Versioning

How the API is versioned

The API is versioned by its URL path. Every endpoint lives under /v1 (for example /api/v1/llm/v1/chat/completions). There is no version request header: you do not need to send one, and sending one has no effect.

Build clients that ignore response fields they do not recognise, so a new optional field cannot break them.

Dated documentation versions

The reference is published as dated snapshots of the /v1 surface. Each snapshot is a complete OpenAPI document, so you can compare exactly what changed between two dates.

Version	Status	What it covers
2026-11-11	Current	The first curated public snapshot: the OpenAI-compatible LLM API, the Anthropic-compatible Messages API (beta) and the Platform API.
next	Preview	Changes that are not released or not stable yet. It currently matches 2026-11-11.

Use the API version selector on any reference page to switch. Each version’s OpenAPI file can be downloaded from /api/openapi-<version>.json on this site. The changelog lists what changed between versions.

The next version

next shows upcoming work so you can plan for it. Anything in next and not in the current version may change shape, be renamed or be withdrawn before release. Do not build production integrations on it.

Labels

Label	Meaning
Current	The latest dated snapshot. New integrations should target it.
Beta	Part of the current version and served in production, but its details may still change. The Messages API is in beta.
Preview	Published for feedback and not released. Can change without notice.