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 token is 64 hex chars; Android token is the FCM registration string.

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": "<string, 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": "<string|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.
• 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 first x-forwarded-for hop, which Cloud Run sets, falling 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.

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.

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 30 d of no contact when no push_devices row still names the host
• 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). 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' }. 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. 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 registrations the gateway reports dead. 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." Below it, two sub-switches "Needs input" and "Task finished" (both default on) that set filter.agentStates; sources is fixed to all three. 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.