feat(plugin): add session request hook

feat(codemode): support property deletion (#37335 )
fix(tui): label only detached subagents as background (#37306 )
2026-07-27 05:35:46 -04:00 · 2026-07-16 17:48:21 +00:00 · 2026-07-16 12:21:28 -05:00 · 2026-07-16 12:21:19 -04:00 · 2026-07-16 11:16:19 -05:00 · 2026-07-16 11:15:29 -05:00
46 changed files with 892 additions and 225 deletions
@@ -5,7 +5,7 @@ import { Endpoint, type EndpointPatch } from "./endpoint"
 import { RequestExecutor } from "./executor"
 import { Framing } from "./framing"
 import { HttpTransport } from "./transport"
-import type { Transport, TransportRuntime } from "./transport"
+import type { RequestTransform, Transport, TransportRuntime } from "./transport"
 import { WebSocketExecutor } from "./transport"
 import type { Protocol } from "./protocol"
 import { applyCachePolicy } from "../cache-policy"
@@ -155,6 +155,7 @@ export interface Interface {
  readonly prepare: <Body = unknown>(request: LLMRequest) => Effect.Effect<PreparedRequestOf<Body>, LLMError>
  readonly stream: StreamMethod
  readonly generate: GenerateMethod
+  readonly withRequestTransform: (transform: RequestTransform) => Interface
 }

 export interface StreamMethod {
@@ -411,6 +412,22 @@ const streamRequestWith = (runtime: TransportRuntime) => (request: LLMRequest) =
    }),
  )

+const makeClient = (runtime: TransportRuntime): Interface => {
+  const stream = streamRequestWith(runtime)
+  return {
+    prepare: prepareWith as Interface["prepare"],
+    stream,
+    generate: generateWith(stream),
+    withRequestTransform: (transform) =>
+      makeClient({
+        ...runtime,
+        transformRequest: runtime.transformRequest
+          ? (request) => runtime.transformRequest!(request).pipe(Effect.flatMap(transform))
+          : transform,
+      }),
+  }
+}
+
 const generateWith = (stream: Interface["stream"]) =>
  Effect.fn("LLM.generate")(function* (request: LLMRequest) {
    const state = yield* stream(request).pipe(Stream.runFold(LLMResponse.empty, LLMResponse.reduce))
@@ -449,11 +466,12 @@ export const streamRequest = (request: LLMRequest) =>
 export const layer: Layer.Layer<Service, never, RequestExecutor.Service> = Layer.effect(
  Service,
  Effect.gen(function* () {
-    const stream = streamRequestWith({
-      http: yield* RequestExecutor.Service,
-      webSocket: Option.getOrUndefined(yield* Effect.serviceOption(WebSocketExecutor.Service)),
-    })
-    return Service.of({ prepare: prepareWith as Interface["prepare"], stream, generate: generateWith(stream) })
+    return Service.of(
+      makeClient({
+        http: yield* RequestExecutor.Service,
+        webSocket: Option.getOrUndefined(yield* Effect.serviceOption(WebSocketExecutor.Service)),
+      }),
+    )
  }),
 )

@@ -22,4 +22,4 @@ export type { ApiKeyMode, AuthOverride, ProviderAuthOption } from "./auth-option
 export type { Definition as EndpointFn, EndpointInput } from "./endpoint"
 export type { Definition as FramingDef } from "./framing"
 export type { Protocol as ProtocolDef } from "./protocol"
-export type { Transport as TransportDef, TransportRuntime } from "./transport"
+export type { RequestTransform, Transport as TransportDef, TransportRuntime } from "./transport"
@@ -5,7 +5,7 @@ import { render as renderEndpoint } from "../endpoint"
 import { Framing } from "../framing"
 import type { Transport, TransportPrepareInput } from "./index"
 import * as ProviderShared from "../../protocols/shared"
-import { mergeJsonRecords, type LLMRequest } from "../../schema"
+import { InvalidRequestReason, LLMError, mergeJsonRecords, type LLMRequest } from "../../schema"

 export type JsonRequestInput<Body> = TransportPrepareInput<Body>

@@ -130,23 +130,36 @@ export const httpJson = <Body, Frame>(input: HttpJsonInput<Body, Frame>): HttpJs
    ),
  frames: (prepared, request, runtime) =>
    Stream.unwrap(
-      runtime.http
-        .execute(prepared.request)
-        .pipe(
-          Effect.map((response) =>
-            prepared.framing.frame(
-              response.stream.pipe(
-                Stream.mapError((error) =>
-                  ProviderShared.eventError(
-                    `${request.model.provider}/${request.model.route.id}`,
-                    `Failed to read ${request.model.provider}/${request.model.route.id} stream`,
-                    ProviderShared.errorText(error),
-                  ),
+      (runtime.transformRequest
+        ? HttpClientRequest.toWeb(prepared.request).pipe(
+            Effect.mapError(
+              (error) =>
+                new LLMError({
+                  module: "HttpTransport",
+                  method: "frames",
+                  reason: new InvalidRequestReason({ message: error.message }),
+                }),
+            ),
+            Effect.flatMap(runtime.transformRequest),
+            Effect.map((request) => HttpClientRequest.fromWeb(request.clone() as Request)),
+            Effect.flatMap(runtime.http.execute),
+          )
+        : runtime.http.execute(prepared.request)
+      ).pipe(
+        Effect.map((response) =>
+          prepared.framing.frame(
+            response.stream.pipe(
+              Stream.mapError((error) =>
+                ProviderShared.eventError(
+                  `${request.model.provider}/${request.model.route.id}`,
+                  `Failed to read ${request.model.provider}/${request.model.route.id} stream`,
+                  ProviderShared.errorText(error),
                ),
              ),
            ),
          ),
        ),
+      ),
    ),
 })

@@ -8,8 +8,11 @@ import type { LLMError, LLMRequest } from "../../schema"
 export interface TransportRuntime {
  readonly http: RequestExecutorInterface
  readonly webSocket?: WebSocketExecutorInterface
+  readonly transformRequest?: RequestTransform
 }

+export type RequestTransform = (request: Request) => Effect.Effect<Request, LLMError>
+
 export interface Transport<Body, Prepared, Frame> {
  readonly id: string
  readonly prepare: (input: TransportPrepareInput<Body>) => Effect.Effect<Prepared, LLMError>
@@ -690,4 +690,33 @@ describe("OpenAI Chat route", () => {
      expect(events.map((event) => event.type)).toEqual(["step-start"])
    }),
  )
+
+  it.effect("transforms the serialized HTTP request before dispatch", () =>
+    Effect.gen(function* () {
+      const llm = yield* LLMClient.Service
+      const seen: string[] = []
+      yield* llm
+        .withRequestTransform((request) =>
+          Effect.sync(() => {
+            seen.push(request.url)
+            const headers = new Headers(request.headers)
+            headers.set("x-hook", "enabled")
+            return new Request(request, { headers })
+          }),
+        )
+        .stream(request)
+        .pipe(Stream.runDrain)
+
+      expect(seen).toEqual(["https://api.openai.test/v1/chat/completions"])
+    }).pipe(
+      Effect.provide(
+        dynamicResponse((input) => {
+          expect(input.request.headers["x-hook"]).toBe("enabled")
+          return Effect.succeed(
+            input.respond(sseEvents(deltaChunk({}, "stop")), { headers: { "content-type": "text/event-stream" } }),
+          )
+        }),
+      ),
+    ),
+  )
 })
@@ -4,10 +4,9 @@ This is the checkable support matrix for CodeMode's confined JavaScript interpre
 standard-library surface that programs can use today, plus concrete gaps that may be implemented later.

 - `[x]` means the feature is implemented at the scope described here.
- `[ ]` means the feature is unavailable, incomplete, or intentionally divergent as described.
- A checked item does not promise complete ECMAScript edge-case parity. Known differences are listed next to the
-  supported surface or under [Known semantic gaps](#known-semantic-gaps).
- [Intentional exclusions](#intentional-exclusions) are boundaries, not backlog.
+- `[ ]` means a concrete compatibility gap remains.
+- Checked items do not promise complete ECMAScript edge-case parity; known differences are stated explicitly.
+- Intentional boundaries are not listed as compatibility work.

 When behavior changes, update this file and the tests in the same change. The implementation and tests remain the
 ultimate source of truth.
@@ -19,42 +18,45 @@ ultimate source of truth.
      TypeScript is transpiled first; the emitted JavaScript must still use the supported subset.
 - [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] Program results use JSON-like boundaries, with `undefined` and non-finite numbers normalized to `null`. Tool
+      arguments remain subject to their schema and the outbound-handling gap listed below.
 - [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, 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

 - [x] `null`, `undefined`, booleans, finite and non-finite numbers, and strings.
 - [x] Array literals, including holes and spread from arrays, strings, Maps, Sets, and URLSearchParams.
- [x] Object literals with shorthand, computed string/number keys, and object spread.
+- [x] Object literals with shorthand, computed string/number keys, and spread from plain data objects; `null` and
+      `undefined` are no-ops, while arrays are rejected.
 - [x] Template literals with interpolation.
 - [x] Regular-expression literals.
 - [x] `NaN` and `Infinity` globals.
- [ ] BigInt literals and values.
- [ ] Symbols.
- [ ] Tagged template literals.
- [ ] Getters and setters in object literals.
+- [ ] BigInt literals and in-interpreter BigInt arithmetic; BigInt remains invalid at JSON-like host boundaries.
+- [ ] Symbol primitive values and symbol-keyed properties.
+- [ ] Tagged-template calls.
+- [ ] Getter and setter definitions in object literals.

 ## Bindings and destructuring

 - [x] `const`, `let`, and accepted `var` declarations.
 - [x] Object and array destructuring in declarations, parameters, assignment expressions, and `for...of` bindings.
 - [x] Nested patterns, defaults, elisions, and rest elements.
- [x] Assignment to identifiers, object fields, array indexes, and writable URL fields.
- [x] Function declarations are hoisted within their interpreted scope.
+- [x] Assignment to identifiers, unblocked plain-object fields, non-negative integer array indexes, and writable URL
+      fields.
+- [x] Direct function declarations are hoisted in program and block statement lists.
 - [x] Parameter defaults observe a temporal dead zone for later parameters.
- [ ] JavaScript-correct `var` function scope, hoisting, and redeclaration. Accepted `var` currently behaves like a
-      lexical declaration; prefer `let` or `const`.
- [ ] Complete `let`/`const` temporal-dead-zone and declaration-hoisting semantics.
+- [ ] JavaScript-correct function scoping, hoisting, and redeclaration for accepted `var` declarations.
+- [ ] Predeclare `let` and `const` bindings in every lexical scope, including program/block bodies, switch bodies, and
+      loop headers, so reads before initialization and self- or cross-referential initializers observe the JavaScript
+      temporal dead zone.
+- [ ] Hoist function declarations accepted directly in switch cases.
 - [ ] Computed object destructuring keys such as `const { [field]: value } = record`.
 - [ ] Object destructuring from arrays, such as `const { length } = values`.
- [ ] Iterable array destructuring from Map, Set, string, or URLSearchParams values.
- [ ] Dynamic property deletion with `delete object[key]`.
+- [ ] Array destructuring from supported non-array iterables: strings, Maps, Sets, and URLSearchParams.

 ## Statements and control flow

@@ -69,7 +71,6 @@ ultimate source of truth.
 - [x] `throw` with arbitrary values.
 - [ ] Labeled statements, labeled `break`, and labeled `continue`.
 - [ ] `for await...of` and async iteration.
- [ ] `with` and `debugger` statements.

 ## Functions and callbacks

@@ -90,15 +91,15 @@ ultimate source of truth.
      like JS.
 - [x] Tool references and detached `Promise` statics are rejected as callbacks with a hint to wrap them in an
      arrow function.
- [x] Async string replacement callbacks; replacements are evaluated sequentially.
+- [ ] Stop automatically awaiting promise-returning string replacers; match JavaScript's synchronous callback-result
+      coercion.
 - [x] The optional `thisArg` of iteration methods is accepted and ignored: CodeMode functions have no `this`, so
      ignoring it matches JS arrow-function semantics exactly.
- [ ] `this`, `super`, user-defined constructor functions, or function prototype methods such as `call`, `apply`,
-      and `bind`.
+- [ ] `this` in non-arrow CodeMode functions and callbacks.
+- [ ] User-defined constructor calls.
+- [ ] `Function.prototype.call`, `apply`, and `bind` for CodeMode functions.
 - [ ] Classes and private fields.
 - [ ] Generator functions and `yield`.
- [ ] Async predicates, reducers, and comparators with automatic awaiting. Async mapping can be joined explicitly with
-      `Promise.all`, but a promise is not a meaningful predicate or sort result.

 ## Expressions and operators

@@ -108,16 +109,16 @@ ultimate source of truth.
 - [x] Sequence expressions (the comma operator).
 - [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] `new` for Array, Object, Error types, Date, RegExp, Map, Set, URL, URLSearchParams, and Promise.
 - [x] Arithmetic operators: `+`, `-`, `*`, `/`, `%`, and `**`.
 - [x] Equality and ordering: `==`, `!=`, `===`, `!==`, `<`, `<=`, `>`, and `>=`.
 - [x] Bitwise operators: `&`, `|`, `^`, `~`, `<<`, `>>`, and `>>>`.
 - [x] Logical operators: `&&`, `||`, `??`, and `!`, with short-circuiting.
- [x] Unary `+`, unary `-`, `typeof`, `instanceof`, and own-property-only `in`.
+- [x] Unary `+`, unary `-`, `void`, `typeof`, `instanceof`, and own-property-only `in`.
 - [x] Prefix and postfix `++` and `--`.
 - [x] Plain, arithmetic, bitwise, and logical assignment operators.
- [ ] Unary `void` and `delete`.
- [ ] Arbitrary constructors.
+- [x] Property deletion on plain data objects and arrays, including computed and optional forms; deleting an array index
+      creates a hole without changing its length.

 ## Promises and tools

@@ -152,8 +153,13 @@ ultimate source of truth.
      promise itself rejects with a `TypeError`. Resolver callables work anywhere callbacks are accepted, including
      `.then`/`.catch` handlers and collection callbacks, but remain opaque references that cannot cross the data
      boundary.
- [ ] Thenable assimilation (objects with a `then` method are plain data, not promises).
- [ ] Async iterables, host streams, and stream consumption.
+- [ ] Thenable assimilation; objects with a callable `then` field remain plain data.
+- [x] Dotted tool names are canonicalized into namespace paths; a path can be both callable and a namespace, and the
+      last definition supplied for a canonical path wins.
+- [x] Tool path segments may be named `constructor`, `prototype`, or `__proto__` because paths use inert Map keys.
+- [ ] Reject `undefined` and non-finite numbers in outbound tool arguments before render-only and OpenAPI tools run;
+      retain null normalization for program results and JSON serialization.
+- [ ] Tokenize and case-fold non-ASCII tool paths, descriptions, and queries for tool search.

 ## Objects and properties

@@ -164,19 +170,17 @@ ultimate source of truth.
 - [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-CodeMode Object helpers.
- [x] Blocked access to `__proto__`, `constructor`, and `prototype`.
- [ ] `Object.is`; runtime and tool-reference identity semantics need to be defined first.
+- [x] Prototype traversal and mutation through `__proto__`, `constructor`, and `prototype` are blocked.
+- [ ] Legal own data fields named `__proto__`, `constructor`, or `prototype` are rejected at JSON/tool boundaries and
+      cannot be created, read, or written in CodeMode; tool path segments with those names remain supported.
+- [x] `Object.is` for supported data values.
 - [ ] `Object.groupBy`.
- [ ] Object creation, descriptors, freezing/sealing, prototype APIs, and reflection APIs.
- [ ] A final policy for legal data keys named `__proto__`, `constructor`, or `prototype` (tool path segments
-      already allow them; see known semantic gaps).

 ## Arrays

- [x] The `Array` constructor with or without `new`: `Array(a, b)` collects arguments, `Array(n)` creates a
-      sparse array of that length (invalid lengths throw a `RangeError`). Holes behave like JS in iteration,
-      spread, join, and JSON; `sort` densifies holes into trailing `undefined`, and results returned to the
-      host normalize holes to `null`.
+- [x] The `Array` constructor with or without `new`: `Array(a, b)` collects arguments and `Array(n)` creates a sparse
+      array of that length; invalid lengths throw `RangeError`. Iteration, spread, join, and JSON handle holes like
+      JavaScript, and host results normalize holes to `null`.
 - [x] Static methods: `Array.isArray`, `Array.of`, and `Array.from`, including the `Array.from` mapper form with
      `(value, index)` arguments.
 - [x] Iteration/transformation: `map`, `filter`, `flatMap`, and `forEach`.
@@ -190,8 +194,10 @@ ultimate source of truth.
 - [x] `length`, numeric indexing, index assignment, spread, and `for...of`.
 - [x] The `thisArg` argument of `Array.from` is accepted and ignored, like JS arrows.
 - [ ] `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.
+- [ ] Canonical array/string index parsing: a key such as `"01"` must remain an ordinary property key rather than
+      aliasing index `1`.
+- [ ] `Array.prototype.sort` and `toSorted` must preserve trailing holes; they currently turn holes into own
+      `undefined` elements.

 ## Strings

@@ -204,8 +210,8 @@ ultimate source of truth.
 - [x] `localeCompare`; locale and options arguments are currently ignored.
 - [x] `toString`, `length`, numeric indexing, spread, and `for...of` by Unicode code point.
 - [x] Static `String.fromCharCode` and `String.fromCodePoint`.
- [ ] Locale/options-aware `localeCompare` and locale formatting APIs.
- [ ] Exact native coercion across every string method; CodeMode often requires explicit strings/numbers.
+- [ ] Native argument coercion for supported String methods; for example, `includes(1)` and `slice("1")` currently
+      reject instead of coercing.
 - [ ] Native no-argument parity for `match()` and `search()`.

 ## Numbers and Math
@@ -221,20 +227,21 @@ ultimate source of truth.
      `floor`, `ceil`, `round`, `trunc`, `sign`, `sqrt`, `cbrt`, `pow`, `hypot`, `cos`, `cosh`, `sin`, `sinh`,
      `tan`, `tanh`, `log`, `log2`, `log10`, `log1p`, `exp`, `expm1`, `f16round`, `fround`, `clz32`, and `imul`.
 - [ ] Native zero-argument behavior for `Number()` and `String()`; they currently do not produce `0` and `""`.
- [ ] Safe interpreter coercion for `++` and `--` rather than host `Number(...)` coercion.
- [ ] Reliable feature detection for unknown static members.
+- [ ] `++` and `--` must use CodeMode numeric coercion and reject opaque runtime references; they currently call host
+      `Number(...)` directly.
+- [ ] Unknown static members must read as `undefined` for feature detection; some currently appear callable or throw
+      during property access.
 - [ ] `Math.sumPrecise`.
 - [ ] Global coercing `isFinite` and `isNaN`.

 ## JSON and console

- [x] `JSON.parse` and `JSON.stringify`.
+- [x] `JSON.parse` and `JSON.stringify` for supported data objects; the blocked data-key gap listed above still applies.
 - [x] Numeric/string indentation for `JSON.stringify`.
 - [x] Captured `console.log`, `console.info`, `console.debug`, `console.warn`, and `console.error`.
 - [x] Captured `console.dir` and `console.table`.
 - [ ] `JSON.parse` reviver callbacks.
 - [ ] `JSON.stringify` function/array replacers.
- [ ] Other console methods, timers, counters, groups, and host console access.

 ## Date

@@ -250,22 +257,22 @@ ultimate source of truth.
 - [x] `getTimezoneOffset`, arithmetic, relational comparison, and `instanceof Date`.
 - [x] Date values serialize to ISO strings; invalid dates serialize to `null`.
 - [ ] Date setters.
- [ ] `toUTCString`, locale methods, and other Date formatting methods.
- [ ] Exact native constructor coercion, local-time, and loose-equality semantics.
+- [ ] `Date.prototype.toUTCString` and its `toGMTString` alias.
+- [ ] Native one-argument Date coercion; unsupported boolean/object inputs currently become invalid dates instead of
+      being coerced.
+- [ ] Native Date loose-equality and default primitive-coercion semantics.
 - [ ] Native `RangeError` branding for invalid `toISOString()` calls.
- [ ] Temporal and Intl date/time APIs.

 ## Regular expressions

 - [x] Literal and `RegExp(pattern, flags)` construction, with or without `new`.
 - [x] `test`, `exec`, and `toString`.
 - [x] Readable `source`, `flags`, `lastIndex`, `global`, `ignoreCase`, `multiline`, `sticky`, `unicode`, and `dotAll`.
- [x] Captures, named groups, match indexes, and stateful global matching.
- [x] Integration with supported String methods, including async function replacers.
+- [x] Captures, safe named groups (blocked member names are omitted), match `.index`, and stateful global matching.
+- [x] Integration with supported String methods, including function replacers.
 - [ ] Writable `lastIndex`.
- [ ] Exposed metadata for the `d` and `v` flags.
+- [ ] `hasIndices`, match `indices`, and `unicodeSets` metadata for the `d` and `v` flags.
 - [ ] `RegExp.escape`.
- [ ] Protection from pathological host-regex backtracking beyond the cooperative execution timeout.

 ## Map and Set

@@ -276,9 +283,8 @@ ultimate source of truth.
 - [x] Materialized `keys`, `values`, and `entries` arrays for Map and Set.
 - [x] Spread, `for...of`, `Array.from`, and `Object.fromEntries` integration.
 - [x] Map and Set values serialize to `{}` at host/JSON boundaries.
- [ ] Set composition methods such as `union`, `intersection`, `difference`, and relation predicates.
- [ ] WeakMap and WeakSet.
- [ ] Native iterator objects and custom iterators.
+- [ ] Set composition and relation methods: `union`, `intersection`, `difference`, `symmetricDifference`, `isSubsetOf`,
+      `isSupersetOf`, and `isDisjointFrom`.

 ## URL and URI helpers

@@ -301,48 +307,12 @@ ultimate source of truth.
      an all-rejected `Promise.any`.
 - [x] Error `name`/`message`, error inheritance through `instanceof`, and plain-data serialization.
 - [x] `instanceof` for Date, RegExp, Map, Set, URL, URLSearchParams, Array, Object, Promise, and Error types.
- [x] Catchable interpreter failures and awaited tool failures.
- [x] Source locations on unsupported-syntax diagnostics when available.
+- [x] Catchable user throws, runtime failures raised during interpreted evaluation, awaited tool failures, and awaited
+      tool-call-limit failures; parse/compile failures, cooperative timeout, and output bounding remain outside program
+      `catch`.
+- [x] Source locations on unsupported-syntax diagnostics for JavaScript-shaped input; TypeScript transpilation may
+      shift them.
 - [x] Sanitized model-visible diagnostics and explicit safe `ToolError` messages.
- [ ] Distinct public categories for user throws, tool refusal, tool internal failure, invalid returned data, compile
-      failures, and genuine interpreter defects.
- [ ] Preservation of detailed recoverable failure categories inside `catch` and `Promise.allSettled`.
-
-## Known semantic gaps
-
-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`.
- [x] Canonicalize dotted tool names into namespace paths so every advertised dotted path is executable, one
-      canonical path can be both a callable tool and a namespace, and the last definition supplied for a canonical
-      path wins.
- [x] Allow blocked member names (`constructor`, `prototype`, `__proto__`) as tool path segments: segments are Map
-      keys and inert strings, never plain-object property accesses, so every advertised path is executable. Blocked
-      member access on data values stays rejected. Tool names with empty segments are rejected at construction.
- [ ] Define safe outbound handling for non-finite numbers and `undefined` so invalid values cannot silently become
-      `null` in render-only or OpenAPI tool calls.
- [ ] Make regular-expression execution genuinely timeout-safe, or narrow the timeout guarantee explicitly.
- [ ] Complete lexical declaration and destructuring semantics listed above.
- [x] Make callback acceptance consistent across built-ins: collections, sort, string replacers, `Array.from`
-      mappers, and promise reactions share one acceptance rule.
- [x] Reject every unsupported callable callback argument explicitly rather than silently ignoring it
-      (`JSON.stringify` replacers and `JSON.parse` revivers fail loudly). The iteration-method `thisArg` is
-      accepted and ignored: CodeMode functions have no `this`, so ignoring it matches JS arrow semantics.
- [ ] Make async callback behavior consistent across built-ins; only string replacers settle async callback results
-      today.
- [ ] Resolve the built-in correctness gaps listed in the Array, String, Number, Date, and RegExp sections.
- [ ] Make tool search tokenization Unicode-aware.
- [ ] Design explicit tagged representations and size limits before adding binary values or streams.
-
-## Intentional exclusions
-
-These constraints preserve CodeMode's confinement and host-neutral scope. They are not TODO items.
-
- Ambient filesystem, process, environment, credential, network, or application access.
- `fetch`, timers, crypto, or other host globals unless a future host explicitly supplies a bounded capability.
- Static imports, dynamic imports, modules, npm packages, and module loading.
- `eval`, `Function(...)`, arbitrary host execution, and prototype mutation.
- Generic permission prompts, authorization policy, persistence, replay, or exactly-once side effects.
- Arbitrary method dispatch outside the documented allowlists.
- Automatic parsing of text tool results as JSON.
- Full browser, Node.js, Bun, or ECMAScript runtime compatibility.
+- [ ] Distinguish user-thrown failures from interpreter defects and explicit tool refusals from sanitized internal tool
+      failures; preserve those categories in caught errors, promise rejection handlers, and `Promise.allSettled`
+      reasons.
@@ -1279,6 +1279,7 @@ export class Interpreter<R> {
  private evaluateUnaryExpression(node: AstNode): Effect.Effect<unknown, unknown, R> {
    const operator = getString(node, "operator")
    const argument = getNode(node, "argument")
+    if (operator === "delete") return this.evaluateDeleteExpression(argument)
    // Undeclared names short-circuit, but declared TDZ bindings must still throw.
    if (operator === "typeof" && argument.type === "Identifier" && !this.scopes.resolve(getString(argument, "name"))) {
      return Effect.succeed("undefined")
@@ -1286,6 +1287,7 @@ export class Interpreter<R> {
    return Effect.map(this.evaluateExpression(argument), (value) => {
      if (operator === "typeof") return typeofValue(value)
      if (operator === "!") return !value
+      if (operator === "void") return undefined
      if (containsOpaqueReference(value)) {
        throw new InterpreterRuntimeError("Unary operators require data values in CodeMode.", node, "InvalidDataValue")
      }
@@ -1729,6 +1731,7 @@ export class Interpreter<R> {

  private getMemberReference(
    node: AstNode,
+    operation: "read" | "delete" = "read",
  ): Effect.Effect<
    | MemberReference
    | ToolReference
@@ -1875,6 +1878,7 @@ export class Interpreter<R> {
      }

      if (Array.isArray(objectValue)) {
+        if (operation === "delete") return { target: objectValue, key }
        if (
          key !== "length" &&
          !(typeof key === "string" && arrayMethods.has(key)) &&
@@ -1923,6 +1927,29 @@ export class Interpreter<R> {
    return this.modifyMember(node, () => Effect.succeed({ write: true, next: value, result: value }))
  }

+  private evaluateDeleteExpression(argument: AstNode): Effect.Effect<boolean, unknown, R> {
+    const target = argument.type === "ChainExpression" ? getNode(argument, "expression") : argument
+    if (target.type !== "MemberExpression") {
+      throw new InterpreterRuntimeError("Only data fields may be deleted in CodeMode.", argument)
+    }
+    return Effect.map(this.getMemberReference(target, "delete"), (reference) => {
+      if (reference === OptionalShortCircuit) return true
+      if (
+        reference instanceof ComputedValue ||
+        reference === undefined ||
+        reference instanceof ToolReference ||
+        reference instanceof PromiseMethodReference ||
+        reference instanceof PromiseInstanceMethodReference ||
+        reference instanceof IntrinsicReference ||
+        reference instanceof GlobalMethodReference ||
+        reference.target instanceof CodeModeURL
+      ) {
+        throw new InterpreterRuntimeError("Only data fields may be deleted in CodeMode.", target, "InvalidDataValue")
+      }
+      return Reflect.deleteProperty(reference.target, reference.key)
+    })
+  }
+
  // Resolve side-effecting object and key expressions exactly once.
  private modifyMember(
    node: AstNode,
@@ -1,4 +1,5 @@
 import { type AstNode, InterpreterRuntimeError } from "../interpreter/model.js"
+import { containsOpaqueReference } from "../interpreter/references.js"
 import { isBlockedMember } from "../tool-runtime.js"
 import { isCodeModeValue, CodeModeMap, CodeModePromise, CodeModeSet, CodeModeURLSearchParams } from "../values.js"
 import { boundedData, coerceToString } from "./value.js"
@@ -44,6 +45,11 @@ export const invokeObjectMethod = (name: string, args: Array<unknown>, node: Ast
      return Object.entries(requireObject()).map(([key, item]) => [key, item])
    case "hasOwn":
      return Object.hasOwn(requireObject(), String(args[1]))
+    case "is":
+      if (containsOpaqueReference(args[0]) || containsOpaqueReference(args[1])) {
+        throw new InterpreterRuntimeError("Object.is requires data values in CodeMode.", node, "InvalidDataValue")
+      }
+      return Object.is(args[0], args[1])
    case "assign": {
      const target = args[0]
      if (target === null || typeof target !== "object" || Array.isArray(target) || isCodeModeValue(target)) {
@@ -99,6 +99,84 @@ describe("H4: typeof on an undeclared identifier is 'undefined'", () => {
  })
 })

+describe("unary void", () => {
+  test("evaluates its operand and returns undefined", async () => {
+    expect(await value(`let count = 0; const result = void (count += 1); return [count, result === undefined]`)).toEqual([
+      1,
+      true,
+    ])
+  })
+
+  test("discards opaque values", async () => {
+    expect(await value(`return void tools === undefined`)).toBe(true)
+  })
+})
+
+describe("property deletion", () => {
+  test("deletes plain object fields and reports missing fields as successful", async () => {
+    expect(
+      await value(`
+        const object = { keep: 1, remove: 2 }
+        return [delete object.remove, delete object.missing, object]
+      `),
+    ).toEqual([true, true, { keep: 1 }])
+  })
+
+  test("evaluates computed object and key expressions once", async () => {
+    expect(
+      await value(`
+        const object = { remove: true }
+        let objectReads = 0
+        let keyReads = 0
+        function getObject() { objectReads++; return object }
+        function getKey() { keyReads++; return "remove" }
+        const removed = delete getObject()[getKey()]
+        return [removed, objectReads, keyReads, Object.hasOwn(object, "remove")]
+      `),
+    ).toEqual([true, 1, 1, false])
+  })
+
+  test("deleting an array index creates a hole without changing its length", async () => {
+    expect(await value(`const values = [1, 2, 3]; const removed = delete values[1]; return [removed, values.length, 1 in values, values]`)).toEqual([
+      true,
+      3,
+      false,
+      [1, null, 3],
+    ])
+  })
+
+  test("array length is not configurable", async () => {
+    expect(await value(`const values = [1, 2]; return [delete values.length, values.length]`)).toEqual([false, 2])
+  })
+
+  test("does not broaden unsupported array property assignment", async () => {
+    expect(
+      await value(`
+        const values = []
+        let rightHandSideRuns = 0
+        function next() { rightHandSideRuns++; return 1 }
+        try { values.field = next() } catch {}
+        return rightHandSideRuns
+      `),
+    ).toBe(0)
+  })
+
+  test("optional deletion short-circuits without evaluating the key", async () => {
+    expect(
+      await value(`let keyReads = 0; const object = null; return [delete object?.[keyReads++], keyReads]`),
+    ).toEqual([true, 0])
+  })
+
+  test("rejects deletion from opaque runtime references", async () => {
+    expect((await error(`return delete tools.example`)).kind).toBe("InvalidDataValue")
+  })
+
+  test("keeps blocked property names unavailable", async () => {
+    expect((await error(`const object = {}; return delete object.__proto__`)).kind).toBe("ExecutionFailure")
+    expect((await error(`const values = []; return delete values["constructor"]`)).kind).toBe("ExecutionFailure")
+  })
+})
+
 describe("H1: NaN/Infinity flow as intermediates and normalize to null at the boundary", () => {
  test("guards run instead of the program crashing on a transient NaN", async () => {
    expect(await value(`return parseInt("abc") || 0`)).toBe(0)
@@ -593,6 +593,24 @@ describe("Set", () => {
 })

 describe("stdlib integration", () => {
+  test("Object.is uses SameValue semantics", async () => {
+    expect(
+      await value(`
+        const object = {}
+        return [
+          Object.is(NaN, NaN),
+          Object.is(0, -0),
+          Object.is(object, object),
+          Object.is({}, {}),
+        ]
+      `),
+    ).toEqual([true, false, true, false])
+  })
+
+  test("Object.is rejects opaque runtime references", async () => {
+    expect((await error(`return Object.is(Math.max, Math.max)`)).kind).toBe("InvalidDataValue")
+  })
+
  test("Object values and entries accept arrays", async () => {
    expect(await value(`return [Object.values(["a", "b"]), Object.entries(["a", "b"])]`)).toEqual([
      ["a", "b"],
@@ -0,0 +1,112 @@
+const token = "dummy-wellknown-token"
+const port = Number(process.env.PORT ?? 8787)
+const config = {
+  $schema: "https://opencode.ai/config.json",
+  share: "manual",
+  model: "example-primary/example-chat",
+  enabled_providers: ["example-primary", "example-secondary"],
+  disabled_providers: ["opencode", "anthropic", "openai", "google", "xai", "amazon-bedrock", "azure"],
+  provider: {
+    "example-primary": {
+      name: "Example Primary",
+      npm: "@ai-sdk/openai-compatible",
+      whitelist: ["example-chat", "example-code"],
+      options: {
+        baseURL: "https://models.example.com/v1",
+        apiKey: "{env:TOKEN}",
+      },
+      models: {
+        "example-chat": {
+          name: "Example Chat",
+          reasoning: true,
+          tool_call: true,
+          attachment: true,
+          modalities: {
+            input: ["text", "image"],
+            output: ["text"],
+          },
+          limit: {
+            context: 128000,
+            output: 16000,
+          },
+        },
+        "example-code": {
+          name: "Example Code",
+          reasoning: true,
+          tool_call: true,
+          limit: {
+            context: 200000,
+            output: 32000,
+          },
+        },
+      },
+    },
+    "example-secondary": {
+      name: "Example Secondary",
+      npm: "@ai-sdk/openai-compatible",
+      whitelist: ["example-fast"],
+      options: {
+        baseURL: "https://inference.example.org/v1",
+        apiKey: "{env:TOKEN}",
+      },
+      models: {
+        "example-fast": {
+          name: "Example Fast",
+          tool_call: true,
+          limit: {
+            context: 64000,
+            output: 8000,
+          },
+        },
+      },
+    },
+  },
+  mcp: {
+    "example-tools": {
+      type: "remote",
+      url: "https://tools.example.net/mcp",
+      enabled: false,
+    },
+  },
+  permission: {
+    bash: "ask",
+    edit: "ask",
+    webfetch: "ask",
+    read: {
+      "*": "allow",
+      "*.env": "deny",
+      "*.env.*": "deny",
+      "*.env.example": "allow",
+    },
+  },
+}
+
+const server = Bun.serve({
+  hostname: "127.0.0.1",
+  port,
+  async fetch(request) {
+    const url = new URL(request.url)
+    if (url.pathname === "/.well-known/opencode") {
+      return Response.json({
+        auth: {
+          command: ["bun", "-e", `await Bun.sleep(5000); process.stdout.write(${JSON.stringify(token)})`],
+          env: "TOKEN",
+        },
+        remote_config: {
+          url: `${url.origin}/config/opencode.json`,
+          headers: { authorization: "Bearer {env:TOKEN}" },
+        },
+      })
+    }
+    if (url.pathname === "/config/opencode.json") {
+      if (request.headers.get("authorization") !== `Bearer ${token}`) {
+        return new Response("Unauthorized", { status: 401 })
+      }
+      return Response.json(config)
+    }
+    return new Response("Not found", { status: 404 })
+  },
+})
+
+console.log(`Well-known fixture listening at ${server.url.origin}`)
+console.log(`Test with: bun run dev auth connect ${server.url.origin}`)
@@ -1,5 +1,6 @@
 export * as AISDK from "./aisdk"

+import { AsyncLocalStorage } from "node:async_hooks"
 import { makeLocationNode } from "./effect/app-node"
 import type {
  JSONSchema7,
@@ -29,7 +30,7 @@ import {
  type ToolDefinition,
  type UsageInput,
 } from "@opencode-ai/ai"
-import { Auth, Endpoint, type AnyRoute } from "@opencode-ai/ai/route"
+import { Auth, Endpoint, type AnyRoute, type TransportRuntime } from "@opencode-ai/ai/route"
 import { Cause, Context, Effect, Layer, Option, Schema, Scope, Stream } from "effect"
 import { ModelV2 } from "./model"
 import { ProviderV2 } from "./provider"
@@ -39,6 +40,7 @@ type SDK = any
 type UserContent = Extract<LanguageModelV3Message, { role: "user" }>["content"]
 type AssistantContent = Extract<LanguageModelV3Message, { role: "assistant" }>["content"]
 type ToolResultContent = Extract<AssistantContent[number], { type: "tool-result" }>
+const requestTransform = new AsyncLocalStorage<TransportRuntime["transformRequest"]>()

 export interface SDKEvent {
  readonly model: ModelV2.Info
@@ -149,10 +151,20 @@ function prepareOptions(model: ModelV2.Info, pkg: string) {
      }
    }

-    const res = await (typeof customFetch === "function" ? customFetch : fetch)(input, {
-      ...opts,
-      timeout: false,
-    })
+    const request = new Request(input as Request, opts)
+    const transform = requestTransform.getStore()
+    const transformed = transform ? await Effect.runPromise(transform(request)) : request
+    const upstream = typeof customFetch === "function" ? customFetch : fetch
+    const res = transform
+      ? await upstream(transformed.url, {
+          ...opts,
+          method: transformed.method,
+          headers: transformed.headers,
+          body: transformed === request || transformed.body === null ? opts.body : await transformed.clone().text(),
+          signal: transformed.signal,
+          timeout: false,
+        })
+      : await upstream(input, { ...opts, timeout: false })
    if (!chunkAbortCtl || typeof chunkTimeout !== "number") return res
    return wrapSSE(res, chunkTimeout, chunkAbortCtl)
  }
@@ -341,7 +353,8 @@ function modelFromLanguage(info: ModelV2.Info, language: LanguageModelV3) {
    with: () => route,
    model: (input) => Model.make({ ...input, provider: "provider" in input ? input.provider : info.providerID, route }),
    prepareTransport: (body) => Effect.succeed(body),
-    streamPrepared: (prepared) => streamLanguage(language, prepared as LanguageModelV3CallOptions),
+    streamPrepared: (prepared, _request, runtime) =>
+      streamLanguage(language, prepared as LanguageModelV3CallOptions, runtime.transformRequest),
  }
  return Model.make({ id: info.modelID ?? info.id, provider: info.providerID, route })
 }
@@ -532,13 +545,17 @@ function providerOptions(input: LLMRequest["providerOptions"]): SharedV3Provider
  return Object.fromEntries(Object.entries(input).map(([key, value]) => [key, jsonObject(value)]))
 }

-function streamLanguage(language: LanguageModelV3, options: LanguageModelV3CallOptions) {
+function streamLanguage(
+  language: LanguageModelV3,
+  options: LanguageModelV3CallOptions,
+  transform: TransportRuntime["transformRequest"],
+) {
  const state = { step: 0, toolNames: {} as Record<string, string> }
  return Stream.concat(
    Stream.make(LLMEvent.stepStart({ index: state.step })),
    Stream.unwrap(
      Effect.tryPromise({
-        try: () => language.doStream(options),
+        try: () => requestTransform.run(transform, () => language.doStream(options)),
        catch: (error) => llmError("doStream", error),
      }).pipe(
        Effect.map((result) =>
@@ -16,6 +16,10 @@ export interface Domains {
 type Callback<Event> = (event: Event) => Effect.Effect<void>

 export interface Interface {
+  readonly has: <Domain extends keyof Domains, Name extends keyof Domains[Domain]>(
+    domain: Domain,
+    name: Name,
+  ) => boolean
  readonly register: <Domain extends keyof Domains, Name extends keyof Domains[Domain]>(
    domain: Domain,
    name: Name,
@@ -60,7 +64,7 @@ const layer = Layer.effect(
      return event
    })

-    return Service.of({ register, trigger })
+    return Service.of({ has: (domain, name) => callbacks.has(key(domain, name)), register, trigger })
  }),
 )

@@ -37,6 +37,7 @@ import { Snapshot } from "./snapshot"
 import { SessionRevert } from "./session/revert"
 import { Session } from "@opencode-ai/schema/session"
 import { FSUtil } from "./fs-util"
+import { Image } from "./image"
 import { Mime } from "./mime"
 import type { EventLog } from "@opencode-ai/schema/event-log"
 import { SkillV2 } from "./skill"
@@ -531,9 +532,13 @@ const layer = Layer.effect(
            // continues from the reverted boundary rather than stale post-boundary history.
            if (session.revert)
              yield* SessionRevert.commit(session).pipe(Effect.provideService(EventV2.Service, events))
-            const prompt = yield* resolvePrompt({ text: input.text, files: input.files, agents: input.agents }).pipe(
-              Effect.provideService(FSUtil.Service, fs),
-            )
+            // Resolved lazily so prompt admission only boots location services when an
+            // image attachment actually needs the resizer.
+            const image = Image.Service.pipe(Effect.provide(locations.get(session.location)))
+            const prompt = yield* resolvePrompt(
+              { text: input.text, files: input.files, agents: input.agents },
+              image,
+            ).pipe(Effect.provideService(FSUtil.Service, fs))
            const messageID = input.id ?? SessionMessage.ID.create()
            const admittedInput = SessionPending.Message.make({
              type: "user",
@@ -859,10 +864,13 @@ function synthesizeTerminalShellInfo(started: ShellSchema.Info): ShellSchema.Inf
  }
 }

-const resolvePrompt = Effect.fn("V2Session.resolvePrompt")(function* (input: PromptInput.Prompt) {
+const resolvePrompt = Effect.fn("V2Session.resolvePrompt")(function* (
+  input: PromptInput.Prompt,
+  image: Effect.Effect<Image.Interface>,
+) {
  const fs = yield* FSUtil.Service
  const files = input.files
-    ? yield* Effect.forEach(input.files, (file) => materializeAttachment(fs, file), { concurrency: 8 })
+    ? yield* Effect.forEach(input.files, (file) => materializeAttachment(fs, file, image), { concurrency: 8 })
    : undefined
  return Prompt.make({ text: input.text, agents: input.agents, files })
 })
@@ -872,6 +880,7 @@ const MAX_ATTACHMENT_BYTES = 20 * 1024 * 1024
 const materializeAttachment = Effect.fn("V2Session.materializeAttachment")(function* (
  fs: FSUtil.Interface,
  input: PromptInput.FileAttachment,
+  image: Effect.Effect<Image.Interface>,
 ) {
  const resolved = input.uri.startsWith("data:")
    ? {
@@ -900,9 +909,15 @@ const materializeAttachment = Effect.fn("V2Session.materializeAttachment")(funct
            .join("\n"),
        )
      : resolved.bytes
-  return FileAttachment.create({
-    data: Base64.make(Buffer.from(content).toString("base64")),
+  const normalized = yield* normalizeImageAttachment(
+    input,
+    Base64.make(Buffer.from(content).toString("base64")),
    mime,
+    image,
+  )
+  return FileAttachment.create({
+    data: normalized.data,
+    mime: normalized.mime,
    source: resolved.source,
    name: input.name ?? resolved.name,
    description: input.description,
@@ -910,6 +925,23 @@ const materializeAttachment = Effect.fn("V2Session.materializeAttachment")(funct
  })
 })

+const normalizeImageAttachment = Effect.fn("V2Session.normalizeImageAttachment")(function* (
+  input: PromptInput.FileAttachment,
+  data: Base64,
+  mime: string,
+  image: Effect.Effect<Image.Interface>,
+) {
+  if (!mime.startsWith("image/")) return { data, mime }
+  const service = yield* image
+  const label = input.name ?? (input.uri.startsWith("data:") ? "inline attachment" : input.uri)
+  const content = { uri: label, content: data, encoding: "base64" as const, mime }
+  const normalized = yield* service.normalize(label, content).pipe(
+    Effect.catchTag("Image.ResizerUnavailableError", () => Effect.succeed(content)),
+    Effect.mapError((error) => new AttachmentError({ uri: label, message: error.message })),
+  )
+  return { data: Base64.make(normalized.content), mime: normalized.mime }
+})
+
 const readFileAttachment = Effect.fn("V2Session.readFileAttachment")(function* (fs: FSUtil.Interface, uri: string) {
  const url = yield* Effect.try({
    try: () => new URL(uri),
@@ -1,15 +1,18 @@
 export * as SessionCompaction from "./compaction"

-import { LLM, LLMClient, LLMError, LLMEvent, Message, type LLMRequest, type Model } from "@opencode-ai/ai"
+import { LLM, LLMClient, LLMEvent, Message, type Model } from "@opencode-ai/ai"
+import type { LLMClientShape } from "@opencode-ai/ai/route"
 import { SessionError } from "@opencode-ai/schema/session-error"
 import { Context, Effect, Layer, Stream } from "effect"
 import { Config } from "../config"
 import { EventV2 } from "../event"
+import { PluginHooks } from "../plugin/hooks"
 import { makeLocationNode } from "../effect/app-node"
 import { llmClient } from "../effect/app-node-platform"
 import { SessionEvent } from "./event"
 import type { SessionMessage } from "./message"
 import { SessionModelHeaders } from "./model-headers"
+import { SessionRequestHook } from "./request-hook"
 import { SessionRunnerModel } from "./runner/model"
 import { SessionSchema } from "./schema"
 import { toSessionError } from "./to-session-error"
@@ -59,11 +62,10 @@ type Settings = {

 type Dependencies = {
  readonly events: EventV2.Interface
-  readonly llm: {
-    readonly stream: (request: LLMRequest) => Stream.Stream<LLMEvent, LLMError>
-  }
+  readonly llm: LLMClientShape
  readonly models: SessionRunnerModel.Interface
  readonly config: Settings
+  readonly hooks: PluginHooks.Interface
 }

 export type AutoInput = {
@@ -240,7 +242,7 @@ const make = (dependencies: Dependencies) => {

    const chunks: string[] = []
    let failure: SessionError.Error | undefined
-    yield* dependencies.llm
+    yield* SessionRequestHook.client(dependencies.llm, dependencies.hooks, plan.session.id)
      .stream(
        LLM.request({
          model: plan.model,
@@ -372,12 +374,13 @@ export const layer = Layer.effect(
    const llm = yield* LLMClient.Service
    const config = yield* Config.Service
    const models = yield* SessionRunnerModel.Service
-    return make({ events, llm, models, config: settings(yield* config.entries()) })
+    const hooks = yield* PluginHooks.Service
+    return make({ events, llm, models, config: settings(yield* config.entries()), hooks })
  }),
 )

 export const node = makeLocationNode({
  service: Service,
  layer,
-  deps: [EventV2.node, llmClient, Config.node, SessionRunnerModel.node],
+  deps: [EventV2.node, llmClient, Config.node, SessionRunnerModel.node, PluginHooks.node],
 })
@@ -0,0 +1,13 @@
+export * as SessionRequestHook from "./request-hook"
+
+import type { LLMClientShape } from "@opencode-ai/ai/route"
+import { Effect } from "effect"
+import { PluginHooks } from "../plugin/hooks"
+import { SessionSchema } from "./schema"
+
+export const client = (llm: LLMClientShape, hooks: PluginHooks.Interface, sessionID: SessionSchema.ID) =>
+  hooks.has("session", "request")
+    ? llm.withRequestTransform((request) =>
+        hooks.trigger("session", "request", { sessionID, request }).pipe(Effect.map((event) => event.request)),
+      )
+    : llm
@@ -8,6 +8,7 @@ import { Database } from "../../database/database"
 import { EventV2 } from "../../event"
 import { ModelV2 } from "../../model"
 import { PermissionV2 } from "../../permission"
+import { PluginHooks } from "../../plugin/hooks"
 import { QuestionTool } from "../../tool/question"
 import { ToolOutputStore } from "../../tool-output-store"
 import { InstructionState } from "../instruction-state"
@@ -15,6 +16,7 @@ import { SessionCompaction } from "../compaction"
 import { SessionContext } from "../context"
 import { SessionEvent } from "../event"
 import { SessionPending } from "../pending"
+import { SessionRequestHook } from "../request-hook"
 import { SessionModelRequest } from "../model-request"
 import { SessionMessage } from "../message"
 import { SessionSchema } from "../schema"
@@ -65,6 +67,7 @@ const layer = Layer.effect(
    const db = (yield* Database.Service).db
    const compaction = yield* SessionCompaction.Service
    const title = yield* SessionTitle.Service
+    const hooks = yield* PluginHooks.Service
    // Title generation is a side effect of the first step; it must not delay step continuation.
    // Tracked per process so repeated wakes before the second user message arrives don't
    // re-fire a redundant LLM call; `SessionTitle` itself is idempotent based on durable history.
@@ -157,7 +160,7 @@ const layer = Layer.effect(
      const serialized = <A, E, R>(effect: Effect.Effect<A, E, R>) => publication.withPermit(effect)
      const publish = (event: LLMEvent, error?: SessionError.Error) => serialized(publisher.publish(event, error))
      let overflowFailure: ProviderErrorEvent | undefined
-      const providerStream = llm.stream(prepared.request).pipe(
+      const providerStream = SessionRequestHook.client(llm, hooks, session.id).stream(prepared.request).pipe(
        Stream.runForEach((event) =>
          Effect.gen(function* () {
            if (overflowFailure || publisher.hasProviderError()) return
@@ -506,5 +509,6 @@ export const node = makeLocationNode({
    SessionTitle.node,
    Snapshot.node,
    Database.node,
+    PluginHooks.node,
  ],
 })
@@ -1,15 +1,18 @@
 export * as SessionTitle from "./title"

-import { LLM, LLMClient, LLMError, LLMEvent, Message, type LLMRequest } from "@opencode-ai/ai"
+import { LLM, LLMClient, LLMEvent, Message } from "@opencode-ai/ai"
+import type { LLMClientShape } from "@opencode-ai/ai/route"
 import { Context, DateTime, Effect, Layer, Stream } from "effect"
 import { AgentV2 } from "../agent"
 import { Database } from "../database/database"
 import { EventV2 } from "../event"
+import { PluginHooks } from "../plugin/hooks"
 import { makeLocationNode } from "../effect/app-node"
 import { llmClient } from "../effect/app-node-platform"
 import { SessionEvent } from "./event"
 import { SessionHistory } from "./history"
 import { SessionModelHeaders } from "./model-headers"
+import { SessionRequestHook } from "./request-hook"
 import { SessionRunnerModel } from "./runner/model"
 import { SessionSchema } from "./schema"

@@ -17,11 +20,10 @@ const MAX_LENGTH = 100

 type Dependencies = {
  readonly events: EventV2.Interface
-  readonly llm: {
-    readonly stream: (request: LLMRequest) => Stream.Stream<LLMEvent, LLMError>
-  }
+  readonly llm: LLMClientShape
  readonly agents: AgentV2.Interface
  readonly models: SessionRunnerModel.Interface
+  readonly hooks: PluginHooks.Interface
 }

 export interface Interface {
@@ -51,7 +53,7 @@ const make = (dependencies: Dependencies) => {
    if (!resolved) return
    const chunks: string[] = []
    let failed = false
-    const streamed = yield* dependencies.llm
+    const streamed = yield* SessionRequestHook.client(dependencies.llm, dependencies.hooks, session.id)
      .stream(
        LLM.request({
          model: resolved.model,
@@ -93,7 +95,8 @@ export const layer = Layer.effect(
    const agents = yield* AgentV2.Service
    const models = yield* SessionRunnerModel.Service
    const database = yield* Database.Service
-    const title = make({ events, llm, agents, models })
+    const hooks = yield* PluginHooks.Service
+    const title = make({ events, llm, agents, models, hooks })
    return Service.of({
      generateForFirstPrompt: (session) => title.generateForFirstPrompt(database.db, session),
    })
@@ -103,5 +106,5 @@ export const layer = Layer.effect(
 export const node = makeLocationNode({
  service: Service,
  layer,
-  deps: [EventV2.node, llmClient, AgentV2.node, SessionRunnerModel.node, Database.node],
+  deps: [EventV2.node, llmClient, AgentV2.node, SessionRunnerModel.node, Database.node, PluginHooks.node],
 })
@@ -6,7 +6,6 @@ import { ToolFailure } from "@opencode-ai/ai"
 import { Effect, Schema } from "effect"
 import { FileSystem } from "../filesystem"
 import { FSUtil } from "../fs-util"
-import { Image } from "../image"
 import { Location } from "../location"
 import { LocationMutation } from "../location-mutation"
 import { PermissionV2 } from "../permission"
@@ -35,7 +34,6 @@ export const Plugin = {
  effect: Effect.fn("ReadTool.Plugin")(function* (ctx: PluginContext) {
    const reader = yield* ReadToolFileSystem.Service
    const mutation = yield* LocationMutation.Service
-    const image = yield* Image.Service
    const permission = yield* PermissionV2.Service
    const sessionInstructions = yield* SessionInstructions.Service
    const fs = yield* FSUtil.Service
@@ -50,6 +48,12 @@ export const Plugin = {
              "Read a text file or supported image, page through a large UTF-8 text file by line offset, or list a directory page. Relative paths resolve from the current location; absolute paths inside it are accepted, while external absolute paths require external_directory approval.",
            input: Input,
            output: Output,
+            structured: Schema.toEncoded(Output),
+            // Image base64 reaches the model through content items (normalized generically
+            // at tool settlement); persisting a second copy in structured would store the
+            // original unresized bytes in the message row.
+            toStructuredOutput: ({ output }) =>
+              "encoding" in output && output.encoding === "base64" ? { ...output, content: "" } : output,
            toModelOutput: ({ input, output }) => {
              if (!("encoding" in output) || output.encoding !== "base64" || !SUPPORTED_IMAGE_MIMES.has(output.mime))
                return []
@@ -117,21 +121,14 @@ export const Plugin = {
                  Effect.catch(() => Effect.void),
                  Effect.catchDefect(() => Effect.void),
                )
-                if ("encoding" in content && content.encoding === "base64" && SUPPORTED_IMAGE_MIMES.has(content.mime)) {
-                  return yield* image
-                    .normalize(resource, { ...content, encoding: "base64" })
-                    .pipe(Effect.catchTag("Image.ResizerUnavailableError", () => Effect.succeed(content)))
-                }
-                if ("encoding" in content && content.encoding === "base64")
+                if ("encoding" in content && content.encoding === "base64" && !SUPPORTED_IMAGE_MIMES.has(content.mime))
                  return yield* Effect.fail(new ReadToolFileSystem.BinaryFileError({ resource }))
                return content
              }).pipe(
                Effect.mapError((error) => {
                  const message =
                    error instanceof ReadToolFileSystem.BinaryFileError ||
-                    error instanceof ReadToolFileSystem.MediaIngestLimitError ||
-                    error instanceof Image.DecodeError ||
-                    error instanceof Image.SizeError
+                    error instanceof ReadToolFileSystem.MediaIngestLimitError
                      ? error.message
                      : `Unable to read ${input.path}`
                  return new ToolFailure({ message, error })
@@ -3,6 +3,7 @@ export * as ToolRegistry from "./registry"
 import { ToolOutput, type ToolCall, type ToolDefinition, type ToolResultValue } from "@opencode-ai/ai"
 import { Context, Effect, Layer, Scope } from "effect"
 import type { AgentV2 } from "../agent"
+import { Image } from "../image"
 import { PermissionV2 } from "../permission"
 import { SessionMessage } from "../session/message"
 import { SessionSchema } from "../session/schema"
@@ -57,6 +58,40 @@ const registryLayer = Layer.effect(
  Effect.gen(function* () {
    const resources = yield* ToolOutputStore.Service
    const toolHooks = yield* ToolHooks.Service
+    const image = yield* Image.Service
+
+    type NormalizedItem = ToolOutput["content"][number] | "decode" | "size"
+    const normalizeImages = Effect.fn("ToolRegistry.normalizeImages")(function* (content: ToolOutput["content"]) {
+      const normalized = yield* Effect.forEach(content, (item): Effect.Effect<NormalizedItem> => {
+        if (item.type !== "file" || !item.mime.startsWith("image/")) return Effect.succeed(item)
+        // RFC 2397 permits parameters between the mime and ";base64".
+        const base64 = /^data:[^,]*;base64,(.*)$/s.exec(item.uri)?.[1]
+        if (base64 === undefined) return Effect.succeed(item)
+        const resource = item.name ?? `${item.mime} tool output`
+        return image
+          .normalize(resource, { uri: resource, content: base64, encoding: "base64", mime: item.mime })
+          .pipe(
+            Effect.map((result) => ({
+              ...item,
+              uri: `data:${result.mime};base64,${result.content}`,
+              mime: result.mime,
+            })),
+            Effect.catchTag("Image.ResizerUnavailableError", () => Effect.succeed(item)),
+            Effect.catchTag("Image.DecodeError", () => Effect.succeed("decode" as const)),
+            Effect.catchTag("Image.SizeError", () => Effect.succeed("size" as const)),
+          )
+      })
+      const note = (reason: "decode" | "size", text: string) => {
+        const count = normalized.filter((item) => item === reason).length
+        if (count === 0) return []
+        return [{ type: "text" as const, text: `[${count} image${count === 1 ? "" : "s"} omitted: ${text}]` }]
+      }
+      return [
+        ...normalized.filter((item) => typeof item !== "string"),
+        ...note("decode", "could not be decoded."),
+        ...note("size", "could not be resized below the image size limit."),
+      ]
+    })
    type Registration = {
      readonly tool: AnyTool
      readonly name: string
@@ -84,10 +119,11 @@ const registryLayer = Layer.effect(
          agent: input.agent,
          messageID: input.messageID,
          callID: input.call.id,
-          progress: (update) =>
-            input.progress?.({
-              structured: update.structured,
-              content: (update.content ?? []).map((part) =>
+          progress: (update) => {
+            const progress = input.progress
+            if (!progress) return Effect.void
+            return normalizeImages(
+              (update.content ?? []).map((part) =>
                part.type === "text"
                  ? { type: "text" as const, text: part.text }
                  : {
@@ -97,7 +133,8 @@ const registryLayer = Layer.effect(
                      name: part.name,
                    },
              ),
-            }) ?? Effect.void,
+            ).pipe(Effect.flatMap((content) => progress({ structured: update.structured, content })))
+          },
        },
      ).pipe(
        Effect.map((output) => ({ output })),
@@ -115,7 +152,7 @@ const registryLayer = Layer.effect(
        const bounded = yield* resources.bound({
          sessionID: input.sessionID,
          callID: input.call.id,
-          output: pending.output,
+          output: { structured: pending.output.structured, content: yield* normalizeImages(pending.output.content) },
        })
        const result = ToolOutput.toResultValue(bounded.output)
        settlement =
@@ -232,11 +269,11 @@ function whollyDisabled(action: string, rules: PermissionV2.Ruleset) {
 export const node = makeLocationNode({
  service: Service,
  layer,
-  deps: [ToolOutputStore.node, ToolHooks.node],
+  deps: [ToolOutputStore.node, ToolHooks.node, Image.node],
 })

 export const toolsNode = makeLocationNode({
  service: Tools.Service,
  layer,
-  deps: [ToolOutputStore.node, ToolHooks.node],
+  deps: [ToolOutputStore.node, ToolHooks.node, Image.node],
 })
@@ -5,7 +5,7 @@ import { ProviderV2 } from "@opencode-ai/core/provider"
 import { LLM, Message } from "@opencode-ai/ai"
 import { LLMClient } from "@opencode-ai/ai/route"
 import { expect } from "bun:test"
-import { Effect } from "effect"
+import { Effect, Stream } from "effect"
 import { testEffect } from "./lib/effect"

 const it = testEffect(AISDK.locationLayer)
@@ -19,6 +19,64 @@ const model = (packageName: string, settings: Record<string, unknown> = {}) =>
    limit: { context: 100, output: 20 },
  })

+it.effect("applies request transforms to AI SDK fetch calls", () =>
+  Effect.gen(function* () {
+    const aisdk = yield* AISDK.Service
+    let received: Request | undefined
+    const input = model("test-sdk")
+    Object.defineProperty(input, "settings", {
+      value: {
+        fetch: async (input: Parameters<typeof fetch>[0], init?: RequestInit) => {
+          received = new Request(input as Request, init)
+          return new Response()
+        },
+      },
+    })
+    yield* aisdk.hook.sdk((event) => {
+      event.sdk = {
+        languageModel: () => ({
+          doStream: async () => {
+            await event.options.fetch("https://provider.test/generate", { method: "POST", body: "{}" })
+            return {
+              stream: new ReadableStream({
+                start(controller) {
+                  controller.enqueue({
+                    type: "finish",
+                    finishReason: { unified: "stop" },
+                    usage: {
+                      inputTokens: { total: 0, noCache: 0, cacheRead: 0, cacheWrite: 0 },
+                      outputTokens: { total: 0, text: 0, reasoning: 0 },
+                    },
+                  })
+                  controller.close()
+                },
+              }),
+            }
+          },
+        }),
+      }
+    })
+    const resolved = yield* aisdk.model(input)
+    const request = LLM.request({ model: resolved, prompt: "Hello" })
+    const body = yield* resolved.route.body.from(request)
+    const prepared = yield* resolved.route.prepareTransport(body, request)
+    yield* resolved.route
+      .streamPrepared(prepared, request, {
+        http: { execute: () => Effect.die("unused") },
+        transformRequest: (request) =>
+          Effect.sync(() => {
+            const headers = new Headers(request.headers)
+            headers.set("x-hook", "enabled")
+            return new Request(request, { headers })
+          }),
+      })
+      .pipe(Stream.runDrain)
+
+    expect(received?.url).toBe("https://provider.test/generate")
+    expect(received?.headers.get("x-hook")).toBe("enabled")
+  }),
+)
+
 it.effect("keys language models by package and flattened overlays", () =>
  Effect.gen(function* () {
    const aisdk = yield* AISDK.Service
@@ -0,0 +1,7 @@
+import { Image } from "@opencode-ai/core/image"
+import { Effect, Layer } from "effect"
+
+/** Passthrough resizer for tests that build ToolRegistry.node without a Location. */
+export const imagePassthrough = Layer.mock(Image.Service, {
+  normalize: (_resource, content) => Effect.succeed(content),
+})
@@ -29,7 +29,9 @@ import { McpTool } from "@opencode-ai/core/tool/mcp"
 import { ToolRegistry } from "@opencode-ai/core/tool/registry"
 import { ToolOutputStore } from "@opencode-ai/core/tool-output-store"
 import { Deferred, Effect, Exit, Fiber, Layer, Schema, Stream } from "effect"
+import { Image } from "@opencode-ai/core/image"
 import { testEffect } from "./lib/effect"
+import { imagePassthrough } from "./lib/image"
 import { location } from "./fixture/location"
 import { settleTool, toolDefinitions, toolIdentity, waitForTool } from "./lib/tool"

@@ -250,6 +252,7 @@ const it = testEffect(
    [PermissionV2.node, permissions],
    [EventV2.node, events],
    [ToolOutputStore.node, ToolOutputStore.nodeWithoutConfig],
+    [Image.node, imagePassthrough],
  ]),
 )

@@ -42,4 +42,24 @@ describe("PluginHooks", () => {
      expect(event.messages).toEqual([Message.user("changed")])
    }),
  )
+
+  it.effect("allows session request hooks to replace the raw request", () =>
+    Effect.gen(function* () {
+      const hooks = yield* PluginHooks.Service
+      expect(hooks.has("session", "request")).toBe(false)
+      yield* hooks.register("session", "request", (event) =>
+        Effect.sync(() => {
+          event.request = new Request(event.request, { headers: { "x-hook": "enabled" } })
+        }),
+      )
+      expect(hooks.has("session", "request")).toBe(true)
+      const event = {
+        sessionID: Session.ID.make("ses_request_hook"),
+        request: new Request("https://example.com"),
+      }
+
+      expect(yield* hooks.trigger("session", "request", event)).toBe(event)
+      expect(event.request.headers.get("x-hook")).toBe("enabled")
+    }),
+  )
 })
@@ -1,5 +1,6 @@
 import { describe, expect } from "bun:test"
 import { LLMClient, LLMEvent, Model, type LLMRequest } from "@opencode-ai/ai"
+import type { LLMClientShape } from "@opencode-ai/ai/route"
 import { OpenAIChat } from "@opencode-ai/ai/protocols"
 import { Config } from "@opencode-ai/core/config"
 import { Database } from "@opencode-ai/core/database/database"
@@ -40,14 +41,16 @@ const projects = Layer.succeed(
  }),
 )
 let requests: LLMRequest[] = []
-const client = Layer.mock(LLMClient.Service)({
+const clientShape: LLMClientShape = {
  prepare: () => Effect.die("unused"),
  stream: (request: LLMRequest) => {
    requests.push(request)
    return Stream.make(LLMEvent.textDelta({ id: "summary", text: "manual session summary" }))
  },
  generate: () => Effect.die("unused"),
-})
+  withRequestTransform: () => clientShape,
+}
+const client = Layer.mock(LLMClient.Service)(clientShape)
 const config = Layer.mock(Config.Service)({ entries: () => Effect.succeed([]) })
 const models = SessionRunnerModel.layerWith(() => Effect.succeed(SessionRunnerModel.resolved(model)))
 const locations = Layer.effect(
@@ -1,5 +1,6 @@
 import { expect, test } from "bun:test"
 import { LLMClient, LLMEvent, Model, type LLMRequest } from "@opencode-ai/ai"
+import type { LLMClientShape } from "@opencode-ai/ai/route"
 import { OpenAIChat } from "@opencode-ai/ai/protocols"
 import { Config } from "@opencode-ai/core/config"
 import { Database } from "@opencode-ai/core/database/database"
@@ -31,14 +32,16 @@ const model = Model.make({
  provider: "test",
  route: OpenAIChat.route.with({ limits: { context: 10_000, output: 1_000 } }),
 })
-const client = Layer.mock(LLMClient.Service)({
+const clientShape: LLMClientShape = {
  prepare: () => Effect.die("unused"),
  stream: (request: LLMRequest) => {
    requests.push(request)
    return Stream.make(LLMEvent.textDelta({ id: "summary", text: "manual summary" }))
  },
  generate: () => Effect.die("unused"),
-})
+  withRequestTransform: () => clientShape,
+}
+const client = Layer.mock(LLMClient.Service)(clientShape)
 const config = Layer.mock(Config.Service)({ entries: () => Effect.succeed([]) })
 const models = Layer.mock(SessionRunnerModel.Service)({
  resolve: () => Effect.succeed(SessionRunnerModel.resolved(model)),
@@ -1,5 +1,5 @@
 import { describe, expect } from "bun:test"
-import { DateTime, Effect, Fiber, Layer, Schema, Stream } from "effect"
+import { DateTime, Effect, Fiber, Layer, LayerMap, Schema, Stream } from "effect"
 import { mkdtemp, rm } from "fs/promises"
 import { tmpdir } from "os"
 import path from "path"
@@ -24,7 +24,10 @@ import { SessionExecution } from "@opencode-ai/core/session/execution"
 import { SessionPending } from "@opencode-ai/core/session/pending"
 import { SessionPendingTable, SessionMessageTable, SessionTable } from "@opencode-ai/core/session/sql"
 import { SessionStore } from "@opencode-ai/core/session/store"
+import { LocationServiceMap } from "@opencode-ai/core/location-service-map"
+import type { LocationServices } from "@opencode-ai/core/location-services"
 import { testEffect } from "./lib/effect"
+import { imagePassthrough } from "./lib/image"

 const executionCalls: SessionV2.ID[] = []
 const interruptCalls: SessionV2.ID[] = []
@@ -49,10 +52,22 @@ const execution = Layer.succeed(
    awaitIdle: () => Effect.void,
  }),
 )
+const locations = Layer.effect(
+  LocationServiceMap.Service,
+  LayerMap.make(
+    () =>
+      // Attachment admission only needs the location-scoped Image service.
+      // oxlint-disable-next-line typescript-eslint/no-unsafe-type-assertion
+      imagePassthrough as unknown as Layer.Layer<LocationServices>,
+  ),
+)
 const it = testEffect(
  AppNodeBuilder.build(
    LayerNode.group([Database.node, EventV2.node, SessionProjector.node, SessionStore.node, SessionV2.node]),
-    [[SessionExecution.node, execution]],
+    [
+      [SessionExecution.node, execution],
+      [LocationServiceMap.node, locations],
+    ],
  ),
 )
 const sessionID = SessionV2.ID.make("ses_prompt_test")
@@ -3,6 +3,7 @@ import { Tool } from "@opencode-ai/core/tool/tool"
 import { AgentV2 } from "@opencode-ai/core/agent"
 import type { PermissionV2 } from "@opencode-ai/core/permission"
 import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
+import { Image } from "@opencode-ai/core/image"
 import { SessionV2 } from "@opencode-ai/core/session"
 import { SessionMessage } from "@opencode-ai/core/session/message"
 import { ToolOutputStore } from "@opencode-ai/core/tool-output-store"
@@ -28,7 +29,28 @@ const outputStore = Layer.mock(ToolOutputStore.Service, {
    )
  },
 })
-const registryLayer = AppNodeBuilder.build(ToolRegistry.node, [[ToolOutputStore.node, outputStore]])
+const imageStore = Layer.mock(Image.Service, {
+  normalize: (resource, content) => {
+    if (resource === "corrupt.png") return Effect.fail(new Image.DecodeError({ resource }))
+    if (resource === "too-large.png")
+      return Effect.fail(
+        new Image.SizeError({
+          resource,
+          width: 9_000,
+          height: 9_000,
+          bytes: content.content.length,
+          maxWidth: 2_000,
+          maxHeight: 2_000,
+          maxBytes: 5,
+        }),
+      )
+    return Effect.succeed({ ...content, content: "bm9ybWFsaXplZA==", mime: "image/jpeg" })
+  },
+})
+const registryLayer = AppNodeBuilder.build(ToolRegistry.node, [
+  [ToolOutputStore.node, outputStore],
+  [Image.node, imageStore],
+])
 const it = testEffect(registryLayer)
 const identity = {
  agent: AgentV2.ID.make("build"),
@@ -255,6 +277,75 @@ describe("ToolRegistry", () => {
    }),
  )

+  it.effect("normalizes image tool output at settlement and drops unresizable images", () =>
+    Effect.gen(function* () {
+      const service = yield* ToolRegistry.Service
+      yield* service.register({
+        snapshot: Tool.make({
+          description: "Return images",
+          input: Schema.Struct({ text: Schema.String }),
+          output: Schema.Struct({ text: Schema.String }),
+          execute: ({ text }) => Effect.succeed({ text }),
+          toModelOutput: ({ output }) => [
+            { type: "file", data: "aW1hZ2U=", mime: "image/png", name: "frame.png" },
+            { type: "file", data: "aW1hZ2U=", mime: "image/png", name: "too-large.png" },
+            { type: "file", data: "aW1hZ2U=", mime: "image/png", name: "corrupt.png" },
+            { type: "text", text: output.text },
+          ],
+        }),
+      }, { codemode: false })
+
+      const settlement = yield* settleTool(service, call("snapshot"))
+      expect(settlement.output?.content).toEqual([
+        { type: "file", uri: "data:image/jpeg;base64,bm9ybWFsaXplZA==", mime: "image/jpeg", name: "frame.png" },
+        { type: "text", text: "snapshot" },
+        { type: "text", text: "[1 image omitted: could not be decoded.]" },
+        { type: "text", text: "[1 image omitted: could not be resized below the image size limit.]" },
+      ])
+    }),
+  )
+
+  it.effect("normalizes image progress content before it is published", () =>
+    Effect.gen(function* () {
+      const service = yield* ToolRegistry.Service
+      yield* service.register({
+        progressive: Tool.make({
+          description: "Emit image progress",
+          input: Schema.Struct({ text: Schema.String }),
+          output: Schema.Struct({ text: Schema.String }),
+          execute: ({ text }, context) =>
+            context
+              .progress({
+                structured: { stage: "capture" },
+                content: [
+                  { type: "file", data: "aW1hZ2U=", mime: "image/png", name: "frame.png" },
+                  { type: "file", data: "aW1hZ2U=", mime: "image/png", name: "too-large.png" },
+                ],
+              })
+              .pipe(Effect.as({ text })),
+        }),
+      }, { codemode: false })
+
+      const updates: ToolRegistry.Progress[] = []
+      yield* settleTool(service, {
+        ...call("progressive"),
+        progress: (update) =>
+          Effect.sync(() => {
+            updates.push(update)
+          }),
+      })
+      expect(updates).toEqual([
+        {
+          structured: { stage: "capture" },
+          content: [
+            { type: "file", uri: "data:image/jpeg;base64,bm9ybWFsaXplZA==", mime: "image/jpeg", name: "frame.png" },
+            { type: "text", text: "[1 image omitted: could not be resized below the image size limit.]" },
+          ],
+        },
+      ])
+    }),
+  )
+
  it.effect("enforces transformed codecs at execution and projection boundaries", () =>
    Effect.gen(function* () {
      const service = yield* ToolRegistry.Service
@@ -89,9 +89,7 @@ let toolExecutionsStarted: Deferred.Deferred<void> | undefined
 let toolExecutionsReady = 5
 let activeToolExecutions = 0
 let maxActiveToolExecutions = 0
-const client = Layer.succeed(
-  LLMClient.Service,
-  LLMClient.Service.of({
+const clientValue: LLMClientShape = LLMClient.Service.of({
    prepare: () => Effect.die("unused"),
    stream: ((request: LLMRequest) => {
      requests.push(request)
@@ -113,8 +111,9 @@ const client = Layer.succeed(
      )
    }) as unknown as LLMClientShape["stream"],
    generate: () => Effect.die("unused"),
-  }),
-)
+    withRequestTransform: () => clientValue,
+  })
+const client = Layer.succeed(LLMClient.Service, clientValue)
 const reply = {
  stop: () => [
    LLMEvent.stepStart({ index: 0 }),
@@ -1,5 +1,6 @@
 import { expect } from "bun:test"
 import { LLMClient, LLMEvent, Model, type LLMRequest } from "@opencode-ai/ai"
+import type { LLMClientShape } from "@opencode-ai/ai/route"
 import { OpenAIChat } from "@opencode-ai/ai/protocols"
 import { AgentV2 } from "@opencode-ai/core/agent"
 import { Database } from "@opencode-ai/core/database/database"
@@ -29,14 +30,16 @@ const model = Model.make({
  provider: "test",
  route: OpenAIChat.route.with({ limits: { context: 10_000, output: 1_000 } }),
 })
-const client = Layer.mock(LLMClient.Service)({
+const clientShape: LLMClientShape = {
  prepare: () => Effect.die("unused"),
  stream: (request: LLMRequest) => {
    requests.push(request)
    return Stream.make(LLMEvent.textDelta({ id: "title", text: "Generated Title\n" }))
  },
  generate: () => Effect.die("unused"),
-})
+  withRequestTransform: () => clientShape,
+}
+const client = Layer.mock(LLMClient.Service)(clientShape)
 const models = Layer.mock(SessionRunnerModel.Service)({
  resolve: () => Effect.succeed(SessionRunnerModel.resolved(model)),
 })
@@ -8,7 +8,9 @@ import { SessionV2 } from "@opencode-ai/core/session"
 import { ToolRegistry } from "@opencode-ai/core/tool/registry"
 import { QuestionTool } from "@opencode-ai/core/tool/question"
 import { ToolOutputStore } from "@opencode-ai/core/tool-output-store"
+import { Image } from "@opencode-ai/core/image"
 import { testEffect } from "./lib/effect"
+import { imagePassthrough } from "./lib/image"
 import { makeLocationNode } from "@opencode-ai/core/effect/app-node"
 import { toolIdentity, executeTool, registerToolPlugin, settleTool, toolDefinitions } from "./lib/tool"

@@ -84,6 +86,7 @@ const it = testEffect(
    [PermissionV2.node, permission],
    [Form.node, form],
    [ToolOutputStore.node, ToolOutputStore.nodeWithoutConfig],
+    [Image.node, imagePassthrough],
  ]),
 )

@@ -291,6 +291,9 @@ describe("ReadTool", () => {
        name: "pixel.png",
        mime: "image/png",
        encoding: "base64",
+        // Image base64 is carried by the content file item only; structured is slimmed
+        // so the original bytes are never persisted twice.
+        content: "",
      })
      expect(settled.output?.content).toMatchObject([
        { type: "text", text: "Image read successfully" },
@@ -364,7 +367,7 @@ describe("ReadTool", () => {
    }),
  )

-  it.effect("rejects invalid image data returned by the filesystem", () =>
+  it.effect("drops undecodable image data at settlement", () =>
    Effect.gen(function* () {
      readResult = {
        uri: "file:///truncated.png",
@@ -381,11 +384,17 @@ describe("ReadTool", () => {
          ...toolIdentity,
          call: { type: "tool-call", id: "call-truncated-image", name: "read", input: { path: "truncated.png" } },
        }),
-      ).toEqual({ type: "error", value: "Image could not be decoded: truncated.png" })
+      ).toEqual({
+        type: "content",
+        value: [
+          { type: "text", text: "Image read successfully" },
+          { type: "text", text: "[1 image omitted: could not be decoded.]" },
+        ],
+      })
    }),
  )

-  it.effect("rejects oversized images when resizing is disabled", () =>
+  it.effect("drops oversized images at settlement when resizing is disabled", () =>
    Effect.gen(function* () {
      const photon = yield* Effect.promise(() => import("@silvia-odwyer/photon-node"))
      const source = new photon.PhotonImage(new Uint8Array(Array.from({ length: 16 * 4 }, () => 255)), 16, 1)
@@ -409,14 +418,20 @@ describe("ReadTool", () => {
        }),
      ]
      const registry = yield* ToolRegistry.Service
-      const result = yield* executeTool(registry, {
-        sessionID,
-        ...toolIdentity,
-        call: { type: "tool-call", id: "call-wide-image", name: "read", input: { path: "wide.png" } },
-      })

-      expect(result.type).toBe("error")
-      if (result.type === "error") expect(result.value).toContain("exceeding configured limits 4x2000")
+      expect(
+        yield* executeTool(registry, {
+          sessionID,
+          ...toolIdentity,
+          call: { type: "tool-call", id: "call-wide-image", name: "read", input: { path: "wide.png" } },
+        }),
+      ).toEqual({
+        type: "content",
+        value: [
+          { type: "text", text: "Image read successfully" },
+          { type: "text", text: "[1 image omitted: could not be resized below the image size limit.]" },
+        ],
+      })
    }),
  )

@@ -460,7 +475,7 @@ describe("ReadTool", () => {
    }),
  )

-  it.effect("enforces max base64 bytes after resize attempts", () =>
+  it.effect("drops images that cannot fit max base64 bytes after resize attempts", () =>
    Effect.gen(function* () {
      const png = "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+A8AAQUBAScY42YAAAAASUVORK5CYII="
      readResult = {
@@ -481,14 +496,20 @@ describe("ReadTool", () => {
        }),
      ]
      const registry = yield* ToolRegistry.Service
-      const result = yield* executeTool(registry, {
-        sessionID,
-        ...toolIdentity,
-        call: { type: "tool-call", id: "call-max-bytes", name: "read", input: { path: "pixel.png" } },
-      })

-      expect(result.type).toBe("error")
-      if (result.type === "error") expect(result.value).toContain("/1 bytes")
+      expect(
+        yield* executeTool(registry, {
+          sessionID,
+          ...toolIdentity,
+          call: { type: "tool-call", id: "call-max-bytes", name: "read", input: { path: "pixel.png" } },
+        }),
+      ).toEqual({
+        type: "content",
+        value: [
+          { type: "text", text: "Image read successfully" },
+          { type: "text", text: "[1 image omitted: could not be resized below the image size limit.]" },
+        ],
+      })
    }),
  )

@@ -12,7 +12,9 @@ import { SkillTool } from "@opencode-ai/core/tool/skill"
 import { ToolRegistry } from "@opencode-ai/core/tool/registry"
 import { ToolOutputStore } from "@opencode-ai/core/tool-output-store"
 import { tmpdir } from "./fixture/tmpdir"
+import { Image } from "@opencode-ai/core/image"
 import { it } from "./lib/effect"
+import { imagePassthrough } from "./lib/image"
 import { makeLocationNode } from "@opencode-ai/core/effect/app-node"
 import { FSUtil } from "@opencode-ai/core/fs-util"
 import { toolIdentity, executeTool, registerToolPlugin, settleTool, toolDefinitions } from "./lib/tool"
@@ -90,6 +92,7 @@ describe("SkillTool", () => {
              [PermissionV2.node, permission],
              [SkillV2.node, skills],
              [ToolOutputStore.node, ToolOutputStore.nodeWithoutConfig],
+              [Image.node, imagePassthrough],
            ],
          )

@@ -11,7 +11,9 @@ import { ToolRegistry } from "@opencode-ai/core/tool/registry"
 import { WebFetchTool } from "@opencode-ai/core/tool/webfetch"
 import { ToolOutputStore } from "@opencode-ai/core/tool-output-store"
 import { makeLocationNode } from "@opencode-ai/core/effect/app-node"
+import { Image } from "@opencode-ai/core/image"
 import { testEffect } from "./lib/effect"
+import { imagePassthrough } from "./lib/image"
 import { toolIdentity, executeTool, registerToolPlugin, settleTool, toolDefinitions } from "./lib/tool"

 const webFetchToolNode = makeLocationNode({
@@ -50,6 +52,7 @@ const toolLayer = (replacements: LayerNode.Replacements = []) =>
  AppNodeBuilder.build(LayerNode.group([ToolRegistry.node, ToolRegistry.toolsNode, webFetchToolNode]), [
    [PermissionV2.node, permission],
    [ToolOutputStore.node, ToolOutputStore.nodeWithoutConfig],
+    [Image.node, imagePassthrough],
    ...replacements,
  ])
 const it = testEffect(toolLayer([[LayerNodePlatform.httpClient, http]]))
@@ -10,7 +10,9 @@ import { ToolRegistry } from "@opencode-ai/core/tool/registry"
 import { WebSearchTool } from "@opencode-ai/core/tool/websearch"
 import { ToolOutputStore } from "@opencode-ai/core/tool-output-store"
 import { makeLocationNode } from "@opencode-ai/core/effect/app-node"
+import { Image } from "@opencode-ai/core/image"
 import { testEffect } from "./lib/effect"
+import { imagePassthrough } from "./lib/image"
 import { toolIdentity, executeTool, registerToolPlugin, settleTool, toolDefinitions } from "./lib/tool"

 const webSearchToolNode = makeLocationNode({
@@ -138,6 +140,7 @@ const it = testEffect(
      [LayerNodePlatform.httpClient, http],
      [WebSearchTool.configNode, websearchConfig],
      [ToolOutputStore.node, ToolOutputStore.nodeWithoutConfig],
+      [Image.node, imagePassthrough],
    ],
  ),
 )
@@ -92,6 +92,19 @@ yield *
  )
 ```

+The serialized provider request is also mutable before it is sent:
+
+```ts
+yield *
+  ctx.session.hook("request", (event) =>
+    Effect.sync(() => {
+      event.request = new Request(event.request, {
+        headers: new Headers([...event.request.headers, ["x-plugin", "enabled"]]),
+      })
+    }),
+  )
+```
+
 ## Reloading A Domain

 When data captured by a transform changes, reload the affected domain:
@@ -15,8 +15,14 @@ export interface SessionContext {
  tools: Record<string, { description: string; input: JsonSchema.JsonSchema }>
 }

+export interface SessionRequest {
+  readonly sessionID: Session.ID
+  request: Request
+}
+
 export interface SessionHooks {
  readonly context: SessionContext
+  readonly request: SessionRequest
 }

 export type SessionDomain = Pick<
@@ -94,6 +94,16 @@ await ctx.session.hook("context", (event) => {
 })
 ```

+The serialized provider request is also mutable before it is sent:
+
+```ts
+await ctx.session.hook("request", (event) => {
+  event.request = new Request(event.request, {
+    headers: new Headers([...event.request.headers, ["x-plugin", "enabled"]]),
+  })
+})
+```
+
 Promise tools use plain object declarations with async executors:

 ```ts
@@ -15,8 +15,14 @@ export interface SessionContext {
  tools: Record<string, { description: string; input: JsonSchema.JsonSchema }>
 }

+export interface SessionRequest {
+  readonly sessionID: Session.ID
+  request: Request
+}
+
 export interface SessionHooks {
  readonly context: SessionContext
+  readonly request: SessionRequest
 }

 export type SessionDomain = Pick<SessionApi, "create" | "get" | "prompt" | "command" | "synthetic" | "interrupt"> & {
@@ -97,7 +97,7 @@ export const Definitions = {
  session_background: keybind("ctrl+b", "Background blocking session tools"),
  session_compact: keybind("<leader>c", "Compact the session"),
  session_queued_prompts: keybind("<leader>q", "Manage queued prompts"),
-  session_child_first: keybind("down,<leader>down", "Show or hide activity"),
+  session_child_first: keybind("down,<leader>down", "Toggle subagent picker"),
  session_child_cycle: keybind("right", "Go to next child session"),
  session_child_cycle_reverse: keybind("left", "Go to previous child session"),
  session_parent: keybind("up", "Go to parent session"),
@@ -93,13 +93,13 @@ export function Composer(props: ComposerProps) {
    mode: "composer",
    enabled: () => props.open,
    commands: [
-      { bind: "left", title: "Previous tab", group: "Activity", run: () => switchTab(-1) },
-      { bind: "right", title: "Next tab", group: "Activity", run: () => switchTab(1) },
-      { bind: "escape", title: "Close activity", group: "Activity", run: close },
+      { bind: "left", title: "Previous tab", group: "Composer", run: () => switchTab(-1) },
+      { bind: "right", title: "Next tab", group: "Composer", run: () => switchTab(1) },
+      { bind: "escape", title: "Close composer", group: "Composer", run: close },
      {
        bind: "<leader>down",
-        title: "Hide activity",
-        group: "Activity",
+        title: "Toggle composer",
+        group: "Composer",
        run: close,
      },
    ],
@@ -57,7 +57,7 @@ export function ShellTab(props: { sessionID: string }) {
      {
        id: "composer.shell.up",
        title: "Previous shell",
-        group: "Activity",
+        group: "Composer",
        bind: "up",
        run() {
          const list = entries()
@@ -68,7 +68,7 @@ export function ShellTab(props: { sessionID: string }) {
      {
        id: "composer.shell.down",
        title: "Next shell",
-        group: "Activity",
+        group: "Composer",
        bind: "down",
        run() {
          const list = entries()
@@ -79,7 +79,7 @@ export function ShellTab(props: { sessionID: string }) {
      {
        id: "composer.shell.kill",
        title: "Kill shell command",
-        group: "Activity",
+        group: "Composer",
        bind: "ctrl+d",
        run() {
          const entry = selectedEntry()
@@ -150,7 +150,7 @@ export function SubagentsTab(props: { sessionID: string }) {
      {
        id: "composer.subagent.up",
        title: "Previous subagent",
-        group: "Activity",
+        group: "Composer",
        bind: "up",
        run() {
          const list = entries()
@@ -161,7 +161,7 @@ export function SubagentsTab(props: { sessionID: string }) {
      {
        id: "composer.subagent.down",
        title: "Next subagent",
-        group: "Activity",
+        group: "Composer",
        bind: "down",
        run() {
          const list = entries()
@@ -172,7 +172,7 @@ export function SubagentsTab(props: { sessionID: string }) {
      {
        id: "composer.subagent.select",
        title: "Navigate to subagent",
-        group: "Activity",
+        group: "Composer",
        bind: "return",
        run() {
          const entry = entries()[store.selected]
@@ -182,7 +182,7 @@ export function SubagentsTab(props: { sessionID: string }) {
      {
        id: "composer.subagent.interrupt",
        title: "Interrupt subagent",
-        group: "Activity",
+        group: "Composer",
        bind: "ctrl+d",
        run() {
          const entry = selectedEntry()
@@ -740,7 +740,7 @@ export function Session() {
      },
    },
    {
-      title: composer.open || !!session()?.parentID ? "Hide activity" : "Show activity",
+      title: "Toggle subagent picker",
      name: "session.child.first",
      category: "Session",
      run: () => {
@@ -2548,10 +2548,8 @@ function WebSearch(props: ToolProps) {
 function Subagent(props: ToolProps) {
  const { navigate } = useRoute()
  const data = useData()
-  const input = createMemo(() => (typeof props.part.state.input === "string" ? {} : props.part.state.input))
-  const metadata = createMemo(() => (props.part.state.status === "streaming" ? {} : props.part.state.structured))
-  const sessionID = createMemo(() => stringValue(metadata().sessionID) ?? stringValue(metadata().sessionId))
-  const description = createMemo(() => stringValue(input().description))
+  const sessionID = createMemo(() => stringValue(props.metadata.sessionID) ?? stringValue(props.metadata.sessionId))
+  const description = createMemo(() => stringValue(props.input.description))
  const isRunning = createMemo(() => {
    const id = sessionID()
    return props.part.state.status === "running" || Boolean(id && data.session.status(id) === "running")
@@ -2569,16 +2567,23 @@ function Subagent(props: ToolProps) {
        if (id) navigate({ type: "session", sessionID: id })
      }}
      status={
-        input().background === true || metadata().status === "running" ? (
+        isBackgroundSubagent(props.metadata, props.part.state.status) ? (
          <StatusBadge>Background</StatusBadge>
        ) : undefined
      }
    >
-      {`${Locale.titlecase(stringValue(input().agent) ?? stringValue(input().subagent_type) ?? "General")} Subagent — ${description() ?? "Subagent"}`}
+      {`${Locale.titlecase(stringValue(props.input.agent) ?? stringValue(props.input.subagent_type) ?? "General")} Subagent — ${description() ?? "Subagent"}`}
    </InlineTool>
  )
 }

+export function isBackgroundSubagent(
+  metadata: Record<string, unknown>,
+  status: SessionMessageAssistantTool["state"]["status"],
+) {
+  return status === "completed" && metadata.status === "running"
+}
+
 export function formatSubagentRetry(attempt: number, message: string) {
  return `Retrying (attempt ${attempt}) · ${message}`
 }
@@ -4,6 +4,7 @@ import { testRender, type JSX } from "@opentui/solid"
 import {
  formatSubagentRetry,
  InlineToolRow,
+  isBackgroundSubagent,
  parseApplyPatchFiles,
  parseDiagnostics,
  parseQuestionAnswers,
@@ -201,6 +202,13 @@ describe("TUI inline tool wrapping", () => {
    expect(formatSubagentRetry(2, "Rate limited by provider")).toBe("Retrying (attempt 2) · Rate limited by provider")
  })

+  test("labels only detached or async subagents as background", () => {
+    expect(isBackgroundSubagent({ status: "running" }, "running")).toBeFalse()
+    expect(isBackgroundSubagent({ status: "running" }, "completed")).toBeTrue()
+    expect(isBackgroundSubagent({ status: "running" }, "error")).toBeFalse()
+    expect(isBackgroundSubagent({ status: "completed" }, "completed")).toBeFalse()
+  })
+
  test("snapshots consecutive grep, glob, and read rows at a narrow width", async () => {
    expect(await renderFrame(() => <Fixture />, { width: 72, height: 12 })).toMatchSnapshot()
  })
@@ -86,7 +86,7 @@ test("resolves a session move keybind", () => {
  expect(config.keybinds.get("session.move")).toMatchObject([{ key: "ctrl+o" }])
 })

-test("opens activity with down", () => {
+test("opens the subagent picker with down", () => {
  const config = resolve({}, { terminalSuspend: true })

  expect(config.keybinds.get("session.child.first")).toMatchObject([{ key: "down,<leader>down" }])
Author	SHA1	Message	Date
Aiden Cline	0e864b223f	feat(plugin): add session request hook	2026-07-16 17:48:21 +00:00
Aiden Cline	ad8e6b1fb6	feat(codemode): support property deletion (#37335 )	2026-07-16 12:21:28 -05:00
Kit Langton	041cda905d	fix(tui): label only detached subagents as background (#37306 )	2026-07-16 12:21:19 -04:00
Aiden Cline	2ad6c42143	feat(core): normalize tool and attachment images at settlement (#37141 )	2026-07-16 11:16:19 -05:00
Aiden Cline	60c7f847c1	feat(codemode): support void and Object.is (#37332 )	2026-07-16 11:15:29 -05:00
Dax Raad	7ab8a08efa	sync	2026-07-16 12:08:12 -04:00
Aiden Cline	7388e69b5c	chore(codemode): update interpreter support	2026-07-16 10:44:44 -05:00