diff --git a/mobile/scripts/repro-terminal-colors.ts b/mobile/scripts/repro-terminal-colors.ts
index 100643d57a7..977d2c00eec 100644
--- a/mobile/scripts/repro-terminal-colors.ts
+++ b/mobile/scripts/repro-terminal-colors.ts
@@ -311,7 +311,11 @@ ws.on('open', () => {
 })
 
 ws.on('message', (data) => {
-  const plaintext = decrypt(data.toString())
+  const raw = data.toString()
+  if (raw.startsWith('{')) {
+    return
+  }
+  const plaintext = decrypt(raw)
   if (!plaintext) return
 
   const response = JSON.parse(plaintext) as RpcResponse
diff --git a/mobile/scripts/repro-worktree-startup-stream.ts b/mobile/scripts/repro-worktree-startup-stream.ts
new file mode 100644
index 00000000000..3d5e38dcd1b
--- /dev/null
+++ b/mobile/scripts/repro-worktree-startup-stream.ts
@@ -0,0 +1,350 @@
+/**
+ * Captures the mobile WebSocket stream during worktree startup.
+ *
+ * Usage:
+ *   pnpm exec tsx mobile/scripts/repro-worktree-startup-stream.ts <repoSelector> <worktreeName> [startupCommand]
+ */
+import { existsSync, mkdirSync, readFileSync, writeFileSync } from 'node:fs'
+import { join } from 'node:path'
+import nacl from 'tweetnacl'
+import WebSocket from 'ws'
+
+const WS_URL = process.env.ORCA_MOBILE_WS_URL ?? 'ws://127.0.0.1:6768'
+const USER_DATA =
+  process.env.ORCA_USER_DATA ?? `${process.env.HOME}/Library/Application Support/orca-dev`
+const repoSelector = process.argv[2]
+const worktreeName = process.argv[3]
+const startupCommand = process.argv[4] || 'claude'
+const ESC = String.fromCharCode(27)
+
+type RpcResponse = {
+  id: string
+  ok: boolean
+  streaming?: true
+  result?: Record<string, unknown>
+  error?: { code: string; message: string }
+}
+
+type PendingRequest = {
+  method: string
+  resolve: (response: RpcResponse) => void
+  reject: (error: Error) => void
+}
+
+type TerminalInfo = {
+  handle: string
+  title: string | null
+}
+
+type Capture = {
+  handle: string
+  title: string | null
+  scrollback: Record<string, unknown> | null
+  chunks: string[]
+}
+
+if (!repoSelector || !worktreeName) {
+  console.error(
+    'Usage: pnpm exec tsx mobile/scripts/repro-worktree-startup-stream.ts <repoSelector> <worktreeName> [startupCommand]'
+  )
+  process.exit(1)
+}
+
+function readJson<T>(path: string): T {
+  if (!existsSync(path)) {
+    throw new Error(`Missing ${path}`)
+  }
+  return JSON.parse(readFileSync(path, 'utf8')) as T
+}
+
+const devices = readJson<Array<{ token: string }>>(join(USER_DATA, 'orca-devices.json'))
+const token = devices[0]?.token
+const keypair = readJson<{ publicKeyB64: string }>(join(USER_DATA, 'orca-e2ee-keypair.json'))
+
+if (!token || !keypair.publicKeyB64) {
+  throw new Error(`Missing mobile token or E2EE public key in ${USER_DATA}`)
+}
+
+let reqId = 0
+const pending = new Map<string, PendingRequest>()
+const streamListeners = new Map<string, (result: Record<string, unknown>) => void>()
+const clientKeys = nacl.box.keyPair()
+const serverPublicKey = Buffer.from(keypair.publicKeyB64, 'base64')
+const sharedKey = nacl.box.before(new Uint8Array(serverPublicKey), clientKeys.secretKey)
+
+function nextId(): string {
+  reqId += 1
+  return `startup-repro-${reqId}`
+}
+
+function toBase64(bytes: Uint8Array): string {
+  return Buffer.from(bytes).toString('base64')
+}
+
+function fromBase64(value: string): Uint8Array {
+  return new Uint8Array(Buffer.from(value, 'base64'))
+}
+
+function encrypt(plaintext: string): string {
+  const nonce = nacl.randomBytes(nacl.box.nonceLength)
+  const message = new TextEncoder().encode(plaintext)
+  const ciphertext = nacl.box.after(message, nonce, sharedKey)
+  const bundle = new Uint8Array(nonce.length + ciphertext.length)
+  bundle.set(nonce)
+  bundle.set(ciphertext, nonce.length)
+  return toBase64(bundle)
+}
+
+function decrypt(payload: string): string | null {
+  const bundle = fromBase64(payload)
+  if (bundle.length < nacl.box.nonceLength + nacl.box.overheadLength) {
+    return null
+  }
+  const nonce = bundle.subarray(0, nacl.box.nonceLength)
+  const ciphertext = bundle.subarray(nacl.box.nonceLength)
+  const plaintext = nacl.box.open.after(ciphertext, nonce, sharedKey)
+  return plaintext ? new TextDecoder().decode(plaintext) : null
+}
+
+function sendRaw(ws: WebSocket, payload: unknown): void {
+  ws.send(encrypt(JSON.stringify(payload)))
+}
+
+function send(
+  ws: WebSocket,
+  method: string,
+  params?: unknown,
+  timeoutMs = 30_000
+): Promise<RpcResponse> {
+  const id = nextId()
+  sendRaw(ws, { id, deviceToken: token, method, params })
+  return new Promise((resolve, reject) => {
+    const timeout = setTimeout(() => {
+      pending.delete(id)
+      reject(new Error(`Timed out waiting for ${method}`))
+    }, timeoutMs)
+    pending.set(id, {
+      method,
+      resolve: (response) => {
+        clearTimeout(timeout)
+        resolve(response)
+      },
+      reject: (error) => {
+        clearTimeout(timeout)
+        reject(error)
+      }
+    })
+  })
+}
+
+function formatError(response: RpcResponse): string {
+  return JSON.stringify(response.error ?? response.result ?? response).slice(0, 1000)
+}
+
+function stripAnsi(value: string): string {
+  return (
+    value
+      // eslint-disable-next-line no-control-regex -- intentional terminal escape stripping for repro summaries
+      .replace(/\u001b\][^\u0007]*(?:\u0007|\u001b\\)/g, '')
+      // eslint-disable-next-line no-control-regex -- intentional terminal escape stripping for repro summaries
+      .replace(/\u001b\[[0-?]*[ -/]*[@-~]/g, '')
+      .replace(/\r/g, '\n')
+  )
+}
+
+function normalizePreview(value: string): string {
+  return stripAnsi(value)
+    .split('\n')
+    .map((line) => line.trim())
+    .filter(Boolean)
+    .slice(0, 8)
+    .join('\n')
+}
+
+async function waitForTerminals(ws: WebSocket, worktreeId: string): Promise<TerminalInfo[]> {
+  const deadline = Date.now() + 60_000
+  while (Date.now() < deadline) {
+    const response = await send(ws, 'terminal.list', { worktree: worktreeId })
+    if (!response.ok) {
+      throw new Error(`terminal.list failed: ${formatError(response)}`)
+    }
+    const terminals = (response.result?.terminals ?? []) as Array<{
+      handle?: string
+      title?: string | null
+    }>
+    const handles = terminals
+      .filter((terminal): terminal is { handle: string; title?: string | null } =>
+        Boolean(terminal.handle)
+      )
+      .map((terminal) => ({ handle: terminal.handle, title: terminal.title ?? null }))
+    if (handles.length > 0) {
+      return handles
+    }
+    await new Promise((resolve) => setTimeout(resolve, 500))
+  }
+  throw new Error('Timed out waiting for startup terminals')
+}
+
+async function subscribe(ws: WebSocket, capture: Capture): Promise<void> {
+  const id = nextId()
+  streamListeners.set(id, (result) => {
+    if (result.type === 'scrollback') {
+      capture.scrollback = result
+      return
+    }
+    if (result.type === 'data' && typeof result.chunk === 'string') {
+      capture.chunks.push(result.chunk)
+    }
+  })
+  sendRaw(ws, {
+    id,
+    deviceToken: token,
+    method: 'terminal.subscribe',
+    params: { terminal: capture.handle }
+  })
+}
+
+function summarize(capture: Capture): Record<string, unknown> {
+  const serialized =
+    typeof capture.scrollback?.serialized === 'string' ? capture.scrollback.serialized : ''
+  const live = capture.chunks.join('')
+  const serializedPreview = normalizePreview(serialized)
+  const livePreview = normalizePreview(live)
+  return {
+    handle: capture.handle,
+    title: capture.title,
+    cols: capture.scrollback?.cols ?? null,
+    rows: capture.scrollback?.rows ?? null,
+    serializedBytes: Buffer.byteLength(serialized),
+    liveBytes: Buffer.byteLength(live),
+    liveChunks: capture.chunks.length,
+    serializedSgr: (serialized.match(new RegExp(`${ESC}\\[[0-9;:]*m`, 'g')) ?? []).length,
+    liveSgr: (live.match(new RegExp(`${ESC}\\[[0-9;:]*m`, 'g')) ?? []).length,
+    livePreviewContainedInSerialized:
+      livePreview.length > 0 && stripAnsi(serialized).includes(livePreview.split('\n')[0] ?? ''),
+    serializedPreview,
+    livePreview
+  }
+}
+
+function save(captures: Capture[], worktreeName: string): string {
+  const dir = join(process.cwd(), 'terminal-startup-repro', worktreeName)
+  mkdirSync(dir, { recursive: true })
+  for (const capture of captures) {
+    const base = capture.handle.replace(/[^a-z0-9_-]/gi, '-')
+    const serialized =
+      typeof capture.scrollback?.serialized === 'string' ? capture.scrollback.serialized : ''
+    writeFileSync(join(dir, `${base}.serialized.ansi`), serialized)
+    writeFileSync(join(dir, `${base}.live.ansi`), capture.chunks.join(''))
+    writeFileSync(join(dir, `${base}.json`), JSON.stringify(capture, null, 2))
+  }
+  writeFileSync(join(dir, 'summary.json'), JSON.stringify(captures.map(summarize), null, 2))
+  return dir
+}
+
+async function run(ws: WebSocket): Promise<void> {
+  ws.send(
+    JSON.stringify({
+      type: 'e2ee_hello',
+      publicKeyB64: toBase64(clientKeys.publicKey),
+      deviceToken: token
+    })
+  )
+
+  await new Promise<void>((resolve, reject) => {
+    const timeout = setTimeout(() => reject(new Error('Timed out waiting for e2ee_ready')), 5000)
+    ws.once('message', (data) => {
+      clearTimeout(timeout)
+      const msg = JSON.parse(data.toString()) as { type?: string }
+      if (msg.type !== 'e2ee_ready') {
+        reject(new Error(`Unexpected handshake response: ${data.toString()}`))
+        return
+      }
+      resolve()
+    })
+  })
+
+  const created = await send(
+    ws,
+    'worktree.create',
+    { repo: repoSelector, name: worktreeName, startupCommand },
+    120_000
+  )
+  if (!created.ok) {
+    throw new Error(`worktree.create failed: ${formatError(created)}`)
+  }
+  const worktree = created.result?.worktree as { id?: string; path?: string } | undefined
+  if (!worktree?.id) {
+    throw new Error(`worktree.create returned no worktree id: ${formatError(created)}`)
+  }
+
+  console.log(`worktree: ${worktree.id}`)
+  const terminals = await waitForTerminals(ws, worktree.id)
+  console.log(`terminals: ${terminals.map((terminal) => terminal.handle).join(', ')}`)
+  const captures = terminals.map((terminal) => ({
+    handle: terminal.handle,
+    title: terminal.title,
+    scrollback: null,
+    chunks: []
+  }))
+  for (const capture of captures) {
+    await subscribe(ws, capture)
+  }
+
+  await new Promise((resolve) => setTimeout(resolve, 15_000))
+  for (const capture of captures) {
+    await send(ws, 'terminal.unsubscribe', { subscriptionId: capture.handle }).catch(() => null)
+  }
+  const dir = save(captures, worktreeName)
+  console.table(captures.map(summarize))
+  console.log(`saved: ${dir}`)
+}
+
+const ws = new WebSocket(WS_URL)
+
+ws.on('open', () => {
+  run(ws)
+    .then(() => {
+      ws.close()
+      process.exit(0)
+    })
+    .catch((error) => {
+      console.error(error.message)
+      ws.close()
+      process.exit(1)
+    })
+})
+
+ws.on('message', (data) => {
+  const raw = data.toString()
+  if (raw.startsWith('{')) {
+    return
+  }
+  const plaintext = decrypt(raw)
+  if (!plaintext) return
+
+  const response = JSON.parse(plaintext) as RpcResponse
+  const result = response.result
+  const streamListener = streamListeners.get(response.id)
+  if (streamListener && response.ok && (response.streaming || result?.type)) {
+    streamListener(result ?? {})
+    return
+  }
+
+  const request = pending.get(response.id)
+  if (!request || request.method === 'terminal.subscribe') return
+  pending.delete(response.id)
+  request.resolve(response)
+})
+
+ws.on('close', () => {
+  for (const request of pending.values()) {
+    request.reject(new Error('WebSocket closed'))
+  }
+  pending.clear()
+})
+
+ws.on('error', (error) => {
+  console.error(`WebSocket error: ${error.message}`)
+  process.exit(1)
+})
diff --git a/src/main/daemon/shell-ready.ts b/src/main/daemon/shell-ready.ts
index f7a2e021fdb..1bccaf63263 100644
--- a/src/main/daemon/shell-ready.ts
+++ b/src/main/daemon/shell-ready.ts
@@ -134,7 +134,11 @@ if [[ "\${ORCA_SHELL_READY_MARKER:-0}" == "1" ]]; then
   __orca_prompt_mark() {
     printf "${SHELL_READY_MARKER}"
   }
-  precmd_functions=(\${precmd_functions[@]} __orca_prompt_mark)
+  # Why: zsh precmd fires before zle switches the PTY into line-editing mode,
+  # so writing startup input there can be echoed once outside the prompt.
+  autoload -Uz add-zle-hook-widget
+  zle -N __orca_prompt_mark
+  add-zle-hook-widget line-init __orca_prompt_mark
 fi
 `
   const bashRc = `# Orca daemon bash shell-ready wrapper
diff --git a/src/main/providers/local-pty-shell-ready.ts b/src/main/providers/local-pty-shell-ready.ts
index 7ad3c09b902..b15d8f59bbc 100644
--- a/src/main/providers/local-pty-shell-ready.ts
+++ b/src/main/providers/local-pty-shell-ready.ts
@@ -210,13 +210,15 @@ __orca_restore_attribution_path() {
   export PATH="\${ORCA_ATTRIBUTION_SHIM_DIR}:$PATH"
 }
 __orca_restore_attribution_path
-# Why: emit OSC 133;A only after the user's startup hooks finish so Orca knows
-# the prompt is actually ready for a long startup command paste.
+# Why: zsh precmd runs before the prompt is drawn and before zle owns input,
+# which can double-echo startup commands. line-init fires when zle is ready.
 if [[ "\${ORCA_SHELL_READY_MARKER:-0}" == "1" ]]; then
   __orca_prompt_mark() {
     printf "\\033]133;A\\007"
   }
-  precmd_functions=(\${precmd_functions[@]} __orca_prompt_mark)
+  autoload -Uz add-zle-hook-widget
+  zle -N __orca_prompt_mark
+  add-zle-hook-widget line-init __orca_prompt_mark
 fi
 `
   const bashRc = getBashShellReadyRcfileContent()