orca/docs/reference/mobile-push-contract.md

Mobile push: contract and build spec

Tracking issue: stablyai/orca#8129. Design page: /tmp/orca-mobile-push/orca-mobile-push.html. This document is the single contract every lane builds against. Do not deviate without updating it.

Summary

A small Orca-hosted push gateway (cloud/apps/push) holds the APNs key and FCM credentials and sends to phones. The desktop host registers each paired phone's native push token with the gateway and asks the gateway to push on every mobile notification it already fans out over the socket. The phone dedupes by notificationId#notificationSeq. No ack gate, no generic mode, no staging gateway, one auth path for signed-in and accountless hosts.

Identities

• Host public key: the desktop's existing X25519 E2EE public key (src/main/runtime/e2ee-keypair.ts), 32 bytes, base64. The phone already stores it per host as publicKeyB64.
• hostFingerprint: sha256(hostPublicKey) base64url, first 16 chars. Identical derivation to deriveRelayHostId in src/main/runtime/relay/relay-http-client.ts. Both desktop and phone can compute it.
• deviceId: the desktop's DeviceEntry.deviceId for the paired phone. Opaque UUID.
• registrationId: gateway-assigned opaque id for one (hostFingerprint, deviceId) pair.

Gateway HTTP API

Base URL: https://push.onorca.dev (dev override via env). JSON bodies, Content-Type: application/json. All schemas are zod, .strict(), exported from cloud/packages/push-contract.

Host authentication: challenge, proof, session

The host keypair is X25519 (box), so it cannot sign. Reuse the relay's challenge shape.

POST /v1/host/challenge

{ "v": 1, "hostPublicKeyB64": "<32 bytes b64>" }

→ 200

{ "challengeId": "<opaque>", "gatewayEphemeralPublicKeyB64": "<32 b64>", "nonceB64": "<24 b64>",
  "ciphertextB64": "<b64>", "expiresAt": <epoch ms> }

• Gateway generates an ephemeral box keypair per challenge, a 24-byte nonce, and a 32-byte secret.
• plaintext = "orca-push-host-challenge/v1\0" || u32be(len(transcript)) || transcript || secret(32)
• ciphertext = nacl.box(plaintext, nonce, hostPublicKey, gatewayEphemeralSecretKey)
• Transcript is the relay's length-prefixed field encoding (field(name, value) = u32be(len(name)) || name || u32be(len(value)) || value), fields in this exact order: protocol="orca-push-host-proof/v1", version=0x01, gatewayOrigin, gatewayEphemeralPublicKey, challengeNonce, challengeId, issuedAt (u64be ms), expiresAt (u64be ms), hostFingerprint, hostPublicKey.
• Challenge TTL 10 s, and 10 s is the whole window the gateway honours. The 30 s clock skew tolerance is the host's alone: it validates a timestamp the gateway chose, so it needs the allowance and the gateway does not. A gateway that subtracted the tolerance from its own check would run a 40 s TTL. Store challenge (id, secret hash, host fingerprint, host public key, expiry) in DB so any Cloud Run instance can verify. Expired rows are pruned 30 s late so a slow proof reads as expired rather than as an unknown challenge.
• Issuing a challenge writes no push_hosts row. It is unauthenticated, so a push_hosts row would be a free permanent write for any caller. The row is upserted in POST /v1/host/session once the proof verifies, from the public key the challenge row carries.

POST /v1/host/session

{ "v": 1, "challengeId": "<opaque>", "proofB64": "<32 b64>" }

• Host opens the box with its secret key, validates every transcript field (same checks as validateTranscript in src/main/runtime/relay/relay-host-proof.ts, adapted to the push fields), and returns proof = HMAC-SHA256(secret, "orca-push-host-proof/v1\0ack\0" || transcript).
• Gateway verifies with timingSafeEqual, consumes the challenge (single use), and returns

{ "sessionToken": "<opaque 32 b64url>", "expiresAt": <epoch ms>, "hostFingerprint": "<16 chars>" }

• Session TTL 24 h. Stored hashed (sha256) in DB. Bearer on every other call: Authorization: Bearer <sessionToken>. 401 with { "error": "session_expired" } on expiry; host re-runs the challenge.

Device registration

POST /v1/devices (Bearer)

{ "v": 1, "deviceId": "<uuid>", "platform": "ios" | "android", "token": "<native token>",
  "apnsEnvironment": "sandbox" | "production",   // ios only, required for ios
  "filter": { "sources": ["agent-task-complete", "terminal-bell", "plugin"],
              "agentStates": ["needs-input", "finished"] } }

→ 200 { "registrationId": "<opaque>" }. Upsert keyed by (hostFingerprint, deviceId); a new token replaces the old. deviceId is caller-chosen, so a host is capped at 64 registrations: the 65th distinct deviceId → 409 { "error": "too_many_devices" }. Re-registering a deviceId the host already owns is always accepted, and deleting a registration frees its slot. GET /v1/devices is bounded at 1024 rows to match its response schema, which the per-host cap keeps well out of reach. filter is stored but enforced by the host (see desktop); gateway stores it only so a host restart can re-read it. iOS tokens are variable-length, hex-encoded byte strings; Android tokens are FCM registration strings.

DELETE /v1/devices/:registrationId (Bearer) → 204. Only the owning host may delete.

GET /v1/devices (Bearer) → { "devices": [{ registrationId, deviceId, platform, dead: boolean }] }.

Send

POST /v1/send (Bearer)

{ "v": 1,
  "registrationIds": ["<id>", "..."],
  "notification": {
    "notificationId": "<max 2048 chars, may be absent for terminal-bell>",
    "notificationSeq": <int>, "notificationEpoch": "<uuid>",
    "source": "agent-task-complete" | "terminal-bell" | "plugin",
    "agentState": "needs-input" | "finished" | null,
    "title": "<max 80 chars>", "body": "<max 180 chars>",
    "worktreeId": "<max 2048 chars|absent>" } }

→ 200

{ "results": [{ "registrationId": "<id>", "status": "queued" | "dead" | "rate_limited" | "error" }] }

• queued means accepted into the coalescing window. dead means the provider reported the token unregistered; the host must drop the registration. Never block the socket fan-out on this call.
• Quota: 60 sends per hostFingerprint per rolling hour, 200 per registration per rolling day. Over quota → rate_limited per result, HTTP 200. Whole request over a hard cap of 20 registrationIds → 400. The cap counts the ids as sent; the gateway then dedupes them, so a repeated id spends quota once, yields one result, and counts once toward coalescedCount. results may therefore be shorter than registrationIds, and callers must match a result by its registrationId, never by position.
• Notification JSON is limited to 3000 UTF-8 bytes to leave provider envelope space; identities are preserved exactly, including long filesystem paths. Oversized payloads fail validation.
• Gateway retries are deduplicated by host, registration, notification epoch, and sequence in the quota ledger for its 25-hour retention window. Duplicates return queued without reserving quota or enqueueing another delivery.
• Both quota counters are reserved under a per-host lock held for the whole transaction. PostgreSQL reads at READ COMMITTED, so a concurrent count-then-insert would otherwise admit a whole burst.

Request limits and unauthenticated abuse

• Every POST is capped at 16 KiB by a streaming body limit, not by Content-Length alone: a chunked body declares no length. Over the cap → 413 { "error": "request_too_large" }.
• POST /v1/host/challenge and POST /v1/host/session are the only unauthenticated routes. They share one token bucket per client IP, 30 requests per minute, refilling continuously. Over the bucket → 429 { "error": "rate_limited" }. The client IP is the last x-forwarded-for hop, not the first: Cloud Run appends the connecting peer, so everything left of that value is caller-supplied and can be a fresh forgery on every request, which would hand a flood a new bucket each time. ORCA_PUSH_TRUSTED_PROXY_HOPS (default 0) says how many appenders sit between the platform and the client, so a future load balancer sets it to 1. A header with fewer hops than that depth is not trusted at all. Falls back to x-real-ip and then to a single shared bucket. The bucket is per instance and in memory, so the effective cap scales with the instance count; it exists to blunt a flood, not to meter.
• Every other /v1 route is capped by a second, wider bucket per client IP, 240 requests per minute, applied before the bearer is looked up. A bearer has to be read from the database before it can be refused, and that read takes one of only two pool connections per instance, so without this cap a flood of forged bearers would starve real hosts of the pool while every one of them got a 401.
• The gateway cannot prove that a host owns the token it registers: any host with a session may register any well-formed token and send text to it, within its own quota. The phone drops such a push in the foreground because the fingerprint resolves to no paired host, and never routes a tap on it, but the OS banner shows while the app is backgrounded. Reaching it needs the victim's native token, which the gateway never returns and which only the phone and its host ever see.

Coalescing (gateway)

Per registrationId, hold sends for 3 s. If one event arrives, send it as-is. If N>1 arrive, send one summary: title Orca, body <N> agents need attention (or <N> updates when no needs-input), data carries the latest event's fields plus coalescedCount. Collapse id for a summary is host:<hostFingerprint> so a later summary replaces it. The window is held in memory per gateway instance, so with more than one instance a burst can produce up to one summary per instance; accepted for this release, and the collapse id keeps the phone showing one banner. Transient provider errors retry at most three attempts within two minutes, honoring Retry-After and FCM minimum delays. Permanent failures are not retried. Unregister/dead-token state is re-read before every attempt. Shutdown stops admission and drains admitted requests, pending windows, and active deliveries before closing resources; a nine-second hard deadline remains below Cloud Run's termination grace. Delivery remains in memory.

Provider payloads

APNs (HTTP/2, api.push.apple.com or api.sandbox.push.apple.com by apnsEnvironment; JWT auth from key id + team id + .p8, token cached and refreshed every 50 min):

• headers: apns-topic: com.stably.orca.mobile, apns-push-type: alert, apns-priority: 10, apns-expiration: now+4h, apns-collapse-id: <notificationId truncated to 64 bytes, or host:<fp>>
• body: {"aps":{"alert":{"title","body"},"sound":"default","thread-id":"<hostFingerprint>"}, "orca":{ hostFingerprint, worktreeId, notificationId, notificationSeq, notificationEpoch, source, agentState, coalescedCount }}
• Dead token: 410, or 400 with BadDeviceToken/Unregistered/DeviceTokenNotForTopic.

FCM (V1 projects/onorca-cloud/messages:send, bearer from the runtime service account via the GCE metadata server or GOOGLE_APPLICATION_CREDENTIALS locally):

• {"message":{"token","notification":{"title","body"},"android":{"priority":"HIGH","ttl":"14400s", "collapse_key":"<sha256(collapseId) hex 32>","notification":{"channel_id":"orca-desktop","tag":"<collapseId>"}}, "data":{ all orca fields as strings }}}
• Dead token: UNREGISTERED, or INVALID_ARGUMENT whose message names the token.

Gateway storage (Postgres in prod, SQLite in tests, same pattern as cloud/apps/relay/src/database.ts)

• push_hosts(host_fingerprint pk, host_public_key, created_at, last_seen_at), written only on a verified proof and pruned after 1 h of no contact when no push_devices row still names the host. Nothing reads it, and any keypair mints a host for free, so it is not allowed to accumulate.
• push_sessions holds one row per host, enforced by a unique index and transaction lock. Minting a session deletes the host's earlier one, since a desktop holds a single session and only re-proves once it is gone.
• push_challenges(challenge_id pk, host_fingerprint, host_public_key, secret_hash, transcript, expires_at, consumed_at)
• push_sessions(token_hash pk, host_fingerprint, expires_at, created_at)
• push_devices(registration_id pk, host_fingerprint, device_id, platform, token, apns_environment, filter_json, dead_at, created_at, updated_at, unique(host_fingerprint, device_id))
• push_send_log(host_fingerprint, registration_id, sent_at) for quota, pruned after 25 h.

Logging: aggregate counters only. Never log tokens, titles, bodies, or raw fingerprints (log the first 4 chars of a fingerprint at most).

Gateway env

PORT, ORCA_PUSH_PUBLIC_URL, ORCA_PUSH_DATABASE_URL (absent → SQLite under ORCA_PUSH_DATA_DIR), ORCA_PUSH_APNS_KEY (PEM text), ORCA_PUSH_APNS_KEY_ID, ORCA_PUSH_APPLE_TEAM_ID, ORCA_PUSH_APNS_TOPIC (default com.stably.orca.mobile), ORCA_PUSH_FCM_PROJECT_ID (default onorca-cloud), ORCA_PUSH_COALESCE_MS (default 3000), ORCA_PUSH_TRUSTED_PROXY_HOPS (default 0, proxies appending to x-forwarded-for after the client). Secret Manager names (already exist in onorca-cloud): orca-cloud-push-apns-key, orca-cloud-push-apns-key-id, orca-cloud-push-apple-team-id. Runtime SA: orca-cloud-push@onorca-cloud.iam.gserviceaccount.com (already has FCM admin + secret accessor).

Desktop (src/main, src/shared)

• Capability NOTIFICATIONS_REMOTE_PUSH_RUNTIME_CAPABILITY = 'notifications.remote-push.v1' in src/shared/protocol-version.ts, advertised statically.
• RPC notifications.registerPush params { platform, token, apnsEnvironment?, filter } (same shapes as the gateway POST /v1/devices minus deviceId, which comes from ctx.pairedDeviceId). Returns { registered: true, registrationId } | { registered: false, reason: 'gateway_unreachable' | 'gateway_rejected' | 'not_mobile' | 'registration_storage_failed' | 'throttled' }. A device may register at most 10 times per minute (throttled beyond that, its earlier registration untouched): each call is a gateway write plus a synchronous registry write on the main thread, and a paired phone could otherwise loop it. The unregister RPC is not throttled, since with nothing registered it is a lookup and with something registered it can only run once per successful register. The params schema is strict, so a caller-supplied deviceId is an error, not a key silently dropped. Persists pushRegistration: { registrationId, platform, filter, registeredAt } on DeviceEntry in device-registry.ts (new optional field, tolerated by old registries). When the gateway accepted the token but the host could not store it — the device left mobile scope mid-call (not_mobile) or the registry write threw (registration_storage_failed) — the host queues the gateway delete in the unregister outbox rather than leaking a registration nothing will ever push to. Registration, unregister, and outbox deletes are serialized per device; re-registration first settles earlier cleanup. Authentication failure never drops a durable delete. Stale send responses only clear the exact local registration observed, while provider dead-token updates match the token/platform/environment that was sent. Phones must treat any registered: false as "retry later", so an unknown reason string is safe to add.
• RPC notifications.unregisterPush params null → { unregistered: boolean }. Removes the field and enqueues a gateway delete in a durable outbox (src/main/runtime/push/push-unregister-outbox.ts, modelled on relay-revoke-outbox.ts). Unpair/revoke (revokeMobileDevice) enqueues the same. The drain re-reads the queue as it goes, so a delete queued mid-drain lands in the same pass, and a pass that leaves retryable items schedules an unref'd backoff retry (30 s, doubling, capped at 10 min) instead of waiting for the next launch.
• Both RPCs added to runtime-rpc-mobile-method-allowlist.ts.
• Push client src/main/runtime/push/push-gateway-client.ts: challenge/proof/session with token cache, register, delete, send. Node fetch. Gateway URL from profile-cloud-auth-config.ts (pushGatewayUrl, default https://push.onorca.dev, env override ORCA_PUSH_GATEWAY_URL).
• Host proof answering: new src/main/runtime/push/push-host-proof.ts, a copy of the relay's answerRelayHostChallenge with the push transcript fields. Shared code with the relay proof is welcome if it stays a pure refactor.
• Dispatch hook: in RuntimeMobileNotificationController.dispatch, after the socket fan-out, call pushDispatcher.enqueue(eventWithSeq). The dispatcher applies each device's filter, skips dismiss events, maps agentState to needs-input | finished (blocked/waiting → needs-input, else finished), batches matching registrationIds into POST /v1/send requests of at most 20 registrations each (the gateway's per-request cap; extra devices get their own request rather than being dropped), and drops unchanged registrations the gateway reports dead. Failure categories are counted without payload values and logged at most once per minute (with a final flush on shutdown). Fire-and-forget with one retry after 2 s per request; never throws into dispatch.
• Add agentState to MobileNotificationDispatchEvent and set it in src/main/ipc/notifications.ts from args.agentState. Fix buildAgentTaskCompleteNotificationOptions so working|running|busy never yields "finished" (title says "working" and the dispatcher treats it as not-final, i.e. no push).
• Headless serve: no renderer means no notifications:dispatch. Document in docs/reference/headless-linux-server.md; do not fix here.

Mobile (mobile/)

• Commit google-services.json (from /tmp/orca-mobile-push/google-services.json) at mobile/ and set "android": { "googleServicesFile": "./google-services.json" } in app.json. Add "expo-notifications" to plugins so prebuild writes the aps-environment entitlement.
• Token: Notifications.getDevicePushTokenAsync(); data is the APNs hex or FCM string. iOS apnsEnvironment: __DEV__ ? 'sandbox' : 'production' (dev-client builds are debug, TestFlight and App Store are release). Listen with addPushTokenListener and re-register on change.
• Settings (mobile/app/notifications.tsx): single "Background notifications" switch, default off, hint text exactly: "Get alerts while Orca is closed. Alerts show the same text as on your desktop. That text, your phone's push token, and opaque host and device ids pass through Orca's push service and Apple or Google. Turning this off or unpairing deletes the token." Event controls live in the shared notification-preferences section and apply to both connected and background notifications. Hide the whole section, with copy "Update your desktop app to enable background notifications", when no paired host advertises notifications.remote-push.v1.
• Registration: on switch-on (after OS permission), and on every host reaching connected while the switch is on, call notifications.registerPush on that host if it advertises the capability. On switch-off call notifications.unregisterPush on every connected host and remember to retry on hosts that were offline. On host removal, best-effort unregister before deleting credentials.
• Receive: addNotificationReceivedListener (foreground) checks data.orca.notificationId + notificationSeq against the host session seen set in notification-reconnect-catchup.ts; if seen, suppress via setNotificationHandler returning no banner; otherwise show and mark seen. Background and killed: OS shows it.
• Tap: data.orca.hostFingerprint → hostId by computing the same sha256/base64url/16 derivation over each stored host's publicKeyB64; then existing getNotificationNavigationTarget + useOpenNotificationRoute.
• Reopen: existing replay catch-up runs unchanged. Dismiss events also dismissNotificationAsync any presented notification whose data.orca.notificationId matches.
• Old host without the capability: nothing changes.

Infra (cloud/infra/terraform, .github/workflows)

• Cloud Run service orca-cloud-push, region us-central1, project from the environment tfvars, runtime SA orca-cloud-push@<project>.iam.gserviceaccount.com (exists in prod; declare and import), the three secrets mounted as env (exist; declare and import), Cloud SQL connector to the shared instance with its own database orca_push, min instances 1, max 4, concurrency 80, ingress all, unauthenticated invoke.
• IAM: roles/firebasecloudmessaging.admin and roles/serviceusage.serviceUsageConsumer on the runtime SA (exist in prod; declare and import). Secret accessor per secret.
• Hostname push.onorca.dev. The DNS zone lives in the apps root in stablyai/orca-cloud; add the Cloud Run domain mapping here and leave a TODO comment naming the record the other repo must add.
• Workflow .github/workflows/cloud-push-deploy.yml: gated on vars.ORCA_CLOUD_OPERATIONS_ENABLED, Workload Identity like cloud-relay-*, builds the image, deploys with --no-traffic, probes the new revision's /ready and a validate-only FCM send, then shifts 100% traffic. Uses .github/actions/cloud-sql-rollout-lease around the schema step.
• Add the new root files to cloud/dev/contracts and cloud/dev/fixtures partitions so terraform-root-partition.test.mjs and Cloud Verify pass.

Non-goals for this release

Ack gate, generic-alert mode, staging gateway, iOS Notification Service Extension, Android data-only messages, Live Activities, account-based quota tiers, dismissal via silent push.

Device delivery preferences

The desktop advertises notifications.delivery-preferences.v1. Completion detection remains active when desktop notifications are off; semantic validity checks still precede delivery. IPC publishes desktopAllowed: false for terminal events disabled by the desktop master or source switch. Desktop focus and native authorization remain desktop-only delivery gates.

notifications.subscribe and notifications.getMissedSince accept optional includeDesktopSuppressed: true. Only opted-in callers receive those events, including replay; legacy callers keep the old filtered stream. A new phone against an older host can narrow the available events but cannot recover events that host never published.

The phone defaults to following each host. filter.followDesktop is optional: absent retains legacy desktop gating; explicit false permits independent event choices. The desktop persists it with the paired registration and evaluates it for every send, so desktop preference changes work while the phone is disconnected. This flag is host-local and is not sent to the gateway. The phone uses the same shared event predicate for socket/replay delivery as the push dispatcher. Optional emittedAt carries the event time for per-device five-second burst suppression after source filtering. Desktop eligibility, source, and agent state use separate upstream cooldown buckets so filtered events cannot suppress the next eligible event. Legacy RPC callers retain workspace-wide burst suppression on the host.

filter.sound is also host-local. False groups that device's requests separately and adds optional notification.sound: false to gateway sends. The gateway omits APNs aps.sound and uses Android's orca-desktop-silent channel. Missing sound preserves existing audible delivery. Deploy the updated gateway before distributing hosts that send the optional sound field: older gateways strictly reject unknown notification fields. No token or database migration is needed.

The phone's master switch disables background registration as well as local scheduling. Sound and viewing preferences belong to the receiving phone. The phone suppresses a banner for its currently viewed host/workspace only while active; it never assumes desktop focus means the phone is viewing that workspace. Changes to an offline host's persisted filter take effect on reconnection. No live APNs/FCM delivery is implied by simulator notification injection.

For a phone registered for background push, socket notification delivery waits while the app is inactive. On foreground, it checks the native push tray before scheduling a local fallback, so a still-connected background socket cannot duplicate APNs/FCM delivery. Unsubscribing cancels the wait without claiming delivery. Hosts without push registration keep local delivery.

Native notification readers accept Expo's iOS request.trigger.payload as well as request.content.data. APNs custom fields can exist only in the former; foreground deduplication, tray replay suppression, dismissal, and tap routing all use the same reader.