fix(opencode): use async prompt for background completions

packages/opencode/src/session/prompt.ts

@@ -128,7 +128,6 @@ export const layer = Layer.effect(
         cancel: (sessionID: SessionID) => cancel(sessionID),
         resolvePromptParts: (template: string) => resolvePromptParts(template),
         prompt: (input: PromptInput) => prompt(input).pipe(Effect.catch(Effect.die)),
-        loop: (input: LoopInput) => loop(input),
       } satisfies TaskPromptOps
     })
 

packages/opencode/src/tool/registry.ts

@@ -7,7 +7,6 @@ import { GlobTool } from "./glob"
 import { GrepTool } from "./grep"
 import { ReadTool } from "./read"
 import { TaskTool } from "./task"
-import { TaskStatusTool } from "./task_status"
 import { TodoWriteTool } from "./todo"
 import { WebFetchTool } from "./webfetch"
 import { WriteTool } from "./write"
@@ -119,7 +118,6 @@ export const layer: Layer.Layer<
 
     const invalid = yield* InvalidTool
     const task = yield* TaskTool
-    const taskStatus = yield* TaskStatusTool
     const read = yield* ReadTool
     const question = yield* QuestionTool
     const todo = yield* TodoWriteTool
@@ -235,7 +233,6 @@ export const layer: Layer.Layer<
           edit: Tool.init(edit),
           write: Tool.init(writetool),
           task: Tool.init(task),
-          task_status: Tool.init(taskStatus),
           fetch: Tool.init(webfetch),
           todo: Tool.init(todo),
           search: Tool.init(websearch),
@@ -260,7 +257,6 @@ export const layer: Layer.Layer<
             tool.edit,
             tool.write,
             tool.task,
-            ...(flags.experimentalBackgroundSubagents ? [tool.task_status] : []),
             tool.fetch,
             tool.todo,
             tool.search,

packages/opencode/src/tool/task.ts

@@ -2,17 +2,14 @@ import * as Tool from "./tool"
 import DESCRIPTION from "./task.txt"
 import { ToolJsonSchema } from "./json-schema"
 import { BackgroundJob } from "@/background/job"
-import { Bus } from "@/bus"
 import { Session } from "@/session/session"
 import { SessionID, MessageID } from "../session/schema"
 import { MessageV2 } from "../session/message-v2"
 import { Agent } from "../agent/agent"
 import { deriveSubagentSessionPermission } from "../agent/subagent-permissions"
 import type { SessionPrompt } from "../session/prompt"
-import { SessionStatus } from "@/session/status"
 import { Config } from "@/config/config"
-import { TuiEvent } from "@/cli/cmd/tui/event"
-import { Cause, Effect, Exit, Option, Schema, Scope } from "effect"
+import { Cause, Effect, Exit, Schema, Scope } from "effect"
 import { EffectBridge } from "@/effect/bridge"
 import { RuntimeFlags } from "@/effect/runtime-flags"
 
@@ -20,7 +17,6 @@ export interface TaskPromptOps {
   cancel(sessionID: SessionID): Effect.Effect<void>
   resolvePromptParts(template: string): Effect.Effect<SessionPrompt.PromptInput["parts"]>
   prompt(input: SessionPrompt.PromptInput): Effect.Effect<MessageV2.WithParts>
-  loop(input: SessionPrompt.LoopInput): Effect.Effect<MessageV2.WithParts>
 }
 
 const id = "task"
@@ -28,8 +24,10 @@ const BACKGROUND_DESCRIPTION = [
   "",
   "",
   [
-    "Background mode: background=true launches the subagent asynchronously.",
-    "Use task_status(task_id=..., wait=false) to poll, or wait=true to block until done.",
+    "Background mode: background=true launches the subagent asynchronously and returns immediately.",
+    "Foreground is the default; use it when you need the result before continuing.",
+    "Use background only for independent work that can run while you continue elsewhere.",
+    "You will be notified automatically when it finishes.",
   ].join(" "),
 ].join("\n")
 
@@ -54,7 +52,7 @@ export const Parameters = Schema.Struct({
   }),
   command: Schema.optional(Schema.String).annotate({ description: "The command that triggered this task" }),
   background: Schema.optional(Schema.Boolean).annotate({
-    description: "When true, launch the subagent in the background and return immediately",
+    description: "Run the agent in the background and deliver a notification when it completes",
   }),
 })
 
@@ -70,11 +68,12 @@ function output(sessionID: SessionID, text: string) {
 
 function backgroundOutput(sessionID: SessionID) {
   return [
-    `task_id: ${sessionID} (for polling this task with task_status)`,
+    `task_id: ${sessionID}`,
     "state: running",
     "",
     "<task_result>",
-    "Background task started. Continue your current work and call task_status when you need the result.",
+    "Background task started. You will be notified automatically when it finishes; do not poll for progress.",
+    "Do not duplicate its work. Continue only with non-overlapping work, or stop if there is nothing else useful to do.",
     "</task_result>",
   ].join("\n")
 }
@@ -105,11 +104,9 @@ export const TaskTool = Tool.define(
   Effect.gen(function* () {
     const agent = yield* Agent.Service
     const background = yield* BackgroundJob.Service
-    const bus = yield* Bus.Service
     const config = yield* Config.Service
     const sessions = yield* Session.Service
     const scope = yield* Scope.Scope
-    const status = yield* SessionStatus.Service
     const flags = yield* RuntimeFlags.Service
 
     const run = Effect.fn("TaskTool.execute")(function* (
@@ -211,68 +208,34 @@ export const TaskTool = Tool.define(
         return result.parts.findLast((item) => item.type === "text")?.text ?? ""
       })
 
-      const resumeWhenIdle: (input: { userID: MessageID; state: "completed" | "error" }) => Effect.Effect<void> =
-        Effect.fn("TaskTool.resumeWhenIdle")(function* (input: { userID: MessageID; state: "completed" | "error" }) {
-          const latest = yield* sessions
-            .findMessage(ctx.sessionID, (item) => item.info.role === "user")
-            .pipe(Effect.orDie)
-          if (Option.isNone(latest)) return
-          if (latest.value.info.id !== input.userID) return
-          if ((yield* status.get(ctx.sessionID)).type !== "idle") {
-            yield* Effect.sleep("300 millis")
-            return yield* resumeWhenIdle(input)
-          }
-          yield* bus.publish(TuiEvent.ToastShow, {
-            title: input.state === "completed" ? "Background task complete" : "Background task failed",
-            message:
-              input.state === "completed"
-                ? `Background task "${params.description}" finished. Resuming the main thread.`
-                : `Background task "${params.description}" failed. Resuming the main thread.`,
-            variant: input.state === "completed" ? "success" : "error",
-            duration: 5000,
-          })
-          yield* ops
-            .loop({ sessionID: ctx.sessionID })
-            .pipe(Effect.ignore, Effect.forkIn(scope, { startImmediately: true }))
-        })
-
-      const continueIfIdle = Effect.fn("TaskTool.continueIfIdle")(function* (input: {
-        userID: MessageID
-        state: "completed" | "error"
-      }) {
-        yield* resumeWhenIdle(input).pipe(Effect.ignore, Effect.forkIn(scope, { startImmediately: true }))
-      })
-
       const inject = Effect.fn("TaskTool.injectBackgroundResult")(function* (
         state: "completed" | "error",
         text: string,
       ) {
         const currentParent = yield* sessions.get(ctx.sessionID)
-        const message = yield* ops.prompt({
-          sessionID: ctx.sessionID,
-          noReply: true,
-          agent: currentParent.agent ?? ctx.agent,
-          parts: [
-            {
-              type: "text",
-              synthetic: true,
-              text: backgroundMessage({
-                sessionID: nextSession.id,
-                description: params.description,
-                state,
-                text,
-              }),
-            },
-          ],
-        })
-        yield* continueIfIdle({ userID: message.info.id, state })
+        yield* ops
+          .prompt({
+            sessionID: ctx.sessionID,
+            agent: currentParent.agent ?? ctx.agent,
+            parts: [
+              {
+                type: "text",
+                synthetic: true,
+                text: backgroundMessage({
+                  sessionID: nextSession.id,
+                  description: params.description,
+                  state,
+                  text,
+                }),
+              },
+            ],
+          })
+          .pipe(Effect.ignore, Effect.forkIn(scope, { startImmediately: true }))
       })
 
       const existing = yield* background.get(nextSession.id)
       if (existing?.status === "running") {
-        return yield* Effect.fail(
-          new Error(`Task ${nextSession.id} is already running. Use task_status to check progress.`),
-        )
+        return yield* Effect.fail(new Error(`Task ${nextSession.id} is already running.`))
       }
 
       if (runInBackground) {

packages/opencode/src/tool/task.txt

@@ -13,6 +13,6 @@ Usage notes:
 1. Launch multiple agents concurrently whenever possible, to maximize performance; to do that, use a single message with multiple tool uses
 2. When the agent is done, it will return a single message back to you. The result returned by the agent is not visible to the user. To show the user the result, you should send a text message back to the user with a concise summary of the result. The output includes a task_id you can reuse later to continue the same subagent session.
 3. Each agent invocation starts with a fresh context unless you provide task_id to resume the same subagent session (which continues with its previous messages and tool outputs). When starting fresh, your prompt should contain a highly detailed task description for the agent to perform autonomously and you should specify exactly what information the agent should return back to you in its final and only message to you.
-4. The agent's outputs should generally be trusted
+4. Treat the agent's response as a report. If it wrote or edited code, inspect the actual changes before reporting that work as done.
 5. Clearly tell the agent whether you expect it to write code or just to do research (search, file reads, web fetches, etc.), since it is not aware of the user's intent. Tell it how to verify its work if possible (e.g., relevant test commands).
 6. If the agent description mentions that it should be used proactively, then you should try your best to use it without the user having to ask for it first. Use your judgement.

packages/opencode/src/tool/task_status.ts

@@ -1,179 +0,0 @@
-import * as Tool from "./tool"
-import DESCRIPTION from "./task_status.txt"
-import { BackgroundJob } from "@/background/job"
-import { Session } from "@/session/session"
-import { MessageV2 } from "@/session/message-v2"
-import { SessionID } from "@/session/schema"
-import { SessionStatus } from "@/session/status"
-import { PositiveInt } from "@opencode-ai/core/schema"
-import { RuntimeFlags } from "@/effect/runtime-flags"
-import { Effect, Option, Schema } from "effect"
-
-const DEFAULT_TIMEOUT = 60_000
-const POLL_MS = 300
-
-const Parameters = Schema.Struct({
-  task_id: SessionID.annotate({ description: "The task_id returned by the task tool" }),
-  wait: Schema.optional(Schema.Boolean).annotate({
-    description: "When true, wait until the task reaches a terminal state or timeout",
-  }),
-  timeout_ms: Schema.optional(PositiveInt).annotate({
-    description: "Maximum milliseconds to wait when wait=true (default: 60000)",
-  }),
-})
-
-type State = BackgroundJob.Status
-type InspectResult = { state: State; text: string }
-
-function format(input: { taskID: SessionID; state: State; text: string }) {
-  const tag = input.state === "completed" || input.state === "running" ? "task_result" : "task_error"
-  return [`task_id: ${input.taskID}`, `state: ${input.state}`, "", `<${tag}>`, input.text, `</${tag}>`].join("\n")
-}
-
-function errorText(error: NonNullable<MessageV2.Assistant["error"]>) {
-  const data = Reflect.get(error, "data")
-  const message = data && typeof data === "object" ? Reflect.get(data, "message") : undefined
-  if (typeof message === "string" && message) return message
-  return error.name
-}
-
-function inspectMessage(message: MessageV2.WithParts): InspectResult | undefined {
-  if (message.info.role !== "assistant") return
-  const text = message.parts.findLast((part) => part.type === "text")?.text ?? ""
-  if (message.info.error) return { state: "error", text: text || errorText(message.info.error) }
-  if (message.info.finish && !["tool-calls", "unknown"].includes(message.info.finish))
-    return { state: "completed", text }
-  return { state: "running", text: text || "Task is still running." }
-}
-
-export const TaskStatusTool = Tool.define(
-  "task_status",
-  Effect.gen(function* () {
-    const jobs = yield* BackgroundJob.Service
-    const sessions = yield* Session.Service
-    const status = yield* SessionStatus.Service
-    const flags = yield* RuntimeFlags.Service
-
-    const inspect: (taskID: SessionID) => Effect.Effect<InspectResult> = Effect.fn("TaskStatusTool.inspect")(function* (
-      taskID: SessionID,
-    ) {
-      const job = yield* jobs.get(taskID)
-      if (job) {
-        return {
-          state: job.status,
-          text:
-            job.output ??
-            job.error ??
-            (job.status === "running"
-              ? "Task is still running."
-              : job.status === "cancelled"
-                ? "Task was cancelled."
-                : ""),
-        }
-      }
-
-      const current = yield* status.get(taskID)
-      if (current.type === "busy" || current.type === "retry") {
-        return {
-          state: "running",
-          text: current.type === "retry" ? `Task is retrying: ${current.message}` : "Task is still running.",
-        }
-      }
-
-      const latestAssistant = yield* sessions
-        .findMessage(taskID, (item) => item.info.role === "assistant")
-        .pipe(Effect.orDie)
-      if (Option.isSome(latestAssistant)) {
-        const latest = inspectMessage(latestAssistant.value)
-        if (!latest) return { state: "error", text: "Task is not running in this process." }
-        if (latest.state === "running")
-          return { state: "error", text: "Task is not running in this process and has no final output." }
-        return latest
-      }
-      return { state: "error", text: "Task is not running in this process and has not produced output." }
-    })
-
-    const waitForTerminal: (
-      taskID: SessionID,
-      timeout: number,
-    ) => Effect.Effect<{ result: InspectResult; timedOut: boolean }> = Effect.fn("TaskStatusTool.waitForTerminal")(
-      function* (taskID: SessionID, timeout: number) {
-        const result = yield* inspect(taskID)
-        if (result.state !== "running") return { result, timedOut: false }
-        if (timeout <= 0) return { result, timedOut: true }
-        const sleep = Math.min(POLL_MS, timeout)
-        yield* Effect.sleep(`${sleep} millis`)
-        return yield* waitForTerminal(taskID, timeout - sleep)
-      },
-    )
-
-    const run = Effect.fn("TaskStatusTool.execute")(function* (
-      params: Schema.Schema.Type<typeof Parameters>,
-      _ctx: Tool.Context,
-    ) {
-      if (!flags.experimentalBackgroundSubagents) {
-        return yield* Effect.fail(new Error("task_status requires OPENCODE_EXPERIMENTAL_BACKGROUND_SUBAGENTS=true"))
-      }
-
-      const session = yield* sessions.get(params.task_id).pipe(Effect.catchCause(() => Effect.succeed(undefined)))
-      if (!session) {
-        return {
-          title: "Task status",
-          metadata: {
-            task_id: params.task_id,
-            state: "error" as const,
-            timed_out: false,
-          },
-          output: format({
-            taskID: params.task_id,
-            state: "error",
-            text: `Task not found: ${params.task_id}`,
-          }),
-        }
-      }
-
-      const waited =
-        params.wait === true
-          ? yield* jobs.wait({ id: params.task_id, timeout: params.timeout_ms ?? DEFAULT_TIMEOUT })
-          : { info: yield* jobs.get(params.task_id), timedOut: false }
-      const inspected = waited.info
-        ? {
-            result: {
-              state: waited.info.status,
-              text:
-                waited.info.output ??
-                waited.info.error ??
-                (waited.info.status === "running" ? "Task is still running." : ""),
-            },
-            timedOut: waited.timedOut,
-          }
-        : params.wait === true
-          ? yield* waitForTerminal(params.task_id, params.timeout_ms ?? DEFAULT_TIMEOUT)
-          : { result: yield* inspect(params.task_id), timedOut: false }
-      const text = inspected.timedOut
-        ? `Timed out after ${params.timeout_ms ?? DEFAULT_TIMEOUT}ms while waiting for task completion.`
-        : inspected.result.text
-
-      return {
-        title: "Task status",
-        metadata: {
-          task_id: params.task_id,
-          state: inspected.result.state,
-          timed_out: inspected.timedOut,
-        },
-        output: format({
-          taskID: params.task_id,
-          state: inspected.result.state,
-          text,
-        }),
-      }
-    })
-
-    return {
-      description: DESCRIPTION,
-      parameters: Parameters,
-      execute: (params: Schema.Schema.Type<typeof Parameters>, ctx: Tool.Context) =>
-        run(params, ctx).pipe(Effect.orDie),
-    }
-  }),
-)

packages/opencode/src/tool/task_status.txt

@@ -1,13 +0,0 @@
-Poll the status of a background subagent task launched with the task tool.
-
-Use this for tasks started with `task(background=true)`.
-
-Parameters:
-- `task_id` (required): the task session id returned by the task tool
-- `wait` (optional): when true, wait for completion
-- `timeout_ms` (optional): max wait duration in milliseconds when `wait=true`
-
-Returns compact, parseable output:
-- `task_id`
-- `state` (`running`, `completed`, `error`, or `cancelled`)
-- `<task_result>...</task_result>` or `<task_error>...</task_error>` containing final output, error summary, or current progress text

packages/opencode/test/tool/registry.test.ts

@@ -99,9 +99,6 @@ const it = testEffect(Layer.mergeAll(registryLayer(), node, Agent.defaultLayer))
 const scout = testEffect(
   Layer.mergeAll(registryLayer({ flags: { experimentalScout: true } }), node, Agent.defaultLayer),
 )
-const background = testEffect(
-  Layer.mergeAll(registryLayer({ flags: { experimentalBackgroundSubagents: true } }), node, Agent.defaultLayer),
-)
 const withBrokenPlugin = testEffect(
   Layer.mergeAll(registryLayer({ plugin: brokenPluginLayer }), node, Agent.defaultLayer),
 )
@@ -131,7 +128,7 @@ describe("tool.registry", () => {
     }),
   )
 
-  it.instance("hides task_status unless experimental background subagents are enabled", () =>
+  it.instance("does not expose task_status", () =>
     Effect.gen(function* () {
       const registry = yield* ToolRegistry.Service
       const ids = yield* registry.ids()
@@ -157,15 +154,6 @@ describe("tool.registry", () => {
     }),
   )
 
-  background.instance("shows task_status when experimental background subagents are enabled", () =>
-    Effect.gen(function* () {
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
-
-      expect(ids).toContain("task_status")
-    }),
-  )
-
   it.instance("loads tools from .opencode/tool (singular)", () =>
     Effect.gen(function* () {
       const test = yield* TestInstance

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

@@ -92,7 +92,6 @@ function stubOps(opts?: { onPrompt?: (input: SessionPrompt.PromptInput) => void;
         opts?.onPrompt?.(input)
         return reply(input, opts?.text ?? "done")
       }),
-    loop: (input) => Effect.succeed(reply({ sessionID: input.sessionID, parts: [] }, opts?.text ?? "done")),
   }
 }
 
@@ -307,7 +306,6 @@ describe("tool.task", () => {
             ready.resolve(input)
             return cancelled.promise
           }).pipe(Effect.as(reply(input, "cancelled"))),
-        loop: (input) => Effect.succeed(reply({ sessionID: input.sessionID, parts: [] }, "done")),
       }
 
       const fiber = yield* def
@@ -549,10 +547,9 @@ describe("tool.task", () => {
     }),
   )
 
-  background.instance("background task completion does not wait for the parent resume loop", () =>
+  background.instance("background task completion does not wait for the parent async prompt", () =>
     Effect.gen(function* () {
       const jobs = yield* BackgroundJob.Service
-      const sessions = yield* Session.Service
       const { chat, assistant } = yield* seed()
       const tool = yield* TaskTool
       const def = yield* tool.init()
@@ -573,27 +570,7 @@ describe("tool.task", () => {
             promptOps: {
               ...stubOps({ text: "background done" }),
               prompt: (input) =>
-                input.noReply
-                  ? Effect.gen(function* () {
-                      const user = yield* sessions.updateMessage({
-                        id: input.messageID ?? MessageID.ascending(),
-                        role: "user",
-                        sessionID: input.sessionID,
-                        agent: input.agent ?? "build",
-                        model: input.model ?? ref,
-                        time: { created: Date.now() },
-                      })
-                      const parts = input.parts.map((part) => ({
-                        ...part,
-                        id: part.id ?? PartID.ascending(),
-                        messageID: user.id,
-                        sessionID: input.sessionID,
-                      }))
-                      yield* Effect.forEach(parts, (part) => sessions.updatePart(part), { discard: true })
-                      return { info: user, parts }
-                    })
-                  : Effect.succeed(reply(input, "background done")),
-              loop: () => Effect.never,
+                input.sessionID === chat.id ? Effect.never : Effect.succeed(reply(input, "background done")),
             } satisfies TaskPromptOps,
           },
           messages: [],

packages/opencode/test/tool/task_status.test.ts

@@ -1,92 +0,0 @@
-import { afterEach, describe, expect } from "bun:test"
-import { Effect, Layer } from "effect"
-import { Agent } from "@/agent/agent"
-import { BackgroundJob } from "@/background/job"
-import { Bus } from "@/bus"
-import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
-import { Session } from "@/session/session"
-import { MessageID } from "@/session/schema"
-import { SessionStatus } from "@/session/status"
-import { TaskStatusTool } from "@/tool/task_status"
-import { Truncate } from "@/tool/truncate"
-import { RuntimeFlags } from "@/effect/runtime-flags"
-import { disposeAllInstances } from "../fixture/fixture"
-import { testEffect } from "../lib/effect"
-
-afterEach(async () => {
-  await disposeAllInstances()
-})
-
-const layer = (flags: Partial<RuntimeFlags.Info> = {}) =>
-  Layer.mergeAll(
-    Agent.defaultLayer,
-    BackgroundJob.defaultLayer,
-    Bus.defaultLayer,
-    CrossSpawnSpawner.defaultLayer,
-    Session.defaultLayer,
-    SessionStatus.defaultLayer,
-    Truncate.defaultLayer,
-    RuntimeFlags.layer(flags),
-  )
-
-const it = testEffect(layer({ experimentalBackgroundSubagents: true }))
-
-describe("tool.task_status", () => {
-  it.instance("returns completed background job output", () =>
-    Effect.gen(function* () {
-      const jobs = yield* BackgroundJob.Service
-      const sessions = yield* Session.Service
-      const tool = yield* TaskStatusTool
-      const def = yield* tool.init()
-      const chat = yield* sessions.create({})
-
-      yield* jobs.start({ id: chat.id, type: "task", run: Effect.succeed("all done") })
-
-      const result = yield* def.execute(
-        { task_id: chat.id, wait: true, timeout_ms: 1_000 },
-        {
-          sessionID: chat.id,
-          messageID: MessageID.ascending(),
-          agent: "build",
-          abort: new AbortController().signal,
-          messages: [],
-          metadata: () => Effect.void,
-          ask: () => Effect.void,
-        },
-      )
-
-      expect(result.output).toContain("state: completed")
-      expect(result.output).toContain("all done")
-      expect(result.metadata.timed_out).toBe(false)
-    }),
-  )
-
-  it.instance("wait=true times out while the background job is running", () =>
-    Effect.gen(function* () {
-      const jobs = yield* BackgroundJob.Service
-      const sessions = yield* Session.Service
-      const tool = yield* TaskStatusTool
-      const def = yield* tool.init()
-      const chat = yield* sessions.create({})
-
-      yield* jobs.start({ id: chat.id, type: "task", run: Effect.never })
-
-      const result = yield* def.execute(
-        { task_id: chat.id, wait: true, timeout_ms: 50 },
-        {
-          sessionID: chat.id,
-          messageID: MessageID.ascending(),
-          agent: "build",
-          abort: new AbortController().signal,
-          messages: [],
-          metadata: () => Effect.void,
-          ask: () => Effect.void,
-        },
-      )
-
-      expect(result.output).toContain("state: running")
-      expect(result.output).toContain("Timed out after 50ms")
-      expect(result.metadata.timed_out).toBe(true)
-    }),
-  )
-})