Files
orca/mobile
Jinwoo Hong ceafdcad2f perf(mobile): race the direct and relay dials from t=0 on every reconnect (#19308)
* perf(mobile): race the direct and relay dials from t=0 on every reconnect

A foreground reconnect gave the direct dial a fixed 2.5s head start, and while
that dial sat in 'connecting'/'handshaking' the supervisor refused to open a
relay socket at all. A phone that is off the LAN paid the full head start on
every reconnect and got nothing for it, and a phone whose relay dropped could
only return to the LAN through three hysteresis probes.

Both dials now start together and the first authenticated socket is adopted
through the existing migrateTo cutover. Nothing about the migration machinery
changes: only who is allowed to start a dial.

- The relay dial now yields to a live session and to nothing else. An unfinished
  direct dial is progress on the other runner, not a reason to stand still.
- The direct return probe grows a second adoption policy. Against a live relay
  hysteresis still has to prove direct stable; during a reconnect there is no
  session to protect, so an authenticated direct socket wins outright. probeNow
  pre-empts a pending 15s tick so that dial starts with the relay dial, not
  after it, and the dial itself no longer waits for the operation mutex — a
  relay dial holding it is exactly the case the race exists for.
- A loser closes and books nothing. The relay dial withdraws inside migrateTo
  and returns 'aborted', so no backoff is booked against it; a direct socket
  that loses leaves the promotion streak untouched. Only a reconnect that both
  paths lose books a failure, once, on the relay cadence.

Kept: the 30s background grace and the foreground gate, because a backgrounded
phone must not open a billed relay splice; the shared failure cooldown, because
a genuine relay failure still has to be paced; the hysteresis dwell after a
migration, because it is what stops a marginal LAN flapping a healthy session.

The accepted cost is one relay socket per reconnect for a phone that is on its
LAN. It closes as soon as the direct path authenticates, before the resume
confirm, because migrateTo only checks the abort predicate after E2EE auth.

Tests that encoded the removed rules:
- 'fails over when the direct retry loop publishes reconnecting' asserted no
  relay dial while direct was handshaking. The failover now precedes the direct
  client giving up, so it asserts the dial instead of its absence.
- 'does not spend a queued relay retry while direct authentication is
  progressing' encoded the block outright; it now asserts the retry runs on the
  failure cadence while a handshake drags on.
- The four grace-race cases move to mobile-endpoint-reconnect-race.test.ts as
  t=0, direct-wins, background/resume and both-lose cases.
- Five relay-bookkeeping cases now state their premise with unreachableDirect.
  They describe a phone with no LAN, which used to be implicit and is now
  load-bearing: with a reachable LAN the direct socket wins those reconnects.

* fix(mobile): withdraw a lost relay dial pre-handshake and damp blip races

Review follow-up to 4e31130471. Racing both paths from t=0 was correct but
charged the LAN case twice: once per reconnect in cell work, and again whenever
the LAN flapped.

Withdraw before the handshake. migrateTo only consults its abort predicate after
E2EE authentication, so a dial that had already lost still made the cell reserve
a splice and the desktop finish a key exchange. The establisher now watches the
logical client across the dial and closes the cell socket the moment direct
authenticates. In the common window, after relay-auth is on the wire and before
the hello lands, nothing of the key exchange has started, so the withdrawal
costs the desktop nothing. The dial still reports itself aborted and still books
nothing. The watch is dropped once migrateTo returns, because past the cutover
this session is the active path and a later direct promotion must not read as a
reason to close the client's own socket.

Damp races that a blip started. relayDialAllowed yields only to a live session
and a lost race books nothing, so a flapping LAN drove one cell socket per blip
with only the relay's per-host rate limiter as a backstop, and reaching that
limiter would have converted a benign race into a booked relay failure. After a
race is lost to direct, the next unforced race is suppressed for 2s, doubling
per consecutive loss to a 30s cap. This is not backoff and is kept separate from
it: a forced replacement is never damped, a relay dial that wins clears the
streak, and a foreground resume clears it too, so the path the user is watching
never waits. The window arms its own lapse timer, so a LAN that dies inside the
window still reaches relay without a new trigger.

A superseded cutover no longer escapes probe() as an unhandled rejection. Only
the probe timer calls it, and it discards the promise, so the routine end of a
lost race would have surfaced as one.

Credential rotation moves to MobileRelayCredentialRefresh. The supervisor
crossed the 300-line cap; rotation is a self-contained responsibility that only
runs over a live direct connection, so it splits cleanly instead of taking a
max-lines bump.

* fix(mobile): end a damper window as soon as the direct path is really gone

Round-2 review follow-up to 9a21da4326. The damper armed its window when direct
won the race, and nothing shortened it. A LAN that died inside that window left
the phone waiting out the whole thing, up to 30s at the cap, with only a log
line to show for it. My previous commit body claimed the path the user watches
never waits; that was true only of a foreground resume, and it is corrected
here.

Losing the direct path now collapses the wait to a 250ms floor, so the next
recovery races almost at once. The floor is not zero because the reason the
damper exists is a LAN that drops and comes straight back, and a disconnect is
how such a blip begins. So the rest of the window is kept aside rather than
spent: if direct returns inside the floor it was a blip and the window resumes,
and if the floor lapses with direct still gone it was an outage and the held
window is void. Without the second half, one blip would have bought a flapping
LAN a free pass on every race that followed, which is the case the damper was
added for.

The streak itself is untouched by the clamp. A LAN that flaps all afternoon
still escalates toward the cap; only the current wait is cut short.

record() now takes the same forceReplacement guard as suppresses(), so a forced
replacement that stands down cannot grow the streak or be read as a loss to
direct. A lease rotation or a reconsidered network change is not a LAN that
flapped.

Also documents that a genuine relay failure deliberately does not reset the
streak, and that the damper and the failure backoff serialize rather than stack:
a damped attempt never reaches the dial that would book a cooldown.

* fix(test): give the direct-probe fixture the race-era hooks

The phase-1 probe test predates canDial and adoptsOutright, so its hooks
literal threw at the first dial. These cases model a live relay session.

* docs(mobile): say why a finished credential refresh races relay instead of waiting on direct
2026-09-07 13:45:51 -04:00
..

Orca Mobile

React Native companion app for Orca. Monitor worktrees, view terminal output, and send commands from your phone.

Local development uses two processes:

  • Orca desktop/Electron from the repo root. This hosts the mobile WebSocket RPC server on port 6768.
  • Expo Metro from mobile/. This serves the React Native app on port 8081.

Unless a command says otherwise, run mobile app commands from the mobile/ directory.

Prerequisites

  • Node.js 24+
  • pnpm
  • Xcode and/or Android Studio tooling for simulator or device builds
  • Expo Go on your phone, or a development client build when native modules are needed
  • Phone and desktop on the same LAN when testing a physical phone

Start Desktop Orca

From the repository root:

pnpm install
pnpm dev

Confirm the mobile RPC server is listening:

lsof -nP -iTCP:6768 -sTCP:LISTEN

Restart pnpm dev after changing Electron main-process code. Metro hot reload only applies to the mobile JavaScript bundle.

Start The Mobile App

cd mobile
pnpm install
pnpm start

Scan the Expo QR code with your phone's camera on iOS, or Expo Go on Android.

For a native dev-client build:

pnpm exec expo run:android
pnpm exec expo run:ios
pnpm start --dev-client

Pair With Desktop Orca

  1. Open Orca desktop.
  2. Go to Settings > Mobile.
  3. Scan the pairing QR code from the mobile app.
  4. Confirm the mobile host endpoint is ws://<desktop-ip>:6768.

For the Android emulator, use ws://10.0.2.2:6768. For a physical phone, use the desktop LAN IP, for example ws://192.168.0.179:6768.

If the phone has a stale host entry, remove it from the app and pair again.

Development Paths

Android Phone

  1. Install Expo Go from Google Play
  2. Run pnpm start, scan QR with Expo Go
  3. For native modules: pnpm exec expo run:android
  4. Run with pnpm start --dev-client

iOS Simulator

  1. Install Xcode from the App Store
  2. Run pnpm start --ios to open in iOS Simulator

Physical Phone Debugging

The phone can be inspected through the connected device tooling:

orca snapshot --json
orca click --element @e3 --json
orca fill --element @e1 --value "ls" --json
orca screenshot --json

Use snapshot first to find the current element refs, then click/fill those refs. After mobile file edits, Metro usually hot reloads automatically, but navigating out of and back into the session screen can be useful because it re-runs terminal.subscribe.

Terminal Streaming Repro Without A Phone

Use this when terminal output does not render on device and you need to split server streaming bugs from WebView/UI bugs:

cd mobile
ORCA_MOBILE_WS_URL=ws://127.0.0.1:6768 pnpm exec tsx scripts/test-subscribe.ts <deviceToken> <serverPublicKeyB64>

You can pass a worktree selector as the third argument:

pnpm exec tsx scripts/test-subscribe.ts <deviceToken> <serverPublicKeyB64> "id:<worktreeId>"
pnpm exec tsx scripts/test-subscribe.ts <deviceToken> <serverPublicKeyB64> "path:/absolute/worktree/path"
pnpm exec tsx scripts/test-subscribe.ts <deviceToken> <serverPublicKeyB64> "name:my-worktree"

The expected result includes:

streamSawMarker: true
readSawMarker: true

If this repro fails, debug the desktop runtime/PTY path before the mobile WebView. If it passes but the phone is blank, debug the session screen or TerminalWebView readiness/queueing path.

Terminal Color Repro Without A Phone

Use this when terminal colors disappear after switching tabs. Open a Claude Code terminal and at least one other terminal in the target worktree, then run:

cd mobile
ORCA_MOBILE_WS_URL=ws://127.0.0.1:6768 pnpm exec tsx scripts/repro-terminal-colors.ts \
  <deviceToken> <serverPublicKeyB64> "id:<worktreeId>"

The script captures terminal.subscribe snapshots in an A → B → A sequence and writes raw snapshots to mobile/terminal-color-repro/. If the two A snapshots have different sgrColor counts, the desktop snapshot changed during the switch. If they match, the ANSI color data is still present and the bug is in mobile replay/rendering.

Validation

Run these checks before committing mobile terminal changes:

cd mobile
pnpm exec tsc --noEmit
pnpm lint
cd ..
pnpm typecheck:node

Protocol Version Compatibility

Mobile and desktop talk over a versioned protocol. Because mobile updates lag desktop by 24-48h via the App Store, both sides exchange version numbers on status.get so a genuinely incompatible combo can hard-block instead of silently misbehaving.

Constants live in two files (Metro can't resolve outside mobile/):

  • src/shared/protocol-version.tsDESKTOP_PROTOCOL_VERSION, MIN_COMPATIBLE_MOBILE_VERSION
  • mobile/src/transport/protocol-version.tsMOBILE_PROTOCOL_VERSION, MIN_COMPATIBLE_DESKTOP_VERSION

Today all four are set so evaluateCompat always returns { kind: 'ok' } — nothing blocks. The wire format is in place to flip a switch when needed.

When to bump

Bump DESKTOP_PROTOCOL_VERSION (and the mobile mirror MOBILE_PROTOCOL_VERSION when relevant) for breaking changes:

  • Removed RPC method or required parameter that mobile uses
  • Changed meaning (units, nullability) of an existing field mobile reads
  • Changed encryption, framing, or auth handshake

Do not bump for additive changes:

  • New RPC methods
  • New optional fields on existing methods
  • New event types in terminal.subscribe

Set MIN_COMPATIBLE_MOBILE_VERSION (kill-switch) when desktop ships a change that requires a minimum mobile version to function safely. Same for MIN_COMPATIBLE_DESKTOP_VERSION from the mobile side.

When a verdict is blocked, mobile/src/components/ProtocolBlockScreen.tsx renders a screen pointing the user at either the App Store (mobile too old) or GitHub Releases (desktop too old).

To exercise the block screen locally: set MIN_COMPATIBLE_DESKTOP_VERSION = 999 in mobile/src/transport/protocol-version.ts, rebuild, pair to any desktop. Revert before merging.

Mock Server

Develop the mobile app without a running Orca desktop instance:

pnpm mock-server           # starts mock WebSocket server on port 6768

Connect from the app using endpoint ws://localhost:6768 and token mock-device-token.

Environment variables

  • MOCK_NATIVE_CHAT=1 — serve the native-chat scenario (one live agent tab, empty transcript, image upload) instead of the default terminal fixtures.
  • MOCK_SERVER_KEY_FILE — persist the server keypair across restarts so a paired device keeps its public-key pin. A missing or invalid file is re-keyed with a warning, which forces a re-pair.

Scenario control files

Read on every request, so behaviour can be flipped mid-session without a restart (a restart would re-key E2EE and force a re-pair). Write the mode into the file, or delete it for the default.

  • MOCK_SEND_MODE_FILE (default orca-mock-send-mode in the system temporary directory) — accept (default) accepts the send, error fails it with mobile_input_floor_unavailable, anything else reports the send as rejected.
  • MOCK_TERMINAL_LIST_MODE_FILE (default orca-mock-terminal-list-mode in the system temporary directory) — omit returns an empty terminal list, other returns a list that omits the chat handle, anything else lists it.
  • MOCK_TERMINAL_STREAM_MODE_FILE (default orca-mock-terminal-stream-mode in the system temporary directory) — dead answers a subscribe with subscribed then end (a gone PTY), which is what exercises the rearm bound and terminal prune; anything else streams normally.

Connecting to Real Orca

  1. Start Orca desktop with WebSocket transport enabled
  2. In Orca, go to Settings > Mobile and scan the QR code with this app
  3. The QR encodes the connection endpoint, device token, and TLS fingerprint

Project Structure

mobile/
├── app/                   # Expo Router screens (file-based routing)
│   ├── _layout.tsx        # Root layout with navigation stack
│   ├── index.tsx          # Home screen — paired hosts list
│   └── pair-scan.tsx      # QR code scanning screen
├── src/
│   ├── terminal/          # Terminal WebView and xterm bridge
│   └── transport/         # WebSocket RPC client
├── scripts/
│   ├── test-subscribe.ts  # Desktop streaming repro without a phone
│   └── mock-server.ts     # Standalone mock WebSocket server
└── assets/                # App icons and splash screen