fix(agent-manager): decode JSON-encoded task arrays

.changeset/agent-manager-json-tasks.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/cli": patch
+---
+
+Allow Agent Manager to start sessions when a model returns the task list as a JSON-encoded array.

packages/opencode/src/kilocode/tool/agent-manager.ts

@@ -128,7 +128,17 @@ const AnswerParams = Schema.Struct({
     }),
 })
 
-export const Params = Schema.Union([StartParams, ListParams, PromptParams, StopParams, MoveParams, AnswerParams])
+export const Params = Schema.Union([
+  Schema.Struct({
+    ...StartParams.fields,
+    tasks: Schema.Union([StartParams.fields.tasks, Schema.fromJsonString(StartParams.fields.tasks)]),
+  }),
+  ListParams,
+  PromptParams,
+  StopParams,
+  MoveParams,
+  AnswerParams,
+])
 
 // Anthropic rejects a top-level anyOf/oneOf/allOf, so the advertised schema has to
 // stay one flat object while Params keeps the real per-operation validation. That

packages/opencode/test/kilocode/agent-manager-tool.test.ts

@@ -1,6 +1,6 @@
 import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
 import { describe, expect, test } from "bun:test"
-import { Effect, Layer, ManagedRuntime, Queue, Schema } from "effect"
+import { Cause, Effect, Exit, Layer, ManagedRuntime, Queue, Schema } from "effect"
 import { MessageID, SessionID } from "../../src/session/schema"
 import { provideTmpdirInstance } from "../fixture/fixture"
 import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
@@ -220,8 +220,58 @@ describe("agent_manager tool", () => {
     // The advertised bounds on tasks must survive being made nullable.
     const tasks = schema.properties?.tasks
     expect(typeof tasks === "object" ? tasks.anyOf?.[0] : undefined).toEqual(
-      expect.objectContaining({ minItems: 1, maxItems: 20 }),
+      expect.objectContaining({ type: "array", minItems: 1, maxItems: 20 }),
     )
+    expect(typeof tasks === "object" ? tasks.anyOf : undefined).toHaveLength(2)
+  })
+
+  test.each(["local", "worktree"])("decodes JSON-encoded tasks for %s sessions", (mode) => {
+    const tasks = [
+      { prompt: 'Check "quoted" text\nC:\\repo', name: "Encoded" },
+      { name: "Prepared", model: null },
+    ]
+    expect(Schema.decodeUnknownSync(Params)({ mode, tasks: JSON.stringify(tasks), action: null })).toEqual({
+      mode,
+      tasks,
+    })
+  })
+
+  test("rejects invalid JSON-encoded tasks before permission or event publication", async () => {
+    const tool: Tool.Def = await init()
+    const permissions: unknown[] = []
+    const events: AgentManagerStart[] = []
+    await runtime.runPromise(
+      provideTmpdirInstance(() =>
+        Effect.gen(function* () {
+          const bus = yield* Bus.Service
+          const off = yield* bus.subscribeCallback(AgentManagerEvent.Start, (item) => events.push(item.properties))
+          yield* Effect.addFinalizer(() => Effect.sync(off))
+          for (const tasks of [
+            "[",
+            "null",
+            "{}",
+            '"[]"',
+            "[]",
+            "[null]",
+            "[{}]",
+            JSON.stringify([{ prompt: 42 }]),
+            JSON.stringify([{ name: "Prepared", model: "test/reasoning/model" }]),
+            JSON.stringify(Array.from({ length: 21 }, () => ({ prompt: "Fix" }))),
+          ]) {
+            const result = yield* tool
+              .execute(
+                { mode: "local", tasks },
+                { ...ctx, ask: (input: unknown) => Effect.sync(() => permissions.push(input)) },
+              )
+              .pipe(Effect.exit)
+            expect(Exit.isFailure(result)).toBe(true)
+            if (Exit.isFailure(result)) expect(Cause.squash(result.cause)).toBeInstanceOf(Tool.InvalidArgumentsError)
+          }
+        }),
+      ).pipe(Effect.scoped),
+    )
+    expect(permissions).toEqual([])
+    expect(events).toEqual([])
   })
 
   test("keeps session ID validation local", () => {
@@ -644,8 +694,9 @@ describe("agent_manager tool", () => {
     expect(task?.variant).toBe("high")
   })
 
-  test("publishes validated model and variant selections", async () => {
-    const tool = await init()
+  test.each(["array", "JSON-encoded"])("publishes validated selections from %s tasks", async (encoding) => {
+    const tool: Tool.Def = await init()
+    const tasks = [{ prompt: "Fix issue", model: "test/reasoning/model", variant: "high" }]
 
     const event = await runtime.runPromise(
       provideTmpdirInstance(() =>
@@ -660,7 +711,7 @@ describe("agent_manager tool", () => {
           yield* tool.execute(
             {
               mode: "local",
-              tasks: [{ prompt: "Fix issue", model: "test/reasoning/model", variant: "high" }],
+              tasks: encoding === "array" ? tasks : JSON.stringify(tasks),
             },
             { ...ctx, ask: () => Effect.void },
           )