Billing subscription state changed | REST API documentation

Billing subscription state changed Webhook

Add MCP server to your AI tool

Allow AI tools and LLMs to interact with the API documentation portal through MCP.

MCP server URL


        
          
            https://api-reference.usecommune.dev/mcp

Standard setup for AI tools providing an mcp.json file

{
  "REST API MCP server": {
    "url": "https://api-reference.usecommune.dev/mcp"
  }
}

POST https://webhook.example.com

Webhook signature

The newsletter's own Commune subscription moved between billing states: trialing, active, past_due, canceled or trial_expired.

Two things move it. Activity at the payment provider: a checkout completing, the subscription being created, updated or deleted, an invoice being paid or failing. And a daily pass that expires trials which have run out, which is why a trial_expired event can arrive with no creator action behind it.

Named billing.subscription.* on purpose. In Commune a "subscriber" is a reader of a newsletter, so an unqualified subscription.updated would read as a reader event. This one is about the creator paying Commune.

A state here gates publishing. Past due beyond the grace window, canceled, and an expired trial each refuse a send with 402. A newsletter that is trialing or past due is additionally capped on how many emails it may send in a day, and exceeding that refuses with 429 rather than 402, so a consumer watching for payment problems should treat both codes as billing refusals.

Delivered as a single HTTPS POST to the consumer's registered endpoint, with the message as the JSON request body. Respond 2xx to acknowledge. Anything else, or a timeout, is retried with backoff, so acknowledge fast and do the work afterwards.

Headers

Commune-Version string Required

API version the payload conforms to. Same value as api_version in the envelope.
Commune-Event-Id string(uuid) Required

Same value as id in the envelope. The dedupe key.
Commune-Event-Type string Required

Same value as type in the envelope. The topic name.
Commune-Signature string Required

HMAC over the raw request body. Verify before parsing.
Commune-Timestamp string Required

Unix seconds the signature was produced at. Reject anything outside your tolerance window.
Commune-Delivery-Attempt integer

1 on the first attempt, incremented on each retry. Informational only. A consumer must be idempotent regardless of its value.

Minimum value is 1.

application/json

Body Required

The newsletter's own Commune subscription changed state.

id string(uuid) Required

Unique id for this event. Stable across redeliveries, so it is the dedupe key. It is the primary key of the row the publisher wrote, which means it is assigned when the state change is recorded, not when the message is dispatched.
type string Required

The topic name, identical to the channel address. Route on this.

Value is billing.subscription.updated.
api_version string Required

The Commune-Version value this payload conforms to. Present on the message itself, not only on the request header, so an event persisted to a consumer's own store stays self-describing.
occurred_at string(date-time) Required

RFC 3339 timestamp of the state change, not of the delivery attempt. Use it to order events, since delivery order is not guaranteed.
newsletter_id string(uuid) | null Required

The newsletter the change belongs to. This is the tenant boundary: a consumer only ever receives events for newsletters its credential can read. Null only for events that are genuinely not newsletter-scoped, which none of the 21 topics currently are.
actor object | null Required

Who caused the change. ALWAYS null today and consumers must treat it that way: the public API is currently read-only, so nothing that reaches this catalog was triggered through it, and Commune does not backfill an actor for changes made in the product UI or by a cron. The field exists now so that populating it, once writes exist, is an additive change rather than a new envelope version.

Additional properties are NOT allowed.
Hide actor attributes Show actor attributes object | null
- type string Required
  
  user for a change a person made through an authenticated session, api_key for a public API write, system for a cron or webhook ingest with no human behind it.
  
  Values are user, api_key, or system.
- id string Required
  
  Identifier of the actor within its type. A user id for user, a key id (never the secret) for api_key, a stable job name for system.
- label string | null
  
  Human-readable name for display. Best effort, may be null.
idempotency_key string | null Required

ALWAYS null today. Once the public API accepts writes this carries the Idempotency-Key header of the write that caused the change, so a consumer can tie an event back to its own request and collapse the duplicates a retried write would otherwise produce. Null stays a legitimate value even then: a change made in the product UI or by a cron has no originating request to key on.

Maximum length is 255.
data object Required

Event-specific body. Narrowed by each concrete event schema below.
Hide data attributes Show data attributes object
- subscription_id string(uuid) Required
  
  Commune's own newsletter_subscriptions row, one per native newsletter. Not a Stripe id. Stripe identifiers are not exposed.
- plan string Required
  
  Values are creator or enterprise.
- status string Required
  
  Values are trialing, active, past_due, canceled, or trial_expired.
- previous_status string | null
  
  The state being left. Null when it could not be established, so treat this as a hint and the new status as the truth.
  
  Values are trialing, active, past_due, canceled, trial_expired, or null.
- trial_ends_at string(date-time) | null
- current_period_start string(date-time) | null
- current_period_end string(date-time) | null
- cancel_at_period_end boolean
  
  The subscription is still active but will not renew. Distinct from status: canceled, which means it already stopped.

Responses

200

The consumer accepted the delivery. Any 2xx acknowledges the message and it is not sent again.
4XX

The consumer rejected the delivery. Handled exactly like a 5xx: the message is retried with backoff, because a rejection cannot be told apart from a consumer that is briefly misconfigured.
5XX

The consumer failed to handle the delivery. Retried with backoff. A timeout is the same case and is retried too.

POST billing.subscription.updated

Request example

{
  "id": "018f2a92-1111-7000-8000-000000000011",
  "type": "billing.subscription.updated",
  "api_version": "2026-08-26",
  "occurred_at": "2026-08-26T17:05:00Z",
  "newsletter_id": "7d3f1c02-58a1-4a4e-9a0b-2f6d1c9e4411",
  "actor": null,
  "idempotency_key": null,
  "data": {
    "subscription_id": "f5061728-394a-4b5c-96d7-e8f90a1b2c3d",
    "plan": "creator",
    "status": "active",
    "previous_status": "trialing",
    "trial_ends_at": "2026-08-26T00:00:00Z",
    "current_period_start": "2026-08-26T17:05:00Z",
    "current_period_end": "2026-09-26T17:05:00Z",
    "cancel_at_period_end": false
  }
}