Contract v1 · generated reference

RuntimeHandler.paymentsWebhook

OP-RUNTIME-PAYMENTS-WEBHOOK is a webhook operation owned by Traveler.

Authority and transport

Actor: verified provider
Authentication: provider signature
Authorization: signature and environment isolation
Resource boundary: server-derived from verified payload and stored state
Transport: WEBHOOK
Deployed export: paymentsWebhook
App Check: NOT_APPLICABLE
Canonical source: functions/src/properties/traveler/payments/handler.ts

Request schema

Request parameters for RuntimeHandler.paymentsWebhook
Field	Required	Schema
`rawBody`	Yes	`Stripe Event JSON bytes, maximum 1,000,000 bytes`
`stripe-signature`	Yes	`timestamp plus one or more v1 HMAC digests`

Response schema

HTTP 200 { received: true | deduplicated: true } or governed JSON error

States, consistency and recovery

State path: RECEIVED → SIZE_AND_SIGNATURE_VALIDATION → ENVIRONMENT_MODE_CHECK → INBOX_CLAIM_OR_DEDUPLICATION → MONOTONIC_SAGA_PROCESSING → BOOKING_PROJECTION_OR_RECONCILIATION → ACKNOWLEDGED_OR_PROVIDER_RETRY
Reads: provider inbox, payment saga, hold, quote, inventory and booking authority
Writes: provider inbox plus monotonic saga, hold, booking and reconciliation projections
Transaction: inbox lease followed by bounded Firestore transactions and final acknowledgement
Idempotency: Stripe event id with a recoverable inbox lease
Concurrency: inbox lease plus monotonic saga and projection transactions
Retry/replay: duplicate and out-of-order safe; 503 includes Retry-After while a lease is busy
Rate limits: Provider delivery policy; busy processing returns HTTP 503 with Retry-After: 60.
Audit: provider event id and privacy-safe failure code; never raw body or signature

Error contract

Exact public webhook response families; internal processing details collapse to a privacy-safe failure code. Never treat an unknown error as success.

raw body unavailable
payments/payload-too-large
payments/missing-signature
payments/invalid-signature
payments/stale-timestamp
payments/invalid-json
payments/invalid-event
payments/invalid-app-environment
payments/provider-mode-mismatch
payments/event-processing-in-progress
payments/processing-failed

Producer test references

Evidence tier: SEMANTIC_CORE_REFERENCE.

Reviewer-mapped semantic/core references

packages/backend-firebase/test/operation-contracts.test.mjs
functions/test/payments-webhook.test.js
functions/test/payments-event-durability.test.js

Protocol or inventory references

packages/backend-firebase/test/operation-contract-detector.mjs

These references prove export, wrapper or protocol behavior only. They are not counted as complete operation semantics.

Example availability

NOT_PUBLIC_TRANSPORT: This handler is provider- or platform-invoked and has no public client invocation.

Common integration contract

Sandbox and Production are isolated

Run examples only in a governed sandbox or local emulator. Sandbox identities, App Check tokens, payment fixtures and data do not grant Production access. The typed ports do not ratify a public numeric quota; enforcement may be stricter. Honor RATE_LIMITED and the server's retry-after value.

Authentication and authorization

Firebase Auth proves identity. App Check proves the approved app where a callable requires it. Roles, organization membership, requester identity and resource ownership are derived and rechecked by the server.

Authentication guide

Errors and recovery

Stable error codes distinguish validation, denial, conflict, expiry, authority pending, rate limiting and temporary unavailability. Never infer success from an HTTP redirect or a browser state.

Error catalogue

Idempotency, concurrency and retry

Reuse an idempotency key only for an identical retry. A new intent needs a new key. Preserve version preconditions and reload after a conflict.

Retry guidance

Changes and escalation

Check compatibility before adopting a new contract version. Review the changelog, service status and support guidance before retrying a persistent failure.

Changelog Service status Developer support

Common failure families
Family	Client decision
Authentication / authorization	Refresh or step up only when instructed; do not retry a denial unchanged.
Validation / conflict / expiry	Correct or reload state, then obtain confirmation for a new intent.
Rate limited / unavailable	Honor retry-after and use bounded backoff; inspect service status.
Unknown / server	Fail closed and escalate with a privacy-safe correlation id.

Executable network examples are published only when the exact wire schema is producer-proven. Check the selected operation's example-availability status; an unresolved schema is a release blocker, not permission to guess.

Verified examples and local-only recovery snippets