> ## Documentation Index
> Fetch the complete documentation index at: https://entendre.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Versioning and deprecation

> How the API versions, how it signals deprecation, and how rate limits appear in responses.

## Versioning

The API is versioned in the URL path. All public endpoints live under `/v1`.

Breaking changes ship in a new version path. Within a version, changes are backward-compatible: new fields, new enum values, and new endpoints can appear at any time. Parse responses tolerantly and ignore fields you do not use.

## Deprecation

When an endpoint or field is scheduled for removal:

1. The OpenAPI specification marks the operation `deprecated: true`.
2. Responses include a `Deprecation` header with the announcement date and a `Sunset` header with the removal date (RFC 8594 and the HTTP Deprecation header draft).
3. The removal is announced in [product updates](https://entendre.ai/product-updates/) with a migration window of at least 90 days.

Integrate against the current version and watch for the `Deprecation` header. Agents can rely on the header pair to detect a sunset before it takes effect.

## Rate limits

Every v1 response carries rate-limit headers:

* `RateLimit-Limit`: the request ceiling for the current window.
* `RateLimit-Remaining`: requests left in the current window.
* `RateLimit-Reset`: Unix time (seconds since epoch) at which the window resets.

A throttled request returns HTTP 429 with a `Retry-After` header. Wait at least that many seconds before you retry. The default ceiling is 600 requests per 60 seconds per API key; a key can carry its own override.