refactor(core): compact question tool schema (#41772)

Co-authored-by: Dax Raad <d@ironbay.co>

packages/app/src/context/server-session-v2-reducer.test.ts

@@ -69,6 +69,63 @@ describe("v2 session reducer", () => {
     })
   })
 
+  test("prefers durable selection predecessors and derives them for older events", () => {
+    const source: SessionMessageInfo[] = [
+      { id: "msg_previous_agent", type: "agent-switched", agent: "build", time: { created: 1 } },
+      {
+        id: "msg_previous_model",
+        type: "model-switched",
+        model: { id: "old", providerID: "provider" },
+        time: { created: 1 },
+      },
+    ]
+    const reducer = createV2SessionReducer()
+
+    const agent = reducer.reduce(
+      source,
+      event({
+        ...base,
+        id: "evt_agent",
+        type: "session.agent.selected",
+        data: { sessionID: "ses_1", agent: "plan", previous: "review" },
+      }),
+    )
+    const model = reducer.reduce(
+      source,
+      event({
+        ...base,
+        id: "evt_model",
+        type: "session.model.selected",
+        data: {
+          sessionID: "ses_1",
+          model: { id: "new", providerID: "provider" },
+          previous: { id: "durable", providerID: "provider" },
+        },
+      }),
+    )
+    const legacyAgent = reducer.reduce(
+      source,
+      event({
+        ...base,
+        id: "evt_legacy_agent",
+        type: "session.agent.selected",
+        data: { sessionID: "ses_1", agent: "plan" },
+      }),
+    )
+
+    expect(agent?.messages.at(-1)).toMatchObject({ type: "agent-switched", agent: "plan", previous: "review" })
+    expect(model?.messages.at(-1)).toMatchObject({
+      type: "model-switched",
+      model: { id: "new" },
+      previous: { id: "durable" },
+    })
+    expect(legacyAgent?.messages.at(-1)).toMatchObject({
+      type: "agent-switched",
+      agent: "plan",
+      previous: "build",
+    })
+  })
+
   test("folds tool, retry, and completion events", () => {
     const reducer = createV2SessionReducer()
     let messages: SessionMessageInfo[] = []

packages/app/src/context/server-session-v2-reducer.ts

@@ -61,6 +61,12 @@ export function createV2SessionReducer() {
           type: "agent-switched",
           metadata: event.metadata,
           agent: event.data.agent,
+          previous:
+            event.data.previous ??
+            source.findLast(
+              (item): item is Extract<SessionMessageInfo, { type: "agent-switched" | "assistant" }> =>
+                item.type === "agent-switched" || item.type === "assistant",
+            )?.agent,
           time: { created: event.created },
         })
       case "session.model.selected":
@@ -69,10 +75,12 @@ export function createV2SessionReducer() {
           type: "model-switched",
           metadata: event.metadata,
           model: event.data.model,
-          previous: source.findLast(
-            (item): item is Extract<SessionMessageInfo, { type: "model-switched" | "assistant" }> =>
-              item.type === "model-switched" || item.type === "assistant",
-          )?.model,
+          previous:
+            event.data.previous ??
+            source.findLast(
+              (item): item is Extract<SessionMessageInfo, { type: "model-switched" | "assistant" }> =>
+                item.type === "model-switched" || item.type === "assistant",
+            )?.model,
           time: { created: event.created },
         })
       case "session.synthetic":

packages/client/src/effect/api/api.ts

@@ -339,7 +339,11 @@ export type Endpoint5_31Output =
           readonly type: "session.agent.selected"
           readonly durable: { readonly aggregateID: string; readonly seq: Event.Seq; readonly version: Event.Version }
           readonly location?: Location.Ref | undefined
-          readonly data: { readonly sessionID: Session.ID; readonly agent: Agent.ID }
+          readonly data: {
+            readonly sessionID: Session.ID
+            readonly agent: Agent.ID
+            readonly previous?: Agent.ID | undefined
+          }
         }
       | {
           readonly id: Event.ID
@@ -348,7 +352,11 @@ export type Endpoint5_31Output =
           readonly type: "session.model.selected"
           readonly durable: { readonly aggregateID: string; readonly seq: Event.Seq; readonly version: Event.Version }
           readonly location?: Location.Ref | undefined
-          readonly data: { readonly sessionID: Session.ID; readonly model: Model.Ref }
+          readonly data: {
+            readonly sessionID: Session.ID
+            readonly model: Model.Ref
+            readonly previous?: Model.Ref | undefined
+          }
         }
       | {
           readonly id: Event.ID

packages/client/src/promise/generated/types.ts

@@ -436,7 +436,7 @@ export type SessionAgentSelected = {
   type: "session.agent.selected"
   durable: { aggregateID: string; seq: number; version: 1 }
   location?: LocationRef
-  data: { sessionID: string; agent: string }
+  data: { sessionID: string; agent: string; previous?: string }
 }
 
 export type SessionModelSelected = {
@@ -446,7 +446,7 @@ export type SessionModelSelected = {
   type: "session.model.selected"
   durable: { aggregateID: string; seq: number; version: 1 }
   location?: LocationRef
-  data: { sessionID: string; model: ModelRef }
+  data: { sessionID: string; model: ModelRef; previous?: ModelRef }
 }
 
 export type SessionMoved = {

packages/core/src/database/v1-migration.ts

@@ -7,7 +7,7 @@ import { SessionV1 } from "@opencode-ai/schema/session-v1"
 import { SessionMessage } from "../session/message"
 import { SessionSchema } from "../session/schema"
 import { KVTable } from "../kv/sql"
-import { EventSequenceTable, EventTable } from "../event/sql"
+import { EventSequenceTable } from "../event/sql"
 import { eq, sql } from "drizzle-orm"
 import { Global } from "@opencode-ai/util/global"
 import { existsSync } from "node:fs"
@@ -161,6 +161,7 @@ type NextMessage = {
 
 const lock = Semaphore.makeUnsafe(1)
 const MIGRATION_STATE_KEY = "migration.v1-v2"
+const EVENT_DELETE_BATCH_SIZE = 1_000
 const decodeJson = Schema.decodeUnknownOption(Schema.UnknownFromJsonString)
 const decodeMessage = Schema.decodeUnknownOption(SessionV1.Info)
 const decodePart = Schema.decodeUnknownOption(SessionV1.Part)
@@ -485,7 +486,15 @@ export function run(options: Options = {}): Effect.Effect<RunResult, never, Data
           yield* db
             .transaction((tx) =>
               Effect.gen(function* () {
-                yield* tx.delete(EventTable).run()
+                while (true) {
+                  yield* tx.run(sql`
+                    DELETE FROM event
+                    WHERE rowid IN (SELECT rowid FROM event LIMIT ${EVENT_DELETE_BATCH_SIZE})
+                  `)
+                  const deleted = (yield* tx.get<{ value: number }>(sql`SELECT changes() AS value`))?.value ?? 0
+                  if (deleted < EVENT_DELETE_BATCH_SIZE) break
+                  yield* Effect.yieldNow
+                }
                 yield* tx
                   .insert(KVTable)
                   .values({ key: MIGRATION_STATE_KEY, value: { phase: "sessions" } })

packages/core/src/plugin/models-dev.ts

@@ -36,6 +36,7 @@ export const ModelsDevPlugin = define({
           draft.integrationID = Integration.ID.make(provider.info.id)
         })
         for (const model of provider.models) {
+          if (model.status === "deprecated") continue
           catalog.model.update(provider.info.id, model.id, (draft) => Object.assign(draft, model))
         }
       }

packages/core/src/session.ts

@@ -716,10 +716,11 @@ const layer = Layer.effect(
             .pipe(Effect.ignore, Effect.forkIn(scope, { startImmediately: true }), Effect.asVoid)
       }),
       switchAgent: Effect.fn("Session.switchAgent")(function* (input) {
-        yield* result.get(input.sessionID)
+        const session = yield* result.get(input.sessionID)
         yield* bus.publish(SessionEvent.AgentSelected, {
           sessionID: input.sessionID,
           agent: input.agent,
+          previous: session.agent,
         })
       }),
       switchModel: Effect.fn("Session.switchModel")(function* (input) {
@@ -733,6 +734,7 @@ const layer = Layer.effect(
         yield* bus.publish(SessionEvent.ModelSelected, {
           sessionID: input.sessionID,
           model: input.model,
+          previous: session.model,
         })
       }),
       rename: Effect.fn("Session.rename")(function* (input) {

packages/core/src/session/message-updater.ts

@@ -61,7 +61,7 @@ export function update(adapter: Adapter, event: SessionEvent.DurableEvent) {
       "session.usage.recorded": () => Effect.void,
       "session.agent.selected": (event) => {
         return Effect.gen(function* () {
-          const previous = yield* adapter.getAgent()
+          const previous = event.data.previous ?? (yield* adapter.getAgent())
           yield* adapter.appendMessage(
             SessionMessage.AgentSelected.make({
               id: SessionMessage.ID.fromEvent(event.id),
@@ -76,7 +76,7 @@ export function update(adapter: Adapter, event: SessionEvent.DurableEvent) {
       },
       "session.model.selected": (event) => {
         return Effect.gen(function* () {
-          const previous = yield* adapter.getModel()
+          const previous = event.data.previous ?? (yield* adapter.getModel())
           yield* adapter.appendMessage(
             SessionMessage.ModelSelected.make({
               id: SessionMessage.ID.fromEvent(event.id),

packages/core/src/tool/plugin/question.ts

@@ -21,7 +21,9 @@ Usage notes:
 - If you recommend a specific option, make that the first option in the list and add "(Recommended)" at the end of the label`
 
 export const Input = Schema.Struct({
-  questions: Schema.NonEmptyArray(Question.Prompt).annotate({ description: "Questions to ask" }),
+  questions: Schema.Array(Question.Prompt)
+    .check(Schema.isNonEmpty())
+    .annotate({ description: "Questions to ask" }),
 })
 
 export const Output = Schema.Struct({

packages/core/test/plugin/models-dev.test.ts

@@ -215,6 +215,66 @@ describe("ModelsDevPlugin", () => {
     }),
   )
 
+  it.effect("omits deprecated models from the catalog", () =>
+    Effect.gen(function* () {
+      const integrations = yield* Integration.Service
+      const catalog = yield* Catalog.Service
+      const providerID = Provider.ID.make("acme")
+      const activeID = Model.ID.make("current")
+      const deprecatedID = Model.ID.make("legacy")
+      const model = {
+        modelID: activeID,
+        providerID,
+        name: "Current",
+        capabilities: { tools: true, input: [], output: [] },
+        variants: [],
+        time: { released: Date.parse("2026-01-01") },
+        cost: [],
+        status: "active",
+        enabled: true,
+        limit: { context: 128_000, output: 32_000 },
+      } satisfies Omit<Model.Info, "id">
+      const snapshots = [
+        {
+          info: {
+            id: providerID,
+            name: "Acme",
+            package: Provider.aisdk("@ai-sdk/openai-compatible"),
+          },
+          environment: [],
+          models: [
+            { id: activeID, ...model },
+            {
+              id: deprecatedID,
+              ...model,
+              modelID: deprecatedID,
+              name: "Legacy",
+              status: "deprecated" as const,
+            },
+          ],
+        },
+      ] satisfies readonly ModelsDev.Snapshot[]
+
+      yield* ModelsDevPlugin.effect(
+        host({
+          catalog: catalogHost(catalog),
+          integration: integrationHost(integrations),
+        }),
+      ).pipe(
+        Effect.provideService(
+          ModelsDev.Service,
+          ModelsDev.Service.of({
+            get: () => Effect.succeed(snapshots),
+            refresh: () => Effect.void,
+          }),
+        ),
+      )
+
+      expect(yield* catalog.model.get(providerID, activeID)).toBeDefined()
+      expect(yield* catalog.model.get(providerID, deprecatedID)).toBeUndefined()
+    }),
+  )
+
   it.effect("registers key methods for providers with environment variables", () =>
     Effect.gen(function* () {
       const integrations = yield* Integration.Service

packages/core/test/session-create.test.ts

@@ -654,7 +654,7 @@ describe("Session.create", () => {
       expect(yield* session.get(created.id)).toMatchObject({ agent: "plan" })
       expect(
         Array.from(yield* logEvents(session, created.id, true).pipe(Stream.drop(1), Stream.take(1), Stream.runCollect)),
-      ).toMatchObject([{ type: "session.agent.selected", data: { agent: "plan" } }])
+      ).toMatchObject([{ type: "session.agent.selected", data: { agent: "plan", previous: "build" } }])
       expect(yield* session.messages({ sessionID: created.id, order: "asc" })).toMatchObject([
         { type: "agent-switched", agent: "plan", previous: "build" },
       ])
@@ -678,7 +678,12 @@ describe("Session.create", () => {
   it.effect("switches the selected model through the durable Session event", () =>
     Effect.gen(function* () {
       const session = yield* Session.Service
-      const created = yield* session.create({ location })
+      const previous = Model.Ref.make({
+        id: Model.ID.make("haiku"),
+        providerID: Provider.ID.anthropic,
+        variant: Model.VariantID.make("default"),
+      })
+      const created = yield* session.create({ location, model: previous })
       const model = Model.Ref.make({
         id: Model.ID.make("sonnet"),
         providerID: Provider.ID.anthropic,
@@ -692,7 +697,10 @@ describe("Session.create", () => {
         yield* logEvents(session, created.id, true).pipe(Stream.drop(1), Stream.take(1), Stream.runCollect),
       )
       expect(bus).toMatchObject([{ type: "session.model.selected" }])
-      expect(bus[0]?.data).toEqual({ sessionID: created.id, model })
+      expect(bus[0]?.data).toEqual({ sessionID: created.id, model, previous })
+      expect(yield* session.messages({ sessionID: created.id, order: "asc" })).toMatchObject([
+        { type: "model-switched", model, previous },
+      ])
     }),
   )
 

packages/core/test/tool-question.test.ts

@@ -89,6 +89,30 @@ const it = testEffect(
 )
 
 describe("QuestionTool", () => {
+  it.effect("emits one item schema for the nonempty questions array", () =>
+    Effect.gen(function* () {
+      captured = undefined
+      const registry = yield* Tool.Service
+      const definition = (yield* toolDefinitions(registry)).find((tool) => tool.name === QuestionTool.name)
+
+      expect(definition?.inputSchema).toHaveProperty("properties.questions.type", "array")
+      expect(definition?.inputSchema).toHaveProperty("properties.questions.minItems", 1)
+      expect(definition?.inputSchema).toHaveProperty("properties.questions.items")
+      expect(definition?.inputSchema).not.toHaveProperty("properties.questions.prefixItems")
+      expect(
+        yield* executeTool(registry, {
+          sessionID,
+          ...toolIdentity,
+          call: { type: "tool-call", id: "call-question-empty", name: QuestionTool.name, input: { questions: [] } },
+        }),
+      ).toMatchObject({
+        status: "error",
+        error: { type: "tool.execution", message: expect.stringContaining("Invalid tool input") },
+      })
+      expect(capturedInput()).toBeUndefined()
+    }),
+  )
+
   it.effect("omits a catalog-denied question and enforces its leaf permission", () =>
     Effect.gen(function* () {
       captured = undefined

packages/core/test/v1-migration.test.ts

@@ -11,7 +11,7 @@ import { Project } from "@opencode-ai/core/project"
 import { ProjectTable } from "@opencode-ai/core/project/sql"
 import { AbsolutePath } from "@opencode-ai/core/schema"
 import { Global } from "@opencode-ai/util/global"
-import { Effect, Layer, Logger, Schedule, Schema, Scope } from "effect"
+import { Effect, Fiber, Layer, Logger, Schedule, Schema, Scope } from "effect"
 import { eq, sql } from "drizzle-orm"
 import type { SqlClient } from "effect/unstable/sql/SqlClient"
 import { tmpdir } from "./fixture/tmpdir"
@@ -798,6 +798,35 @@ describe("V1Migration database workflow", () => {
     )
   })
 
+  test("yields while clearing stale events in batches", async () => {
+    await database(
+      Effect.gen(function* () {
+        const { db } = yield* Database.Service
+        yield* db.run(sql`INSERT INTO event_sequence (aggregate_id, seq) VALUES ('stale', 2500)`)
+        yield* db.run(sql`
+          WITH RECURSIVE rows(value) AS (
+            VALUES(1)
+            UNION ALL
+            SELECT value + 1 FROM rows WHERE value < 2500
+          )
+          INSERT INTO event (id, aggregate_id, seq, created, type, data)
+          SELECT printf('event_%04d', value), 'stale', value, 1, 'session.renamed.1', '{}'
+          FROM rows
+        `)
+        let yielded = false
+        const heartbeat = yield* Effect.yieldNow.pipe(
+          Effect.andThen(Effect.sync(() => (yielded = true))),
+          Effect.forkChild({ startImmediately: true }),
+        )
+
+        expect(yield* V1Migration.run()).toEqual({ status: "completed" })
+        expect(yielded).toBe(true)
+        yield* Fiber.join(heartbeat)
+        expect(yield* db.get<{ value: number }>(sql`SELECT COUNT(*) AS value FROM event`)).toEqual({ value: 0 })
+      }),
+    )
+  })
+
   test("imports previous V2 sessions and messages as part of the migration", async () => {
     await using tmp = await tmpdir()
     const filename = path.join(tmp.path, "opencode-next.db")

packages/protocol/openapi.json

@@ -14373,6 +14373,9 @@
               },
               "agent": {
                 "type": "string"
+              },
+              "previous": {
+                "type": "string"
               }
             },
             "required": ["sessionID", "agent"],
@@ -14441,6 +14444,9 @@
               },
               "model": {
                 "$ref": "#/components/schemas/Model.Ref"
+              },
+              "previous": {
+                "$ref": "#/components/schemas/Model.Ref"
               }
             },
             "required": ["sessionID", "model"],

packages/schema/src/session-event.ts

@@ -69,6 +69,7 @@ export const AgentSelected = Event.durable({
   schema: {
     ...Base,
     agent: Agent.ID,
+    previous: Agent.ID.pipe(optional),
   },
 })
 export type AgentSelected = typeof AgentSelected.Type
@@ -79,6 +80,7 @@ export const ModelSelected = Event.durable({
   schema: {
     ...Base,
     model: Model.Ref,
+    previous: Model.Ref.pipe(optional),
   },
 })
 export type ModelSelected = typeof ModelSelected.Type

packages/util/src/npm-config.ts

@@ -7,15 +7,13 @@ import Config from "@npmcli/config"
 import { definitions, flatten, nerfDarts, shorthands } from "@npmcli/config/lib/definitions/index.js"
 import { Effect } from "effect"
 
-// Lazy: on workerd import.meta.url is undefined and constructing a URL from it
-// at module scope fails startup validation; npm config is never used there.
-const npmPath = () => fileURLToPath(new URL("..", import.meta.url))
+const npmPath = fileURLToPath(new URL("..", import.meta.url))
 
 export const load = (dir: string) =>
   Effect.tryPromise({
     try: async () => {
       const config = new Config({
-        npmPath: npmPath(),
+        npmPath,
         cwd: dir,
         env: { ...process.env },
         argv: [process.execPath, process.execPath, "--prefix", dir],

packages/util/src/observability.ts

@@ -1,6 +1,6 @@
 export * as Observability from "./observability.js"
 
-import * as NodeFileSystem from "@effect/platform-node/NodeFileSystem"
+import { NodeFileSystem } from "@effect/platform-node"
 import { LayerNode } from "./effect/layer-node.js"
 import { Effect, Layer, Logger, References, Schema } from "effect"
 import { FetchHttpClient } from "effect/unstable/http"
@@ -50,10 +50,4 @@ export function layer(
   ).pipe(Layer.catchCause(() => local))
 }
 
-// Layer.suspend: constructing the loggers eagerly at module scope performs
-// I/O (file logger, run id) that workerd forbids in global scope.
-export const node = LayerNode.make({
-  name: "observability",
-  layer: Layer.suspend(() => layer()),
-  deps: [],
-})
+export const node = LayerNode.make({ name: "observability", layer: layer(), deps: [] })

packages/util/src/observability/logging.ts

@@ -3,7 +3,7 @@ import path from "path"
 import { Global } from "../global.js"
 import { runID } from "./shared.js"
 
-function formatter(id: string = runID()) {
+function formatter(id: string = runID) {
   return Logger.map(Logger.formatStructured, (output) => {
     const messages = Array.isArray(output.message) ? output.message : [output.message]
     return [
@@ -51,7 +51,7 @@ export function file(local = true, channel = "local") {
   return path.join(Global.Path.log, `opencode-${channel.replace(/[^a-zA-Z0-9._-]/g, "-")}.log`)
 }
 
-export function fileLogger(target = file(), id: string = runID()) {
+export function fileLogger(target = file(), id: string = runID) {
   // Do not set batchWindow to 0; it causes high idle CPU usage.
   return Effect.gen(function* () {
     const fs = yield* FileSystem.FileSystem

packages/util/src/observability/otlp.ts

@@ -54,8 +54,8 @@ export function resource(app: App = { client: "opencode", version: "unknown", ch
       ...resourceAttributes(),
       "deployment.environment.name": app.channel,
       "opencode.client": app.client,
-      "opencode.run": runID(),
-      "service.instance.id": runID(),
+      "opencode.run": runID,
+      "service.instance.id": runID,
     },
   }
 }

packages/util/src/observability/shared.ts

@@ -1,8 +1 @@
-// Lazy: workerd forbids generating random values in global scope, so the id
-// materializes on first call (inside a handler) and stays stable afterwards.
-let generated: string | undefined
-
-export function runID(): string {
-  generated ??= crypto.randomUUID().slice(0, 8)
-  return generated
-}
+export const runID = crypto.randomUUID().slice(0, 8)

packages/www/openapi.json

@@ -14373,6 +14373,9 @@
               },
               "agent": {
                 "type": "string"
+              },
+              "previous": {
+                "type": "string"
               }
             },
             "required": ["sessionID", "agent"],
@@ -14441,6 +14444,9 @@
               },
               "model": {
                 "$ref": "#/components/schemas/Model.Ref"
+              },
+              "previous": {
+                "$ref": "#/components/schemas/Model.Ref"
               }
             },
             "required": ["sessionID", "model"],

packages/www/public/openapi.json

@@ -14373,6 +14373,9 @@
               },
               "agent": {
                 "type": "string"
+              },
+              "previous": {
+                "type": "string"
               }
             },
             "required": ["sessionID", "agent"],
@@ -14441,6 +14444,9 @@
               },
               "model": {
                 "$ref": "#/components/schemas/Model.Ref"
+              },
+              "previous": {
+                "$ref": "#/components/schemas/Model.Ref"
               }
             },
             "required": ["sessionID", "model"],