Google Analytics 4 Webhooks

generated: '2026-08-13'
method: derived
source:
  - openapi/_original/google-analytics-4-data-v1alpha-discovery.json
  - openapi/google-analytics-4-data-v1alpha-openapi.yml
  - https://developers.google.com/analytics/devguides/reporting/data/v1/audience-list-basics
spec_type: Webhooks
asyncapi_published: false
asyncapi_note: >-
  Google publishes no AsyncAPI document for any GA4 surface. /asyncapi.yaml, /asyncapi.json
  and the googleanalytics GitHub organization were all checked. This artifact captures the
  real webhook surface instead, derived verbatim from the WebhookNotification schema in
  Google's own v1alpha Discovery document — it is not a fabricated event spec.
note: >-
  GA4 has exactly one push surface, and it is narrow: long-running Audience Export
  operations can notify a caller-supplied HTTPS endpoint when their state changes. There is
  no event bus, no property-level event subscription and no webhook for reporting,
  configuration changes or data-stream activity. Everything else in GA4 is pull-only. The
  Measurement Protocol is inbound ingest, not an event surface, and is deliberately excluded
  here.
surface:
  kind: long-running-operation-callback
  api: Google Analytics Data API
  version: v1alpha
  configured_on:
    - resource: AudienceList
      field: webhookNotification
      operations:
        - properties_audienceLists_create
        - properties_audienceLists_get
    - resource: RecurringAudienceList
      field: webhookNotification
      operations:
        - properties_recurringAudienceLists_create
  gated: false
  subscription_model: >-
    Per-resource, per-GCP-project. The notification config is attached when the long-running
    operation resource is created and is only visible to the project that attached it;
    different projects may attach different webhooks to the same resource.
delivery:
  transport: HTTPS POST
  direction: Google to consumer
  body: >-
    A JSON representation of the long-running operation resource, plus a sentTimestamp field
    (unix microseconds since epoch) that lets a consumer identify replayed notifications.
  trigger: state change of the long-running operation resource
  expected_response: HTTP 200
  response_deadline_seconds: 5
  replay: >-
    Replays are possible and are the consumer's problem to detect — sentTimestamp is the only
    de-duplication signal offered. There is no delivery id, no signature and no retry policy
    published.
security:
  authentication: Google-issued OIDC ID token in the Authorization bearer header
  service_account: google-analytics-audience-export@system.gserviceaccount.com
  verification_secret:
    field: channelToken
    type: string
    max_length: 64
    description: >-
      Arbitrary caller-supplied string echoed back so the consumer can verify the source of a
      notification.
  signature: none
  note: >-
    Two independent verification mechanisms are offered — the ID token (for Cloud Run / Cloud
    Functions IAM) and the channelToken (for arbitrary servers). Google states the ID token
    may be ignored by non-Google-Cloud webhook servers that do not need it.
constraints:
  uri_scheme: https
  uri_max_length: 128
  uri_charset: allowlisted characters from RFC 1738
  tls: valid SSL certificate required on the receiving server
events:
  - name: audienceList.stateChanged
    resource: AudienceList
    description: >-
      Fired as an audience export moves through its lifecycle. State is carried on the
      resource's `state` field; `percentageCompleted`, `rowCount` and `errorMessage` carry
      progress and failure detail.
    payload_schema: openapi/google-analytics-4-data-v1alpha-openapi.yml#/components/schemas/AudienceList
  - name: recurringAudienceList.stateChanged
    resource: RecurringAudienceList
    description: >-
      Fired as a recurring audience list produces new AudienceList instances;
      `activeDaysRemaining` and `audienceLists` carry the schedule state.
    payload_schema: openapi/google-analytics-4-data-v1alpha-openapi.yml#/components/schemas/RecurringAudienceList
history:
  - date: '2024-01-30'
    change: >-
      Webhook notification support introduced on AudienceList.webhookNotification and
      RecurringAudienceList.webhookNotification (Data API v1alpha changelog).
gaps:
  - No AsyncAPI or other machine-readable event contract is published.
  - Alpha-channel only; the stable v1beta Data API has no webhook surface at all.
  - No delivery retry policy, no delivery id, no HMAC signature, no dead-letter behaviour published.
  - No webhook for Admin API configuration changes, key events, or data-stream health.