Versioning and changes

Every response carries X-Accounting-API-Version, the date of the contract it follows. Today that's 2026-09-22.

What we change without notice

These changes are backwards compatible, so build your integration to accept them:

• new actions, and new optional input fields
• new fields in responses
• new webhook event types, and new fields in event data
• new error codes, and clearer error messages

Ignore fields you don't use, branch on error code rather than message, and subscribe to exact event names (or handle unknown types gracefully) if you use wildcards.

What we don't change

We don't remove or rename actions, fields or events, change their meaning, or make an optional field required without a new version date and notice to everyone with an active key or webhook.

Staying current

The OpenAPI document, these docs and the llms.txt files are generated from the code that runs the API, so they change in the same release as the API itself.