refactor(task): split task spec from prompt execution

packages/opencode/src/session/prompt.ts

@@ -47,6 +47,7 @@ import { Cause, Effect, Exit, Layer, Option, Scope, ServiceMap } from "effect"
 import { InstanceState } from "@/effect/instance-state"
 import { makeRuntime } from "@/effect/run-service"
 import { TaskTool } from "@/tool/task"
+import { Config } from "@/config/config"
 import { SessionRunState } from "./run-state"
 
 // @ts-ignore
@@ -88,6 +89,7 @@ export namespace SessionPrompt {
       const compaction = yield* SessionCompaction.Service
       const plugin = yield* Plugin.Service
       const commands = yield* Command.Service
+      const config = yield* Config.Service
       const permission = yield* Permission.Service
       const fsys = yield* AppFileSystem.Service
       const mcp = yield* MCP.Service
@@ -140,6 +142,17 @@ export namespace SessionPrompt {
         return parts
       })
 
+      let prompt!: Interface["prompt"]
+
+      const taskTool = () =>
+        TaskTool.build({
+          agent: agents,
+          config,
+          cancel: SessionPrompt.cancel,
+          resolvePromptParts: SessionPrompt.resolvePromptParts,
+          prompt: SessionPrompt.prompt,
+        })
+
       const title = Effect.fn("SessionPrompt.ensureTitle")(function* (input: {
         session: Session.Info
         history: MessageV2.WithParts[]
@@ -391,6 +404,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
           providerID: input.model.providerID,
           agent: input.agent,
         })) {
+          const toolDef = item.id === TaskTool.id ? yield* Tool.init(taskTool()) : item
           const schema = ProviderTransform.schema(input.model, z.toJSONSchema(item.parameters))
           tools[item.id] = tool({
             id: item.id as any,
@@ -405,7 +419,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
                     { tool: item.id, sessionID: ctx.sessionID, callID: ctx.callID },
                     { args },
                   )
-                  const result = yield* Effect.promise(() => item.execute(args, ctx))
+                  const result = yield* Effect.promise(() => toolDef.execute(args, ctx))
                   const output = {
                     ...result,
                     attachments: result.attachments?.map((attachment) => ({
@@ -521,7 +535,6 @@ NOTE: At any point in time through this workflow you should feel free to ask the
       }) {
         const { task, model, lastUser, sessionID, session, msgs } = input
         const ctx = yield* InstanceState.context
-        const { task: taskTool } = yield* registry.named()
         const taskModel = task.model ? yield* getModel(task.model.providerID, task.model.modelID, sessionID) : model
         const assistantMessage: MessageV2.Assistant = yield* sessions.updateMessage({
           id: MessageID.ascending(),
@@ -578,8 +591,9 @@ NOTE: At any point in time through this workflow you should feel free to ask the
         }
 
         let error: Error | undefined
+        const taskDef = yield* Tool.init(taskTool())
         const result = yield* Effect.promise((signal) =>
-          taskTool
+          taskDef
             .execute(taskArgs, {
               agent: task.agent,
               messageID: assistantMessage.id,
@@ -1267,26 +1281,24 @@ NOTE: At any point in time through this workflow you should feel free to ask the
         return { info, parts }
       }, Effect.scoped)
 
-      const prompt: (input: PromptInput) => Effect.Effect<MessageV2.WithParts> = Effect.fn("SessionPrompt.prompt")(
-        function* (input: PromptInput) {
-          const session = yield* sessions.get(input.sessionID)
-          yield* revert.cleanup(session)
-          const message = yield* createUserMessage(input)
-          yield* sessions.touch(input.sessionID)
+      prompt = Effect.fn("SessionPrompt.prompt")(function* (input: PromptInput) {
+        const session = yield* sessions.get(input.sessionID)
+        yield* revert.cleanup(session)
+        const message = yield* createUserMessage(input)
+        yield* sessions.touch(input.sessionID)
 
-          const permissions: Permission.Ruleset = []
-          for (const [t, enabled] of Object.entries(input.tools ?? {})) {
-            permissions.push({ permission: t, action: enabled ? "allow" : "deny", pattern: "*" })
-          }
-          if (permissions.length > 0) {
-            session.permission = permissions
-            yield* sessions.setPermission({ sessionID: session.id, permission: permissions })
-          }
+        const permissions: Permission.Ruleset = []
+        for (const [t, enabled] of Object.entries(input.tools ?? {})) {
+          permissions.push({ permission: t, action: enabled ? "allow" : "deny", pattern: "*" })
+        }
+        if (permissions.length > 0) {
+          session.permission = permissions
+          yield* sessions.setPermission({ sessionID: session.id, permission: permissions })
+        }
 
-          if (input.noReply === true) return message
-          return yield* loop({ sessionID: input.sessionID })
-        },
-      )
+        if (input.noReply === true) return message
+        return yield* loop({ sessionID: input.sessionID })
+      })
 
       const lastAssistant = (sessionID: SessionID) =>
         Effect.promise(async () => {
@@ -1667,28 +1679,30 @@ NOTE: At any point in time through this workflow you should feel free to ask the
   )
 
   const defaultLayer = Layer.suspend(() =>
-    layer.pipe(
-      Layer.provide(SessionRunState.defaultLayer),
-      Layer.provide(SessionStatus.defaultLayer),
-      Layer.provide(SessionCompaction.defaultLayer),
-      Layer.provide(SessionProcessor.defaultLayer),
-      Layer.provide(Command.defaultLayer),
-      Layer.provide(Permission.defaultLayer),
-      Layer.provide(MCP.defaultLayer),
-      Layer.provide(LSP.defaultLayer),
-      Layer.provide(FileTime.defaultLayer),
-      Layer.provide(ToolRegistry.defaultLayer),
-      Layer.provide(Truncate.defaultLayer),
-      Layer.provide(Provider.defaultLayer),
-      Layer.provide(Instruction.defaultLayer),
-      Layer.provide(AppFileSystem.defaultLayer),
-      Layer.provide(Plugin.defaultLayer),
-      Layer.provide(Session.defaultLayer),
-      Layer.provide(SessionRevert.defaultLayer),
-      Layer.provide(Agent.defaultLayer),
-      Layer.provide(Bus.layer),
-      Layer.provide(CrossSpawnSpawner.defaultLayer),
-    ),
+    layer
+      .pipe(
+        Layer.provide(SessionRunState.defaultLayer),
+        Layer.provide(SessionStatus.defaultLayer),
+        Layer.provide(SessionCompaction.defaultLayer),
+        Layer.provide(SessionProcessor.defaultLayer),
+        Layer.provide(Command.defaultLayer),
+        Layer.provide(Permission.defaultLayer),
+        Layer.provide(MCP.defaultLayer),
+        Layer.provide(LSP.defaultLayer),
+        Layer.provide(FileTime.defaultLayer),
+        Layer.provide(ToolRegistry.defaultLayer),
+        Layer.provide(Truncate.defaultLayer),
+        Layer.provide(Provider.defaultLayer),
+        Layer.provide(Config.defaultLayer),
+        Layer.provide(Instruction.defaultLayer),
+        Layer.provide(AppFileSystem.defaultLayer),
+        Layer.provide(Plugin.defaultLayer),
+        Layer.provide(Session.defaultLayer),
+        Layer.provide(SessionRevert.defaultLayer),
+        Layer.provide(Agent.defaultLayer),
+        Layer.provide(Bus.layer),
+      )
+      .pipe(Layer.provide(CrossSpawnSpawner.defaultLayer)),
   )
   const { runPromise } = makeRuntime(Service, defaultLayer)
 

packages/opencode/src/tool/registry.ts

@@ -43,6 +43,7 @@ import { AppFileSystem } from "../filesystem"
 import { Agent } from "../agent/agent"
 import { Skill } from "../skill"
 import { Permission } from "@/permission"
+import type { TaskMetadata } from "./task"
 
 export namespace ToolRegistry {
   const log = Log.create({ service: "tool.registry" })
@@ -94,7 +95,7 @@ export namespace ToolRegistry {
       const agents = yield* Agent.Service
       const skill = yield* Skill.Service
 
-      const task = yield* TaskTool
+      const task: Tool.Info<typeof TaskTool.parameters, TaskMetadata> = yield* TaskTool
       const read = yield* ReadTool
       const question = yield* QuestionTool
       const todo = yield* TodoWriteTool

packages/opencode/src/tool/task.ts

@@ -5,10 +5,9 @@ import { Session } from "../session"
 import { SessionID, MessageID } from "../session/schema"
 import { MessageV2 } from "../session/message-v2"
 import { Agent } from "../agent/agent"
-import { SessionPrompt } from "../session/prompt"
 import { Config } from "../config/config"
+import type { SessionPrompt } from "../session/prompt"
 import { Effect } from "effect"
-import { Log } from "@/util/log"
 
 const id = "task"
 
@@ -25,153 +24,180 @@ const parameters = z.object({
   command: z.string().describe("The command that triggered this task").optional(),
 })
 
-export const TaskTool = Tool.defineEffect(
-  id,
-  Effect.gen(function* () {
-    const agent = yield* Agent.Service
-    const config = yield* Config.Service
+type Metadata = {
+  sessionId: SessionID
+  model: {
+    modelID: MessageV2.Assistant["modelID"]
+    providerID: MessageV2.Assistant["providerID"]
+  }
+}
 
-    const run = Effect.fn("TaskTool.execute")(function* (params: z.infer<typeof parameters>, ctx: Tool.Context) {
-      const cfg = yield* config.get()
+export type TaskMetadata = Metadata
 
-      if (!ctx.extra?.bypassAgentCheck) {
-        yield* Effect.promise(() =>
-          ctx.ask({
-            permission: id,
-            patterns: [params.subagent_type],
-            always: ["*"],
-            metadata: {
-              description: params.description,
-              subagent_type: params.subagent_type,
-            },
-          }),
-        )
-      }
+type Runtime = {
+  agent: Agent.Interface
+  config: Config.Interface
+  cancel: (sessionID: SessionID) => Promise<void>
+  resolvePromptParts: (template: string) => Promise<SessionPrompt.PromptInput["parts"]>
+  prompt: (input: SessionPrompt.PromptInput) => Promise<MessageV2.WithParts>
+}
 
-      const next = yield* agent.get(params.subagent_type)
-      if (!next) {
-        return yield* Effect.fail(new Error(`Unknown agent type: ${params.subagent_type} is not a valid agent type`))
-      }
+const unbound: Tool.DefWithoutID<typeof parameters, Metadata> = {
+  description: DESCRIPTION,
+  parameters,
+  async execute() {
+    throw new Error("Task tool execution is only available from the prompt runtime")
+  },
+}
 
-      const canTask = next.permission.some((rule) => rule.permission === id)
-      const canTodo = next.permission.some((rule) => rule.permission === "todowrite")
+const build = (runtime: Runtime) => {
+  const run = Effect.fn("TaskTool.execute")(function* (params: z.infer<typeof parameters>, ctx: Tool.Context) {
+    const cfg = yield* runtime.config.get()
 
-      const taskID = params.task_id
-      const session = taskID
-        ? yield* Effect.promise(() => {
-            const id = SessionID.make(taskID)
-            return Session.get(id).catch(() => undefined)
-          })
-        : undefined
-      const nextSession =
-        session ??
-        (yield* Effect.promise(() =>
-          Session.create({
-            parentID: ctx.sessionID,
-            title: params.description + ` (@${next.name} subagent)`,
-            permission: [
-              ...(canTodo
-                ? []
-                : [
-                    {
-                      permission: "todowrite" as const,
-                      pattern: "*" as const,
-                      action: "deny" as const,
-                    },
-                  ]),
-              ...(canTask
-                ? []
-                : [
-                    {
-                      permission: id,
-                      pattern: "*" as const,
-                      action: "deny" as const,
-                    },
-                  ]),
-              ...(cfg.experimental?.primary_tools?.map((item) => ({
-                pattern: "*",
-                action: "allow" as const,
-                permission: item,
-              })) ?? []),
-            ],
-          }),
-        ))
-
-      const msg = yield* Effect.sync(() => MessageV2.get({ sessionID: ctx.sessionID, messageID: ctx.messageID }))
-      if (msg.info.role !== "assistant") return yield* Effect.fail(new Error("Not an assistant message"))
-
-      const model = next.model ?? {
-        modelID: msg.info.modelID,
-        providerID: msg.info.providerID,
-      }
-
-      ctx.metadata({
-        title: params.description,
-        metadata: {
-          sessionId: nextSession.id,
-          model,
-        },
-      })
-
-      const messageID = MessageID.ascending()
-
-      function cancel() {
-        SessionPrompt.cancel(nextSession.id)
-      }
-
-      return yield* Effect.acquireUseRelease(
-        Effect.sync(() => {
-          ctx.abort.addEventListener("abort", cancel)
+    if (!ctx.extra?.bypassAgentCheck) {
+      yield* Effect.promise(() =>
+        ctx.ask({
+          permission: id,
+          patterns: [params.subagent_type],
+          always: ["*"],
+          metadata: {
+            description: params.description,
+            subagent_type: params.subagent_type,
+          },
         }),
-        () =>
-          Effect.gen(function* () {
-            const parts = yield* Effect.promise(() => SessionPrompt.resolvePromptParts(params.prompt))
-            const result = yield* Effect.promise(() =>
-              SessionPrompt.prompt({
-                messageID,
-                sessionID: nextSession.id,
-                model: {
-                  modelID: model.modelID,
-                  providerID: model.providerID,
-                },
-                agent: next.name,
-                tools: {
-                  ...(canTodo ? {} : { todowrite: false }),
-                  ...(canTask ? {} : { task: false }),
-                  ...Object.fromEntries((cfg.experimental?.primary_tools ?? []).map((item) => [item, false])),
-                },
-                parts,
-              }),
-            )
-
-            return {
-              title: params.description,
-              metadata: {
-                sessionId: nextSession.id,
-                model,
-              },
-              output: [
-                `task_id: ${nextSession.id} (for resuming to continue this task if needed)`,
-                "",
-                "<task_result>",
-                result.parts.findLast((item) => item.type === "text")?.text ?? "",
-                "</task_result>",
-              ].join("\n"),
-            }
-          }),
-        () =>
-          Effect.sync(() => {
-            ctx.abort.removeEventListener("abort", cancel)
-          }),
       )
+    }
+
+    const next = yield* runtime.agent.get(params.subagent_type)
+    if (!next) {
+      return yield* Effect.fail(new Error(`Unknown agent type: ${params.subagent_type} is not a valid agent type`))
+    }
+
+    const canTask = next.permission.some((rule) => rule.permission === id)
+    const canTodo = next.permission.some((rule) => rule.permission === "todowrite")
+
+    const taskID = params.task_id
+    const session = taskID
+      ? yield* Effect.promise(() => {
+          const id = SessionID.make(taskID)
+          return Session.get(id).catch(() => undefined)
+        })
+      : undefined
+    const nextSession =
+      session ??
+      (yield* Effect.promise(() =>
+        Session.create({
+          parentID: ctx.sessionID,
+          title: params.description + ` (@${next.name} subagent)`,
+          permission: [
+            ...(canTodo
+              ? []
+              : [
+                  {
+                    permission: "todowrite" as const,
+                    pattern: "*" as const,
+                    action: "deny" as const,
+                  },
+                ]),
+            ...(canTask
+              ? []
+              : [
+                  {
+                    permission: id,
+                    pattern: "*" as const,
+                    action: "deny" as const,
+                  },
+                ]),
+            ...(cfg.experimental?.primary_tools?.map((item) => ({
+              pattern: "*",
+              action: "allow" as const,
+              permission: item,
+            })) ?? []),
+          ],
+        }),
+      ))
+
+    const msg = yield* Effect.sync(() => MessageV2.get({ sessionID: ctx.sessionID, messageID: ctx.messageID }))
+    if (msg.info.role !== "assistant") return yield* Effect.fail(new Error("Not an assistant message"))
+
+    const model = next.model ?? {
+      modelID: msg.info.modelID,
+      providerID: msg.info.providerID,
+    }
+
+    ctx.metadata({
+      title: params.description,
+      metadata: {
+        sessionId: nextSession.id,
+        model,
+      },
     })
 
-    return {
-      description: DESCRIPTION,
-      parameters,
-      async execute(params: z.infer<typeof parameters>, ctx) {
-        return Effect.runPromise(run(params, ctx))
-      },
+    const messageID = MessageID.ascending()
+
+    function cancel() {
+      return runtime.cancel(nextSession.id)
     }
-  }),
-)
+
+    return yield* Effect.acquireUseRelease(
+      Effect.sync(() => {
+        ctx.abort.addEventListener("abort", cancel)
+      }),
+      () =>
+        Effect.gen(function* () {
+          const parts = yield* Effect.promise(() => runtime.resolvePromptParts(params.prompt))
+          const result = yield* Effect.promise(() =>
+            runtime.prompt({
+              messageID,
+              sessionID: nextSession.id,
+              model: {
+                modelID: model.modelID,
+                providerID: model.providerID,
+              },
+              agent: next.name,
+              tools: {
+                ...(canTodo ? {} : { todowrite: false }),
+                ...(canTask ? {} : { task: false }),
+                ...Object.fromEntries((cfg.experimental?.primary_tools ?? []).map((item) => [item, false])),
+              },
+              parts,
+            }),
+          )
+
+          return {
+            title: params.description,
+            metadata: {
+              sessionId: nextSession.id,
+              model,
+            },
+            output: [
+              `task_id: ${nextSession.id} (for resuming to continue this task if needed)`,
+              "",
+              "<task_result>",
+              result.parts.findLast((item) => item.type === "text")?.text ?? "",
+              "</task_result>",
+            ].join("\n"),
+          }
+        }),
+      () =>
+        Effect.sync(() => {
+          ctx.abort.removeEventListener("abort", cancel)
+        }),
+    )
+  })
+
+  return Tool.define(id, {
+    description: DESCRIPTION,
+    parameters,
+    async execute(params: z.infer<typeof parameters>, ctx) {
+      return Effect.runPromise(run(params, ctx))
+    },
+  })
+}
+
+export const TaskTool = Object.assign(Effect.succeed(Tool.define(id, unbound)), {
+  id,
+  description: DESCRIPTION,
+  parameters,
+  build,
+})

packages/opencode/test/session/prompt-effect.test.ts

@@ -33,6 +33,7 @@ import { SessionStatus } from "../../src/session/status"
 import { Skill } from "../../src/skill"
 import { Shell } from "../../src/shell/shell"
 import { Snapshot } from "../../src/snapshot"
+import { TaskTool } from "../../src/tool/task"
 import { ToolRegistry } from "../../src/tool/registry"
 import { Truncate } from "../../src/tool/truncate"
 import { Log } from "../../src/util/log"
@@ -727,23 +728,31 @@ it.live(
         Effect.gen(function* () {
           const ready = defer<void>()
           const aborted = defer<void>()
-          const registry = yield* ToolRegistry.Service
-          const { task } = yield* registry.named()
-          const original = task.execute
-          task.execute = async (_args, ctx) => {
-            ready.resolve()
-            ctx.abort.addEventListener("abort", () => aborted.resolve(), { once: true })
-            await new Promise<void>(() => {})
+          const original = TaskTool.build
+          TaskTool.build = ((runtime: Parameters<typeof TaskTool.build>[0]) => {
+            const base = original(runtime)
             return {
-              title: "",
-              metadata: {
-                sessionId: SessionID.make("task"),
-                model: ref,
+              id: base.id,
+              async init() {
+                const next = await base.init()
+                next.execute = async (_args: any, ctx: any) => {
+                  ready.resolve()
+                  ctx.abort.addEventListener("abort", () => aborted.resolve(), { once: true })
+                  await new Promise<void>(() => {})
+                  return {
+                    title: "",
+                    metadata: {
+                      sessionId: SessionID.make("task"),
+                      model: ref,
+                    },
+                    output: "",
+                  }
+                }
+                return next
               },
-              output: "",
             }
-          }
-          yield* Effect.addFinalizer(() => Effect.sync(() => void (task.execute = original)))
+          }) as typeof TaskTool.build
+          yield* Effect.addFinalizer(() => Effect.sync(() => void (TaskTool.build = original)))
 
           const { prompt, chat } = yield* boot()
           const msg = yield* user(chat.id, "hello")

packages/opencode/test/tool/task.test.ts

@@ -10,6 +10,7 @@ import { SessionPrompt } from "../../src/session/prompt"
 import { MessageID, PartID } from "../../src/session/schema"
 import { ModelID, ProviderID } from "../../src/provider/schema"
 import { TaskTool } from "../../src/tool/task"
+import { Tool } from "../../src/tool/tool"
 import { ToolRegistry } from "../../src/tool/registry"
 import { provideTmpdirInstance } from "../fixture/fixture"
 import { testEffect } from "../lib/effect"
@@ -23,6 +24,15 @@ const ref = {
   modelID: ModelID.make("test-model"),
 }
 
+const bindTask = (agent: Agent.Interface, config: Config.Interface) =>
+  TaskTool.build({
+    agent,
+    config,
+    cancel: (sessionID) => SessionPrompt.cancel(sessionID),
+    resolvePromptParts: (template) => SessionPrompt.resolvePromptParts(template),
+    prompt: (input) => SessionPrompt.prompt(input),
+  })
+
 const it = testEffect(
   Layer.mergeAll(
     Agent.defaultLayer,
@@ -175,11 +185,12 @@ describe("tool.task", () => {
   it.live("execute resumes an existing task session from task_id", () =>
     provideTmpdirInstance(() =>
       Effect.gen(function* () {
+        const agent = yield* Agent.Service
+        const config = yield* Config.Service
         const sessions = yield* Session.Service
         const { chat, assistant } = yield* seed()
         const child = yield* sessions.create({ parentID: chat.id, title: "Existing child" })
-        const tool = yield* TaskTool
-        const def = yield* Effect.promise(() => tool.init())
+        const def = yield* Tool.init(bindTask(agent, config))
         const resolve = SessionPrompt.resolvePromptParts
         const prompt = SessionPrompt.prompt
         let seen: Parameters<typeof SessionPrompt.prompt>[0] | undefined
@@ -229,9 +240,10 @@ describe("tool.task", () => {
   it.live("execute asks by default and skips checks when bypassed", () =>
     provideTmpdirInstance(() =>
       Effect.gen(function* () {
+        const agent = yield* Agent.Service
+        const config = yield* Config.Service
         const { chat, assistant } = yield* seed()
-        const tool = yield* TaskTool
-        const def = yield* Effect.promise(() => tool.init())
+        const def = yield* Tool.init(bindTask(agent, config))
         const resolve = SessionPrompt.resolvePromptParts
         const prompt = SessionPrompt.prompt
         const calls: unknown[] = []
@@ -288,10 +300,11 @@ describe("tool.task", () => {
   it.live("execute creates a child when task_id does not exist", () =>
     provideTmpdirInstance(() =>
       Effect.gen(function* () {
+        const agent = yield* Agent.Service
+        const config = yield* Config.Service
         const sessions = yield* Session.Service
         const { chat, assistant } = yield* seed()
-        const tool = yield* TaskTool
-        const def = yield* Effect.promise(() => tool.init())
+        const def = yield* Tool.init(bindTask(agent, config))
         const resolve = SessionPrompt.resolvePromptParts
         const prompt = SessionPrompt.prompt
         let seen: Parameters<typeof SessionPrompt.prompt>[0] | undefined
@@ -342,10 +355,11 @@ describe("tool.task", () => {
     provideTmpdirInstance(
       () =>
         Effect.gen(function* () {
+          const agent = yield* Agent.Service
+          const config = yield* Config.Service
           const sessions = yield* Session.Service
           const { chat, assistant } = yield* seed()
-          const tool = yield* TaskTool
-          const def = yield* Effect.promise(() => tool.init())
+          const def = yield* Tool.init(bindTask(agent, config))
           const resolve = SessionPrompt.resolvePromptParts
           const prompt = SessionPrompt.prompt
           let seen: Parameters<typeof SessionPrompt.prompt>[0] | undefined