { editor: false, paste: "full" },
+      session: { sidebar: "hide", scrollbar: true, thinking: "show", grouping: "none" },
+      hints: { tips: false, onboarding: false },
+      animations: false,
+      mouse: false,
+    })
+    expect(config).not.toHaveProperty("skipped_version")
+    expect(config).not.toHaveProperty("which_key")
+    expect((await Bun.file(path.join(directory, "cli.json")).json()).keybinds).toEqual({ leader: "ctrl+o" })
+    expect(await Bun.file(path.join(directory, "cli.json")).exists()).toBe(true)
+    expect(await Bun.file(path.join(directory, "tui.json")).exists()).toBe(true)
+    expect(await Bun.file(path.join(directory, "kv.json")).exists()).toBe(true)
+  } finally {
+    await Bun.$`rm -rf ${directory}`
+  }
+})
+
+test("migrates before the first update and does not remigrate afterward", async () => {
+  const directory = await Bun.$`mktemp -d`.text().then((value) => value.trim())
+  await Bun.write(path.join(directory, "tui.json"), JSON.stringify({ theme: "legacy" }))
+
+  try {
+    const config = await run(
+      directory,
+      Effect.gen(function* () {
+        const service = yield* Config.Service
+        yield* service.update((draft) => {
+          draft.animations = false
+          draft.mouse = false
+        })
+        yield* Effect.promise(() =>
+          Bun.write(path.join(directory, "tui.json"), JSON.stringify({ theme: "changed" })),
+        )
+        return yield* service.get()
+      }),
+    )
+
+    expect(config).toEqual({ theme: { name: "legacy" }, animations: false, mouse: false })
+    expect(await Bun.file(path.join(directory, "cli.json")).json()).toEqual({
+      theme: { name: "legacy" },
+      animations: false,
+      mouse: false,
+    })
+  } finally {
+    await Bun.$`rm -rf ${directory}`
+  }
+})
+
+test("updates a config draft while preserving JSONC comments", async () => {
+  const directory = await Bun.$`mktemp -d`.text().then((value) => value.trim())
+  await Bun.write(path.join(directory, "cli.json"), "{\n  // Keep this comment\n  \"animations\": true\n}\n")
+
+  try {
+    const config = await run(
+      directory,
+      Effect.gen(function* () {
+        const service = yield* Config.Service
+        return yield* service.update((draft) => {
+          draft.prompt = { paste: "compact" }
+        })
+      }),
+    )
+
+    expect(config).toEqual({ animations: true, prompt: { paste: "compact" } })
+    expect(await Bun.file(path.join(directory, "cli.json")).text()).toContain("// Keep this comment")
+  } finally {
+    await Bun.$`rm -rf ${directory}`
+  }
+})

packages/cli/test/tui-config.test.ts

@@ -1,25 +0,0 @@
-import { NodeFileSystem } from "@effect/platform-node"
-import { Global } from "@opencode-ai/core/global"
-import { Effect } from "effect"
-import { expect, test } from "bun:test"
-import path from "path"
-import { TuiConfig } from "../src/tui-config"
-
-test("loads the global tui config", async () => {
-  const directory = await Bun.$`mktemp -d`.text().then((value) => value.trim())
-  await Bun.write(path.join(directory, "tui.json"), JSON.stringify({ keybinds: { leader: "ctrl+o" } }))
-
-  try {
-    const config = await Effect.runPromise(
-      TuiConfig.load().pipe(
-        Effect.provide(Global.layerWith({ config: directory })),
-        Effect.provide(NodeFileSystem.layer),
-      ),
-    )
-
-    expect(config.keybinds.get("leader")?.[0]?.key).toBe("ctrl+o")
-    expect(config.keybinds.get("session.new")?.[0]?.key).toBe("<leader>n")
-  } finally {
-    await Bun.$`rm -rf ${directory}`
-  }
-})

packages/client/src/effect/service.ts

@@ -59,11 +59,11 @@ const discoverLocal = Effect.fnUntraced(function* (options: Options) {
 export const start = Effect.fn("service.start")(function* (options: StartOptions = {}) {
   const compatible = yield* discover(options)
   if (compatible !== undefined) return compatible
-  const mismatched = yield* find(options)
-  yield* Effect.sync(() =>
-    options.onStart?.(mismatched === undefined ? "missing" : "version-mismatch", mismatched?.info),
-  )
-  if (mismatched !== undefined) yield* kill(mismatched.info, options).pipe(Effect.ignore)
+  const existing = yield* find(options)
+  if (existing?.version !== undefined && (options.version === undefined || existing.version === options.version))
+    return existing.endpoint
+  yield* Effect.sync(() => options.onStart?.(existing === undefined ? "missing" : "version-mismatch", existing?.info))
+  if (existing !== undefined) yield* kill(existing.info, options).pipe(Effect.ignore)
 
   const [command, ...args] = options.command ?? ["opencode", "serve", "--service"]
   if (command === undefined) return yield* Effect.fail(new Error("Missing service command"))
@@ -138,6 +138,7 @@ const read = Effect.fnUntraced(function* (file?: string) {
 type LocalService = {
   readonly info: Info
   readonly endpoint: Endpoint
+  readonly version?: string
 }
 
 const probe = Effect.fnUntraced(function* (info: Info, version?: string, allowLegacy = false) {
@@ -161,7 +162,7 @@ const probe = Effect.fnUntraced(function* (info: Info, version?: string, allowLe
     if (health.value.pid !== info.pid) return undefined
     if (info.version !== undefined && health.value.version !== info.version) return undefined
     if (version !== undefined && health.value.version !== version) return undefined
-    return { info, endpoint } satisfies LocalService
+    return { info, endpoint, version: health.value.version } satisfies LocalService
   }
   if (
     !allowLegacy ||

packages/client/test/fixture/service.ts

@@ -0,0 +1,39 @@
+import { rename, writeFile } from "node:fs/promises"
+
+const [registration, mode] = process.argv.slice(2)
+if (registration === undefined || mode === undefined) throw new Error("Missing service fixture arguments")
+
+let requests = 0
+const server = Bun.serve({
+  port: 0,
+  async fetch(request) {
+    if (new URL(request.url).pathname !== "/api/health") return new Response(null, { status: 404 })
+    requests += 1
+    if (mode === "modern" && requests === 1) {
+      await writeFile(registration + ".first-request", "")
+      while (!(await Bun.file(registration + ".release").exists())) await Bun.sleep(5)
+      return new Response(null, { status: 503 })
+    }
+    if (mode === "legacy") return Response.json({ healthy: true })
+    return Response.json({ healthy: true, version: "test", pid: process.pid })
+  },
+})
+
+await writeFile(
+  registration + ".tmp",
+  JSON.stringify({
+    id: crypto.randomUUID(),
+    version: mode === "legacy" ? undefined : "test",
+    url: server.url.toString(),
+    pid: process.pid,
+  }),
+  { mode: 0o600 },
+)
+await rename(registration + ".tmp", registration)
+
+const shutdown = () => {
+  server.stop(true)
+  process.exit()
+}
+process.on("SIGTERM", shutdown)
+process.on("SIGINT", shutdown)

packages/client/test/service.test.ts

@@ -0,0 +1,91 @@
+import { NodeFileSystem } from "@effect/platform-node"
+import { afterEach, expect, test } from "bun:test"
+import { Effect } from "effect"
+import { mkdtemp, rm, writeFile } from "node:fs/promises"
+import { tmpdir } from "node:os"
+import { join } from "node:path"
+import { Service } from "../src/effect/index"
+
+const fixture = join(import.meta.dir, "fixture/service.ts")
+const processes: Bun.Subprocess[] = []
+const directories: string[] = []
+
+afterEach(async () => {
+  processes.forEach((process) => process.kill("SIGTERM"))
+  await Promise.all(processes.splice(0).map((process) => process.exited))
+  await Promise.all(directories.splice(0).map((directory) => rm(directory, { recursive: true, force: true })))
+})
+
+test("a concurrent same-version start cannot invalidate a resolved endpoint", async () => {
+  const directory = await temp()
+  const registration = join(directory, "service.json")
+  spawn(registration, "modern")
+  await waitForFile(registration)
+  const original = await Bun.file(registration).json()
+
+  const starts: Service.StartReason[] = []
+  const first = run(
+    Service.start({
+      file: registration,
+      version: "test",
+      command: [],
+      onStart: (reason) => starts.push(reason),
+    }),
+  )
+  await waitForFile(registration + ".first-request")
+
+  const resolved = await run(Service.start({ file: registration, version: "test" }))
+  expect(resolved.url).toBe(original.url)
+
+  await writeFile(registration + ".release", "")
+  await first
+
+  expect(starts).toEqual([])
+  expect(await Bun.file(registration).json()).toEqual(original)
+  expect(await health(resolved.url)).toEqual({ healthy: true, version: "test", pid: original.pid })
+})
+
+test("a legacy health response is still replaced", async () => {
+  const directory = await temp()
+  const registration = join(directory, "service.json")
+  const existing = spawn(registration, "legacy")
+  await waitForFile(registration)
+
+  const starts: Service.StartReason[] = []
+  const result = run(Service.start({ file: registration, command: [], onStart: (reason) => starts.push(reason) }))
+
+  await expect(result).rejects.toThrow("Missing service command")
+  expect(starts).toEqual(["version-mismatch"])
+  await existing.exited
+})
+
+function run<A, E>(effect: Effect.Effect<A, E, never>) {
+  return Effect.runPromise(effect.pipe(Effect.provide(NodeFileSystem.layer)))
+}
+
+function spawn(registration: string, mode: string, ...args: string[]) {
+  const subprocess = Bun.spawn([process.execPath, fixture, registration, mode, ...args], {
+    stdout: "ignore",
+    stderr: "inherit",
+  })
+  processes.push(subprocess)
+  return subprocess
+}
+
+async function temp() {
+  const directory = await mkdtemp(join(tmpdir(), "opencode-client-service-"))
+  directories.push(directory)
+  return directory
+}
+
+async function waitForFile(file: string) {
+  for (let attempt = 0; attempt < 600; attempt++) {
+    if (await Bun.file(file).exists()) return
+    await Bun.sleep(5)
+  }
+  throw new Error(`Timed out waiting for ${file}`)
+}
+
+async function health(url: string) {
+  return fetch(new URL("/api/health", url), { signal: AbortSignal.timeout(1_000) }).then((response) => response.json())
+}

packages/codemode/AGENTS.md

@@ -4,7 +4,7 @@
 - Do not add a speculative generic permission or approval policy. A host omits tools it does not expose and enforces domain authorization inside each provided tool.
 - Keep Code Mode unaware of host session, channel, and conversation models. The hosting application supplies trusted execution scope around it.
 - Tool schemas are the model-facing Interface. Keep arguments minimal and natural to the operation; never add unrelated IDs as ambient capability tokens.
-- When interpreter behavior or support changes, update `interpreter-support.md` and direct tests in the same PR. Update `codemode.md` when the package design, integration status, or rationale changes.
+- When interpreter behavior or support changes, update `interpreter-support.md` and direct tests in the same PR.
 
 ## OpenAPI
 
@@ -16,8 +16,8 @@
 
 ## Future Design Notes
 
-- If a captured user-visible output channel returns (an earlier `output.text`/`output.file`/`output.image` API was removed from v1), keep `output` as its name, distinct from the program return value: `return` stays the structured result for the model, while `output.*` describes artifacts the host may render into a conversation or UI after execution. Keep this host-neutral and let applications decide how captured output is delivered. In v1, hosts collect media host-side (outside the sandbox) instead.
-- Improve the sandbox failure taxonomy. Distinguish parse/compile mistakes, unsupported syntax, user-thrown errors, invalid returned data, tool refusal, tool internal failure, timeout, and genuine runtime defects so agents can recover accurately instead of treating everything as a generic execution failure.
+- If a captured user-visible output channel returns (an earlier `output.text`/`output.file`/`output.image` API was removed from v1), keep `output` as its name, distinct from the program return value: `return` stays the structured result for the model, while `output.*` describes artifacts the host may render into a conversation or UI after execution. Keep this host-neutral and let applications decide how captured output is delivered. In v1, hosts collect media host-side (outside CodeMode) instead.
+- Improve the failure taxonomy. Distinguish parse/compile mistakes, unsupported syntax, user-thrown errors, invalid returned data, tool refusal, tool internal failure, timeout, and genuine runtime defects so agents can recover accurately instead of treating everything as a generic execution failure.
 - Preserve the public/private error split. Tool authors should be able to return a safe model-visible message while retaining a private cause for host diagnostics. Unknown host failures must remain sanitized by default.
 - Think deliberately about richer binary boundaries before allowing `Blob`, `File`, `ArrayBuffer`, streams, or typed arrays beyond today's JSON-like values. If CodeMode supports binary tool args/results, use explicit tagged data shapes and clear size limits rather than relying on ambient runtime serialization.
 - Keep host capabilities explicit. Globals such as `fetch`, `crypto`, filesystem handles, extra modules, or network clients should be opt-in runtime capabilities with obvious policy defaults, not ambient authority. Default to unavailable unless a host deliberately provides the capability.

packages/codemode/README.md

@@ -177,8 +177,8 @@ No limit has a default, on purpose: execution budgets are host policy. A host wi
 interruption should set `maxOutputBytes` and `timeoutMs`. Limits are safe integers; invalid configuration throws a
 `RangeError` at construction. Exceeding `maxOutputBytes` never fails the execution - oversized output is truncated
 with an in-band marker. The timeout interrupts in-flight tool fibers and pure busy loops alike; a value the program
-already returned survives a cleanup timeout as a success with a `TimeoutExceeded` warning. Two internals are fixed
-constants, not knobs: at most 8 concurrent tool calls, and 32 levels of data nesting at boundaries.
+already returned survives a cleanup timeout as a success with a `TimeoutExceeded` warning. CodeMode does not limit
+tool-call concurrency. Data nesting at boundaries is limited to 32 levels.
 
 ## Boundaries and Non-Goals
 

packages/codemode/codemode.md

@@ -1,164 +0,0 @@
-# CodeMode Design and Status
-
-This is the living design and status document for `@opencode-ai/codemode` and its existing V2 OpenCode adapter.
-It records current behavior, intentional boundaries, durable rationale, and material remaining work.
-
-Completed implementation history, branch names, test counts, and closed findings belong in git, not here. Remove
-completed work instead of preserving checked-off chronology.
-
-Detailed package API documentation lives in [README.md](./README.md), and the checkable language/runtime matrix lives
-in [interpreter-support.md](./interpreter-support.md). OpenAPI-specific follow-ups live in
-[src/openapi/TODO.md](./src/openapi/TODO.md).
-
-## How CodeMode Works
-
-### Purpose
-
-CodeMode gives a model one `execute` tool backed by a confined JavaScript interpreter. Inside the program, the model
-can call an explicit tree of schema-described tools, sequence dependent work, run independent calls concurrently,
-and filter or aggregate results before returning them to the agent loop.
-
-The goals are:
-
-- Reduce model context consumed by large tool catalogs.
-- Avoid an agent round-trip between every dependent tool call.
-- Keep large intermediate results inside the program instead of sending them through model context.
-- Give generated code only the authority explicitly supplied by the host.
-
-CodeMode is an orchestration language, not a general JavaScript runtime or an application authorization system.
-
-### Runtime
-
-The generic runtime lives in `packages/codemode` and is host-neutral:
-
-1. The host builds a tree of `Tool.make(...)` definitions and calls `CodeMode.make(...)` or `CodeMode.execute(...)`.
-2. CodeMode generates model instructions, a budgeted inline catalog, and the global `search(...)` built-in.
-3. TypeScript syntax is transpiled away, Acorn parses the resulting JavaScript, and an owned tree-walking interpreter
-   executes it without `eval`.
-4. Tool inputs and outputs cross schema and plain-data boundaries before they become visible on either side.
-5. Execution returns `CodeMode.Result`. Expected program and tool failures are diagnostic data; host interruption
-   remains Effect interruption.
-
-Effect Schemas validate and transform tool inputs and outputs. JSON Schemas render model-facing signatures but do not
-validate values; adapter-provided values still cross the plain-data boundary. A tool without an output schema is
-advertised as `Promise<unknown>`.
-
-### Discovery and model workflow
-
-The model sees a token-budgeted catalog. Every namespace remains visible, and complete signatures are selected
-round-robin across namespaces so one large namespace cannot starve the others. The global `search(...)` built-in is
-always callable - synchronously, counted as an admitted tool call - and is advertised when the inline catalog is
-partial.
-
-The intended workflow is:
-
-1. Pick an exact signature from the inline catalog, or return `search(...)` results and use a selected path in the
-   next execution.
-2. Call the exact returned path without guessing or normalizing segments.
-3. Narrow `Promise<unknown>` results before reading fields.
-4. Start independent calls together and await them with `Promise.all`.
-5. Filter and aggregate inside the program, then return only the data needed by the model.
-
-Search returns directly usable JavaScript paths, descriptions, and complete TypeScript signatures. It supports exact
-path lookup, namespace browsing, deterministic ranking, and pagination.
-
-### Tool execution
-
-Every sandbox promise starts eagerly on a run-once fiber owned by the whole CodeMode execution, including tool calls,
-async functions, chained `.then`/`.catch`/`.finally` reactions, `new Promise(executor)` constructions, and the
-`Promise.all`/`allSettled`/`race`/`any`/`resolve`/`reject` statics. Nested functions therefore cannot end the lifetime
-of work they started.
-Independent aggregate batches overlap, and rejection is observed at the eventual `await` or chained rejection handler.
-`Promise.race` and `Promise.any` use native non-cancelling settlement semantics: the deciding member wins while losers
-continue running, and an all-rejected `Promise.any` rejects with an `AggregateError`. `new Promise(...)` hands the
-executor first-class resolve/reject callables that may escape and settle the promise later, exactly once.
-Reaction ordering matches what V8 makes observable - handlers and await continuations are deferred and run in attach
-order, and a combinator settles one reaction turn after its deciding member - without promising exact microtask-count
-parity beyond that. At normal completion CodeMode interrupts everything still running - race losers,
-fail-fast `Promise.all` stragglers, and fire-and-forget calls alike: the program has returned, so no future await can
-exist, and work whose completion matters must be awaited by the program. Waiting for any class of leftover instead
-would let it hold the execution open, or deadlock it when queued work needs tool-call permits the leftovers occupy.
-Rejections that settled un-awaited before the return become `Success.warnings` diagnostics. A fatal program failure or
-host interruption closes the execution promise scope and interrupts its active fibers instead. A timeout does the
-same, except that a value the program already returned is preserved alongside a `TimeoutExceeded` warning rather than
-discarded. At most eight tool calls execute concurrently.
-
-The public execution-policy knobs are `timeoutMs`, `maxToolCalls`, and `maxOutputBytes`. The package supplies no
-defaults because budgets are host policy. The interpreter also enforces fixed internal boundaries for tool-call
-concurrency and data nesting depth. `maxOutputBytes` bounds retained payload bytes, not the complete rendered message;
-warning diagnostics have an equal separate budget so a large value cannot starve them, and fixed truncation notices and
-host-added framing are intentionally outside the budgets.
-
-### Data, files, and failures
-
-Program results and tool arguments are JSON-like data. Dates become ISO strings at host boundaries; RegExp, Map, and
-Set values become `{}` as they do under JSON serialization. Promise and runtime reference values cannot cross the
-boundary.
-
-Unknown host failures and invalid outputs are sanitized. `ToolError` is the explicit channel for a safe message that a
-tool wants the model to see. Diagnostic categories distinguish parsing, unsupported syntax, unknown tools, invalid
-data, tool failures, limits, timeouts, execution failures, and warning truncation.
-
-Files and other attachment content stay outside the interpreter. A host may collect them while child tools execute and
-attach them to the outer result, but the program receives only the structured tool output.
-
-### V2 OpenCode adapter
-
-CodeMode is integrated into V2 through `packages/core/src/tool/registry.ts` and
-`packages/core/src/tool/execute.ts`:
-
-- Core has one canonical `Tool` representation. Location-scoped producers register direct or deferred tools through
-  `Tools.Service`.
-- Each model step snapshots effective registrations, applies catalog visibility filtering, and exposes direct tools
-  normally.
-- When visible deferred tools exist, Core reserves and materializes one `execute` tool. Grouped deferred tools become
-  CodeMode namespaces instead of flattened model-facing names.
-- Nested calls execute the registered `Tool` values captured for the model request; later registrations affect later
-  requests.
-- Authorization and side-effect ordering remain responsibilities of the leaf tool. Catalog visibility is not execution
-  authorization.
-- Structured child output enters the interpreter. File parts are collected host-side and attached to the outer result.
-- Nested call statuses are returned as final `execute` metadata for the TUI.
-- `execute` is the one model-facing tool invocation. Nested calls reuse its invocation context and do not independently
-  run registry hooks or model-output bounding; this keeps complete intermediate structured values available for
-  in-program filtering. The outer `execute` settlement is the single model-output bounding boundary.
-- Core supplies no CodeMode timeout or tool-call limit. User cancellation interrupts the outer invocation and its
-  supervised children; the outer settlement applies Core's normal output-retention policy.
-
-MCP tools use this canonical path: they register as grouped tools and are deferred while CodeMode is enabled. Existing
-output schemas are preserved in generated signatures. Direct Core tools remain direct and are not ambient globals
-inside CodeMode.
-
-## Intentionally Unsupported
-
-These are product boundaries rather than DSL backlog:
-
-- Ambient filesystem, process, environment, network, credential, or application access. External work must go through
-  supplied tools.
-- Modules, imports, dynamic imports, `eval`, arbitrary host globals, npm packages, and prototype mutation.
-- Generic permission prompts, authorization policy, durable pause/resume, replay, storage, or exactly-once external
-  side effects. Hosts and tools own those concerns.
-- Heuristic parsing of text tool results as JSON. A result should not silently change type based on its contents.
-
-The OpenAPI adapter may gain more transports and encodings, but it must continue skipping operations it cannot
-represent accurately rather than guessing semantics.
-
-## Decisions and Rationale
-
-| Decision                                                     | Rationale                                                                                                                                                                                                                |
-| ------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
-| Keep an owned tree-walking interpreter.                      | The product need is bounded tool orchestration, not arbitrary JavaScript. Owning the language surface keeps authority and behavior explicit.                                                                             |
-| Treat schemas as the model-facing interface.                 | Signatures drive correct calls; Effect Schema also provides the runtime validation boundary, while JSON Schema supports adapter interoperability.                                                                        |
-| Keep authority host-owned.                                   | CodeMode can only confine programs to supplied tools. The host chooses those tools, and each tool enforces its own authorization and side-effect policy.                                                                 |
-| Use progressive catalog disclosure plus search.              | Large tool sets should not consume the prompt, but every namespace must remain discoverable and speculative search calls should remain valid.                                                                            |
-| Start promises eagerly and supervise them for the execution. | This preserves normal call-time parallelism and run-once settlement while allowing pending work to be interrupted when the program returns.                                                                              |
-| Keep files outside the sandbox value space.                  | Models should compose structured data without routing binary payloads through generated code or context.                                                                                                                 |
-| Treat `execute` as the model-facing invocation boundary.     | Nested calls are implementation details of one orchestration program. Reusing the outer context and bounding only the final result preserves complete intermediate data without inventing durable child-call identities. |
-| Return expected failures as data.                            | Models need actionable diagnostics without exposing private host causes; host interruption and defects must still propagate correctly.                                                                                   |
-| Leave execution-limit defaults to hosts.                     | Appropriate budgets depend on the surrounding product and its own cancellation, retention, and output-bounding policies.                                                                                                 |
-| Skip unsupported OpenAPI operations.                         | Incorrect parameter encoding, authentication, or transport behavior is worse than a precise `skipped` reason.                                                                                                            |
-
-## Remaining Work
-
-The [interpreter support checklist](./interpreter-support.md) owns concrete DSL, standard-library, semantic-correctness,
-diagnostic, and data-boundary work. OpenAPI adapter work remains in [src/openapi/TODO.md](./src/openapi/TODO.md).

packages/codemode/interpreter-support.md

@@ -20,11 +20,11 @@ ultimate source of truth.
 - [x] Top-level `await` and `return` through the program's implicit async-function scope.
 - [x] Explicit `return`, final top-level expression as a REPL-style result, and `null` when no value is produced.
 - [x] JSON-like host boundaries with `undefined` and non-finite numbers normalized to `null`.
-- [x] Live Date, RegExp, Map, Set, URL, and URLSearchParams values inside the sandbox.
+- [x] Live Date, RegExp, Map, Set, URL, and URLSearchParams values inside CodeMode.
 - [x] Tool calls through the host-provided `tools` tree only.
 - [x] The global `search(...)` built-in: synchronous tool discovery that counts as an admitted tool call and is
       shadowable by program declarations like other globals.
-- [x] Cooperative timeout, tool-call accounting, output bounding, and a maximum of eight concurrent tool calls.
+- [x] Cooperative timeout, an optional total tool-call limit, output bounding, and unrestricted tool-call concurrency.
 - [ ] Full JavaScript or TypeScript compatibility. CodeMode is a bounded orchestration language.
 
 ## Values and literals
@@ -94,7 +94,7 @@ ultimate source of truth.
 - [x] Optional property access and optional calls.
 - [x] Function/tool calls and spread arguments.
 - [x] Sequence expressions (the comma operator).
-- [x] `await` for sandbox promises; a plain value passes through unchanged, though every `await` still defers its
+- [x] `await` for CodeMode promises; a plain value passes through unchanged, though every `await` still defers its
       continuation one reaction turn.
 - [x] `new` for Error types, Date, RegExp, Map, Set, URL, URLSearchParams, and Promise.
 - [x] Arithmetic operators: `+`, `-`, `*`, `/`, `%`, and `**`.
@@ -109,7 +109,7 @@ ultimate source of truth.
 
 ## Promises and tools
 
-- [x] Tool calls start eagerly and return supervised, run-once sandbox promises.
+- [x] Tool calls start eagerly and return supervised, run-once CodeMode promises.
 - [x] Direct `await`, repeated awaits, and implicit resolution when a promise is returned from a function/program.
 - [x] `Promise.resolve` and `Promise.reject`.
 - [x] `Promise.all`, `Promise.allSettled`, `Promise.race`, and `Promise.any` over supported collections containing
@@ -148,7 +148,7 @@ ultimate source of truth.
 - [x] Computed property names and object spread.
 - [x] `Object.keys`, `Object.values`, `Object.entries`, `Object.hasOwn`, `Object.assign`, and `Object.fromEntries`.
 - [x] `Object.keys` over arrays and tool references.
-- [x] Object identity is preserved by in-sandbox Object helpers.
+- [x] Object identity is preserved by in-CodeMode Object helpers.
 - [x] Blocked access to `__proto__`, `constructor`, and `prototype`.
 - [ ] `Object.is`; runtime and tool-reference identity semantics need to be defined first.
 - [ ] `Object.groupBy`.
@@ -171,14 +171,13 @@ ultimate source of truth.
 - [ ] `Array.prototype.toSpliced`.
 - [ ] Canonical index handling: a key such as `"01"` must not alias index `1`.
 - [ ] Complete sparse-array parity. Promise combinators do consume holes as `undefined` members, as in JS.
-- [ ] Correct `findLast` return behavior when its predicate mutates the examined element.
 
 ## Strings
 
 - [x] Case/normalization: `toLowerCase`, `toUpperCase`, `normalize`.
-- [x] Trimming: `trim`, `trimStart`, `trimEnd`, `trimLeft`, and `trimRight`.
+- [x] Trimming: `trim`, `trimStart`, and `trimEnd`.
 - [x] Searching/tests: `includes`, `startsWith`, `endsWith`, `indexOf`, `lastIndexOf`, and `search`.
-- [x] Slicing/access: `slice`, `substring`, `substr`, `at`, `charAt`, `charCodeAt`, and `codePointAt`.
+- [x] Slicing/access: `slice`, `substring`, `at`, `charAt`, `charCodeAt`, and `codePointAt`.
 - [x] Construction/transformation: `split`, `concat`, `repeat`, `padStart`, `padEnd`, `replace`, and `replaceAll`.
 - [x] Regular-expression integration: `match`, materialized `matchAll`, `replace`, `replaceAll`, `split`, and `search`.
 - [x] `localeCompare`; locale and options arguments are currently ignored.
@@ -291,7 +290,6 @@ ultimate source of truth.
 These are actionable implementation items. Check them off only when behavior and direct tests land.
 
 - [x] Return real promises from `Promise.all`, `Promise.allSettled`, and `Promise.race`.
-- [ ] Bound pending tool-call admission/allocation in addition to execution concurrency.
 - [ ] Guarantee every advertised tool path is executable, including dotted and blocked path segments.
 - [ ] Define safe outbound handling for non-finite numbers and `undefined` so invalid values cannot silently become
       `null` in render-only or OpenAPI tool calls.

packages/codemode/src/codemode.ts

@@ -1,5 +1,5 @@
 import { Effect, Schema } from "effect"
-import { executeWithLimits } from "./interpreter/runtime.js"
+import { executeWithLimits } from "./interpreter/execute.js"
 import { type HostTools, type Services, type ToolDescription, ToolRuntime } from "./tool-runtime.js"
 import type { Definition } from "./tool.js"
 
@@ -9,15 +9,15 @@ export type { ToolCall, ToolCallEnded, ToolCallHooks, ToolCallStarted, ToolDescr
 /** Resource budgets enforced independently during each CodeMode program execution. */
 export type ExecutionLimits = {
   /**
-   * Wall-clock milliseconds before execution is interrupted; result delivery additionally
-   * waits for tool interruption cleanup. No default: absent means no timeout.
+   * Wall-clock milliseconds before interruption. Result delivery waits for tool cleanup.
+   * No default: absent means no timeout.
    */
   readonly timeoutMs?: number
   /** Maximum number of tool calls admitted by the runtime. No default: absent means unlimited. */
   readonly maxToolCalls?: number
   /**
-   * Maximum UTF-8 bytes retained from the result value and logs; warnings have a separate
-   * budget of the same size. Fixed truncation notices and host formatting are additional.
+   * Maximum UTF-8 bytes retained from the result and logs. Warnings have a separate equal budget;
+   * truncation notices and host formatting are additional.
    */
   readonly maxOutputBytes?: number
 }
@@ -94,7 +94,6 @@ const ToolCallSchema = Schema.Struct({ name: Schema.String })
 export const Success = Schema.Struct({
   ok: Schema.Literal(true),
   value: Schema.Json,
-  // Runtime-authored non-fatal diagnostics; program console output stays in `logs`.
   warnings: Schema.optionalKey(Schema.Array(Diagnostic)),
   logs: Schema.optionalKey(Schema.Array(Schema.String)),
   truncated: Schema.optionalKey(Schema.Boolean),

packages/codemode/src/interpreter/errors.ts

@@ -0,0 +1,93 @@
+import type { Diagnostic } from "../codemode.js"
+import { ToolError } from "../tool-error.js"
+import { copyOut, ToolRuntimeError, type SafeObject } from "../tool-runtime.js"
+import { type AstNode, formatLocation, InterpreterRuntimeError, ProgramThrow, sourceLocation } from "./model.js"
+import { containsRuntimeReference } from "./references.js"
+import { spreadItems } from "../stdlib/collections.js"
+import { coerceToString, createAggregateErrorValue, createErrorValue, errorConstructors } from "../stdlib/value.js"
+
+export const normalizeError = (error: unknown): Diagnostic => {
+  if (error instanceof InterpreterRuntimeError) {
+    return {
+      kind: error.kind,
+      message: `${error.message}${formatLocation(error.node)}`,
+      ...(error.node?.loc ? { location: sourceLocation(error.node) } : {}),
+      ...(error.suggestions ? { suggestions: error.suggestions } : {}),
+    }
+  }
+
+  if (error instanceof ToolRuntimeError) {
+    return {
+      kind: error.kind,
+      message: error.message,
+      ...(error.suggestions.length > 0 ? { suggestions: error.suggestions } : {}),
+    }
+  }
+
+  if (error instanceof ToolError) {
+    return { kind: "ToolFailure", message: error.message }
+  }
+
+  if (error instanceof ProgramThrow) {
+    const value = error.value
+    let message: string
+    if (containsRuntimeReference(value)) {
+      // Never expose runtime reference internals through thrown values.
+      message = "a non-data value"
+    } else if (typeof value === "string") {
+      message = value
+    } else if (
+      value !== null &&
+      typeof value === "object" &&
+      typeof (value as { message?: unknown }).message === "string"
+    ) {
+      message = (value as { message: string }).message
+    } else {
+      try {
+        message = JSON.stringify(copyOut(value)) ?? String(value)
+      } catch {
+        message = String(value)
+      }
+    }
+    return { kind: "ExecutionFailure", message: `Uncaught: ${message}` }
+  }
+
+  if (error instanceof RangeError && /call stack|recursion/i.test(error.message)) {
+    return {
+      kind: "ExecutionFailure",
+      message: "Execution exceeded the maximum nesting depth.",
+    }
+  }
+
+  if (error instanceof Error) {
+    return {
+      kind: error.name === "SyntaxError" ? "ParseError" : "ExecutionFailure",
+      message: error.message,
+    }
+  }
+
+  return {
+    kind: "ExecutionFailure",
+    message: String(error),
+  }
+}
+
+export const caughtErrorValue = (thrown: unknown): unknown => {
+  if (thrown instanceof ProgramThrow) return thrown.value
+  if (thrown instanceof InterpreterRuntimeError) return createErrorValue(thrown.errorName, thrown.message)
+  const name = thrown instanceof Error && errorConstructors.has(thrown.name) ? thrown.name : "Error"
+  return createErrorValue(name, normalizeError(thrown).message)
+}
+
+export const constructErrorValue = (name: string, args: Array<unknown>, node: AstNode): SafeObject => {
+  if (name !== "AggregateError") return createErrorValue(name, args[0] === undefined ? "" : coerceToString(args[0]))
+  const errors = spreadItems(args[0])
+  if (errors === undefined) {
+    throw new InterpreterRuntimeError(
+      "new AggregateError(...) expects an array of errors (e.g. new AggregateError(errors, message?)).",
+      node,
+    ).as("TypeError")
+  }
+  // Error values must not alias caller-owned arrays.
+  return createAggregateErrorValue([...errors], args[1] === undefined ? "" : coerceToString(args[1]))
+}

packages/codemode/src/interpreter/execute.ts

@@ -0,0 +1,224 @@
+import { parse } from "acorn"
+import { Cause, Effect, Scope } from "effect"
+import { DiagnosticCategory, ModuleKind, ScriptTarget, flattenDiagnosticMessageText, transpileModule } from "typescript"
+import type { DataValue, Diagnostic, ExecuteOptions, ResolvedExecutionLimits, Result } from "../codemode.js"
+import { copyIn, copyOut, ToolRuntime, type HostTools, type Services } from "../tool-runtime.js"
+import { normalizeError } from "./errors.js"
+import { InterpreterRuntimeError, isRecord, type ProgramNode } from "./model.js"
+import { PromiseRuntime } from "./promises.js"
+import { Interpreter } from "./runtime.js"
+
+export const executeWithLimits = <const Tools extends Record<string, unknown>>(
+  options: ExecuteOptions<Tools>,
+  limits: ResolvedExecutionLimits,
+  searchIndex: ToolRuntime.DiscoveryPlan["searchIndex"],
+): Effect.Effect<Result, never, Services<Tools>> => {
+  if (options.code.trim().length === 0) {
+    return Effect.succeed({
+      ok: false,
+      error: { kind: "ParseError", message: "Code cannot be empty." },
+      toolCalls: [],
+    })
+  }
+
+  // Allocate execution state inside suspension so reused Effects never share it.
+  return Effect.suspend(() => {
+    const tools = ToolRuntime.make(
+      (options.tools ?? {}) as HostTools<Services<Tools>>,
+      limits.maxToolCalls,
+      searchIndex,
+      {
+        onToolCallStart: options.onToolCallStart,
+        onToolCallEnd: options.onToolCallEnd,
+      },
+    )
+    const logs: Array<string> = []
+    const logged = () => (logs.length > 0 ? { logs: [...logs] } : {})
+    // Set only after copy-out so timeouts cannot report invalid values as completed.
+    let returned: { value: DataValue; promises: PromiseRuntime<Services<Tools>> } | undefined
+
+    const base = Effect.acquireUseRelease(
+      Scope.make("parallel"),
+      (scope) =>
+        Effect.gen(function* () {
+          const program = parseProgram(options.code)
+          const promises = new PromiseRuntime<Services<Tools>>(scope)
+          const interpreter = new Interpreter<Services<Tools>>(tools.invoke, tools.search, tools.keys, promises, logs)
+          const value = yield* interpreter.run(program)
+          const result = copyOut(copyIn(value, "Execution result"), true) as DataValue
+          returned = { value: result, promises }
+          const warnings = yield* promises.interrupt()
+          return {
+            ok: true,
+            value: result,
+            ...(warnings.length > 0 ? { warnings } : {}),
+            ...logged(),
+            toolCalls: tools.calls,
+          } satisfies Result
+        }),
+      (scope, exit) => Scope.close(scope, exit),
+    )
+    const timeoutMs = limits.timeoutMs
+    const operation =
+      timeoutMs === undefined
+        ? base
+        : base.pipe(
+            Effect.timeoutOrElse({
+              duration: timeoutMs,
+              orElse: () =>
+                Effect.sync(() => {
+                  if (returned === undefined) {
+                    return {
+                      ok: false,
+                      error: { kind: "TimeoutExceeded", message: `Execution timed out after ${timeoutMs}ms.` },
+                      ...logged(),
+                      toolCalls: tools.calls,
+                    } satisfies Result
+                  }
+                  // Keep the timeout warning first so truncation preserves it.
+                  return {
+                    ok: true,
+                    value: returned.value,
+                    warnings: [
+                      {
+                        kind: "TimeoutExceeded",
+                        message: `The program returned, but background work was still running at the ${timeoutMs}ms timeout and was interrupted. Await all started promises.`,
+                      },
+                      ...returned.promises.diagnostics(),
+                    ],
+                    ...logged(),
+                    toolCalls: tools.calls,
+                  } satisfies Result
+                }),
+            }),
+          )
+
+    return operation.pipe(
+      Effect.catchCause((cause) =>
+        Cause.hasInterruptsOnly(cause)
+          ? Effect.interrupt
+          : Effect.succeed({
+              ok: false,
+              error: normalizeError(Cause.squash(cause)),
+              ...logged(),
+              toolCalls: tools.calls,
+            } satisfies Result),
+      ),
+      Effect.map((result) =>
+        limits.maxOutputBytes === undefined ? result : boundOutput(result, limits.maxOutputBytes),
+      ),
+    )
+  })
+}
+
+const parseProgram = (code: string): ProgramNode => {
+  const transpiled = transpileModule(`async function __codemode__() {\n${code}\n}`, {
+    reportDiagnostics: true,
+    compilerOptions: {
+      target: ScriptTarget.ESNext,
+      module: ModuleKind.ESNext,
+    },
+  })
+  const diagnostic = transpiled.diagnostics?.find((item) => item.category === DiagnosticCategory.Error)
+
+  if (diagnostic) {
+    throw new InterpreterRuntimeError(
+      `Failed to parse TypeScript: ${flattenDiagnosticMessageText(diagnostic.messageText, "\n")}`,
+      undefined,
+      "ParseError",
+    )
+  }
+
+  const bodyStart = transpiled.outputText.indexOf("{") + 1
+  const bodyEnd = transpiled.outputText.lastIndexOf("}")
+  const executableCode = transpiled.outputText.slice(bodyStart, bodyEnd)
+  const parsed = parse(executableCode, {
+    ecmaVersion: "latest",
+    sourceType: "script",
+    allowReturnOutsideFunction: true,
+    allowAwaitOutsideFunction: true,
+    locations: true,
+  }) as unknown
+
+  if (!isRecord(parsed) || parsed.type !== "Program" || !Array.isArray(parsed.body)) {
+    throw new InterpreterRuntimeError("Failed to parse script as a Program node.")
+  }
+
+  return parsed as ProgramNode
+}
+
+const utf8ByteLength = (value: string): number => new TextEncoder().encode(value).byteLength
+
+// Drop a replacement character produced by truncating inside a UTF-8 sequence.
+const utf8Truncate = (value: string, maxBytes: number): string => {
+  const bytes = new TextEncoder().encode(value)
+  if (bytes.byteLength <= maxBytes) return value
+  const text = new TextDecoder("utf-8").decode(bytes.slice(0, Math.max(0, maxBytes)))
+  return text.endsWith("\uFFFD") ? text.slice(0, -1) : text
+}
+
+// Warnings have a separate budget so result data cannot starve diagnostics.
+const boundOutput = (result: Result, maxOutputBytes: number): Result => {
+  let truncated = false
+
+  let value: DataValue = null
+  let valueBytes = 0
+  if (result.ok) {
+    const serialized = JSON.stringify(result.value) ?? "null"
+    const bytes = utf8ByteLength(serialized)
+    if (bytes > maxOutputBytes) {
+      truncated = true
+      value = `${utf8Truncate(serialized, maxOutputBytes)} [result truncated: ${bytes} bytes exceeds the ${maxOutputBytes}-byte output limit; return a smaller value]`
+      valueBytes = maxOutputBytes
+    } else {
+      value = result.value
+      valueBytes = bytes
+    }
+  }
+
+  const warnings = result.ok ? (result.warnings ?? []) : []
+  const keptWarnings: Array<Diagnostic> = []
+  let warningBytes = 0
+  for (const warning of warnings) {
+    const bytes = utf8ByteLength(JSON.stringify(warning)) + 1
+    if (warningBytes + bytes > maxOutputBytes) break
+    warningBytes += bytes
+    keptWarnings.push(warning)
+  }
+  if (keptWarnings.length < warnings.length) {
+    truncated = true
+    keptWarnings.push({
+      kind: "Truncated",
+      message: `${warnings.length - keptWarnings.length} additional warnings omitted by the output limit.`,
+    })
+  }
+
+  const logs = result.logs ?? []
+  const kept: Array<string> = []
+  const logBudget = Math.max(0, maxOutputBytes - valueBytes)
+  let logBytes = 0
+  for (const line of logs) {
+    const lineBytes = utf8ByteLength(line) + 1
+    if (logBytes + lineBytes > logBudget) break
+    logBytes += lineBytes
+    kept.push(line)
+  }
+  if (kept.length < logs.length) {
+    truncated = true
+    kept.push(`[logs truncated: showing ${kept.length} of ${logs.length} lines]`)
+  }
+
+  if (!truncated) return result
+  const warningsPart = keptWarnings.length > 0 ? { warnings: keptWarnings } : {}
+  const logsPart = kept.length > 0 ? { logs: kept } : {}
+  return result.ok
+    ? {
+        ok: true,
+        value,
+        ...warningsPart,
+        ...logsPart,
+        truncated: true,
+        toolCalls: result.toolCalls,
+      }
+    : { ok: false, error: result.error, ...logsPart, truncated: true, toolCalls: result.toolCalls }
+}

packages/codemode/src/interpreter/methods.ts

@@ -0,0 +1,820 @@
+import { Effect } from "effect"
+import {
+  type AstNode,
+  CodeModeFunction,
+  CoercionFunction,
+  GlobalMethodReference,
+  IntrinsicReference,
+  InterpreterRuntimeError,
+  PromiseCapabilityFunction,
+  supportedSyntaxMessage,
+  UriFunction,
+} from "./model.js"
+import { rejectCircularInsertion } from "./references.js"
+import { isBlockedMember, type SafeObject } from "../tool-runtime.js"
+import {
+  CodeModeDate,
+  CodeModeMap,
+  CodeModePromise,
+  CodeModeRegExp,
+  CodeModeSet,
+  CodeModeURL,
+  CodeModeURLSearchParams,
+} from "../values.js"
+import { invokeDateMethod, invokeDateStatic } from "../stdlib/date.js"
+import { invokeJsonMethod } from "../stdlib/json.js"
+import { invokeMathMethod } from "../stdlib/math.js"
+import { invokeNumberMethod, invokeNumberStatic } from "../stdlib/number.js"
+import { invokeObjectMethod } from "../stdlib/object.js"
+import { invokeRegExpMethod, matchToValue, toHostRegex } from "../stdlib/regexp.js"
+import { invokeStringStatic } from "../stdlib/string.js"
+import { invokeUriFunction, invokeURLMethod, invokeURLStatic, uriArgument } from "../stdlib/url.js"
+import { boundedData, coerceToNumber, coerceToString, invokeCoercion } from "../stdlib/value.js"
+
+export type CallbackRunner<R> = {
+  readonly invokeFunction: (fn: CodeModeFunction, args: Array<unknown>) => Effect.Effect<unknown, unknown, R>
+  readonly settlePromise: (promise: CodeModePromise) => Effect.Effect<unknown, unknown, never>
+}
+
+export const invokeIntrinsic = <R>(
+  runner: CallbackRunner<R>,
+  ref: IntrinsicReference,
+  args: Array<unknown>,
+  node: AstNode,
+): Effect.Effect<unknown, unknown, R> => {
+  if (typeof ref.receiver === "string") {
+    if (
+      (ref.name === "replace" || ref.name === "replaceAll") &&
+      (args[1] instanceof CodeModeFunction || args[1] instanceof CoercionFunction || args[1] instanceof UriFunction)
+    ) {
+      return invokeStringReplacer(runner, ref.receiver, ref.name, args, node)
+    }
+    return Effect.succeed(invokeStringMethod(ref.receiver, ref.name, args, node))
+  }
+  if (typeof ref.receiver === "number") {
+    return Effect.succeed(invokeNumberMethod(ref.receiver, ref.name, args, node))
+  }
+  if (Array.isArray(ref.receiver)) {
+    return invokeArrayMethod(runner, ref.receiver, ref.name, args, node)
+  }
+  if (ref.receiver instanceof CodeModeDate) {
+    return Effect.succeed(invokeDateMethod(ref.receiver, ref.name, node))
+  }
+  if (ref.receiver instanceof CodeModeRegExp) {
+    return Effect.succeed(invokeRegExpMethod(ref.receiver, ref.name, args, node))
+  }
+  if (ref.receiver instanceof CodeModeMap) {
+    return invokeMapMethod(runner, ref.receiver, ref.name, args, node)
+  }
+  if (ref.receiver instanceof CodeModeSet) {
+    return invokeSetMethod(runner, ref.receiver, ref.name, args, node)
+  }
+  if (ref.receiver instanceof CodeModeURL) {
+    return Effect.succeed(invokeURLMethod(ref.receiver, ref.name, node))
+  }
+  if (ref.receiver instanceof CodeModeURLSearchParams) {
+    return invokeURLSearchParamsMethod(runner, ref.receiver, ref.name, args, node)
+  }
+  throw new InterpreterRuntimeError(`Method '${ref.name}' is not available in CodeMode.`, node)
+}
+
+export const invokeGlobalMethod = (ref: GlobalMethodReference, args: Array<unknown>, node: AstNode): unknown => {
+  if (ref.namespace === "console")
+    throw new InterpreterRuntimeError(`console.${ref.name} is not available in CodeMode.`, node)
+  if (ref.namespace === "Object") return invokeObjectMethod(ref.name, args, node)
+  if (ref.namespace === "Math") return invokeMathMethod(ref.name, args, node)
+  if (ref.namespace === "Array") return invokeArrayStatic(ref.name, args, node)
+  if (ref.namespace === "Number") return invokeNumberStatic(ref.name, args, node)
+  if (ref.namespace === "String") return invokeStringStatic(ref.name, args, node)
+  if (ref.namespace === "URL") return invokeURLStatic(ref.name, args, node)
+  if (ref.namespace === "Date") return invokeDateStatic(ref.name, args, node)
+  if (
+    ref.namespace === "RegExp" ||
+    ref.namespace === "Map" ||
+    ref.namespace === "Set" ||
+    ref.namespace === "URLSearchParams"
+  ) {
+    throw new InterpreterRuntimeError(`${ref.namespace}.${ref.name} is not available in CodeMode.`, node)
+  }
+  return invokeJsonMethod(ref.name, args, node)
+}
+
+const invokeStringMethod = (value: string, name: string, args: Array<unknown>, node: AstNode): unknown => {
+  const str = (index: number): string => {
+    const arg = args[index]
+    if (typeof arg !== "string")
+      throw new InterpreterRuntimeError(`String.${name} expects argument ${index + 1} to be a string.`, node)
+    return arg
+  }
+  const num = (index: number): number => {
+    const arg = args[index]
+    if (typeof arg !== "number")
+      throw new InterpreterRuntimeError(`String.${name} expects argument ${index + 1} to be a number.`, node)
+    return arg
+  }
+  const optNum = (index: number): number | undefined => (args[index] === undefined ? undefined : num(index))
+  const optStr = (index: number): string | undefined => (args[index] === undefined ? undefined : str(index))
+
+  let result: unknown
+  switch (name) {
+    case "toLowerCase":
+      result = value.toLowerCase()
+      break
+    case "toUpperCase":
+      result = value.toUpperCase()
+      break
+    case "trim":
+      result = value.trim()
+      break
+    case "trimStart":
+      result = value.trimStart()
+      break
+    case "trimEnd":
+      result = value.trimEnd()
+      break
+    // Locale/options are deliberately unsupported; comparison uses the host default locale.
+    case "localeCompare":
+      result = value.localeCompare(str(0))
+      break
+    case "normalize": {
+      const form = optStr(0)
+      try {
+        result = value.normalize(form)
+      } catch {
+        throw new InterpreterRuntimeError(
+          `String.normalize expects the form "NFC", "NFD", "NFKC", or "NFKD" (got ${JSON.stringify(form)}).`,
+          node,
+        ).as("RangeError")
+      }
+      break
+    }
+    case "split": {
+      if (args.length === 0) {
+        result = [value]
+        break
+      }
+      if (args[0] instanceof CodeModeRegExp) {
+        result = value.split(args[0].regex, optNum(1))
+        break
+      }
+      const requestedLimit = optNum(1)
+      result = value.split(str(0), requestedLimit === undefined ? undefined : requestedLimit >>> 0)
+      break
+    }
+    case "slice":
+      result = value.slice(optNum(0), optNum(1))
+      break
+    case "includes":
+      result = value.includes(str(0), optNum(1))
+      break
+    case "startsWith":
+      result = value.startsWith(str(0), optNum(1))
+      break
+    case "endsWith":
+      result = value.endsWith(str(0), optNum(1))
+      break
+    case "indexOf":
+      result = value.indexOf(str(0), optNum(1))
+      break
+    case "lastIndexOf":
+      result = value.lastIndexOf(str(0), optNum(1))
+      break
+    case "replace":
+    case "replaceAll": {
+      if (args[0] instanceof CodeModeRegExp) {
+        const pattern = args[0].regex
+        const replacement = str(1)
+        if (name === "replaceAll" && !pattern.global) {
+          throw new InterpreterRuntimeError(
+            `String.replaceAll requires a regular expression with the global (g) flag: write /${pattern.source}/${pattern.flags}g, or use String.replace to replace only the first match.`,
+            node,
+          )
+        }
+        result = name === "replace" ? value.replace(pattern, replacement) : value.replaceAll(pattern, replacement)
+        break
+      }
+      if (name === "replace") {
+        result = value.replace(str(0), str(1))
+        break
+      }
+      result = value.replaceAll(str(0), str(1))
+      break
+    }
+    case "match": {
+      const pattern = toHostRegex(args[0], name, node)
+      const matched = value.match(pattern)
+      if (matched === null) return null
+      // Preserve the own `index` and `groups` properties on non-global matches.
+      if (pattern.global) return boundedData(matched, "String.match result")
+      return matchToValue(matched)
+    }
+    case "matchAll": {
+      const pattern = toHostRegex(args[0], name, node, "g")
+      if (!pattern.global) {
+        throw new InterpreterRuntimeError(
+          `String.matchAll requires a regular expression with the global (g) flag: write /${pattern.source}/${pattern.flags}g, or use String.match for a single match.`,
+          node,
+        )
+      }
+      return Array.from(value.matchAll(pattern), matchToValue)
+    }
+    case "search": {
+      result = value.search(toHostRegex(args[0], name, node))
+      break
+    }
+    case "repeat": {
+      const count = num(0)
+      if (!Number.isFinite(count) || count < 0)
+        throw new InterpreterRuntimeError("String.repeat expects a finite non-negative count.", node)
+      result = value.repeat(count)
+      break
+    }
+    case "padStart":
+      result = value.padStart(num(0), optStr(1))
+      break
+    case "padEnd":
+      result = value.padEnd(num(0), optStr(1))
+      break
+    case "charAt":
+      result = value.charAt(optNum(0) ?? 0)
+      break
+    case "at":
+      result = value.at(optNum(0) ?? 0)
+      break
+    case "substring":
+      result = value.substring(optNum(0) ?? 0, optNum(1))
+      break
+    case "charCodeAt":
+      result = value.charCodeAt(optNum(0) ?? 0)
+      break
+    case "codePointAt":
+      result = value.codePointAt(optNum(0) ?? 0)
+      break
+    case "toString":
+      result = value
+      break
+    case "concat": {
+      result = value.concat(...args.map((_, index) => str(index)))
+      break
+    }
+    default:
+      throw new InterpreterRuntimeError(`String method '${name}' is not available in CodeMode.`, node)
+  }
+  return boundedData(result, `String.${name} result`)
+}
+
+const invokeArrayStatic = (name: string, args: Array<unknown>, node: AstNode): unknown => {
+  switch (name) {
+    case "isArray":
+      return Array.isArray(args[0])
+    case "of":
+      return [...args]
+    case "from": {
+      if (args.length > 1) {
+        throw new InterpreterRuntimeError(
+          "Array.from(...) does not support a map function in CodeMode; call .map() on the result instead.",
+          node,
+          "UnsupportedSyntax",
+          [supportedSyntaxMessage],
+        )
+      }
+      if (args[0] instanceof CodeModeMap) return Array.from(args[0].map.entries(), ([key, item]) => [key, item])
+      if (args[0] instanceof CodeModeSet) return Array.from(args[0].set.values())
+      if (args[0] instanceof CodeModeURLSearchParams) {
+        return Array.from(args[0].params.entries(), ([key, value]) => [key, value])
+      }
+      const source = args[0]
+      if (source instanceof CodeModePromise) {
+        throw new InterpreterRuntimeError(
+          "Array.from received an un-awaited Promise; await it before creating the array.",
+          node,
+          "InvalidDataValue",
+        )
+      }
+      if (typeof source === "string") return Array.from(source)
+      if (Array.isArray(source)) return [...source]
+      if (
+        source !== null &&
+        typeof source === "object" &&
+        (Object.getPrototypeOf(source) === Object.prototype || Object.getPrototypeOf(source) === null) &&
+        typeof (source as { length?: unknown }).length === "number"
+      ) {
+        return Array.from(source as ArrayLike<unknown>)
+      }
+      throw new InterpreterRuntimeError(
+        "Array.from expects an array, string, Map, Set, or array-like value.",
+        node,
+        "InvalidDataValue",
+      )
+    }
+    default:
+      throw new InterpreterRuntimeError(`Array.${name} is not available in CodeMode.`, node)
+  }
+}
+
+const invokeStringReplacer = <R>(
+  runner: CallbackRunner<R>,
+  value: string,
+  name: "replace" | "replaceAll",
+  args: Array<unknown>,
+  node: AstNode,
+): Effect.Effect<unknown, unknown, R> => {
+  const apply = applyCollectionCallback(runner, args[1], `String.${name}`, node)
+  const matches: Array<{ readonly match: string; readonly offset: number; readonly args: Array<unknown> }> = []
+  const collect = (...callbackArgs: Array<unknown>): string => {
+    const match = callbackArgs[0]
+    const groups = callbackArgs[callbackArgs.length - 1]
+    const hasGroups = groups !== null && typeof groups === "object"
+    const offset = callbackArgs[callbackArgs.length - (hasGroups ? 3 : 2)]
+    if (typeof match !== "string" || typeof offset !== "number") {
+      throw new InterpreterRuntimeError(`String.${name} produced an invalid replacement match.`, node)
+    }
+    if (hasGroups) {
+      const safeGroups: SafeObject = Object.create(null) as SafeObject
+      for (const [key, group] of Object.entries(groups)) {
+        if (!isBlockedMember(key)) safeGroups[key] = group
+      }
+      callbackArgs[callbackArgs.length - 1] = safeGroups
+    }
+    matches.push({ match, offset, args: callbackArgs })
+    return match
+  }
+
+  const pattern = args[0]
+  if (pattern instanceof CodeModeRegExp) {
+    if (name === "replaceAll" && !pattern.regex.global) {
+      throw new InterpreterRuntimeError(
+        `String.replaceAll requires a regular expression with the global (g) flag: write /${pattern.regex.source}/${pattern.regex.flags}g, or use String.replace to replace only the first match.`,
+        node,
+      )
+    }
+    if (name === "replace") value.replace(pattern.regex, collect)
+    else value.replaceAll(pattern.regex, collect)
+  } else {
+    if (typeof pattern !== "string") {
+      throw new InterpreterRuntimeError(`String.${name} expects argument 1 to be a string.`, node)
+    }
+    if (name === "replace") value.replace(pattern, collect)
+    else value.replaceAll(pattern, collect)
+  }
+
+  return Effect.gen(function* () {
+    const output: Array<string> = []
+    let end = 0
+    for (const match of matches) {
+      const replacement = yield* apply(match.args)
+      const resolved =
+        args[1] instanceof CodeModeFunction && args[1].async && replacement instanceof CodeModePromise
+          ? yield* runner.settlePromise(replacement)
+          : replacement
+      output.push(
+        value.slice(end, match.offset),
+        coerceToString(boundedData(resolved, `String.${name} replacer result`)),
+      )
+      end = match.offset + match.match.length
+    }
+    output.push(value.slice(end))
+    return boundedData(output.join(""), `String.${name} result`)
+  })
+}
+
+export const applyCollectionCallback = <R>(
+  runner: CallbackRunner<R>,
+  callback: unknown,
+  name: string,
+  node: AstNode,
+): ((args: Array<unknown>) => Effect.Effect<unknown, unknown, R>) => {
+  if (
+    !(callback instanceof CodeModeFunction) &&
+    !(callback instanceof CoercionFunction) &&
+    !(callback instanceof UriFunction) &&
+    !(callback instanceof PromiseCapabilityFunction)
+  ) {
+    throw new InterpreterRuntimeError(`${name} expects a function callback.`, node)
+  }
+  return (callbackArgs) =>
+    callback instanceof CoercionFunction
+      ? Effect.succeed(invokeCoercion(callback, callbackArgs, node))
+      : callback instanceof UriFunction
+        ? Effect.succeed(invokeUriFunction(callback, callbackArgs, node))
+        : callback instanceof PromiseCapabilityFunction
+          ? Effect.sync(() => callback.settle(callbackArgs[0]))
+          : runner.invokeFunction(callback, callbackArgs)
+}
+
+const invokeMapMethod = <R>(
+  runner: CallbackRunner<R>,
+  target: CodeModeMap,
+  name: string,
+  args: Array<unknown>,
+  node: AstNode,
+): Effect.Effect<unknown, unknown, R> => {
+  switch (name) {
+    case "get":
+      return Effect.succeed(target.map.get(args[0]))
+    case "has":
+      return Effect.succeed(target.map.has(args[0]))
+    case "set":
+      return Effect.sync(() => {
+        target.map.set(args[0], args[1])
+        return target
+      })
+    case "delete":
+      return Effect.sync(() => target.map.delete(args[0]))
+    case "clear":
+      return Effect.sync(() => {
+        target.map.clear()
+        return undefined
+      })
+    case "keys":
+      return Effect.sync(() => Array.from(target.map.keys()))
+    case "values":
+      return Effect.sync(() => Array.from(target.map.values()))
+    case "entries":
+      return Effect.sync(() => Array.from(target.map.entries(), ([key, item]): Array<unknown> => [key, item]))
+    case "forEach": {
+      const apply = applyCollectionCallback(runner, args[0], "Map.forEach", node)
+      return Effect.gen(function* () {
+        for (const [key, item] of Array.from(target.map.entries())) yield* apply([item, key, target])
+        return undefined
+      })
+    }
+    default:
+      throw new InterpreterRuntimeError(`Map method '${name}' is not available in CodeMode.`, node)
+  }
+}
+
+const invokeSetMethod = <R>(
+  runner: CallbackRunner<R>,
+  target: CodeModeSet,
+  name: string,
+  args: Array<unknown>,
+  node: AstNode,
+): Effect.Effect<unknown, unknown, R> => {
+  switch (name) {
+    case "has":
+      return Effect.succeed(target.set.has(args[0]))
+    case "add":
+      return Effect.sync(() => {
+        target.set.add(args[0])
+        return target
+      })
+    case "delete":
+      return Effect.sync(() => target.set.delete(args[0]))
+    case "clear":
+      return Effect.sync(() => {
+        target.set.clear()
+        return undefined
+      })
+    case "keys":
+    case "values":
+      return Effect.sync(() => Array.from(target.set.values()))
+    case "entries":
+      return Effect.sync(() => Array.from(target.set.values(), (item): Array<unknown> => [item, item]))
+    case "forEach": {
+      const apply = applyCollectionCallback(runner, args[0], "Set.forEach", node)
+      return Effect.gen(function* () {
+        for (const item of Array.from(target.set.values())) yield* apply([item, item, target])
+        return undefined
+      })
+    }
+    default:
+      throw new InterpreterRuntimeError(`Set method '${name}' is not available in CodeMode.`, node)
+  }
+}
+
+const invokeURLSearchParamsMethod = <R>(
+  runner: CallbackRunner<R>,
+  target: CodeModeURLSearchParams,
+  name: string,
+  args: Array<unknown>,
+  node: AstNode,
+): Effect.Effect<unknown, unknown, R> => {
+  const arg = (index: number): string => uriArgument(args[index], `URLSearchParams.${name} argument ${index + 1}`)
+  const requireArgs = (count: number): void => {
+    if (args.length < count) {
+      throw new InterpreterRuntimeError(
+        `URLSearchParams.${name} requires ${count} argument${count === 1 ? "" : "s"}.`,
+        node,
+      ).as("TypeError")
+    }
+  }
+  switch (name) {
+    case "append": {
+      requireArgs(2)
+      return Effect.sync(() => {
+        target.params.append(arg(0), arg(1))
+        return undefined
+      })
+    }
+    case "delete": {
+      requireArgs(1)
+      return Effect.sync(() => {
+        if (args[1] !== undefined) target.params.delete(arg(0), arg(1))
+        else target.params.delete(arg(0))
+        return undefined
+      })
+    }
+    case "get":
+      requireArgs(1)
+      return Effect.sync(() => target.params.get(arg(0)))
+    case "getAll":
+      requireArgs(1)
+      return Effect.sync(() => target.params.getAll(arg(0)))
+    case "has":
+      requireArgs(1)
+      return Effect.sync(() => (args[1] !== undefined ? target.params.has(arg(0), arg(1)) : target.params.has(arg(0))))
+    case "set": {
+      requireArgs(2)
+      return Effect.sync(() => {
+        target.params.set(arg(0), arg(1))
+        return undefined
+      })
+    }
+    case "sort":
+      return Effect.sync(() => {
+        target.params.sort()
+        return undefined
+      })
+    case "keys":
+      return Effect.sync(() => Array.from(target.params.keys()))
+    case "values":
+      return Effect.sync(() => Array.from(target.params.values()))
+    case "entries":
+      return Effect.sync(() => Array.from(target.params.entries(), ([key, value]): Array<unknown> => [key, value]))
+    case "toString":
+      return Effect.sync(() => target.params.toString())
+    case "forEach": {
+      requireArgs(1)
+      const apply = applyCollectionCallback(runner, args[0], "URLSearchParams.forEach", node)
+      return Effect.gen(function* () {
+        for (const [key, value] of Array.from(target.params.entries())) yield* apply([value, key, target])
+        return undefined
+      })
+    }
+    default:
+      throw new InterpreterRuntimeError(`URLSearchParams method '${name}' is not available in CodeMode.`, node)
+  }
+}
+
+const invokeArrayMethod = <R>(
+  runner: CallbackRunner<R>,
+  target: Array<unknown>,
+  name: string,
+  args: Array<unknown>,
+  node: AstNode,
+): Effect.Effect<unknown, unknown, R> => {
+  const optNumber = (value: unknown, label: string): number | undefined => {
+    if (value === undefined) return undefined
+    if (typeof value !== "number")
+      throw new InterpreterRuntimeError(`Array.${name} expects ${label} to be a number.`, node)
+    return value
+  }
+  switch (name) {
+    case "join": {
+      if (args.length > 1 || (args.length === 1 && typeof args[0] !== "string")) {
+        throw new InterpreterRuntimeError("Array.join expects zero arguments or one string separator.", node)
+      }
+      const input = boundedData(target, "Array.join input") as Array<unknown>
+      return Effect.succeed(
+        input.map((item) => coerceToString(item ?? "")).join(args.length === 0 ? "," : (args[0] as string)),
+      )
+    }
+    case "includes":
+      if (args.length === 0 || args.length > 2)
+        throw new InterpreterRuntimeError("Array.includes expects a value and optional start index.", node)
+      return Effect.succeed(target.includes(args[0], optNumber(args[1], "start index")))
+    case "indexOf":
+      return Effect.succeed(target.indexOf(args[0], optNumber(args[1], "start index")))
+    case "lastIndexOf":
+      return Effect.succeed(
+        args[1] === undefined
+          ? target.lastIndexOf(args[0])
+          : target.lastIndexOf(args[0], optNumber(args[1], "start index")),
+      )
+    case "at":
+      return Effect.succeed(target.at(optNumber(args[0], "index") ?? 0))
+    case "slice":
+      return Effect.succeed(target.slice(optNumber(args[0], "start"), optNumber(args[1], "end")))
+    case "concat":
+      return Effect.succeed(target.concat(...args))
+    case "flat":
+      return Effect.succeed(target.flat(optNumber(args[0], "depth") ?? 1))
+    case "reverse":
+      return Effect.succeed(target.reverse())
+    case "sort":
+      return Effect.map(sortArray(runner, target, args[0], node), (sorted) => {
+        target.splice(0, target.length, ...sorted)
+        return target
+      })
+    case "toSorted":
+      return sortArray(runner, target, args[0], node)
+    case "toReversed":
+      return Effect.succeed([...target].reverse())
+    case "with": {
+      const index = optNumber(args[0], "index") ?? 0
+      const resolved = index < 0 ? target.length + index : index
+      if (resolved < 0 || resolved >= target.length) {
+        throw new InterpreterRuntimeError("Array.with index is out of range.", node)
+      }
+      const copied = [...target]
+      copied[resolved] = args[1]
+      return Effect.succeed(copied)
+    }
+    case "push": {
+      // Validate all insertions before mutating to avoid partial cyclic updates.
+      for (const item of args) rejectCircularInsertion(target, item, "Array.push result", node)
+      target.push(...args)
+      return Effect.succeed(target.length)
+    }
+    case "unshift": {
+      for (const item of args) rejectCircularInsertion(target, item, "Array.unshift result", node)
+      target.unshift(...args)
+      return Effect.succeed(target.length)
+    }
+    case "pop":
+      return Effect.succeed(target.pop())
+    case "shift":
+      return Effect.succeed(target.shift())
+    case "splice": {
+      if (args.length === 0) return Effect.succeed(target.splice(0, 0))
+      const start = optNumber(args[0], "start") ?? 0
+      if (args.length === 1) return Effect.succeed(target.splice(start))
+      const deleteCount = optNumber(args[1], "delete count") ?? 0
+      const inserted = args.slice(2)
+      for (const item of inserted) rejectCircularInsertion(target, item, "Array.splice result", node)
+      return Effect.succeed(target.splice(start, deleteCount, ...inserted))
+    }
+    case "fill": {
+      rejectCircularInsertion(target, args[0], "Array.fill result", node)
+      return Effect.succeed(target.fill(args[0], optNumber(args[1], "start"), optNumber(args[2], "end")))
+    }
+    case "copyWithin":
+      return Effect.succeed(
+        target.copyWithin(
+          optNumber(args[0], "target index") ?? 0,
+          optNumber(args[1], "start") ?? 0,
+          optNumber(args[2], "end"),
+        ),
+      )
+    case "keys":
+      return Effect.succeed(Array.from(target.keys()))
+    case "values":
+      return Effect.succeed([...target])
+    case "entries":
+      return Effect.succeed(Array.from(target.entries(), ([index, item]): Array<unknown> => [index, item]))
+  }
+
+  const apply = applyCollectionCallback(runner, args[0], `Array.${name}`, node)
+  return Effect.gen(function* () {
+    // Fix iteration length while reading existing elements live.
+    const length = target.length
+    switch (name) {
+      case "map": {
+        const values: Array<unknown> = []
+        values.length = length
+        for (let index = 0; index < length; index += 1) {
+          if (!(index in target)) continue
+          values[index] = yield* apply([target[index], index, target])
+        }
+        return values
+      }
+      case "flatMap": {
+        const values: Array<unknown> = []
+        for (let index = 0; index < length; index += 1) {
+          if (!(index in target)) continue
+          const mapped = yield* apply([target[index], index, target])
+          if (Array.isArray(mapped)) values.push(...mapped)
+          else values.push(mapped)
+        }
+        return values
+      }
+      case "filter": {
+        const values: Array<unknown> = []
+        for (let index = 0; index < length; index += 1) {
+          if (!(index in target)) continue
+          const item = target[index]
+          if (yield* apply([item, index, target])) values.push(item)
+        }
+        return values
+      }
+      case "find":
+        for (let index = 0; index < length; index += 1) {
+          const item = target[index]
+          if (yield* apply([item, index, target])) return item
+        }
+        return undefined
+      case "findIndex":
+        for (let index = 0; index < length; index += 1) {
+          if (yield* apply([target[index], index, target])) return index
+        }
+        return -1
+      case "some":
+        for (let index = 0; index < length; index += 1) {
+          if (!(index in target)) continue
+          if (yield* apply([target[index], index, target])) return true
+        }
+        return false
+      case "every":
+        for (let index = 0; index < length; index += 1) {
+          if (!(index in target)) continue
+          if (!(yield* apply([target[index], index, target]))) return false
+        }
+        return true
+      case "forEach":
+        for (let index = 0; index < length; index += 1) {
+          if (index in target) yield* apply([target[index], index, target])
+        }
+        return undefined
+      case "reduce": {
+        let start = 0
+        let accumulator = args[1]
+        if (args.length < 2) {
+          while (start < length && !(start in target)) start += 1
+          if (start === length)
+            throw new InterpreterRuntimeError("Array.reduce of an empty array with no initial value.", node).as(
+              "TypeError",
+            )
+          accumulator = target[start]
+          start += 1
+        }
+        for (let index = start; index < length; index += 1) {
+          if (!(index in target)) continue
+          accumulator = yield* apply([accumulator, target[index], index, target])
+        }
+        return accumulator
+      }
+      case "reduceRight": {
+        let start = length - 1
+        let accumulator = args[1]
+        if (args.length < 2) {
+          while (start >= 0 && !(start in target)) start -= 1
+          if (start < 0)
+            throw new InterpreterRuntimeError("Array.reduceRight of an empty array with no initial value.", node).as(
+              "TypeError",
+            )
+          accumulator = target[start]
+          start -= 1
+        }
+        for (let index = start; index >= 0; index -= 1) {
+          if (!(index in target)) continue
+          accumulator = yield* apply([accumulator, target[index], index, target])
+        }
+        return accumulator
+      }
+      case "findLast":
+        for (let index = length - 1; index >= 0; index -= 1) {
+          const item = target[index]
+          if (yield* apply([item, index, target])) return item
+        }
+        return undefined
+      case "findLastIndex":
+        for (let index = length - 1; index >= 0; index -= 1) {
+          if (yield* apply([target[index], index, target])) return index
+        }
+        return -1
+    }
+    throw new InterpreterRuntimeError(`Array method '${name}' is not available in CodeMode.`, node)
+  })
+}
+
+const sortArray = <R>(
+  runner: CallbackRunner<R>,
+  target: Array<unknown>,
+  comparator: unknown,
+  node: AstNode,
+): Effect.Effect<Array<unknown>, unknown, R> => {
+  if (comparator !== undefined && !(comparator instanceof CodeModeFunction)) {
+    throw new InterpreterRuntimeError("Array.sort expects an arrow function comparator.", node)
+  }
+  if (!(comparator instanceof CodeModeFunction)) {
+    return Effect.sync(() =>
+      [...target].sort((a, b) => {
+        const left = coerceToString(a)
+        const right = coerceToString(b)
+        return left < right ? -1 : left > right ? 1 : 0
+      }),
+    )
+  }
+  const mergeSort = (items: Array<unknown>): Effect.Effect<Array<unknown>, unknown, R> => {
+    if (items.length <= 1) return Effect.succeed(items)
+    const midpoint = Math.floor(items.length / 2)
+    return Effect.gen(function* () {
+      const left = yield* mergeSort(items.slice(0, midpoint))
+      const right = yield* mergeSort(items.slice(midpoint))
+      const merged: Array<unknown> = []
+      let leftIndex = 0
+      let rightIndex = 0
+      while (leftIndex < left.length && rightIndex < right.length) {
+        // Treat a NaN comparator result as equal to preserve stable ordering.
+        const order = coerceToNumber(yield* runner.invokeFunction(comparator, [left[leftIndex], right[rightIndex]]))
+        if (Number.isNaN(order) || order <= 0) merged.push(left[leftIndex++])
+        else merged.push(right[rightIndex++])
+      }
+      return [...merged, ...left.slice(leftIndex), ...right.slice(rightIndex)]
+    })
+  }
+  const defined = target.filter((item) => item !== undefined)
+  const undefinedCount = target.length - defined.length
+  return Effect.map(mergeSort(defined), (items) => [...items, ...Array(undefinedCount).fill(undefined)])
+}

packages/codemode/src/interpreter/model.ts

@@ -1,5 +1,5 @@
 import type { SafeObject } from "../tool-runtime.js"
-import type { SandboxPromise, SandboxURL } from "../values.js"
+import type { CodeModePromise, CodeModeURL } from "../values.js"
 
 export type SourcePosition = {
   line: number
@@ -35,7 +35,7 @@ export type StatementResult =
   | { kind: "continue" }
 
 export type MemberReference = {
-  target: SafeObject | Array<unknown> | SandboxURL
+  target: SafeObject | Array<unknown> | CodeModeURL
   key: string | number
 }
 
@@ -71,13 +71,11 @@ export type PromiseInstanceMethodName = "then" | "catch" | "finally"
 
 export class PromiseInstanceMethodReference {
   constructor(
-    readonly promise: SandboxPromise,
+    readonly promise: CodeModePromise,
     readonly name: PromiseInstanceMethodName,
   ) {}
 }
 
-// The resolve/reject callables handed to a `new Promise(executor)` executor. `settle` closes
-// over the promise's deferred and is first-settlement-wins; later calls are no-ops, as in JS.
 export class PromiseCapabilityFunction {
   constructor(readonly settle: (value: unknown) => void) {}
 }
@@ -114,8 +112,6 @@ export class UriFunction {
   constructor(readonly name: "encodeURI" | "encodeURIComponent" | "decodeURI" | "decodeURIComponent") {}
 }
 
-// The global `search` built-in: synchronous tool discovery that shares the tool admission
-// pipeline (budget, audit, hooks) without living in the `tools` tree.
 export class SearchFunction {}
 
 export class ProgramThrow {

packages/codemode/src/interpreter/promises.ts

@@ -0,0 +1,336 @@
+import { Cause, Deferred, Effect, Exit, Fiber, Scope } from "effect"
+import type { Diagnostic } from "../codemode.js"
+import type { SafeObject } from "../tool-runtime.js"
+import {
+  type AstNode,
+  CodeModeFunction,
+  CoercionFunction,
+  InterpreterRuntimeError,
+  ProgramThrow,
+  PromiseCapabilityFunction,
+  PromiseInstanceMethodReference,
+  PromiseMethodReference,
+  UriFunction,
+} from "./model.js"
+import { caughtErrorValue, normalizeError } from "./errors.js"
+import { applyCollectionCallback, type CallbackRunner } from "./methods.js"
+import { typeofValue } from "./references.js"
+import { spreadItems } from "../stdlib/collections.js"
+import { createAggregateErrorValue } from "../stdlib/value.js"
+import { CodeModePromise } from "../values.js"
+
+// Observation only controls rejection reporting; program completion interrupts all promise work.
+export class PromiseRuntime<R> {
+  private readonly active = new Set<CodeModePromise>()
+  private readonly ids = new WeakMap<CodeModePromise, number>()
+  private readonly observed = new WeakSet<CodeModePromise>()
+  private readonly failures = new Map<number, Diagnostic>()
+  private nextID = 0
+
+  constructor(private readonly scope: Scope.Scope) {}
+
+  create(effect: Effect.Effect<unknown, unknown, R>): Effect.Effect<CodeModePromise, never, R> {
+    return Effect.suspend(() => {
+      // Allocate before forking so reruns get distinct IDs and diagnostics retain creation order.
+      const id = this.nextID++
+      return Effect.map(Effect.forkIn(effect, this.scope, { startImmediately: true }), (fiber) => {
+        const promise = new CodeModePromise(fiber)
+        this.active.add(promise)
+        this.ids.set(promise, id)
+        fiber.addObserver((exit) => {
+          this.active.delete(promise)
+          if (Exit.isSuccess(exit) || Cause.hasInterruptsOnly(exit.cause) || this.observed.has(promise)) {
+            this.ids.delete(promise)
+            return
+          }
+          const failure = normalizeError(Cause.squash(exit.cause))
+          this.failures.set(id, {
+            ...failure,
+            message: `Unhandled rejection from an un-awaited promise: ${failure.message}`,
+          })
+        })
+        return promise
+      })
+    })
+  }
+
+  // Observation must be recorded when responsibility transfers, before the consumer fiber runs.
+  markObserved(promise: CodeModePromise): void {
+    this.observed.add(promise)
+    const id = this.ids.get(promise)
+    this.ids.delete(promise)
+    if (id !== undefined) this.failures.delete(id)
+  }
+
+  await(promise: CodeModePromise): Effect.Effect<Exit.Exit<unknown, unknown>> {
+    return Fiber.await(promise.fiber)
+  }
+
+  diagnostics(): Array<Diagnostic> {
+    return [...this.failures].sort(([left], [right]) => left - right).map(([, failure]) => failure)
+  }
+
+  // Re-check because a straggler can create promises before its interruption lands.
+  interrupt(): Effect.Effect<Array<Diagnostic>> {
+    const self = this
+    return Effect.gen(function* () {
+      while (self.active.size > 0) {
+        yield* Fiber.interruptAll([...self.active].map((promise) => promise.fiber))
+      }
+      return self.diagnostics()
+    })
+  }
+}
+
+export const selfResolutionError = (node?: AstNode): InterpreterRuntimeError =>
+  new InterpreterRuntimeError("Chaining cycle detected: a promise cannot resolve with itself.", node).as("TypeError")
+
+export const invokePromiseMethod = <R>(
+  runner: CallbackRunner<R>,
+  promises: PromiseRuntime<R>,
+  ref: PromiseMethodReference,
+  args: Array<unknown>,
+  node: AstNode,
+): Effect.Effect<unknown, unknown, R> => {
+  if (ref.name === "resolve") {
+    const value = args[0]
+    return value instanceof CodeModePromise ? Effect.succeed(value) : promises.create(Effect.succeed(value))
+  }
+  if (ref.name === "reject") {
+    return promises.create(Effect.fail(new ProgramThrow(args[0])))
+  }
+
+  const spread = spreadItems(args[0])
+  if (spread === undefined) {
+    return promises.create(
+      Effect.fail(
+        new InterpreterRuntimeError(
+          `Promise.${ref.name} expects an array of promises or plain values (e.g. Promise.${ref.name}(items.map((item) => tools.ns.tool(item)))).`,
+          node,
+        ).as("TypeError"),
+      ),
+    )
+  }
+  const items = Array.from(spread)
+
+  for (const item of items) {
+    if (item instanceof CodeModePromise) promises.markObserved(item)
+  }
+
+  switch (ref.name) {
+    case "all": {
+      const observations = items.map((item) =>
+        item instanceof CodeModePromise ? Effect.flatten(promises.await(item)) : Effect.succeed(item),
+      )
+      return promises.create(settleAfterTurn(Effect.all(observations, { concurrency: "unbounded" })))
+    }
+    case "allSettled": {
+      const observations = items.map((item) =>
+        item instanceof CodeModePromise ? promises.await(item) : Effect.succeed(Exit.succeed(item)),
+      )
+      return promises.create(
+        settleAfterTurn(
+          Effect.gen(function* () {
+            const outcomes: Array<unknown> = []
+            for (const observation of observations) {
+              const exit = yield* observation
+              if (Exit.isSuccess(exit)) {
+                outcomes.push(
+                  Object.assign(Object.create(null) as SafeObject, { status: "fulfilled", value: exit.value }),
+                )
+                continue
+              }
+              if (Cause.hasInterruptsOnly(exit.cause)) {
+                // Teardown interruption is not a program-level rejection.
+                return yield* Effect.failCause(exit.cause)
+              }
+              outcomes.push(
+                Object.assign(Object.create(null) as SafeObject, {
+                  status: "rejected",
+                  reason: caughtErrorValue(Cause.squash(exit.cause)),
+                }),
+              )
+            }
+            return outcomes
+          }),
+        ),
+      )
+    }
+    case "race": {
+      if (items.length === 0) {
+        return promises.create(
+          Effect.fail(
+            new InterpreterRuntimeError(
+              "Promise.race([]) would never settle; provide at least one promise or value.",
+              node,
+            ),
+          ),
+        )
+      }
+      const observations = items.map((item) =>
+        item instanceof CodeModePromise ? promises.await(item) : Effect.succeed(Exit.succeed(item)),
+      )
+      return promises.create(settleAfterTurn(Effect.flatten(Effect.raceAll(observations))))
+    }
+    case "any": {
+      const flipped = items.map((item) =>
+        item instanceof CodeModePromise
+          ? Effect.flatMap(promises.await(item), (exit) => {
+              if (Exit.isSuccess(exit)) return Effect.fail(new PromiseAnyFulfilled(exit.value))
+              if (Cause.hasInterruptsOnly(exit.cause)) return Effect.failCause(exit.cause)
+              return Effect.succeed(caughtErrorValue(Cause.squash(exit.cause)))
+            })
+          : Effect.fail(new PromiseAnyFulfilled(item)),
+      )
+      const body = Effect.all(flipped, { concurrency: "unbounded" }).pipe(
+        Effect.flatMap((reasons) =>
+          Effect.fail(new ProgramThrow(createAggregateErrorValue(reasons, "All promises were rejected"))),
+        ),
+        Effect.catch((error) =>
+          error instanceof PromiseAnyFulfilled ? Effect.succeed(error.value) : Effect.fail(error),
+        ),
+      )
+      return promises.create(settleAfterTurn(body))
+    }
+  }
+}
+
+export const invokePromiseInstanceMethod = <R>(
+  runner: CallbackRunner<R>,
+  promises: PromiseRuntime<R>,
+  ref: PromiseInstanceMethodReference,
+  args: Array<unknown>,
+  node: AstNode,
+): Effect.Effect<CodeModePromise, never, R> => {
+  const method = `Promise.prototype.${ref.name}`
+  promises.markObserved(ref.promise)
+  if (ref.name === "finally") {
+    return chainFinally(runner, promises, ref.promise, reactionHandler(args[0], method, node), method, node)
+  }
+  const onFulfilled = ref.name === "then" ? reactionHandler(args[0], method, node) : undefined
+  const onRejected = reactionHandler(ref.name === "then" ? args[1] : args[0], method, node)
+  return chainReaction(runner, promises, ref.promise, onFulfilled, onRejected, method, node)
+}
+
+export const constructPromise = <R>(
+  runner: CallbackRunner<R>,
+  promises: PromiseRuntime<R>,
+  executor: unknown,
+  node: AstNode,
+): Effect.Effect<CodeModePromise, unknown, R> => {
+  if (!(executor instanceof CodeModeFunction)) {
+    throw new InterpreterRuntimeError(
+      "new Promise(...) expects an executor function (e.g. new Promise((resolve, reject) => { ... })).",
+      node,
+    ).as("TypeError")
+  }
+  return Effect.gen(function* () {
+    const deferred = Deferred.makeUnsafe<unknown, unknown>()
+    const box: { own?: CodeModePromise } = {}
+    const promise = yield* promises.create(
+      Effect.flatMap(Deferred.await(deferred), (value) => {
+        if (!(value instanceof CodeModePromise)) return Effect.succeed(value)
+        if (value === box.own) return Effect.fail(selfResolutionError(node))
+        return runner.settlePromise(value)
+      }),
+    )
+    box.own = promise
+    const resolve = new PromiseCapabilityFunction((value) => {
+      Deferred.doneUnsafe(deferred, Exit.succeed(value))
+    })
+    const reject = new PromiseCapabilityFunction((value) => {
+      Deferred.doneUnsafe(deferred, Exit.fail(new ProgramThrow(value)))
+    })
+    const executed = yield* Effect.exit(runner.invokeFunction(executor, [resolve, reject]))
+    if (!Exit.isSuccess(executed)) {
+      if (Cause.hasInterruptsOnly(executed.cause)) return yield* Effect.failCause(executed.cause)
+      Deferred.doneUnsafe(deferred, Exit.fail(Cause.squash(executed.cause)))
+    }
+    return promise
+  })
+}
+
+// Settle one reaction turn after the deciding member, after its existing reactions.
+const settleAfterTurn = <A, E, R>(body: Effect.Effect<A, E, R>): Effect.Effect<A, E, R> =>
+  Effect.flatMap(Effect.exit(body), (exit) => Effect.andThen(Effect.yieldNow, exit))
+
+class PromiseAnyFulfilled {
+  constructor(readonly value: unknown) {}
+}
+
+type ReactionHandler = CodeModeFunction | CoercionFunction | UriFunction | PromiseCapabilityFunction
+
+const reactionHandler = (value: unknown, method: string, node: AstNode): ReactionHandler | undefined => {
+  if (
+    value instanceof CodeModeFunction ||
+    value instanceof CoercionFunction ||
+    value instanceof UriFunction ||
+    value instanceof PromiseCapabilityFunction
+  ) {
+    return value
+  }
+  if (typeofValue(value) === "function") {
+    throw new InterpreterRuntimeError(
+      `${method} handlers must be plain functions; wrap other callables in an arrow function, e.g. (value) => tools.ns.tool(value).`,
+      node,
+    )
+  }
+  return undefined
+}
+
+// Teardown bypasses handlers; settled reactions yield once so handlers never run inline.
+const reactionExit = <R>(
+  promises: PromiseRuntime<R>,
+  source: CodeModePromise,
+): Effect.Effect<Exit.Exit<unknown, unknown>, unknown, R> =>
+  Effect.gen(function* () {
+    const exit = yield* promises.await(source)
+    if (!Exit.isSuccess(exit) && Cause.hasInterruptsOnly(exit.cause)) return yield* Effect.failCause(exit.cause)
+    yield* Effect.yieldNow
+    return exit
+  })
+
+const chainReaction = <R>(
+  runner: CallbackRunner<R>,
+  promises: PromiseRuntime<R>,
+  source: CodeModePromise,
+  onFulfilled: ReactionHandler | undefined,
+  onRejected: ReactionHandler | undefined,
+  method: string,
+  node: AstNode,
+): Effect.Effect<CodeModePromise, never, R> => {
+  const box: { derived?: CodeModePromise } = {}
+  const body = Effect.gen(function* () {
+    const exit = yield* reactionExit(promises, source)
+    const handler = Exit.isSuccess(exit) ? onFulfilled : onRejected
+    if (handler === undefined) return yield* exit
+    const input = Exit.isSuccess(exit) ? exit.value : caughtErrorValue(Cause.squash(exit.cause))
+    const result = yield* applyCollectionCallback(runner, handler, method, node)([input])
+    if (result === box.derived) return yield* Effect.fail(selfResolutionError(node))
+    if (result instanceof CodeModePromise) return yield* runner.settlePromise(result)
+    return result
+  })
+  return Effect.map(promises.create(body), (derived) => {
+    box.derived = derived
+    return derived
+  })
+}
+
+const chainFinally = <R>(
+  runner: CallbackRunner<R>,
+  promises: PromiseRuntime<R>,
+  source: CodeModePromise,
+  cleanup: ReactionHandler | undefined,
+  method: string,
+  node: AstNode,
+): Effect.Effect<CodeModePromise, never, R> =>
+  promises.create(
+    Effect.gen(function* () {
+      const exit = yield* reactionExit(promises, source)
+      if (cleanup !== undefined) {
+        const result = yield* applyCollectionCallback(runner, cleanup, method, node)([])
+        if (result instanceof CodeModePromise) yield* runner.settlePromise(result)
+      }
+      return yield* exit
+    }),
+  )

packages/codemode/src/interpreter/references.ts

@@ -0,0 +1,99 @@
+import {
+  type AstNode,
+  CodeModeFunction,
+  CoercionFunction,
+  ErrorConstructorReference,
+  GlobalMethodReference,
+  GlobalNamespace,
+  InterpreterRuntimeError,
+  IntrinsicReference,
+  PromiseCapabilityFunction,
+  PromiseInstanceMethodReference,
+  PromiseMethodReference,
+  PromiseNamespace,
+  SearchFunction,
+  UriFunction,
+} from "./model.js"
+import { ToolReference } from "../tool-runtime.js"
+import { isCodeModeValue, CodeModePromise } from "../values.js"
+
+export const isRuntimeReference = (value: unknown): boolean =>
+  value instanceof CodeModeFunction ||
+  value instanceof ToolReference ||
+  value instanceof IntrinsicReference ||
+  value instanceof GlobalNamespace ||
+  value instanceof GlobalMethodReference ||
+  value instanceof PromiseNamespace ||
+  value instanceof PromiseMethodReference ||
+  value instanceof PromiseInstanceMethodReference ||
+  value instanceof CodeModePromise ||
+  value instanceof CoercionFunction ||
+  value instanceof UriFunction ||
+  value instanceof SearchFunction ||
+  value instanceof PromiseCapabilityFunction ||
+  value instanceof ErrorConstructorReference ||
+  isCodeModeValue(value)
+
+export const containsRuntimeReference = (value: unknown, seen = new Set<object>()): boolean => {
+  if (isRuntimeReference(value)) return true
+  if (value === null || typeof value !== "object") return false
+  if (seen.has(value)) return false
+  seen.add(value)
+  const contains = Array.isArray(value)
+    ? value.some((item) => containsRuntimeReference(item, seen))
+    : Object.values(value).some((item) => containsRuntimeReference(item, seen))
+  seen.delete(value)
+  return contains
+}
+
+// CodeMode values are data here, not opaque interpreter references.
+export const containsOpaqueReference = (value: unknown, seen = new Set<object>()): boolean => {
+  if (isCodeModeValue(value)) return false
+  if (isRuntimeReference(value)) return true
+  if (value === null || typeof value !== "object") return false
+  if (seen.has(value)) return false
+  seen.add(value)
+  const contains = Array.isArray(value)
+    ? value.some((item) => containsOpaqueReference(item, seen))
+    : Object.values(value).some((item) => containsOpaqueReference(item, seen))
+  seen.delete(value)
+  return contains
+}
+
+// Reject cycles before mutation so later boundary walks remain safe.
+export const rejectCircularInsertion = (
+  container: object,
+  value: unknown,
+  label: string,
+  node: AstNode,
+  seen = new Set<object>(),
+): void => {
+  if (value === container)
+    throw new InterpreterRuntimeError(`${label} contains a circular value.`, node, "InvalidDataValue")
+  if (value === null || typeof value !== "object" || isRuntimeReference(value) || seen.has(value)) return
+  seen.add(value)
+  const items = Array.isArray(value) ? value : Object.values(value)
+  for (const item of items) rejectCircularInsertion(container, item, label, node, seen)
+  seen.delete(value)
+}
+
+export const typeofValue = (value: unknown): string => {
+  if (
+    value instanceof CodeModeFunction ||
+    value instanceof CoercionFunction ||
+    value instanceof IntrinsicReference ||
+    value instanceof GlobalMethodReference ||
+    value instanceof PromiseMethodReference ||
+    value instanceof PromiseInstanceMethodReference ||
+    value instanceof PromiseNamespace ||
+    value instanceof PromiseCapabilityFunction ||
+    value instanceof ErrorConstructorReference
+  )
+    return "function"
+  if (value instanceof UriFunction || value instanceof SearchFunction) return "function"
+  if (value instanceof ToolReference) return value.path.length > 0 ? "function" : "object"
+  if (value instanceof GlobalNamespace) {
+    return value.name === "Math" || value.name === "JSON" || value.name === "console" ? "object" : "function"
+  }
+  return typeof value
+}

packages/codemode/src/interpreter/scope.ts

@@ -0,0 +1,84 @@
+import { type AstNode, type Binding, InterpreterRuntimeError } from "./model.js"
+
+export class ScopeStack {
+  private readonly scopes: Array<Map<string, Binding>>
+
+  constructor(scopes: Array<Map<string, Binding>>) {
+    this.scopes = scopes
+  }
+
+  declare(name: string, value: unknown, mutable: boolean, node: AstNode): void {
+    const scope = this.current()
+
+    const existing = scope.get(name)
+    if (existing && existing.initialized !== false) {
+      throw new InterpreterRuntimeError(`Identifier '${name}' has already been declared.`, node)
+    }
+
+    scope.set(name, { mutable, value, initialized: true })
+  }
+
+  get(name: string, node: AstNode): unknown {
+    const binding = this.resolve(name)
+
+    if (!binding) {
+      throw new InterpreterRuntimeError(`Unknown identifier '${name}'.`, node).as("ReferenceError")
+    }
+
+    if (binding.initialized === false) {
+      throw new InterpreterRuntimeError(`Cannot access '${name}' before initialization.`, node).as("ReferenceError")
+    }
+
+    return binding.value
+  }
+
+  set(name: string, value: unknown, node: AstNode): unknown {
+    const binding = this.resolve(name)
+
+    if (!binding) {
+      throw new InterpreterRuntimeError(`Unknown identifier '${name}'.`, node).as("ReferenceError")
+    }
+
+    if (!binding.mutable) {
+      throw new InterpreterRuntimeError(`Cannot assign to constant '${name}'.`, node).as("TypeError")
+    }
+
+    binding.value = value
+    return value
+  }
+
+  resolve(name: string): Binding | undefined {
+    for (let index = this.scopes.length - 1; index >= 0; index -= 1) {
+      const scope = this.scopes[index]
+      const binding = scope?.get(name)
+
+      if (binding) {
+        return binding
+      }
+    }
+
+    return undefined
+  }
+
+  current(): Map<string, Binding> {
+    const scope = this.scopes[this.scopes.length - 1]
+
+    if (!scope) {
+      throw new InterpreterRuntimeError("Interpreter scope stack is empty.")
+    }
+
+    return scope
+  }
+
+  push(scope: Map<string, Binding> = new Map()): void {
+    this.scopes.push(scope)
+  }
+
+  pop(): void {
+    this.scopes.pop()
+  }
+
+  capture(): Array<Map<string, Binding>> {
+    return this.scopes.slice()
+  }
+}

packages/codemode/src/openapi/index.ts

@@ -31,10 +31,8 @@ export type {
 } from "./types.js"
 
 /**
- * Builds a CodeMode tool subtree from an OpenAPI 3.x document, one tool per
- * operation. Auth is resolved host-side via `auth.resolve` and never
- * model-visible. Tools require `HttpClient.HttpClient`; unrepresentable
- * operations land in `skipped`.
+ * Builds one CodeMode tool per representable OpenAPI 3.x operation. Auth remains host-side,
+ * tools require `HttpClient.HttpClient`, and unrepresentable operations land in `skipped`.
  */
 export const fromSpec = (options: Options): Result => {
   const document = options.spec

packages/codemode/src/openapi/runtime.ts

@@ -56,7 +56,7 @@ const buildRequest = (
   input: Readonly<Record<string, unknown>>,
 ): Effect.Effect<HttpClientRequest.HttpClientRequest, ToolError> =>
   Effect.gen(function* () {
-    // Validate every model-controlled value before auth resolution, which may refresh tokens.
+    // Validate model input before auth resolution can refresh credentials.
     const url = buildUrl(plan, input)
     if (url instanceof ToolError) return yield* Effect.fail(url)
     const missing = plan.fields.find(
@@ -77,7 +77,6 @@ const buildRequest = (
       request = serialized
     }
 
-    // Host headers first, then declared header parameters.
     request = HttpClientRequest.setHeaders(request, plan.headers)
     for (const field of plan.fields) {
       if (field.location !== "header") continue
@@ -169,7 +168,7 @@ const applyCredentials = (
       continue
     }
     if (credential.type === "basic") {
-      // Buffer instead of btoa: btoa throws on non-Latin-1 credentials.
+      // Basic auth credentials are UTF-8; btoa rejects non-Latin-1 input.
       const duplicate = add(
         "header",
         "authorization",
@@ -183,7 +182,6 @@ const applyCredentials = (
       if (duplicate !== undefined) return duplicate
       continue
     }
-    // apiKey: the carrier comes from the scheme declaration.
     if (definition.type !== "apiKey") {
       return toolError(
         `Security scheme '${name}' is not an apiKey scheme; resolve a bearer, basic, or header credential for it.`,
@@ -212,8 +210,7 @@ const buildUrl = (plan: Plan, input: Readonly<Record<string, unknown>>): string
       ),
     )
     if (fieldValue instanceof ToolError) return fieldValue
-    // '.'/'..' survive encoding and URL normalization collapses them, letting a
-    // model-supplied value retarget the request to a different endpoint.
+    // URL normalization collapses encoded `.` and `..`, which could retarget the request.
     if (fieldValue === "" || fieldValue === "." || fieldValue === "..") {
       return toolError(`Invalid path parameter '${field.inputName}'.`)
     }

packages/codemode/src/openapi/spec.ts

@@ -23,8 +23,7 @@ const asArray = (value: unknown): ReadonlyArray<unknown> => (Array.isArray(value
 export const nonEmptyString = (value: unknown): string | undefined =>
   typeof value === "string" && value !== "" ? value : undefined
 
-// Guards record lookups keyed by spec- or model-controlled names against
-// prototype-inherited values (e.g. a parameter named `toString`).
+// Spec- and model-controlled keys must not resolve inherited properties.
 export const own = <T>(record: Readonly<Record<string, T>>, key: string): T | undefined =>
   Object.hasOwn(record, key) ? record[key] : undefined
 
@@ -106,7 +105,7 @@ const operationParameters = (
   pathItem: Record<string, unknown>,
   operation: Record<string, unknown>,
 ): Parsed<ReadonlyArray<PlannedField>> => {
-  // Operation-level parameters override path-level ones sharing (location, name).
+  // OpenAPI operation parameters override path parameters with the same location and name.
   const declared = new Map<
     string,
     { readonly name: string; readonly location: string; readonly parameter: Record<string, unknown> }

packages/codemode/src/openapi/types.ts

@@ -22,9 +22,8 @@ export type SecurityScheme =
   | { readonly type: "openIdConnect" }
 
 /**
- * Credential material returned by a host auth resolver. The carrier for `apiKey`
- * comes from the scheme definition, not the credential. `header` is the escape
- * hatch for nonstandard schemes.
+ * Credential material returned by a host auth resolver. `apiKey` uses the scheme's carrier;
+ * `header` supports nonstandard schemes.
  */
 export type Credential =
   | { readonly type: "bearer"; readonly token: string }
@@ -33,9 +32,7 @@ export type Credential =
   | { readonly type: "header"; readonly name: string; readonly value: string }
 
 /**
- * Resolves credential material for one named security scheme at call time.
- * `undefined` means unavailable, try the next OR alternative; a failure aborts
- * the call rather than falling through.
+ * Resolves credentials at call time. `undefined` tries the next OR alternative; failure aborts.
  */
 export type AuthResolver = (context: {
   readonly name: string
@@ -74,9 +71,7 @@ export type Parsed<T> = { readonly ok: true; readonly value: T } | { readonly ok
 export type InputLocation = "path" | "query" | "header" | "body"
 
 export type InputField = {
-  /** Model-visible field name after cross-location collision handling. */
   readonly inputName: string
-  /** Original parameter or body-property name used on the wire. */
   readonly name: string
   readonly location: InputLocation
   readonly required: boolean
@@ -92,7 +87,6 @@ export type OperationInput = {
   readonly body: Body | undefined
 }
 
-/** One OR alternative: scheme name -> required scopes. Empty object = unauthenticated is acceptable. */
 export type SecurityRequirement = Readonly<Record<string, ReadonlyArray<string>>>
 
 export type Plan = {

packages/codemode/src/stdlib/collections.ts

@@ -43,9 +43,9 @@ export const setMethods = new Set(["add", "has", "delete", "clear", "forEach", "
 export const spreadItems = (value: unknown): Array<unknown> | undefined => {
   if (Array.isArray(value)) return value
   if (typeof value === "string") return Array.from(value)
-  if (value instanceof SandboxMap) return Array.from(value.map.entries(), ([key, item]) => [key, item])
-  if (value instanceof SandboxSet) return Array.from(value.set.values())
-  if (value instanceof SandboxURLSearchParams) return Array.from(value.params.entries(), ([key, item]) => [key, item])
+  if (value instanceof CodeModeMap) return Array.from(value.map.entries(), ([key, item]) => [key, item])
+  if (value instanceof CodeModeSet) return Array.from(value.set.values())
+  if (value instanceof CodeModeURLSearchParams) return Array.from(value.params.entries(), ([key, item]) => [key, item])
   return undefined
 }
-import { SandboxMap, SandboxSet, SandboxURLSearchParams } from "../values.js"
+import { CodeModeMap, CodeModeSet, CodeModeURLSearchParams } from "../values.js"

packages/codemode/src/stdlib/console.ts

@@ -1,4 +1,122 @@
+import { containsOpaqueReference, containsRuntimeReference, isRuntimeReference } from "../interpreter/references.js"
+import { copyIn, copyOut } from "../tool-runtime.js"
+import {
+  isCodeModeValue,
+  CodeModeDate,
+  CodeModeMap,
+  CodeModePromise,
+  CodeModeRegExp,
+  CodeModeSet,
+  CodeModeURL,
+  CodeModeURLSearchParams,
+} from "../values.js"
+import { boundedData, coerceToString } from "./value.js"
+
 export const consoleMethods = new Set(["log", "info", "debug", "warn", "error", "dir", "table"])
 
-/** Console formatting recursion ceiling; deeper values render as "...". */
-export const MAX_CONSOLE_DEPTH = 32
+const MAX_CONSOLE_DEPTH = 32
+
+export const formatConsoleMessage = (name: string, args: Array<unknown>): string => {
+  if (name === "dir") return args.length === 0 ? "undefined" : formatConsoleArgument(args[0])
+  if (name === "table") return formatConsoleTable(args[0], args[1])
+  const prefix = name === "warn" ? "[warn] " : name === "error" ? "[error] " : name === "debug" ? "[debug] " : ""
+  return `${prefix}${args.map((arg) => formatConsoleArgument(arg)).join(" ")}`
+}
+
+const formatConsoleArgument = (value: unknown): string => {
+  if (value === undefined) return "undefined"
+  if (typeof value === "string") return value
+  return formatConsoleValue(value, new Set(), 0)
+}
+
+const formatConsoleValue = (value: unknown, seen: Set<object>, depth: number): string => {
+  if (value === null || value === undefined) return "null"
+  if (typeof value === "string") return JSON.stringify(value)
+  if (typeof value === "number" || typeof value === "boolean") return String(value)
+  if (typeof value !== "object") return String(value)
+  if (value instanceof CodeModePromise) return "[Promise (await it to get its value)]"
+  if (value instanceof CodeModeDate) return coerceToString(value)
+  if (value instanceof CodeModeRegExp) return coerceToString(value)
+  if (value instanceof CodeModeURL) return coerceToString(value)
+  if (value instanceof CodeModeURLSearchParams) return coerceToString(value)
+  if (depth > MAX_CONSOLE_DEPTH) return "..."
+  if (seen.has(value)) return "[Circular]"
+  if (value instanceof CodeModeMap) {
+    seen.add(value)
+    try {
+      const entries = Array.from(value.map.entries(), ([key, item]): Array<unknown> => [key, item])
+      return `Map(${value.map.size}) ${formatConsoleValue(entries, seen, depth + 1)}`
+    } finally {
+      seen.delete(value)
+    }
+  }
+  if (value instanceof CodeModeSet) {
+    seen.add(value)
+    try {
+      return `Set(${value.set.size}) ${formatConsoleValue(Array.from(value.set.values()), seen, depth + 1)}`
+    } finally {
+      seen.delete(value)
+    }
+  }
+  if (isRuntimeReference(value)) return "[CodeMode reference]"
+  seen.add(value)
+  try {
+    if (Array.isArray(value)) {
+      return `[${value.map((item) => formatConsoleValue(item, seen, depth + 1)).join(",")}]`
+    }
+    return `{${Object.entries(value)
+      .map(([key, item]) => `${JSON.stringify(key)}:${formatConsoleValue(item, seen, depth + 1)}`)
+      .join(",")}}`
+  } finally {
+    seen.delete(value)
+  }
+}
+
+const formatConsoleTable = (value: unknown, columnsArgument: unknown): string => {
+  if (value === undefined) return "undefined"
+  if (containsOpaqueReference(value)) return "[CodeMode reference]"
+  const data = boundedData(value, "console.table argument")
+  const columns = consoleTableColumns(columnsArgument)
+  const rows = consoleTableRows(data, columns)
+  const keys = columns ?? Array.from(new Set(rows.flatMap((row) => Object.keys(row.values))))
+  const header = ["(index)", ...keys].join("\t")
+  return [
+    header,
+    ...rows.map((row) => [row.index, ...keys.map((key) => formatConsoleTableCell(row.values[key]))].join("\t")),
+  ].join("\n")
+}
+
+const consoleTableColumns = (value: unknown): ReadonlyArray<string> | undefined => {
+  if (value === undefined) return undefined
+  if (containsRuntimeReference(value)) return undefined
+  const columns = copyOut(copyIn(value, "console.table columns"), true)
+  return Array.isArray(columns) ? columns.map((column) => String(column)) : undefined
+}
+
+const consoleTableRows = (
+  data: unknown,
+  columns: ReadonlyArray<string> | undefined,
+): Array<{ readonly index: string; readonly values: Record<string, unknown> }> => {
+  if (Array.isArray(data)) {
+    return data.map((item, index) => ({ index: String(index), values: consoleTableValues(item, columns) }))
+  }
+  if (data !== null && typeof data === "object" && !isCodeModeValue(data)) {
+    return Object.entries(data).map(([index, item]) => ({ index, values: consoleTableValues(item, columns) }))
+  }
+  return [{ index: "0", values: { Value: data } }]
+}
+
+const consoleTableValues = (value: unknown, columns: ReadonlyArray<string> | undefined): Record<string, unknown> => {
+  if (value !== null && typeof value === "object" && !Array.isArray(value) && !isCodeModeValue(value)) {
+    const source = value as Record<string, unknown>
+    if (columns !== undefined) return Object.fromEntries(columns.map((column) => [column, source[column]]))
+    return Object.fromEntries(Object.entries(source))
+  }
+  return { Value: value }
+}
+
+const formatConsoleTableCell = (value: unknown): string => {
+  if (value === undefined) return ""
+  if (typeof value === "string") return value
+  return formatConsoleValue(value, new Set(), 0)
+}

packages/codemode/src/stdlib/date.ts

@@ -36,7 +36,7 @@ export const invokeDateStatic = (name: string, args: Array<unknown>, node: AstNo
   }
 }
 
-export const invokeDateMethod = (value: SandboxDate, name: string, node: AstNode): unknown => {
+export const invokeDateMethod = (value: CodeModeDate, name: string, node: AstNode): unknown => {
   const hosted = new Date(value.time)
   switch (name) {
     case "getTime":
@@ -88,5 +88,5 @@ export const invokeDateMethod = (value: SandboxDate, name: string, node: AstNode
   }
 }
 import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
-import { SandboxDate } from "../values.js"
+import { CodeModeDate } from "../values.js"
 import { coerceToNumber, coerceToString } from "./value.js"

packages/codemode/src/stdlib/object.ts

@@ -1,6 +1,6 @@
 import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
 import { isBlockedMember } from "../tool-runtime.js"
-import { isSandboxValue, SandboxMap, SandboxPromise, SandboxSet, SandboxURLSearchParams } from "../values.js"
+import { isCodeModeValue, CodeModeMap, CodeModePromise, CodeModeSet, CodeModeURLSearchParams } from "../values.js"
 import { boundedData, coerceToString } from "./value.js"
 
 export const objectMethodsPreservingIdentity = new Set(["assign", "values", "entries", "fromEntries"])
@@ -9,8 +9,8 @@ export const invokeObjectMethod = (name: string, args: Array<unknown>, node: Ast
   const requireObject = (): Record<string, unknown> => {
     const input = args[0]
     if (Array.isArray(input)) return input as unknown as Record<string, unknown>
-    if (isSandboxValue(input)) return {}
-    if (input instanceof SandboxPromise) {
+    if (isCodeModeValue(input)) return {}
+    if (input instanceof CodeModePromise) {
       throw new InterpreterRuntimeError(
         `Object.${name} received an un-awaited Promise; await it before inspecting the result.`,
         node,
@@ -46,12 +46,12 @@ export const invokeObjectMethod = (name: string, args: Array<unknown>, node: Ast
       return Object.hasOwn(requireObject(), String(args[1]))
     case "assign": {
       const target = args[0]
-      if (target === null || typeof target !== "object" || Array.isArray(target) || isSandboxValue(target)) {
+      if (target === null || typeof target !== "object" || Array.isArray(target) || isCodeModeValue(target)) {
         throw new InterpreterRuntimeError("Object.assign expects a data object target.", node)
       }
       const out = target as Record<string, unknown>
       for (const source of args.slice(1)) {
-        if (source === null || source === undefined || isSandboxValue(source)) continue
+        if (source === null || source === undefined || isCodeModeValue(source)) continue
         if (typeof source !== "object" || Array.isArray(source)) {
           throw new InterpreterRuntimeError("Object.assign expects data objects.", node)
         }
@@ -60,17 +60,17 @@ export const invokeObjectMethod = (name: string, args: Array<unknown>, node: Ast
       return out
     }
     case "fromEntries": {
-      if (args[0] instanceof SandboxMap) {
+      if (args[0] instanceof CodeModeMap) {
         const out: Record<string, unknown> = Object.create(null)
         for (const [key, item] of args[0].map.entries()) addEntry(out, key, item)
         return out
       }
-      if (args[0] instanceof SandboxURLSearchParams) {
+      if (args[0] instanceof CodeModeURLSearchParams) {
         const out: Record<string, unknown> = Object.create(null)
         for (const [key, value] of args[0].params.entries()) guardedSet(out, key, value)
         return out
       }
-      const pairs = args[0] instanceof SandboxSet ? Array.from(args[0].set.values()) : args[0]
+      const pairs = args[0] instanceof CodeModeSet ? Array.from(args[0].set.values()) : args[0]
       if (!Array.isArray(pairs)) {
         boundedData(args[0], "Object.fromEntries input")
         throw new InterpreterRuntimeError("Object.fromEntries expects an array of [key, value] pairs.", node)
@@ -78,7 +78,7 @@ export const invokeObjectMethod = (name: string, args: Array<unknown>, node: Ast
       const out: Record<string, unknown> = Object.create(null)
       for (const pair of pairs) {
         const validated = boundedData(pair, "Object.fromEntries entry")
-        if (validated === null || typeof validated !== "object" || isSandboxValue(validated))
+        if (validated === null || typeof validated !== "object" || isCodeModeValue(validated))
           throw new InterpreterRuntimeError("Object.fromEntries expects [key, value] entry objects.", node)
         const entry = pair as Record<string, unknown>
         addEntry(out, entry[0], entry[1])

packages/codemode/src/stdlib/promise.ts

@@ -1,6 +1,3 @@
 import type { PromiseMethodName } from "../interpreter/model.js"
 
 export const promiseStatics = new Set<PromiseMethodName>(["all", "allSettled", "race", "any", "resolve", "reject"])
-
-/** Maximum number of eagerly forked tool calls that may run concurrently. */
-export const TOOL_CALL_CONCURRENCY = 8

packages/codemode/src/stdlib/regexp.ts

@@ -19,7 +19,7 @@ export const escapeRegexHint =
   'To match special characters like ( ) [ ] { } + * ? . literally, escape them with a backslash (e.g. "\\\\(") or test for them with String.includes instead.'
 
 export const toHostRegex = (arg: unknown, method: string, node: AstNode, extraFlags = ""): RegExp => {
-  if (arg instanceof SandboxRegExp) return arg.regex
+  if (arg instanceof CodeModeRegExp) return arg.regex
   if (typeof arg === "string") {
     try {
       return new RegExp(arg, extraFlags)
@@ -50,7 +50,7 @@ export const matchToValue = (match: RegExpMatchArray): Array<unknown> => {
 }
 
 export const invokeRegExpMethod = (
-  value: SandboxRegExp,
+  value: CodeModeRegExp,
   name: string,
   args: Array<unknown>,
   node: AstNode,
@@ -70,5 +70,5 @@ export const invokeRegExpMethod = (
 }
 import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
 import { isBlockedMember, type SafeObject } from "../tool-runtime.js"
-import { SandboxRegExp } from "../values.js"
+import { CodeModeRegExp } from "../values.js"
 import { coerceToString } from "./value.js"

packages/codemode/src/stdlib/string.ts

@@ -4,12 +4,9 @@ export const stringMethods = new Set([
   "trim",
   "trimStart",
   "trimEnd",
-  "trimLeft",
-  "trimRight",
   "split",
   "slice",
   "substring",
-  "substr",
   "includes",
   "startsWith",
   "endsWith",

packages/codemode/src/stdlib/url.ts

@@ -66,7 +66,7 @@ export const invokeUriFunction = (ref: UriFunction, args: Array<unknown>, node:
 }
 
 export const urlArgument = (value: unknown, label: string): string =>
-  value instanceof SandboxURL ? value.url.href : uriArgument(value, label)
+  value instanceof CodeModeURL ? value.url.href : uriArgument(value, label)
 
 export const invokeURLStatic = (name: string, args: Array<unknown>, node: AstNode): unknown => {
   if (!urlStatics.has(name)) throw new InterpreterRuntimeError(`URL.${name} is not available in CodeMode.`, node)
@@ -75,16 +75,16 @@ export const invokeURLStatic = (name: string, args: Array<unknown>, node: AstNod
   const base = args[1] === undefined ? undefined : urlArgument(args[1], `URL.${name} base`)
   try {
     const url = new URL(input, base)
-    return name === "canParse" ? true : new SandboxURL(url)
+    return name === "canParse" ? true : new CodeModeURL(url)
   } catch {
     return name === "canParse" ? false : null
   }
 }
 
-export const invokeURLMethod = (value: SandboxURL, name: string, node: AstNode): string => {
+export const invokeURLMethod = (value: CodeModeURL, name: string, node: AstNode): string => {
   if (name === "toString" || name === "toJSON") return value.url.href
   throw new InterpreterRuntimeError(`URL method '${name}' is not available in CodeMode.`, node)
 }
 import { type AstNode, InterpreterRuntimeError, UriFunction } from "../interpreter/model.js"
-import { SandboxURL } from "../values.js"
+import { CodeModeURL } from "../values.js"
 import { boundedData, coerceToString } from "./value.js"

packages/codemode/src/stdlib/value.ts

@@ -34,13 +34,13 @@ export const boundedData = (value: unknown, label: string): unknown => copyIn(va
 export const coerceToString = (value: unknown): string => {
   if (value === null) return "null"
   if (value === undefined) return "undefined"
-  if (value instanceof SandboxDate)
+  if (value instanceof CodeModeDate)
     return Number.isFinite(value.time) ? new Date(value.time).toISOString() : "Invalid Date"
-  if (value instanceof SandboxRegExp) return `/${value.regex.source}/${value.regex.flags}`
-  if (value instanceof SandboxMap) return "[object Map]"
-  if (value instanceof SandboxSet) return "[object Set]"
-  if (value instanceof SandboxURL) return value.url.href
-  if (value instanceof SandboxURLSearchParams) return value.params.toString()
+  if (value instanceof CodeModeRegExp) return `/${value.regex.source}/${value.regex.flags}`
+  if (value instanceof CodeModeMap) return "[object Map]"
+  if (value instanceof CodeModeSet) return "[object Set]"
+  if (value instanceof CodeModeURL) return value.url.href
+  if (value instanceof CodeModeURLSearchParams) return value.params.toString()
   if (typeof value === "object") {
     return Array.isArray(value)
       ? value.map((item) => (item === null || item === undefined ? "" : coerceToString(item))).join(",")
@@ -50,14 +50,14 @@ export const coerceToString = (value: unknown): string => {
 }
 
 export const coerceToNumber = (value: unknown): number => {
-  if (value instanceof SandboxDate) return value.time
-  if (isSandboxValue(value)) return Number.NaN
+  if (value instanceof CodeModeDate) return value.time
+  if (isCodeModeValue(value)) return Number.NaN
   return value !== null && typeof value === "object" && !Array.isArray(value) ? Number.NaN : Number(value)
 }
 
 export const invokeCoercion = (ref: CoercionFunction, args: Array<unknown>, node: AstNode): unknown => {
   const raw = args[0]
-  if (isSandboxValue(raw)) {
+  if (isCodeModeValue(raw)) {
     if (ref.name === "Boolean") return true
     if (ref.name === "Number") return coerceToNumber(raw)
     if (ref.name === "String") return coerceToString(raw)
@@ -80,11 +80,11 @@ export const invokeCoercion = (ref: CoercionFunction, args: Array<unknown>, node
 import { type AstNode, CoercionFunction, InterpreterRuntimeError } from "../interpreter/model.js"
 import { copyIn, type SafeObject } from "../tool-runtime.js"
 import {
-  isSandboxValue,
-  SandboxDate,
-  SandboxMap,
-  SandboxRegExp,
-  SandboxSet,
-  SandboxURL,
-  SandboxURLSearchParams,
+  isCodeModeValue,
+  CodeModeDate,
+  CodeModeMap,
+  CodeModeRegExp,
+  CodeModeSet,
+  CodeModeURL,
+  CodeModeURLSearchParams,
 } from "../values.js"

packages/codemode/src/tool-runtime.ts

@@ -10,13 +10,13 @@ import {
 } from "./tool-schema.js"
 import { isDefinition as isToolDefinition, type Definition } from "./tool.js"
 import {
-  SandboxDate,
-  SandboxMap,
-  SandboxPromise,
-  SandboxRegExp,
-  SandboxSet,
-  SandboxURL,
-  SandboxURLSearchParams,
+  CodeModeDate,
+  CodeModeMap,
+  CodeModePromise,
+  CodeModeRegExp,
+  CodeModeSet,
+  CodeModeURL,
+  CodeModeURLSearchParams,
 } from "./values.js"
 
 const estimateTokens = (input: string) => Math.max(0, Math.round(input.length / 4))
@@ -44,36 +44,30 @@ type ServicesOf<Tools, Depth extends ReadonlyArray<unknown>> = Depth["length"] e
           : ServicesOf<Tools[keyof Tools], [...Depth, unknown]>
         : never
 
-/** Minimal audit record retained for each admitted tool call. */
 export type ToolCall = {
   readonly name: string
 }
 
-/** Decoded tool call observed immediately before tool execution. */
 export type ToolCallStarted = {
   readonly index: number
   readonly name: string
   readonly input: unknown
 }
 
-/** Completed tool call observed immediately after tool execution settles. */
 export type ToolCallEnded = {
   readonly index: number
   readonly name: string
   readonly input: unknown
   readonly durationMs: number
   readonly outcome: "success" | "failure"
-  /** Model-safe failure message; present only when `outcome` is `"failure"`. */
   readonly message?: string
 }
 
-/** Non-throwing observation hooks fired around each admitted tool call. */
 export type ToolCallHooks<R = never> = {
   readonly onToolCallStart?: ((call: ToolCallStarted) => Effect.Effect<void, never, R>) | undefined
   readonly onToolCallEnd?: ((call: ToolCallEnded) => Effect.Effect<void, never, R>) | undefined
 }
 
-/** Model-visible description of one schema-backed tool. */
 export type ToolDescription = {
   readonly path: string
   readonly description: string
@@ -113,11 +107,6 @@ export class ToolReference {
   constructor(readonly path: ReadonlyArray<string>) {}
 }
 
-/**
- * Maximum nesting depth for values crossing a data boundary. Fixed (not a configurable
- * limit) purely because it produces a clearer diagnostic than a native stack-overflow
- * RangeError would.
- */
 const MAX_VALUE_DEPTH = 32
 
 export class ToolRuntimeError extends Error {
@@ -152,30 +141,16 @@ const blockedMemberNames = new Set(["__proto__", "constructor", "prototype"])
 
 export const isBlockedMember = (name: string): boolean => blockedMemberNames.has(name)
 
-/**
- * Validates and copies a value against the plain-data contract (depth, circularity, plain
- * objects only, blocked properties, data-only leaves).
- *
- * Two modes share the walk:
- * - **Boundary** (`preserveSandboxValues` false, the default): the host<->sandbox boundary -
- *   final results, tool-call arguments, `JSON.stringify`. Sandbox value types serialize
- *   exactly as JSON.stringify would: Date/URL -> strings, the remaining value types -> {}.
- * - **Intra-sandbox checkpoint** (`preserveSandboxValues` true; see `boundedData` in
- *   codemode.ts): standard-library value instances pass through untouched (treated as leaves,
- *   contents not walked), so values flowing through `Object.*` helpers, coercion inputs, and
- *   other in-sandbox checkpoints stay fully usable (`.getTime()`, `.has()`, ...).
- *
- * Both modes reject un-awaited promises with an await-hinting diagnostic.
- */
-export const copyIn = (value: unknown, label: string, preserveSandboxValues = false): unknown =>
-  copyBounded(value, label, 0, new Set(), preserveSandboxValues)
+// Checkpoint mode preserves CodeMode values; boundary mode JSON-normalizes them.
+export const copyIn = (value: unknown, label: string, preserveCodeModeValues = false): unknown =>
+  copyBounded(value, label, 0, new Set(), preserveCodeModeValues)
 
 const copyBounded = (
   value: unknown,
   label: string,
   depth: number,
   seen: Set<object>,
-  preserveSandboxValues: boolean,
+  preserveCodeModeValues: boolean,
 ): unknown => {
   if (depth > MAX_VALUE_DEPTH) {
     throw new ToolRuntimeError("InvalidDataValue", `${label} exceeds the maximum value depth of ${MAX_VALUE_DEPTH}.`)
@@ -185,10 +160,6 @@ const copyBounded = (
     value === undefined ||
     typeof value === "string" ||
     typeof value === "boolean" ||
-    // NaN/Infinity are allowed to exist as in-sandbox intermediates (matching real JS and a real
-    // engine) so defensive guards like `Number.isNaN(x)` / `parseInt(x) || 0` can run. They are
-    // normalized to `null` when the value leaves the sandbox - see copyOut - exactly as
-    // JSON.stringify already does at any tool boundary.
     typeof value === "number"
   ) {
     return value
@@ -198,65 +169,55 @@ const copyBounded = (
     throw new ToolRuntimeError("InvalidDataValue", `${label} must contain data only.`)
   }
 
-  // An un-awaited promise never crosses a data checkpoint as `{}`; the diagnostic tells the
-  // model exactly how to fix the program instead.
-  if (value instanceof SandboxPromise) {
+  if (value instanceof CodeModePromise) {
     throw new ToolRuntimeError(
       "InvalidDataValue",
       `${label} contains an un-awaited Promise; await tool calls (e.g. \`const result = await tools.ns.tool(...)\`) before using their results.`,
     )
   }
 
-  if (preserveSandboxValues) {
-    // Intra-sandbox checkpoints keep sandbox value instances alive as leaves; their contents
-    // are never walked here (Map/Set members are validated where mutation happens, and the
-    // real boundary still serializes them below).
+  if (preserveCodeModeValues) {
     if (
-      value instanceof SandboxDate ||
-      value instanceof SandboxRegExp ||
-      value instanceof SandboxMap ||
-      value instanceof SandboxSet ||
-      value instanceof SandboxURL ||
-      value instanceof SandboxURLSearchParams
+      value instanceof CodeModeDate ||
+      value instanceof CodeModeRegExp ||
+      value instanceof CodeModeMap ||
+      value instanceof CodeModeSet ||
+      value instanceof CodeModeURL ||
+      value instanceof CodeModeURLSearchParams
     ) {
       return value
     }
-    // Host instances cannot normally reach an intra-sandbox checkpoint (tool results cross
-    // the boundary first), but wrap them defensively rather than degrading to JSON forms.
-    if (value instanceof Date) return new SandboxDate(value.getTime())
-    if (value instanceof RegExp) return new SandboxRegExp(value.source, value.flags)
+    if (value instanceof Date) return new CodeModeDate(value.getTime())
+    if (value instanceof RegExp) return new CodeModeRegExp(value.source, value.flags)
     if (value instanceof Map) {
-      const wrapped = new SandboxMap()
+      const wrapped = new CodeModeMap()
       for (const [key, item] of value.entries()) {
         wrapped.map.set(copyBounded(key, label, depth + 1, seen, true), copyBounded(item, label, depth + 1, seen, true))
       }
       return wrapped
     }
     if (value instanceof Set) {
-      const wrapped = new SandboxSet()
+      const wrapped = new CodeModeSet()
       for (const item of value.values()) wrapped.set.add(copyBounded(item, label, depth + 1, seen, true))
       return wrapped
     }
-    if (value instanceof URL) return new SandboxURL(new URL(value.href))
-    if (value instanceof URLSearchParams) return new SandboxURLSearchParams(new URLSearchParams(value))
+    if (value instanceof URL) return new CodeModeURL(new URL(value.href))
+    if (value instanceof URLSearchParams) return new CodeModeURLSearchParams(new URLSearchParams(value))
   }
 
-  // Sandbox value types (and their host counterparts, which a host tool may legitimately
-  // return) serialize exactly as JSON.stringify would at the data boundary: Date/URL use
-  // toJSON(), while RegExp/Map/Set/URLSearchParams have no JSON form beyond {}.
-  if (value instanceof SandboxDate) {
+  if (value instanceof CodeModeDate) {
     return Number.isFinite(value.time) ? new Date(value.time).toISOString() : null
   }
   if (value instanceof Date) {
     return Number.isFinite(value.getTime()) ? value.toISOString() : null
   }
-  if (value instanceof SandboxURL) return value.url.href
+  if (value instanceof CodeModeURL) return value.url.href
   if (value instanceof URL) return value.href
   if (
-    value instanceof SandboxRegExp ||
-    value instanceof SandboxMap ||
-    value instanceof SandboxSet ||
-    value instanceof SandboxURLSearchParams ||
+    value instanceof CodeModeRegExp ||
+    value instanceof CodeModeMap ||
+    value instanceof CodeModeSet ||
+    value instanceof CodeModeURLSearchParams ||
     value instanceof RegExp ||
     value instanceof Map ||
     value instanceof Set ||
@@ -272,9 +233,9 @@ const copyBounded = (
   seen.add(value)
 
   if (Array.isArray(value)) {
-    const copied = value.map((item) => copyBounded(item, label, depth + 1, seen, preserveSandboxValues))
-    if (preserveSandboxValues) {
-      // Array metadata is not serialized, but intra-sandbox copies must retain it.
+    const copied = value.map((item) => copyBounded(item, label, depth + 1, seen, preserveCodeModeValues))
+    if (preserveCodeModeValues) {
+      // Checkpoint copies retain array metadata that boundary copies omit.
       for (const [key, item] of Object.entries(value)) {
         if (Object.hasOwn(copied, key)) continue
         if (isBlockedMember(key)) {
@@ -297,7 +258,7 @@ const copyBounded = (
     if (isBlockedMember(key)) {
       throw new ToolRuntimeError("InvalidDataValue", `${label} contains blocked property '${key}'.`)
     }
-    copied[key] = copyBounded(item, label, depth + 1, seen, preserveSandboxValues)
+    copied[key] = copyBounded(item, label, depth + 1, seen, preserveCodeModeValues)
   }
   seen.delete(value)
   return copied
@@ -305,9 +266,6 @@ const copyBounded = (
 
 export const copyOut = (value: unknown, undefinedAsNull = false): unknown => {
   if (value === undefined && undefinedAsNull) return null
-  // Normalize non-finite numbers to null as the value crosses out of the sandbox (final return
-  // and tool-call arguments both funnel through here), matching JSON semantics - NaN/Infinity
-  // have no JSON representation, so JSON.stringify would produce null anyway.
   if (typeof value === "number" && !Number.isFinite(value)) {
     return null
   }
@@ -353,18 +311,10 @@ export type DiscoveryPlan = {
 
 export type SearchEntry = {
   readonly description: ToolDescription
-  /** Top-level namespace (first path segment), matched by the search `namespace` option. */
   readonly namespace: string
-  /** Lowercased path + description + input property names/descriptions, for substring matching. */
   readonly searchText: string
 }
 
-/**
- * Split a query into lowercased search terms. camelCase boundaries are split
- * (`resolveLibrary` -> `resolve library`) and every non-alphanumeric character is a
- * separator, so `resolve-library-id`, `resolveLibraryId`, and `resolve library id` all
- * tokenize alike. Empties and the `*` wildcard are dropped.
- */
 const tokenize = (query: string): Array<string> =>
   query
     .replace(/([a-z0-9])([A-Z])/g, "$1 $2")
@@ -372,13 +322,6 @@ const tokenize = (query: string): Array<string> =>
     .split(/[^a-z0-9]+/)
     .filter((term) => term.length > 0 && term !== "*")
 
-/**
- * A term plus its naive singular variants (trailing "s"/"es" stripped), so a plural
- * query term ("issues") still matches indexed text that only carries the singular
- * ("issue"). Matching is one-directional substring containment, so the variants are
- * needed only on the query side; scoring weights are unchanged - each field check
- * passes when ANY form matches.
- */
 const termForms = (term: string): Array<string> => {
   const forms = [term]
   if (term.endsWith("es") && term.length > 3) forms.push(term.slice(0, -2))
@@ -400,8 +343,6 @@ const makeSearchTool = (searchIndex: ReadonlyArray<SearchEntry>): Definition =>
         request.namespace === undefined
           ? searchIndex
           : searchIndex.filter((entry) => entry.namespace === request.namespace)
-      // A query that names one tool path exactly (canonical path or rendered JavaScript
-      // expression) is a lookup, not a search: return that tool alone.
       const trimmed = query.trim()
       const pathQuery = trimmed.startsWith("tools.") ? trimmed.slice("tools.".length) : trimmed
       const exact =
@@ -411,9 +352,6 @@ const makeSearchTool = (searchIndex: ReadonlyArray<SearchEntry>): Definition =>
               (entry) => entry.description.path === pathQuery || toolExpression(entry.description.path) === trimmed,
             )
       const terms = tokenize(query).map(termForms)
-      // Additive field-weighted scoring, summed across terms: exact path or path segment
-      // (20) > path substring (8) > description substring (4) > any searchable text,
-      // including input parameter names and descriptions (2).
       const ranked =
         exact !== undefined
           ? [exact]
@@ -451,15 +389,12 @@ const makeSearchTool = (searchIndex: ReadonlyArray<SearchEntry>): Definition =>
     }),
 })
 
-// The built-in `search` is a synchronous global function, not a tool-tree entry, so its
-// advertised signature is rendered by hand instead of through `describeDefinition`.
 const searchSignature = (() => {
   const definition = makeSearchTool([])
   return `search(input: ${inputTypeScript(definition, true)}): ${outputTypeScript(definition, true)}`
 })()
 
 const catalogLine = (tool: ToolDescription) => {
-  // Keep the tool description concise; the full schema documentation remains in the signature.
   const line = tool.description.split("\n", 1)[0]!.trim()
   const description = line.length > 120 ? line.slice(0, 119) + "..." : line
   return description === "" ? `  - ${tool.signature}` : `  - ${tool.signature} // ${description}`
@@ -479,21 +414,10 @@ const toSearchEntry = <R>(path: string, definition: Definition<R>, description:
     .toLowerCase(),
 })
 
-/** The runtime search index over every described tool. Search is always registered. */
 export const searchIndex = <R>(tools: HostTools<R>): ReadonlyArray<SearchEntry> =>
   visibleDefinitions(tools).map(({ path, definition, description }) => toSearchEntry(path, definition, description))
 
-/**
- * Budgeted catalog: every namespace is always listed with its tool count; full call
- * signatures are inlined against the `catalogBudget` (estimated tokens,
- * chars/4) round-robin across namespaces - in each round (namespaces alphabetical), every
- * namespace still holding un-inlined tools attempts to place its next-cheapest line, and
- * a namespace whose next line does not fit is done while the others keep going - so every
- * namespace gets some representation before any namespace gets everything. The section
- * states exactly how comprehensive it is - overall (COMPLETE vs PARTIAL) and per
- * namespace. Namespace stub lines are never budgeted: every namespace appears with its
- * tool count even at budget 0.
- */
+// Budget signatures round-robin so every namespace remains visible.
 export const prepare = <R>(tools: HostTools<R>, catalogBudget = defaultCatalogBudget): DiscoveryPlan => {
   if (!Number.isSafeInteger(catalogBudget) || catalogBudget < 0) {
     throw new RangeError("discovery.catalogBudget must be a non-negative safe integer")
@@ -510,12 +434,6 @@ export const prepare = <R>(tools: HostTools<R>, catalogBudget = defaultCatalogBu
   }
   const ordered = [...namespaces].sort(([left], [right]) => left.localeCompare(right))
 
-  // Select which signatures fit the budget before emitting, so the list can state
-  // exactly how comprehensive it is. Round-robin fairness: in each round (namespaces
-  // alphabetical), every namespace still holding un-inlined tools tries to place its
-  // next-cheapest line against the shared budget; a namespace whose next line does not
-  // fit is done - the others keep going - so every namespace gets some representation
-  // before any namespace gets everything.
   const selections = ordered.map(([namespace, group]) => ({
     namespace,
     picked: new Set<ToolDescription>(),
@@ -547,10 +465,6 @@ export const prepare = <R>(tools: HostTools<R>, catalogBudget = defaultCatalogBu
 
   const empty = described.length === 0
 
-  // Section order is deliberate: workflow first (the top is the least likely part of a long
-  // description to be truncated or skimmed away), then rules, then syntax, with the budgeted
-  // catalog at the bottom. Example call forms use placeholders - never a real or fabricated
-  // tool name - and show both dot and bracket notation so non-identifier names are not normalized.
   const intro = [
     empty
       ? "This is a restricted JavaScript language for calling tools, not a general-purpose runtime."
@@ -562,8 +476,6 @@ export const prepare = <R>(tools: HostTools<R>, catalogBudget = defaultCatalogBu
       : ["Do not infer or normalize tool names; use only exact signatures shown below or returned by search."]),
   ]
 
-  // The search step exists only when search is advertised (PARTIAL catalog); a COMPLETE
-  // catalog already shows every signature, so step 1 picks from the list instead.
   const workflow = empty
     ? []
     : [
@@ -627,8 +539,6 @@ export const prepare = <R>(tools: HostTools<R>, catalogBudget = defaultCatalogBu
     for (const [namespace, group] of ordered) {
       const picked = shown.get(namespace)!
       const count = `${group.length} tool${group.length === 1 ? "" : "s"}`
-      // Annotate only when a namespace is not fully shown, so a comprehensive
-      // namespace reads cleanly and a truncated one is unambiguous.
       const label =
         picked.size === group.length
           ? count
@@ -651,13 +561,6 @@ export const prepare = <R>(tools: HostTools<R>, catalogBudget = defaultCatalogBu
   }
 }
 
-/**
- * The enumerable names at one node of the callable tool tree - namespace names at the root,
- * tool/namespace names below - powering `Object.keys(tools)` and `for...in` over tool
- * references. A callable tool is a leaf and enumerates as `[]` (like `Object.keys` of a
- * function in JS). An unknown path is an `UnknownTool` error pointing at the working
- * discovery idioms, mirroring how calling an unknown tool fails.
- */
 const namespaceKeys = <R>(tools: HostTools<R>, path: ReadonlyArray<string>): ReadonlyArray<string> => {
   let value: HostTool<R> | Definition<R> | HostTools<R> = tools
   for (const segment of path) {
@@ -705,18 +608,12 @@ export type ToolRuntime<R = never> = {
   readonly root: ToolReference
   readonly calls: Array<ToolCall>
   readonly invoke: (path: ReadonlyArray<string>, args: Array<unknown>) => Effect.Effect<unknown, unknown, R>
-  /**
-   * The built-in `search` global: a synchronous discovery call that shares the tool
-   * admission pipeline (budget, audit, hooks) without living in the `tools` tree.
-   */
   readonly search: (args: Array<unknown>) => Effect.Effect<unknown, unknown, R>
-  /** Enumerable namespace/tool names at one node of the callable tool tree; see `namespaceKeys`. */
   readonly keys: (path: ReadonlyArray<string>) => ReadonlyArray<string>
 }
 
 export const make = <R>(
   tools: HostTools<R>,
-  /** Undefined means unlimited tool calls. */
   maxToolCalls: number | undefined,
   searchIndex: ReadonlyArray<SearchEntry>,
   hooks?: ToolCallHooks<R>,
@@ -724,8 +621,7 @@ export const make = <R>(
   const calls: Array<ToolCall> = []
   const searchTool = makeSearchTool(searchIndex)
 
-  // Wraps the settling portion of a tool call so onToolCallEnd observes success and failure
-  // symmetrically. Interruption (e.g. the execution timeout) fires neither outcome.
+  // End hooks observe settled success or failure; interruption emits neither outcome.
   const observeEnd = <A, E>(effect: Effect.Effect<A, E, R>, call: ToolCallStarted): Effect.Effect<A, E, R> => {
     const onEnd = hooks?.onToolCallEnd
     if (onEnd === undefined) return effect

packages/codemode/src/tool-schema.ts

@@ -5,13 +5,8 @@ const isEffectSchema = (schema: SchemaType): schema is Schema.Decoder<unknown> &
 
 const renderLiteral = (value: unknown): string => JSON.stringify(value) ?? "unknown"
 
-/**
- * Bare TypeScript identifier - usable unquoted as an object key (and, in the tool runtime,
- * with dot access as a tool-path segment). Anything else must be quoted/bracketed.
- */
 export const identifierSegment = /^[A-Za-z_$][A-Za-z0-9_$]*$/
 
-/** Renders a property name as a valid TS object key: bare when an identifier, quoted otherwise. */
 const renderKey = (name: string): string => (identifierSegment.test(name) ? name : JSON.stringify(name))
 
 const effectNumberSentinel = (schema: JsonSchema) =>
@@ -27,16 +22,10 @@ const intersection = (members: ReadonlyArray<string>): string => {
   return concrete.map((member) => (member.includes(" | ") ? `(${member})` : member)).join(" & ")
 }
 
-/**
- * Recursion ceiling for schema rendering. Object, array, and union recursion all increment
- * depth, so this bounds every recursion path - pathological or structurally cyclic schemas
- * degrade to `unknown` instead of overflowing the stack (rendering must never throw).
- */
 const MAX_RENDER_DEPTH = 8
 
 type RenderContext = {
   readonly definitions: Readonly<Record<string, JsonSchema>>
-  /** Indented, JSDoc-annotated multiline rendering (search results); compact single line otherwise. */
   readonly pretty: boolean
 }
 
@@ -64,10 +53,6 @@ const hasUnresolvedRef = (
   ].some((item) => hasUnresolvedRef(item, definitions, seen, nextVisited))
 }
 
-/**
- * Schema constraints a TypeScript type cannot express natively but a model benefits from,
- * surfaced as JSDoc tags (`@deprecated`, `@default`, `@format`, `@minItems`, `@maxItems`).
- */
 const docTags = (schema: JsonSchema): Array<string> => {
   const tags: Array<string> = []
   if (schema.deprecated === true) tags.push("@deprecated")
@@ -75,9 +60,7 @@ const docTags = (schema: JsonSchema): Array<string> => {
     try {
       const rendered = JSON.stringify(schema.default)
       if (rendered !== undefined) tags.push(`@default ${rendered}`)
-    } catch {
-      // unserializable default: skip rather than emit a broken tag
-    }
+    } catch {}
   }
   if (typeof schema.format === "string") tags.push(`@format ${schema.format}`)
   if (typeof schema.minItems === "number") tags.push(`@minItems ${schema.minItems}`)
@@ -85,13 +68,7 @@ const docTags = (schema: JsonSchema): Array<string> => {
   return tags
 }
 
-/**
- * Format a schema `description` plus `tags` as a JSDoc comment at the given indent,
- * preserving multi-line text (a single line stays `/** ... *\/`; multiple lines become a
- * `*`-prefixed block). `*\/` is neutralized so nothing can close the comment early, and
- * blank leading/trailing lines are trimmed. Returns "" (else a trailing newline) so
- * callers can prepend it directly to the field line.
- */
+// Neutralize `*\/` so model-provided schema text cannot terminate generated documentation.
 const jsdoc = (description: string | undefined, tags: ReadonlyArray<string>, pad: string): string => {
   const lines = [...(description === undefined ? [] : description.split("\n")), ...tags].map((line) =>
     line.replaceAll("*/", "* /").replace(/\s+$/, ""),
@@ -128,17 +105,11 @@ const renderSchema = (
   if (schema.enum) return schema.enum.map(renderLiteral).join(" | ")
   const alternatives = schema.anyOf ?? schema.oneOf
   if (alternatives) {
-    // Effect's number schema emits `anyOf: [{ type: "number" }, { const: "NaN" },
-    // { const: "Infinity" }, { const: "-Infinity" }]`. Collapse only that artifact;
-    // real JSON Schema unions such as `string | number` or `number | null` must keep
-    // every branch.
     if (
       alternatives.some((item) => item.type === "number") &&
       alternatives.every((item) => item.type === "number" || effectNumberSentinel(item))
     )
       return "number"
-    // An empty Schema.Struct({}) emits `anyOf: [{ type: "object" }, { type: "array" }]`
-    // (no properties/items); render the bare shape as {} instead of `{} | Array<unknown>`.
     if (
       alternatives.length === 2 &&
       alternatives[0]?.type === "object" &&
@@ -183,7 +154,6 @@ const renderSchema = (
       return fields.length === 0 ? "{}" : `{ ${fields.join("; ")} }`
     }
 
-    // Pretty: an indented block, each described field preceded by its JSDoc comment.
     if (properties.length === 0 && indexType === undefined) return "{}"
     const pad = "  ".repeat(depth + 1)
     const lines = properties.map(
@@ -208,7 +178,6 @@ export const toTypeScript = (schema: Schema.Top, decoded = false, pretty = false
   }
 }
 
-/** Renders a raw JSON Schema document as a TypeScript type string. */
 export const jsonSchemaToTypeScript = (schema: JsonSchema, pretty = false): string => {
   try {
     return renderSchema(schema, { definitions: { ...(schema.definitions ?? {}), ...(schema.$defs ?? {}) }, pretty })
@@ -217,20 +186,12 @@ export const jsonSchemaToTypeScript = (schema: JsonSchema, pretty = false): stri
   }
 }
 
-/** One input property of a tool, extracted best-effort from its input schema. */
 export type InputProperty = {
   readonly name: string
   readonly description: string | undefined
   readonly required: boolean
 }
 
-/**
- * The property names, descriptions, and required flags of a tool's input schema - the raw
- * material for search text. Best-effort: Effect Schemas go through their
- * JSON Schema document (the same emission signature rendering uses); JSON Schemas are read
- * directly, resolving a trivial top-level `$ref` into `$defs`/`definitions` when present.
- * Anything unresolvable yields `[]` (search falls back to path + description).
- */
 export const inputProperties = <R>(definition: Definition<R>): Array<InputProperty> => {
   try {
     const document = isEffectSchema(definition.input)
@@ -262,20 +223,11 @@ export const inputProperties = <R>(definition: Definition<R>): Array<InputProper
   }
 }
 
-/**
- * The model-visible TypeScript type of a tool's input. `pretty` renders an indented
- * multiline block with schema descriptions and constraints as JSDoc comments on the
- * fields; the default stays the compact single-line form.
- */
 export const inputTypeScript = <R>(definition: Definition<R>, pretty = false): string =>
   isEffectSchema(definition.input)
     ? toTypeScript(definition.input, false, pretty)
     : jsonSchemaToTypeScript(definition.input, pretty)
 
-/**
- * The model-visible TypeScript type of a tool's result; tools without an output schema
- * return `unknown`. `pretty` renders the JSDoc-annotated multiline form, as for inputs.
- */
 export const outputTypeScript = <R>(definition: Definition<R>, pretty = false): string =>
   definition.output === undefined
     ? "unknown"
@@ -283,18 +235,9 @@ export const outputTypeScript = <R>(definition: Definition<R>, pretty = false):
       ? toTypeScript(definition.output, true, pretty)
       : jsonSchemaToTypeScript(definition.output, pretty)
 
-/**
- * Decodes tool input before `run` is invoked. Effect Schemas validate (throwing on failure);
- * JSON-Schema-described inputs pass through unvalidated (render-only).
- */
 export const decodeInput = <R>(definition: Definition<R>, value: unknown): unknown =>
   isEffectSchema(definition.input) ? Schema.decodeUnknownSync(definition.input)(value) : value
 
-/**
- * Decodes a tool result before it is exposed to the program. Effect Schemas validate and
- * transform (throwing on failure); JSON Schema outputs and tools without an output schema pass
- * the host value through unchanged.
- */
 export const decodeOutput = <R>(definition: Definition<R>, value: unknown): unknown =>
   definition.output !== undefined && isEffectSchema(definition.output)
     ? Schema.decodeUnknownSync(definition.output)(value)

packages/codemode/src/tool.ts

@@ -1,11 +1,8 @@
 import { Effect, Schema } from "effect"
 
 /**
- * JSON Schema subset accepted for render-only tool schemas.
- *
- * A JSON-Schema-described side of a tool is used to generate the model-visible TypeScript
- * signature only - CodeMode performs no validation against it. This is the natural shape for
- * adapter-provided tools (e.g. MCP definitions) whose schemas arrive as JSON Schema documents.
+ * JSON Schema subset for model-visible signatures. CodeMode does not validate values against
+ * these schemas.
  */
 export type JsonSchema = {
   readonly type?: string | ReadonlyArray<string>
@@ -41,10 +38,8 @@ export type Definition<R = never> = {
   readonly run: (input: unknown) => Effect.Effect<unknown, unknown, R>
 }
 
-/** The value `run` receives: the decoded type for Effect Schemas, `unknown` for JSON Schemas. */
 type InputType<S> = S extends Schema.Decoder<unknown> ? S["Type"] : unknown
 
-/** The value `run` returns: the encoded type for Effect Schemas, `unknown` otherwise. */
 type ResultType<S> = S extends Schema.Decoder<unknown> ? S["Encoded"] : unknown
 
 /** Options for defining one CodeMode tool. */
@@ -61,29 +56,9 @@ export const isDefinition = <R = never>(value: unknown): value is Definition<R>
 /**
  * Defines one schema-described tool available to a CodeMode program through `tools.*`.
  *
- * `input` and `output` each accept a validating Effect Schema or a render-only JSON Schema
- * document. Effect Schema input is decoded before `run` is invoked, and `run` returns the
- * encoded representation of an Effect Schema `output`, which CodeMode decodes before returning
- * it to the program. JSON Schemas only shape the model-visible signature; values pass through
- * unvalidated. `output` is optional - without it the signature advertises `unknown` and the
- * host result is exposed as-is. The host tool remains responsible for authorization and
- * durable side-effect handling.
- *
- * @example
- * ```ts
- * const lookup = Tool.make({
- *   description: "Look up an order",
- *   input: Schema.Struct({ id: Schema.String }),
- *   output: Schema.Struct({ status: Schema.String }),
- *   run: ({ id }) => Effect.succeed({ status: "open" }),
- * })
- *
- * const fromJsonSchema = Tool.make({
- *   description: "Call an adapter-described tool",
- *   input: { type: "object", properties: { id: { type: "string" } }, required: ["id"] },
- *   run: (input) => callHost(input),
- * })
- * ```
+ * Effect Schemas validate values; JSON Schemas only shape the model-visible signature.
+ * Without `output`, results are exposed as `unknown`. Hosts remain responsible for authorization
+ * and durable side effects.
  */
 export const make = <I extends SchemaType, const O extends SchemaType | undefined = undefined, R = never>(
   options: Options<I, O, R>,

packages/codemode/src/values.ts

@@ -1,45 +1,45 @@
 import type { Fiber } from "effect"
 
-export class SandboxPromise {
+export class CodeModePromise {
   constructor(readonly fiber: Fiber.Fiber<unknown, unknown>) {}
 }
 
-export class SandboxDate {
+export class CodeModeDate {
   constructor(readonly time: number) {}
 }
 
-export class SandboxRegExp {
+export class CodeModeRegExp {
   readonly regex: RegExp
   constructor(pattern: string, flags: string) {
     this.regex = new RegExp(pattern, flags)
   }
 }
 
-export class SandboxMap {
+export class CodeModeMap {
   readonly map = new Map<unknown, unknown>()
 }
 
-export class SandboxSet {
+export class CodeModeSet {
   readonly set = new Set<unknown>()
 }
 
-export class SandboxURLSearchParams {
+export class CodeModeURLSearchParams {
   constructor(readonly params: URLSearchParams) {}
 }
 
-export class SandboxURL {
-  readonly searchParams: SandboxURLSearchParams
+export class CodeModeURL {
+  readonly searchParams: CodeModeURLSearchParams
   constructor(readonly url: URL) {
-    this.searchParams = new SandboxURLSearchParams(url.searchParams)
+    this.searchParams = new CodeModeURLSearchParams(url.searchParams)
   }
 }
 
-export const isSandboxValue = (
+export const isCodeModeValue = (
   value: unknown,
-): value is SandboxDate | SandboxRegExp | SandboxMap | SandboxSet | SandboxURL | SandboxURLSearchParams =>
-  value instanceof SandboxDate ||
-  value instanceof SandboxRegExp ||
-  value instanceof SandboxMap ||
-  value instanceof SandboxSet ||
-  value instanceof SandboxURL ||
-  value instanceof SandboxURLSearchParams
+): value is CodeModeDate | CodeModeRegExp | CodeModeMap | CodeModeSet | CodeModeURL | CodeModeURLSearchParams =>
+  value instanceof CodeModeDate ||
+  value instanceof CodeModeRegExp ||
+  value instanceof CodeModeMap ||
+  value instanceof CodeModeSet ||
+  value instanceof CodeModeURL ||
+  value instanceof CodeModeURLSearchParams

packages/codemode/test/array-callbacks-test262.test.ts

@@ -26,9 +26,11 @@
  * - test/built-ins/Array/prototype/forEach/15.4.4.18-7-1.js
  * - test/built-ins/Array/prototype/forEach/15.4.4.18-7-2.js
  * - test/built-ins/Array/prototype/reduce/15.4.4.21-9-5.js
+ * - test/built-ins/Array/prototype/reduce/15.4.4.21-9-c-ii-20.js
  * - test/built-ins/Array/prototype/reduce/15.4.4.21-9-1.js
  * - test/built-ins/Array/prototype/reduce/15.4.4.21-10-1.js
  * - test/built-ins/Array/prototype/reduceRight/15.4.4.22-9-5.js
+ * - test/built-ins/Array/prototype/reduceRight/15.4.4.22-9-c-ii-20.js
  * - test/built-ins/Array/prototype/reduceRight/15.4.4.22-9-1.js
  * - test/built-ins/Array/prototype/reduceRight/15.4.4.22-10-1.js
  * - test/built-ins/Array/prototype/flatMap/depth-always-one.js
@@ -210,6 +212,11 @@ const cases = [
     code: `let calls = 0; const result = [1].reduce(() => { calls += 1; return 2 }); return [result, calls]`,
     expected: [1, 0],
   },
+  {
+    path: "test/built-ins/Array/prototype/reduce/15.4.4.21-9-c-ii-20.js",
+    code: `let accessed = false; const result = [11].reduce((previous) => { accessed = true; return previous === undefined }, undefined); return [result, accessed]`,
+    expected: [true, true],
+  },
   {
     path: "test/built-ins/Array/prototype/reduce/15.4.4.21-10-1.js",
     code: `const input = [1, 2, 3, 4, 5]; input.reduce(() => 1); return input`,
@@ -225,6 +232,11 @@ const cases = [
     code: `let calls = 0; const result = [1].reduceRight(() => { calls += 1; return 2 }); return [result, calls]`,
     expected: [1, 0],
   },
+  {
+    path: "test/built-ins/Array/prototype/reduceRight/15.4.4.22-9-c-ii-20.js",
+    code: `let accessed = false; const result = [11].reduceRight((previous) => { accessed = true; return previous === undefined }, undefined); return [result, accessed]`,
+    expected: [true, true],
+  },
   {
     path: "test/built-ins/Array/prototype/reduceRight/15.4.4.22-10-1.js",
     code: `const input = [1, 2, 3, 4, 5]; input.reduceRight(() => 1); return input`,
@@ -323,3 +335,46 @@ describe("Test262 Array callback adaptations", () => {
     })
   }
 })
+
+describe("Array callback regressions", () => {
+  test("reduce and reduceRight find the first present element", async () => {
+    expect(
+      await value(`
+        const left = []
+        left[2] = 3
+        const right = []
+        right[0] = 4
+        right[3] = 1
+        right.pop()
+        return [left.reduce((a, b) => a + b), right.reduceRight((a, b) => a + b)]
+      `),
+    ).toEqual([3, 4])
+  })
+
+  test("reduce and reduceRight reject arrays containing only holes", async () => {
+    expect(
+      await value(`
+        const values = []
+        values[2] = 1
+        values.pop()
+        let left
+        let right
+        try { values.reduce((a, b) => a + b) } catch (error) { left = error.name }
+        try { values.reduceRight((a, b) => a + b) } catch (error) { right = error.name }
+        return [left, right]
+      `),
+    ).toEqual(["TypeError", "TypeError"])
+  })
+
+  test("findLast returns the value observed before predicate mutation", async () => {
+    expect(
+      await value(`
+        const values = [1]
+        return values.findLast((item, index, array) => {
+          array[index] = 2
+          return true
+        })
+      `),
+    ).toBe(1)
+  })
+})

packages/codemode/test/codemode.test.ts

@@ -26,6 +26,22 @@ describe("CodeMode host failure boundary", () => {
     })
   })
 
+  test("does not rewrite explicit safe tool failures", async () => {
+    const result = await run(
+      Tool.make({
+        description: "Fail safely",
+        input: Schema.Struct({}),
+        output: Schema.String,
+        run: () => Effect.fail(toolError("File not found: /tmp/report.json")),
+      }),
+    )
+
+    expect(result.ok ? undefined : result.error).toStrictEqual({
+      kind: "ToolFailure",
+      message: "File not found: /tmp/report.json",
+    })
+  })
+
   test("sanitizes unknown host failures and defects", async () => {
     for (const failure of [
       Effect.fail(new UnsafeHostError({ reason: "Authorization: Bearer typed-secret" })),
@@ -260,7 +276,7 @@ describe("CodeMode console capture", () => {
     expect(result.logs).toStrictEqual(["NaN", "Infinity -Infinity", '{"ratio":NaN,"bounds":[Infinity]}'])
   })
 
-  test("renders sandbox values nested inside logged containers", async () => {
+  test("renders CodeMode values nested inside logged containers", async () => {
     const result = await Effect.runPromise(
       CodeMode.execute({
         code: `
@@ -295,7 +311,7 @@ describe("CodeMode console capture", () => {
     expect(result.logs).toStrictEqual(['{"box":Map(1) [["self",[Circular]]]}', '{"fn":[CodeMode reference],"ok":1}'])
   })
 
-  test("console.table renders sandbox value cells", async () => {
+  test("console.table renders CodeMode value cells", async () => {
     const result = await Effect.runPromise(
       CodeMode.execute({
         code: `

packages/codemode/test/parity.test.ts

@@ -8,7 +8,7 @@ import { ToolRuntime } from "../src/tool-runtime.js"
 // a strict interpreter would throw but idiomatic JS yields undefined / succeeds.
 //
 // Note on the result boundary: this package normalizes a bare `undefined` result to `null` when
-// it crosses out of the sandbox (results are JSON data), so tests asserting an in-sandbox
+// it crosses out of CodeMode (results are JSON data), so tests asserting an in-CodeMode
 // `undefined` read check `=== undefined` inside the program and `null` at the boundary.
 const run = (code: string) => Effect.runPromise(CodeMode.execute({ code, tools: {} }))
 const value = async (code: string) => {
@@ -108,7 +108,7 @@ describe("H1: NaN/Infinity flow as intermediates and normalize to null at the bo
     expect(await value(`const a = []; return a.length ? a.reduce((s,x)=>s+x,0)/a.length : 0`)).toBe(0)
   })
 
-  test("a non-finite value becomes null when it leaves the sandbox", async () => {
+  test("a non-finite value becomes null when it leaves CodeMode", async () => {
     expect(await value(`return 5/0`)).toBeNull()
     expect(await value(`return 0/0`)).toBeNull()
     expect(await value(`return Math.max()`)).toBeNull()
@@ -116,12 +116,12 @@ describe("H1: NaN/Infinity flow as intermediates and normalize to null at the bo
     expect(await value(`return { a: Number("x"), b: 2, c: [1/0] }`)).toEqual({ a: null, b: 2, c: [null] })
   })
 
-  test("NaN and Infinity are usable identifiers and inspectable in-sandbox", async () => {
+  test("NaN and Infinity are usable identifiers and inspectable in-CodeMode", async () => {
     expect(await value(`return Number.isNaN(NaN)`)).toBe(true)
     expect(await value(`return Infinity > 1e9`)).toBe(true)
     expect(await value(`return Number.isFinite(1/0)`)).toBe(false)
     expect(await value(`return [3,1,2].reduce((a,b)=>Math.max(a,b), -Infinity)`)).toBe(3)
-    // JSON.stringify inside the sandbox matches JS: non-finite serializes to null
+    // JSON.stringify inside CodeMode matches JS: non-finite serializes to null
     expect(await value(`return JSON.stringify({ x: Number("z") })`)).toBe('{"x":null}')
   })
 
@@ -302,9 +302,12 @@ describe("CodeMode-specific string behavior", () => {
     expect(await value(`try { "x".normalize("nope"); return "no" } catch (e) { return e.message }`)).toContain('"NFC"')
   })
 
-  test("trimLeft/trimRight alias trimStart/trimEnd", async () => {
-    expect(await value(`return "  x ".trimLeft()`)).toBe("x ")
-    expect(await value(`return "  x ".trimRight()`)).toBe("  x")
+  test("does not expose obsolete string aliases", async () => {
+    expect(await value(`return [typeof "x".trimLeft, typeof "x".trimRight, typeof "x".substr]`)).toEqual([
+      "undefined",
+      "undefined",
+      "undefined",
+    ])
   })
 })
 
@@ -318,12 +321,12 @@ describe("compound assignment matches its binary operator", () => {
     return a
   }
 
-  test("sandbox Date += concatenates its string form, like d = d + 1", async () => {
+  test("CodeMode Date += concatenates its string form, like d = d + 1", async () => {
     const result = await pair(`let d = new Date(1000); d += 1; return d`, `let d = new Date(1000); d = d + 1; return d`)
     expect(result).toBe("1970-01-01T00:00:01.000Z1")
   })
 
-  test("sandbox Date numeric compound ops use its time value", async () => {
+  test("CodeMode Date numeric compound ops use its time value", async () => {
     expect(
       await pair(`let d = new Date(1000); d -= 400; return d`, `let d = new Date(1000); d = d - 400; return d`),
     ).toBe(600)

packages/codemode/test/promise-test262.test.ts

@@ -212,7 +212,7 @@ describe("Test262 Promise statics", () => {
     ])
   })
 
-  test("Promise.resolve adopts values and preserves sandbox-promise identity", async () => {
+  test("Promise.resolve adopts values and preserves CodeMode-promise identity", async () => {
     // Sources:
     // test/built-ins/Promise/resolve/S25.4.4.5_A2.1_T1.js
     // test/built-ins/Promise/resolve/resolve-non-obj.js
@@ -289,7 +289,7 @@ describe("Test262 Promise statics", () => {
     // test/built-ins/Promise/all/reject-immed.js
     // test/built-ins/Promise/allSettled/reject-immed.js
     // test/built-ins/Promise/race/reject-immed.js
-    // (adapted: immediately-rejecting thenables become sandbox promises that settled,
+    // (adapted: immediately-rejecting thenables become CodeMode promises that settled,
     //  and were even observed, before the combinator call)
     expect(
       await value(`
@@ -360,7 +360,7 @@ describe("Test262 Promise statics", () => {
     // test/built-ins/Promise/race/S25.4.4.3_A2.1_T1.js
     // test/built-ins/Promise/race/S25.4.4.3_A5.1_T1.js
     // (adapted: upstream requires Promise.race([]) to never settle; CodeMode intentionally
-    //  rejects with a catchable diagnostic instead of hanging, so this asserts the sandbox
+    //  rejects with a catchable diagnostic instead of hanging, so this asserts CodeMode
     //  divergence rather than the spec never-settles behavior)
     expect(
       await value(`
@@ -375,7 +375,7 @@ describe("Test262 Promise statics", () => {
     ).toEqual([true, true])
   })
 
-  test("Promise.resolve passes the same sandbox promise through nested chains", async () => {
+  test("Promise.resolve passes the same CodeMode promise through nested chains", async () => {
     // Source: test/built-ins/Promise/resolve/S25.4.4.5_A2.2_T1.js
     // (adapted: no executor construction, and identity is observed with Array includes
     //  because promises are not comparable data values in CodeMode)
@@ -1208,7 +1208,7 @@ describe("Test262 AggregateError", () => {
 
   test("coerces a non-string message to a string", async () => {
     // Source: test/built-ins/AggregateError/message-method-prop-cast.js (value coercion only; the
-    // upstream object-with-toString case is omitted because the sandbox has no user toString dispatch)
+    // upstream object-with-toString case is omitted because CodeMode has no user toString dispatch)
     expect(
       await value(`
         return [
@@ -1408,7 +1408,7 @@ describe("Test262 Promise constructor", () => {
 
   test.failing("calling Promise without new throws TypeError", async () => {
     // Source: test/built-ins/Promise/undefined-newtarget.js
-    // The sandbox currently reports a generic Error ("Only tools are callable in CodeMode.").
+    // CodeMode currently reports a generic Error ("Only tools are callable in CodeMode.").
     expect(
       await value(`
         try {

packages/codemode/test/promise.test.ts

@@ -560,7 +560,7 @@ describe("Promise.all over arbitrary arrays", () => {
     expect(trace.maxActive).toBeGreaterThan(1)
   })
 
-  test("caps live tool-call concurrency at the fixed internal constant (8)", async () => {
+  test("does not cap live tool-call concurrency", async () => {
     const trace = makeTrace()
     const result = await value(
       `
@@ -572,8 +572,7 @@ describe("Promise.all over arbitrary arrays", () => {
       { trace },
     )
     expect(result).toBe(20)
-    expect(trace.maxActive).toBeGreaterThan(1)
-    expect(trace.maxActive).toBeLessThanOrEqual(8)
+    expect(trace.maxActive).toBe(20)
   })
 
   test("resolves the empty array", async () => {

packages/codemode/test/stdlib.test.ts

@@ -3,7 +3,7 @@ import { Effect, Schema } from "effect"
 import { CodeMode, Tool } from "../src/index.js"
 
 // Standard-library value types: Date, RegExp, Map, Set. Programs use them as ordinary JS;
-// intra-sandbox checkpoints (Object.* helpers, spread, coercion inputs) preserve the live
+// intra-CodeMode checkpoints (Object.* helpers, spread, coercion inputs) preserve the live
 // values, while at the host boundary (final result, tool arguments, JSON.stringify) they
 // serialize exactly as JSON.stringify would: Date -> ISO string (invalid -> null),
 // URL -> href, and RegExp/Map/Set/URLSearchParams -> {}.
@@ -69,7 +69,7 @@ describe("Date", () => {
     ).toEqual([2024, 2, 5, 6, 7, 8, 9])
   })
 
-  test("invalid dates yield NaN times, guardable in-sandbox", async () => {
+  test("invalid dates yield NaN times, guardable in-CodeMode", async () => {
     expect(await value(`return Number.isNaN(new Date("garbage").getTime())`)).toBe(true)
     expect(await value(`return new Date("garbage").toJSON()`)).toBeNull()
   })
@@ -702,11 +702,11 @@ describe("stdlib integration", () => {
     expect(await value(`const fn = () => 1; return !fn`)).toBe(false)
   })
 
-  test("object spread of sandbox values is a no-op, like JS", async () => {
+  test("object spread of CodeMode values is a no-op, like JS", async () => {
     expect(await value(`return { ...new Map([["a", 1]]), kept: true }`)).toEqual({ kept: true })
   })
 
-  test("dates inside Map values survive in-sandbox reads", async () => {
+  test("dates inside Map values survive in-CodeMode reads", async () => {
     expect(
       await value(`
       const m = new Map([["start", new Date(1000)]])
@@ -748,7 +748,7 @@ describe("stdlib integration", () => {
   })
 })
 
-describe("sandbox values at intra-sandbox checkpoints", () => {
+describe("CodeMode values at intra-CodeMode checkpoints", () => {
   test("Object.values/entries keep Dates usable", async () => {
     expect(await value(`return Object.values({ d: new Date(0) })[0].getTime()`)).toBe(0)
     expect(await value(`const [key, d] = Object.entries({ d: new Date(0) })[0]; return key + ":" + d.getTime()`)).toBe(
@@ -799,7 +799,7 @@ describe("sandbox values at intra-sandbox checkpoints", () => {
     )
   })
 
-  test("object and array spread keep sandbox values usable", async () => {
+  test("object and array spread keep CodeMode values usable", async () => {
     expect(
       await value(`
       const src = { m: new Map([["a", 1]]) }
@@ -811,7 +811,7 @@ describe("sandbox values at intra-sandbox checkpoints", () => {
     expect(await value(`const list = [new Date(1000)]; const copy = [...list]; return copy[0].getTime()`)).toBe(1000)
   })
 
-  test("Array.from over arrays keeps nested sandbox values usable", async () => {
+  test("Array.from over arrays keeps nested CodeMode values usable", async () => {
     expect(await value(`return Array.from([new Date(5)])[0].getTime()`)).toBe(5)
   })
 
@@ -866,7 +866,7 @@ describe("sandbox values at intra-sandbox checkpoints", () => {
     expect(await value(`return Object.values({ r: /ab+/ })[0].test("abb")`)).toBe(true)
   })
 
-  test("Object.* helpers see sandbox values as empty objects, never internals", async () => {
+  test("Object.* helpers see CodeMode values as empty objects, never internals", async () => {
     expect(await value(`return Object.keys(new Map([["a", 1]]))`)).toEqual([])
     expect(await value(`return Object.values(new Date(0))`)).toEqual([])
     expect(await value(`return Object.entries(new Set([1]))`)).toEqual([])

packages/codemode/test/string-search-test262.test.ts

@@ -49,12 +49,6 @@
  * - test/built-ins/String/prototype/substring/S15.5.4.15_A2_T8.js
  * - test/built-ins/String/prototype/substring/S15.5.4.15_A2_T9.js
  * - test/built-ins/String/prototype/substring/S15.5.4.15_A2_T10.js
- * - test/annexB/built-ins/String/prototype/substr/start-negative.js
- * - test/annexB/built-ins/String/prototype/substr/length-negative.js
- * - test/annexB/built-ins/String/prototype/substr/length-positive.js
- * - test/annexB/built-ins/String/prototype/substr/length-falsey.js
- * - test/annexB/built-ins/String/prototype/substr/length-undef.js
- * - test/annexB/built-ins/String/prototype/substr/surrogate-pairs.js
  * - test/built-ins/String/prototype/includes/String.prototype.includes_FailMissingLetter.js
  * - test/built-ins/String/prototype/includes/String.prototype.includes_SuccessNoLocation.js
  * - test/built-ins/String/prototype/includes/String.prototype.includes_FailBadLocation.js
@@ -460,67 +454,6 @@ const cases = [
     expected: ["this_is_"],
     labels: ['#1: __string.substring(0,8) === "this_is_"'],
   },
-  {
-    path: "test/annexB/built-ins/String/prototype/substr/start-negative.js",
-    code: `return ["abc".substr(-1), "abc".substr(-2), "abc".substr(-3), "abc".substr(-4), "abc".substr(-1.1)]`,
-    expected: ["c", "bc", "abc", "abc", "c"],
-    labels: ["-1", "-2", "-3", "size + intStart < 0", "floating point rounding semantics"],
-  },
-  {
-    path: "test/annexB/built-ins/String/prototype/substr/length-negative.js",
-    code: `return [
-      "abc".substr(0, -1), "abc".substr(0, -2), "abc".substr(0, -3), "abc".substr(0, -4),
-      "abc".substr(1, -1), "abc".substr(1, -2), "abc".substr(1, -3), "abc".substr(1, -4),
-      "abc".substr(2, -1), "abc".substr(2, -2), "abc".substr(2, -3), "abc".substr(2, -4),
-      "abc".substr(3, -1), "abc".substr(3, -2), "abc".substr(3, -3), "abc".substr(3, -4),
-    ]`,
-    expected: ["", "", "", "", "", "", "", "", "", "", "", "", "", "", "", ""],
-    labels: [
-      "0, -1", "0, -2", "0, -3", "0, -4", "1, -1", "1, -2", "1, -3", "1, -4",
-      "2, -1", "2, -2", "2, -3", "2, -4", "3, -1", "3, -2", "3, -3", "3, -4",
-    ],
-  },
-  {
-    path: "test/annexB/built-ins/String/prototype/substr/length-positive.js",
-    code: `return [
-      "abc".substr(0, 1), "abc".substr(0, 2), "abc".substr(0, 3), "abc".substr(0, 4),
-      "abc".substr(1, 1), "abc".substr(1, 2), "abc".substr(1, 3), "abc".substr(1, 4),
-      "abc".substr(2, 1), "abc".substr(2, 2), "abc".substr(2, 3), "abc".substr(2, 4),
-      "abc".substr(3, 1), "abc".substr(3, 2), "abc".substr(3, 3), "abc".substr(3, 4),
-    ]`,
-    expected: ["a", "ab", "abc", "abc", "b", "bc", "bc", "bc", "c", "c", "c", "c", "", "", "", ""],
-    labels: [
-      "0, 1", "0, 1", "0, 1", "0, 1", "1, 1", "1, 1", "1, 1", "1, 1",
-      "2, 1", "2, 1", "2, 1", "2, 1", "3, 1", "3, 1", "3, 1", "3, 1",
-    ],
-  },
-  {
-    path: "test/annexB/built-ins/String/prototype/substr/length-falsey.js",
-    code: `return ["abc".substr(0, NaN), "abc".substr(1, NaN), "abc".substr(2, NaN), "abc".substr(3, NaN)]`,
-    expected: ["", "", "", ""],
-    labels: ["start: 0, length: NaN", "start: 1, length: NaN", "start: 2, length: NaN", "start: 3, length: NaN"],
-  },
-  {
-    path: "test/annexB/built-ins/String/prototype/substr/length-undef.js",
-    code: `return [
-      "abc".substr(0), "abc".substr(1), "abc".substr(2), "abc".substr(3),
-      "abc".substr(0, undefined), "abc".substr(1, undefined), "abc".substr(2, undefined), "abc".substr(3, undefined),
-    ]`,
-    expected: ["abc", "bc", "c", "", "abc", "bc", "c", ""],
-    labels: [
-      "start: 0, length: unspecified", "start: 1, length: unspecified", "start: 2, length: unspecified", "start: 3, length: unspecified",
-      "start: 0, length: undefined", "start: 1, length: undefined", "start: 2, length: undefined", "start: 3, length: undefined",
-    ],
-  },
-  {
-    path: "test/annexB/built-ins/String/prototype/substr/surrogate-pairs.js",
-    code: `return [
-      "\uD834\uDF06".substr(0), "\uD834\uDF06".substr(1), "\uD834\uDF06".substr(2),
-      "\uD834\uDF06".substr(0, 0), "\uD834\uDF06".substr(0, 1), "\uD834\uDF06".substr(0, 2),
-    ]`,
-    expected: ["\uD834\uDF06", "\uDF06", "", "", "\uD834", "\uD834\uDF06"],
-    labels: ["start: 0", "start: 1", "start: 2", "end: 0", "end: 1", "end: 2"],
-  },
   {
     path: "test/built-ins/String/prototype/includes/String.prototype.includes_FailMissingLetter.js",
     code: `return ["word".includes("a", 0)]`, expected: [false], labels: ['"word".includes("a", 0)'],

packages/codemode/tsconfig.json

@@ -2,6 +2,7 @@
   "$schema": "https://json.schemastore.org/tsconfig",
   "extends": "@tsconfig/bun/tsconfig.json",
   "compilerOptions": {
-    "noUncheckedIndexedAccess": false
+    "noUncheckedIndexedAccess": false,
+    "noUnusedLocals": true
   }
 }

packages/core/src/config.ts

@@ -200,7 +200,6 @@ const layer = Layer.effect(
             .up({
               targets: [".opencode", ".claude", ".agents", ...names.toReversed()],
               start: location.directory,
-              stop: location.project.directory,
             })
           .pipe(Effect.orDie)
 

packages/core/src/flag/flag.ts

@@ -52,9 +52,6 @@ export const Flag = {
   get OPENCODE_EXPERIMENTAL_REFERENCES() {
     return enabledByExperimental("OPENCODE_EXPERIMENTAL_REFERENCES")
   },
-  get CODEMODE_ENABLED() {
-    return process.env["CODEMODE_ENABLED"] === undefined || truthy("CODEMODE_ENABLED")
-  },
   get OPENCODE_TUI_CONFIG() {
     return process.env["OPENCODE_TUI_CONFIG"]
   },

packages/core/src/mcp/guidance.ts

@@ -1,7 +1,6 @@
 export * as McpGuidance from "./guidance"
 
 import { makeLocationNode } from "../effect/app-node"
-import { Flag } from "../flag/flag"
 import { Context, Effect, Layer, Schema } from "effect"
 import { AgentV2 } from "../agent"
 import { PermissionV2 } from "../permission"
@@ -18,11 +17,7 @@ type Summary = typeof Summary.Type
 const entries = (servers: ReadonlyArray<Summary>) =>
   servers.flatMap((server) => [
     `  <server name="${server.server}">`,
-    ...(Flag.CODEMODE_ENABLED
-      ? [
-          `    Use tools from this server through \`execute\` under \`tools[${JSON.stringify(McpTool.group(server.server))}]\`.`,
-        ]
-      : []),
+    `    Use tools from this server through \`execute\` under \`tools[${JSON.stringify(McpTool.group(server.server))}]\`.`,
     ...server.instructions.split("\n").map((line) => `    ${line}`),
     "  </server>",
   ])
@@ -81,7 +76,7 @@ export const layer = Layer.effect(
               removed: () => "MCP server instructions are no longer available.",
             },
           })
-        if (Flag.CODEMODE_ENABLED && PermissionV2.evaluate("execute", "*", agent.permissions).effect === "deny")
+        if (PermissionV2.evaluate("execute", "*", agent.permissions).effect === "deny")
           return source(Instructions.removed)
         const [instructions, tools] = yield* Effect.all([mcp.instructions(), mcp.tools()], {
           concurrency: "unbounded",
@@ -90,12 +85,9 @@ export const layer = Layer.effect(
         const visible = instructions
           .filter((item) => {
             const owned = tools.filter((tool) => tool.server === item.server)
-            return (
-              (!Flag.CODEMODE_ENABLED && owned.length === 0) ||
-              owned.some(
-                (tool) =>
-                  PermissionV2.evaluate(McpTool.name(tool.server, tool.name), "*", agent.permissions).effect !== "deny",
-              )
+            return owned.some(
+              (tool) =>
+                PermissionV2.evaluate(McpTool.name(tool.server, tool.name), "*", agent.permissions).effect !== "deny",
             )
           })
           .map((item) => ({ server: item.server, instructions: item.instructions }))

packages/core/src/session/compaction.ts

@@ -16,6 +16,7 @@ import { Token } from "../util/token"
 
 const DEFAULT_BUFFER = 20_000
 const DEFAULT_KEEP_TOKENS = 8_000
+const OUTPUT_TOKEN_MAX = 32_000
 const TOOL_OUTPUT_MAX_CHARS = 2_000
 const SUMMARY_TEMPLATE = `Output exactly the Markdown structure shown inside <template> and keep the section order unchanged. Do not include the <template> tags in your response.
 <template>
@@ -320,7 +321,7 @@ const make = (dependencies: Dependencies) => {
         message.type === "assistant" && message.tokens !== undefined,
     )
     if (!last) return false
-    const output = input.model.route.defaults.limits?.output ?? 0
+    const output = Math.min(input.model.route.defaults.limits?.output ?? 0, OUTPUT_TOKEN_MAX)
     const used =
       last.tokens.input + last.tokens.output + last.tokens.reasoning + last.tokens.cache.read + last.tokens.cache.write
     if (used <= 0) return false

packages/core/src/session/runner/llm.ts

@@ -543,7 +543,8 @@ const layer = Layer.effect(
           needsContinuation = result.needsContinuation
           step = result.step + 1
           if (needsContinuation) {
-            promotion = (yield* SessionPending.compaction(db, input.sessionID)) ? undefined : "steer"
+            yield* runPendingCompaction(input.sessionID)
+            promotion = "steer"
             continue
           }
           yield* runPendingCompaction(input.sessionID)

packages/core/src/tool/AGENTS.md

@@ -29,7 +29,8 @@ Leaves own resolution, permission, and side-effect ordering. Translate only expe
 ## Registration
 
 Built-ins and plugin tools register through `Tools.Service.register({ [name]: tool })`. Registrations may provide a
-group, which flattens direct model names to `<group>_<tool>`, and may be deferred from direct model exposure.
+group, which flattens direct model names to `<group>_<tool>`, and default into CodeMode (`codemode` defaults true;
+`codemode: false` keeps the tool on the provider's native tool list).
 
 Registrations are scoped:
 

packages/core/src/tool/edit.ts

@@ -212,6 +212,7 @@ export const Plugin = {
             }),
             "edit",
           ),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)

packages/core/src/tool/execute.ts

@@ -58,16 +58,16 @@ export const create = (registrations: ReadonlyMap<string, Registration>) => {
       })
       if (registration.group === undefined) {
         const path = registration.name
-        if (Object.hasOwn(tools, path)) throw new TypeError(`Deferred tool namespace conflict: ${path}`)
+        if (Object.hasOwn(tools, path)) throw new TypeError(`CodeMode tool namespace conflict: ${path}`)
         tools[path] = value
         continue
       }
       const path = registration.name
       const namespace = registration.group
       const group = tools[namespace]
-      if (group && Tool.isDefinition(group)) throw new TypeError(`Deferred tool namespace conflict: ${namespace}`)
+      if (group && Tool.isDefinition(group)) throw new TypeError(`CodeMode tool namespace conflict: ${namespace}`)
       if (group) {
-        if (Object.hasOwn(group, path)) throw new TypeError(`Deferred tool namespace conflict: ${namespace}.${path}`)
+        if (Object.hasOwn(group, path)) throw new TypeError(`CodeMode tool namespace conflict: ${namespace}.${path}`)
         group[path] = value
         continue
       }

packages/core/src/tool/glob.ts

@@ -106,6 +106,7 @@ export const Plugin = {
                 ),
               ),
           }),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)

packages/core/src/tool/grep.ts

@@ -137,6 +137,7 @@ export const Plugin = {
                 ),
               ),
           }),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)

packages/core/src/tool/mcp.ts

@@ -5,7 +5,7 @@ import { McpEvent } from "@opencode-ai/schema/mcp-event"
 import { Effect, Exit, type JsonSchema, Layer, Scope, Semaphore, Stream } from "effect"
 import { makeLocationNode } from "../effect/app-node"
 import { EventV2 } from "../event"
-import { Flag } from "../flag/flag"
+
 import { MCP } from "../mcp"
 import { PermissionV2 } from "../permission"
 import { Tool } from "./tool"
@@ -107,7 +107,7 @@ export const layer = Layer.effectDiscard(
         const next = yield* Scope.fork(scope)
         yield* Effect.forEach(
           groups,
-          ([group, record]) => tools.register(record, { group, deferred: Flag.CODEMODE_ENABLED }),
+          ([group, record]) => tools.register(record, { group }),
           {
             discard: true,
           },

packages/core/src/tool/patch.ts

@@ -191,6 +191,7 @@ export const Plugin = {
             }),
             "edit",
           ),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)

packages/core/src/tool/question.ts

@@ -106,6 +106,7 @@ export const Plugin = {
                   }),
                 ),
           }),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)

packages/core/src/tool/read.ts

@@ -139,6 +139,7 @@ export const Plugin = {
               )
             },
           }),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)

packages/core/src/tool/registry.ts

@@ -3,7 +3,6 @@ export * as ToolRegistry from "./registry"
 import { ToolOutput, type ToolCall, type ToolDefinition, type ToolResultValue } from "@opencode-ai/llm"
 import { Context, Effect, Layer, Scope } from "effect"
 import type { AgentV2 } from "../agent"
-import { Flag } from "../flag/flag"
 import { PermissionV2 } from "../permission"
 import { SessionMessage } from "../session/message"
 import { SessionSchema } from "../session/schema"
@@ -56,7 +55,7 @@ const registryLayer = Layer.effect(
       readonly tool: AnyTool
       readonly name: string
       readonly group?: string
-      readonly deferred: boolean
+      readonly codemode: boolean
     }
     const local = new Map<string, Array<{ readonly token: object; readonly registration: Registration }>>()
 
@@ -132,7 +131,8 @@ const registryLayer = Layer.effect(
       register: Effect.fn("ToolRegistry.register")(function* (tools, options) {
         const entries = registrationEntries(tools, options?.group)
         if (entries.length === 0) return
-        const reserved = options?.deferred ? undefined : entries.find((entry) => entry.key === "execute")
+        const codemode = options?.codemode ?? true
+        const reserved = codemode ? undefined : entries.find((entry) => entry.key === "execute")
         if (reserved)
           return yield* Effect.fail(
             new RegistrationError({ name: reserved.key, message: 'Tool name "execute" is reserved for CodeMode' }),
@@ -149,7 +149,7 @@ const registryLayer = Layer.effect(
                     tool: entry.tool,
                     name: entry.name,
                     group: entry.group,
-                    deferred: options?.deferred ?? false,
+                    codemode,
                   },
                 },
               ])
@@ -168,18 +168,17 @@ const registryLayer = Layer.effect(
       }),
       materialize: Effect.fn("ToolRegistry.materialize")(function* (permissions) {
         const direct = new Map<string, Registration>()
-        const deferred = new Map<string, Registration>()
+        const codemode = new Map<string, Registration>()
         const rules = permissions ?? []
         for (const [name, entries] of local) {
           const registration = entries.at(-1)?.registration
           if (!registration) continue
-          if (registration.deferred && !Flag.CODEMODE_ENABLED) continue
           if (whollyDisabled(permission(registration.tool, name), rules)) continue
-          if (registration.deferred) deferred.set(name, registration)
+          if (registration.codemode) codemode.set(name, registration)
           else direct.set(name, registration)
         }
         const execute =
-          deferred.size > 0 && !whollyDisabled("execute", rules) ? ExecuteTool.create(deferred) : undefined
+          codemode.size > 0 && !whollyDisabled("execute", rules) ? ExecuteTool.create(codemode) : undefined
         return {
           definitions: [
             ...Array.from(direct, ([name, registration]) => definition(name, registration.tool)),

packages/core/src/tool/shell.ts

@@ -132,6 +132,8 @@ export const Plugin = {
           return runtime.session.synthetic({
             sessionID,
             text: `<shell id="${callID}" state="${state}" command="${command}">\n${text}\n</shell>`,
+            description: command,
+            metadata: { source: "shell", state },
           })
         }),
         Effect.forkIn(scope, { startImmediately: true }),
@@ -276,6 +278,7 @@ export const Plugin = {
                 ),
               ),
           }),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)

packages/core/src/tool/skill.ts

@@ -97,6 +97,7 @@ export const Plugin = {
                 }).pipe(Effect.mapError((error) => unableToLoad(input.id, error)))
               }),
           }),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)

packages/core/src/tool/subagent.ts

@@ -208,6 +208,7 @@ export const Plugin = {
                 return { sessionID: child.id, status: "completed" as const, output: result?.info.output ?? NO_TEXT }
               }),
           }),
+          { codemode: false },
         ),
       )
       .pipe(Effect.orDie)