diff --git a/.agents/skills/developing-agent-flow/SKILL.md b/.agents/skills/developing-agent-flow/SKILL.md
index c2e96c0..61dac8b 100644
--- a/.agents/skills/developing-agent-flow/SKILL.md
+++ b/.agents/skills/developing-agent-flow/SKILL.md
@@ -78,6 +78,7 @@ pnpm run build:extension
 ```
 
 Also run `pnpm run build:app` when the standalone binary or its packaged UI can change.
+Run `pnpm run test:pi-smoke` after `pnpm run build:app` when the standalone Pi path can change.
 Run `git diff --check` after the final edit.
 
 ## Pitfalls
@@ -103,6 +104,7 @@ Run `git diff --check` after the final edit.
 - `pnpm run build:webview` produces the VS Code webview bundle.
 - Extension lint, test types, tests, and build pass when extension code changed.
 - `pnpm run build:app` produces `app/dist/app.js` and `app/dist/webview/` when standalone behavior changed.
+- `pnpm run test:pi-smoke` verifies Pi replay, child events, failures, and live JSONL-to-SSE updates against the built app.
 - The direct browser probe covers the requested state transition and keyboard path.
 - `git diff --check` reports no whitespace errors.
 
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0a8162f..de8cbc0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -34,3 +34,12 @@ jobs:
 
       - name: Web typecheck
         run: pnpm --dir web exec tsc --noEmit
+
+      - name: Production builds
+        run: |
+          pnpm run build:web
+          pnpm run build:extension
+          pnpm run build:app
+
+      - name: Pi standalone smoke
+        run: pnpm run test:pi-smoke
diff --git a/package.json b/package.json
index 1cd0c2f..165a7bb 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,8 @@
     "build:webview": "pnpm --filter agent-flow-web run build:webview",
     "build:all": "pnpm run build:webview && pnpm run build:extension",
     "build:app": "node app/build.js",
-    "test": "node --import tsx --test \"scripts/**/*.test.ts\" \"app/src/**/*.test.ts\""
+    "test": "node --import tsx --test \"scripts/**/*.test.ts\" \"app/src/**/*.test.ts\"",
+    "test:pi-smoke": "node --test scripts/pi-standalone-smoke.test.mjs"
   },
   "devDependencies": {
     "concurrently": "^9.2.1",
diff --git a/scripts/pi-standalone-smoke.test.mjs b/scripts/pi-standalone-smoke.test.mjs
new file mode 100644
index 0000000..2c60987
--- /dev/null
+++ b/scripts/pi-standalone-smoke.test.mjs
@@ -0,0 +1,117 @@
+import { test } from 'node:test'
+import assert from 'node:assert/strict'
+import { spawn } from 'node:child_process'
+import { once } from 'node:events'
+import * as fs from 'node:fs'
+import * as http from 'node:http'
+import * as net from 'node:net'
+import * as os from 'node:os'
+import * as path from 'node:path'
+
+function entry(value) {
+  return JSON.stringify(value) + '\n'
+}
+
+async function waitFor(predicate, description, timeoutMs = 8_000) {
+  const deadline = Date.now() + timeoutMs
+  while (!await predicate()) {
+    if (Date.now() >= deadline) throw new Error(`Timed out waiting for ${description}`)
+    await new Promise(resolve => setTimeout(resolve, 25))
+  }
+}
+
+async function freePort() {
+  const server = net.createServer()
+  await new Promise((resolve, reject) => {
+    server.once('error', reject)
+    server.listen(0, '127.0.0.1', resolve)
+  })
+  const port = server.address().port
+  await new Promise(resolve => server.close(resolve))
+  return port
+}
+
+test('the standalone app streams Pi replay and live file activity', async () => {
+  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'agent-flow-pi-smoke-'))
+  const workspace = path.join(root, 'workspace')
+  const sessionDir = path.join(root, 'sessions')
+  const mainFile = path.join(sessionDir, 'main.jsonl')
+  const started = Date.now()
+  fs.mkdirSync(workspace, { recursive: true })
+  fs.mkdirSync(path.dirname(mainFile), { recursive: true })
+  fs.writeFileSync(mainFile, [
+    { type: 'session', id: 'pi-main', timestamp: started, cwd: workspace },
+    { type: 'message', id: 'user-1', timestamp: started + 1, message: { role: 'user', content: 'Pi standalone smoke' } },
+    { type: 'message', id: 'assistant-1', timestamp: started + 2, message: { role: 'assistant', stopReason: 'toolUse', content: [{ type: 'toolCall', id: 'call-1', name: 'read', arguments: { path: 'missing' } }] } },
+    { type: 'message', id: 'result-1', timestamp: started + 3, message: { role: 'toolResult', toolCallId: 'call-1', toolName: 'read', isError: true, content: [{ type: 'text', text: 'not found' }] } },
+  ].map(entry).join(''))
+
+  const childFile = path.join(path.dirname(mainFile), 'main', 'child123', 'run-0', 'session.jsonl')
+  fs.mkdirSync(path.dirname(childFile), { recursive: true })
+  fs.writeFileSync(childFile, [
+    { type: 'session', id: 'pi-child', timestamp: started + 4, cwd: path.join(root, 'other') },
+    { type: 'session_info', id: 'child-info', timestamp: started + 5, name: 'subagent-reviewer-child123-1' },
+    { type: 'message', id: 'child-user', timestamp: started + 6, message: { role: 'user', content: 'Review the relay' } },
+  ].map(entry).join(''))
+
+  const port = await freePort()
+  const app = path.resolve('app/dist/app.js')
+  const child = spawn(process.execPath, [app, '--port', String(port), '--no-open', '--pi-session-dir', sessionDir], {
+    cwd: workspace,
+    env: {
+      ...process.env,
+      HOME: root,
+      PI_CODING_AGENT_DIR: path.join(root, '.opi'),
+      AGENT_FLOW_RUNTIME: 'pi',
+      AGENT_FLOW_TELEMETRY: 'false',
+    },
+    stdio: ['ignore', 'ignore', 'pipe'],
+  })
+  let stderr = ''
+  child.stderr.on('data', chunk => { stderr = (stderr + chunk).slice(-4_000) })
+
+  let request
+  try {
+    await waitFor(async () => {
+      if (child.exitCode !== null) throw new Error(`Standalone app exited early: ${stderr}`)
+      try { return (await fetch(`http://127.0.0.1:${port}/`)).ok } catch { return false }
+    }, 'the standalone HTTP server')
+
+    const messages = []
+    let pending = ''
+    request = http.get(`http://127.0.0.1:${port}/events`, response => response.on('data', chunk => {
+      pending += chunk.toString()
+      for (;;) {
+        const end = pending.indexOf('\n\n')
+        if (end < 0) break
+        const line = pending.slice(0, end).split('\n').find(value => value.startsWith('data: '))
+        pending = pending.slice(end + 2)
+        if (line) messages.push(JSON.parse(line.slice(6)))
+      }
+    }))
+    request.on('error', error => { if (error.code !== 'ECONNRESET') throw error })
+
+    await waitFor(() => messages.some(message => message.type === 'agent-event-batch'), 'the initial Pi event batch')
+    const sessions = messages.find(message => message.type === 'session-list')?.sessions
+    assert.deepEqual(sessions?.map(session => session.id), ['pi-main'])
+
+    const replay = messages.find(message => message.type === 'agent-event-batch')?.events ?? []
+    assert.equal(replay.find(event => event.type === 'agent_spawn' && event.payload.parent)?.payload.runtime, 'pi')
+    assert.equal(replay.find(event => event.type === 'tool_call_end')?.payload.isError, true)
+
+    fs.appendFileSync(mainFile, entry({
+      type: 'message', id: 'live-user', timestamp: Date.now(), message: { role: 'user', content: 'Live update' },
+    }))
+    await waitFor(() => messages.some(message => message.type === 'agent-event' && message.event?.type === 'message' && message.event.payload.content === 'Live update'), 'the appended Pi message')
+  } finally {
+    request?.destroy()
+    if (child.exitCode === null) {
+      child.kill('SIGTERM')
+      const forceKill = setTimeout(() => child.kill('SIGKILL'), 2_000)
+      forceKill.unref()
+      await once(child, 'exit')
+      clearTimeout(forceKill)
+    }
+    fs.rmSync(root, { recursive: true, force: true })
+  }
+})