API versioning

The current API version is 2026-09-01. It is shown in the OpenAPI document and in every event's api_version field.

What we may change without notice

• Adding new endpoints, optional request parameters and response fields.
• Adding new event types, error codes and enum values (for example a new payment method).
• Changing the length or format of object IDs (treat IDs as opaque strings up to 255 characters).

Build your integration to ignore unknown fields and to handle unknown enum values gracefully.

Breaking changes

Removing or renaming fields, or changing behaviour you rely on, happens only in a new dated API version, announced in the changelog and by email to organisation owners before it takes effect.

One exception was made before general availability: POST /v1/payments/{id}/refunds now requires an Idempotency-Key (see the changelog).