REST API Reference

The Declined REST API is available at https://app.declined.io/api. All endpoints accept and return JSON unless noted. List endpoints support cursor pagination via limit and starting_after query parameters.

Endpoints

Method	Path	Description
POST	/v1/events	Ingest billing and recovery events (idempotent)
GET	/v1/customers	List customers with recovery context
GET	/v1/recoveries	List recovery attempts
POST	/v1/recoveries/:id/mark-recovered	Mark a recovery attempt recovered
GET	/v1/sequences	List dunning sequences
GET	/v1/webhooks	List outbound webhook endpoints
GET	/v1/incentives	List incentive offers
GET	/v1/analytics	Recovery analytics summary

HTTP status codes

Code	Meaning
200	Duplicate event (same event_id already ingested)
201	Event accepted and processed
401	Missing, invalid, or revoked API key
422	Validation error (malformed payload or unknown event type)
429	Rate limited — retry after Retry-After seconds

Pagination

json

{
  "data": [ ... ],
  "has_more": true,
  "next_cursor": "ra_abc123"
}

Idempotency

POST /v1/events requires a stable event_id per logical occurrence. Duplicate submissions return HTTP 200:

json

{
  "status": "duplicate",
  "event_id": "evt_unique_001",
  "inbound_event_id": "ie_existing"
}

Marking recoveries

See the dedicated Recoveries guide for POST /v1/recoveries/:id/mark-recovered and the payment_recovered event type.

Rate limits

Event ingestion is optimized for high throughput. If you exceed workspace limits, responses include 429 with a Retry-After header. Implement exponential backoff with jitter on retries.