diff --git a/packages/opencode/src/id/id.ts b/packages/opencode/src/id/id.ts
index d86b99250d..91783ceae2 100644
--- a/packages/opencode/src/id/id.ts
+++ b/packages/opencode/src/id/id.ts
@@ -3,6 +3,7 @@ import { randomBytes } from "crypto"
 
 export namespace Identifier {
   const prefixes = {
+    job: "job",
     event: "evt",
     session: "ses",
     message: "msg",
diff --git a/packages/opencode/src/shell-job/index.ts b/packages/opencode/src/shell-job/index.ts
new file mode 100644
index 0000000000..c722367915
--- /dev/null
+++ b/packages/opencode/src/shell-job/index.ts
@@ -0,0 +1,301 @@
+import path from "path"
+import * as NodeFS from "fs/promises"
+import { InstanceState } from "@/effect/instance-state"
+import { AppFileSystem } from "@/filesystem"
+import { Shell } from "@/shell/shell"
+import { Effect, Layer, Scope, Deferred, Stream, Context, Exit, Schema, Struct } from "effect"
+import { ChildProcess } from "effect/unstable/process"
+import { ChildProcessSpawner } from "effect/unstable/process/ChildProcessSpawner"
+import type { ChildProcessHandle } from "effect/unstable/process/ChildProcessSpawner"
+
+import { JobID } from "./schema"
+
+const PS = new Set(["powershell", "pwsh"])
+
+export namespace ShellJob {
+  export const Status = Schema.Literals(["running", "completed", "failed", "killed", "timed_out"])
+  export type Status = Schema.Schema.Type<typeof Status>
+
+  export class Info extends Schema.Class<Info>("ShellJob.Info")({
+    id: JobID,
+    command: Schema.String,
+    cwd: Schema.String,
+    shell: Schema.String,
+    title: Schema.optional(Schema.String),
+    status: Status,
+    pid: Schema.optional(Schema.Number),
+    started_at: Schema.Number,
+    ended_at: Schema.optional(Schema.Number),
+    exit_code: Schema.optional(Schema.NullOr(Schema.Number)),
+    output_path: Schema.String,
+    meta_path: Schema.String,
+    cursor: Schema.Number,
+  }) {}
+
+  export class Output extends Schema.Class<Output>("ShellJob.Output")({
+    text: Schema.String,
+    cursor: Schema.Number,
+    done: Schema.Boolean,
+  }) {}
+
+  export class StartInput extends Schema.Class<StartInput>("ShellJob.StartInput")({
+    command: Schema.String,
+    cwd: Schema.optional(Schema.String),
+    shell: Schema.optional(Schema.String),
+    title: Schema.optional(Schema.String),
+    timeout: Schema.optional(Schema.Number),
+    env: Schema.optional(Schema.Record(Schema.String, Schema.String)),
+  }) {}
+
+  export class WaitInput extends Schema.Class<WaitInput>("ShellJob.WaitInput")({
+    id: JobID,
+    timeout: Schema.optional(Schema.Number),
+  }) {}
+
+  export class OutputInput extends Schema.Class<OutputInput>("ShellJob.OutputInput")({
+    id: JobID,
+    cursor: Schema.optional(Schema.Number),
+  }) {}
+
+  type Active = {
+    info: Struct.Mutable<Info>
+    next: Status | undefined
+    done: Deferred.Deferred<Info>
+    handle: ChildProcessHandle | undefined
+  }
+
+  type State = {
+    dir: string
+    root: string
+    jobs: Map<JobID, Active>
+    scope: Scope.Scope
+  }
+
+  export interface Interface {
+    readonly list: () => Effect.Effect<Info[]>
+    readonly get: (id: JobID) => Effect.Effect<Info | undefined>
+    readonly start: (input: StartInput) => Effect.Effect<Info>
+    readonly output: (input: OutputInput) => Effect.Effect<Output | undefined>
+    readonly wait: (input: WaitInput) => Effect.Effect<Info | undefined>
+    readonly kill: (id: JobID) => Effect.Effect<Info | undefined>
+  }
+
+  export class Service extends Context.Service<Service, Interface>()("@opencode/ShellJob") {}
+
+  function spawn(shell: string, name: string, command: string, cwd: string, env: NodeJS.ProcessEnv) {
+    if (process.platform === "win32" && PS.has(name)) {
+      return ChildProcess.make(shell, ["-NoLogo", "-NoProfile", "-NonInteractive", "-Command", command], {
+        cwd,
+        env,
+        stdin: "ignore",
+        detached: false,
+      })
+    }
+
+    return ChildProcess.make(command, [], {
+      shell,
+      cwd,
+      env,
+      stdin: "ignore",
+      detached: process.platform !== "win32",
+    })
+  }
+
+  const snap = (job: Active) =>
+    new Info({
+      ...job.info,
+      id: String(job.info.id),
+    })
+
+  export const layer: Layer.Layer<Service, never, AppFileSystem.Service | ChildProcessSpawner> = Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      const fs = yield* AppFileSystem.Service
+      const spawner = yield* ChildProcessSpawner
+
+      const append = Effect.fn("ShellJob.append")(function* (job: Active, chunk: string) {
+        yield* Effect.tryPromise({
+          try: () => NodeFS.appendFile(job.info.output_path, chunk, "utf8"),
+          catch: () => new Error("Failed to append shell job output"),
+        }).pipe(Effect.orDie)
+      })
+
+      const write = Effect.fn("ShellJob.write")(function* (job: Active) {
+        yield* fs.writeJson(job.info.meta_path, job.info).pipe(Effect.orDie)
+      })
+
+      const end = Effect.fn("ShellJob.end")(function* (job: Active, status: Status, code?: number | null) {
+        if (job.info.status !== "running") return snap(job)
+        job.info.status = status
+        job.info.ended_at = Date.now()
+        job.info.exit_code = code
+        job.handle = undefined
+        job.next = undefined
+        yield* write(job)
+        const info = snap(job)
+        yield* Deferred.succeed(job.done, info).pipe(Effect.ignore)
+        return info
+      })
+
+      const watch = Effect.fn("ShellJob.watch")(function* (job: Active, timeout?: number) {
+        const handle = job.handle
+        if (!handle) return snap(job)
+
+        if (timeout) {
+          yield* Effect.sleep(`${timeout} millis`).pipe(
+            Effect.andThen(
+              Effect.gen(function* () {
+                if (job.info.status !== "running") return
+                job.next = "timed_out"
+                yield* handle.kill({ forceKillAfter: "3 seconds" }).pipe(Effect.ignore)
+              }),
+            ),
+            Effect.forkScoped,
+          )
+        }
+
+        yield* Effect.forkScoped(
+          Stream.runForEach(Stream.decodeText(handle.all), (chunk) =>
+            Effect.gen(function* () {
+              job.info.cursor += chunk.length
+              yield* append(job, chunk)
+            }),
+          ),
+        )
+
+        const exit = yield* Effect.exit(handle.exitCode)
+        if (Exit.isSuccess(exit)) {
+          const code = Number(exit.value)
+          return yield* end(job, code === 0 ? "completed" : "failed", code)
+        }
+
+        return yield* end(job, job.next ?? "killed", null)
+      })
+
+      const state = yield* InstanceState.make<State>(
+        Effect.fn("ShellJob.state")(function* (ctx) {
+          const dir = ctx.project.vcs ? ctx.worktree : ctx.directory
+          const root = path.join(dir, ".opencode", "jobs")
+          const state: State = {
+            dir: ctx.directory,
+            root,
+            jobs: new Map(),
+            scope: yield* Scope.Scope,
+          }
+
+          yield* fs.ensureDir(root).pipe(Effect.orDie)
+          yield* Effect.addFinalizer(() =>
+            Effect.gen(function* () {
+              state.jobs.clear()
+            }),
+          )
+
+          return state
+        }),
+      )
+
+      const list: Interface["list"] = Effect.fn("ShellJob.list")(function* () {
+        const s = yield* InstanceState.get(state)
+        return Array.from(s.jobs.values())
+          .map(snap)
+          .toSorted((a, b) => a.started_at - b.started_at)
+      })
+
+      const get: Interface["get"] = Effect.fn("ShellJob.get")(function* (id: JobID) {
+        const s = yield* InstanceState.get(state)
+        const job = s.jobs.get(id)
+        if (!job) return
+        return snap(job)
+      })
+
+      const start: Interface["start"] = Effect.fn("ShellJob.start")(function* (input: StartInput) {
+        const s = yield* InstanceState.get(state)
+        const id = JobID.ascending()
+        const dir = path.join(s.root, String(id))
+        const cwd = input.cwd ?? s.dir
+        const shell = input.shell ?? Shell.acceptable()
+        const name = Shell.name(shell)
+        const handle = yield* Scope.provide(s.scope)(
+          spawner.spawn(
+            spawn(shell, name, input.command, cwd, {
+              ...process.env,
+              ...input.env,
+            }),
+          ),
+        ).pipe(Effect.orDie)
+
+        const job: Active = {
+          info: {
+            id,
+            command: input.command,
+            cwd,
+            shell,
+            title: input.title,
+            status: "running",
+            pid: Number(handle.pid),
+            started_at: Date.now(),
+            output_path: path.join(dir, "output.log"),
+            meta_path: path.join(dir, "meta.json"),
+            cursor: 0,
+          } satisfies Struct.Mutable<Info>,
+          next: undefined,
+          done: yield* Deferred.make<Info>(),
+          handle,
+        }
+
+        s.jobs.set(id, job)
+        yield* fs.writeWithDirs(job.info.output_path, "").pipe(Effect.orDie)
+        yield* write(job)
+        yield* Effect.sync(() => {
+          Effect.runFork(Scope.provide(s.scope)(watch(job, input.timeout)))
+        })
+        return snap(job)
+      })
+
+      const output: Interface["output"] = Effect.fn("ShellJob.output")(function* (input: OutputInput) {
+        const s = yield* InstanceState.get(state)
+        const job = s.jobs.get(input.id)
+        if (!job) return
+        const cursor = input.cursor ?? 0
+        const text = yield* fs.readFileString(job.info.output_path).pipe(Effect.catch(() => Effect.succeed("")))
+        return new Output({
+          text: cursor >= text.length ? "" : text.slice(cursor),
+          cursor: text.length,
+          done: job.info.status !== "running",
+        })
+      })
+
+      const wait: Interface["wait"] = Effect.fn("ShellJob.wait")(function* (input: WaitInput) {
+        const s = yield* InstanceState.get(state)
+        const job = s.jobs.get(input.id)
+        if (!job) return
+        if (job.info.status !== "running") return snap(job)
+        if (!input.timeout) return yield* Deferred.await(job.done)
+        return yield* Effect.raceAll([
+          Deferred.await(job.done),
+          Effect.sleep(`${input.timeout} millis`).pipe(Effect.as(snap(job))),
+        ])
+      })
+
+      const kill: Interface["kill"] = Effect.fn("ShellJob.kill")(function* (id: JobID) {
+        const s = yield* InstanceState.get(state)
+        const job = s.jobs.get(id)
+        if (!job) return
+        if (job.info.status !== "running") return snap(job)
+        if (!job.handle) return snap(job)
+        if (!job.next) job.next = "killed"
+        yield* job.handle.kill({ forceKillAfter: "3 seconds" }).pipe(Effect.ignore)
+        return yield* Deferred.await(job.done)
+      })
+
+      return Service.of({
+        list,
+        get,
+        start,
+        output,
+        wait,
+        kill,
+      })
+    }),
+  )
+}
diff --git a/packages/opencode/src/shell-job/schema.ts b/packages/opencode/src/shell-job/schema.ts
new file mode 100644
index 0000000000..b359547cb9
--- /dev/null
+++ b/packages/opencode/src/shell-job/schema.ts
@@ -0,0 +1,10 @@
+import { Schema } from "effect"
+
+import { Identifier } from "@/id/id"
+import { Newtype } from "@/util/schema"
+
+export class JobID extends Newtype<JobID>()("JobID", Schema.String) {
+  static ascending(id?: string): JobID {
+    return this.make(Identifier.ascending("job", id))
+  }
+}
diff --git a/packages/opencode/test/shell-job/shell-job.test.ts b/packages/opencode/test/shell-job/shell-job.test.ts
new file mode 100644
index 0000000000..002eed9080
--- /dev/null
+++ b/packages/opencode/test/shell-job/shell-job.test.ts
@@ -0,0 +1,143 @@
+import { describe, expect } from "bun:test"
+import { Effect, Layer } from "effect"
+
+import * as CrossSpawnSpawner from "../../src/effect/cross-spawn-spawner"
+import { AppFileSystem } from "../../src/filesystem"
+import { Instance } from "../../src/project/instance"
+import { ShellJob } from "../../src/shell-job"
+import { provideTmpdirInstance } from "../fixture/fixture"
+import { testEffect } from "../lib/effect"
+
+const it = testEffect(
+  Layer.mergeAll(
+    CrossSpawnSpawner.defaultLayer,
+    ShellJob.layer.pipe(Layer.provide(CrossSpawnSpawner.defaultLayer), Layer.provide(AppFileSystem.defaultLayer)),
+  ),
+)
+
+const node = (script: string) => `${JSON.stringify(process.execPath)} -e ${JSON.stringify(script)}`
+
+const alive = (pid: number) => {
+  try {
+    process.kill(pid, 0)
+    return true
+  } catch {
+    return false
+  }
+}
+
+describe("shell-job", () => {
+  it.live("captures output and persists spool files", () =>
+    provideTmpdirInstance((dir) =>
+      Effect.gen(function* () {
+        const jobs = yield* ShellJob.Service
+        const job = yield* jobs.start({
+          command: node('process.stdout.write("ok")'),
+          cwd: dir,
+          title: "ok",
+        })
+        const done = yield* jobs.wait({ id: job.id })
+        const out = yield* jobs.output({ id: job.id })
+
+        expect(done).toBeDefined()
+        expect(done?.status).toBe("completed")
+        expect(done?.pid).toBeGreaterThan(0)
+        expect(out).toEqual({ text: "ok", cursor: 2, done: true })
+
+        const log = yield* Effect.promise(() => Bun.file(done!.output_path).text())
+        const meta = yield* Effect.promise(() => Bun.file(done!.meta_path).json())
+        expect(log).toBe("ok")
+        expect(meta).toMatchObject({
+          id: done!.id,
+          status: "completed",
+          title: "ok",
+          cursor: 2,
+        })
+      }),
+    ),
+  )
+
+  it.live("reads output incrementally with a cursor", () =>
+    provideTmpdirInstance((dir) =>
+      Effect.gen(function* () {
+        const jobs = yield* ShellJob.Service
+        const job = yield* jobs.start({
+          command: node(
+            'process.stdout.write("a"); setTimeout(() => process.stdout.write("b"), 200); setTimeout(() => process.exit(0), 350)',
+          ),
+          cwd: dir,
+        })
+
+        yield* Effect.sleep("100 millis")
+        const a = yield* jobs.output({ id: job.id })
+        const done = yield* jobs.wait({ id: job.id })
+        const b = yield* jobs.output({ id: job.id, cursor: a?.cursor ?? 0 })
+
+        expect(a).toEqual({ text: "a", cursor: 1, done: false })
+        expect(done?.status).toBe("completed")
+        expect(b).toEqual({ text: "b", cursor: 2, done: true })
+      }),
+    ),
+  )
+
+  it.live("marks non-zero exits as failed", () =>
+    provideTmpdirInstance((dir) =>
+      Effect.gen(function* () {
+        const jobs = yield* ShellJob.Service
+        const job = yield* jobs.start({
+          command: node('process.stderr.write("bad"); process.exit(7)'),
+          cwd: dir,
+        })
+        const done = yield* jobs.wait({ id: job.id })
+        const out = yield* jobs.output({ id: job.id })
+
+        expect(done).toBeDefined()
+        expect(done?.status).toBe("failed")
+        expect(done?.exit_code).toBe(7)
+        expect(out?.text).toBe("bad")
+        expect(out?.done).toBe(true)
+      }),
+    ),
+  )
+
+  it.live("kills a running job and returns final state", () =>
+    provideTmpdirInstance((dir) =>
+      Effect.gen(function* () {
+        const jobs = yield* ShellJob.Service
+        const job = yield* jobs.start({
+          command: node("setInterval(() => {}, 1000)"),
+          cwd: dir,
+        })
+
+        yield* Effect.sleep("50 millis")
+        const done = yield* jobs.kill(job.id)
+
+        expect(done).toBeDefined()
+        expect(done?.status).toBe("killed")
+        expect(done?.exit_code).toBeNull()
+      }),
+    ),
+  )
+
+  it.live("kills running jobs when the instance is disposed", () => {
+    if (process.platform === "win32") return Effect.void
+
+    return provideTmpdirInstance((dir) =>
+      Effect.gen(function* () {
+        const jobs = yield* ShellJob.Service
+        const job = yield* jobs.start({
+          command: node("setInterval(() => {}, 1000)"),
+          cwd: dir,
+        })
+
+        expect(job.pid).toBeGreaterThan(0)
+        yield* Effect.sleep("50 millis")
+        expect(alive(job.pid!)).toBe(true)
+
+        yield* Effect.promise(() => Instance.dispose())
+        yield* Effect.sleep("100 millis")
+        expect(alive(job.pid!)).toBe(false)
+      }),
+    )
+  })
+})