# Altss public API versioning and deprecation policy

Applies to the published public website interfaces. Version 1 is supported; no endpoint is currently deprecated and no sunset date is scheduled.

## Versioning

The public interface uses URL major versions. /api/v1 provides descriptive catalogs, JSON Schema documents, bounded public profile reads and durable checks of four fixed public integration metadata documents. Public check jobs accept no profiles, supplied URLs or application data. Original root catalog URLs remain supported aliases; production profile reads and metadata check jobs exist only under /api/v1/public. /api/v1/sandbox/public uses the same profile contract with fictional fixtures, separate instance budgets and replay caches, and no production queries. /api and /api/v1 describe the available public interfaces. The contract version describes response structure, not a frozen price, coverage count or record-verification date.

## Compatibility

Breaking response-shape changes require a new URL major version. Within v1, existing fields retain their types and meaning. Changes that would invalidate a response against the v1 contract belong in a new major version. Catalog values and their own version or update dates can change within that contract without a transport-version change.

## Deprecation and Sunset

No published public descriptive endpoint is currently deprecated or scheduled for removal. Before retiring a supported endpoint, publish a migration notice and replacement, signal deprecation with the Deprecation header (RFC 9745), and use Sunset (RFC 8594) only when an actual withdrawal date has been announced. Supported aliases are not silently redirected to a different major version.

A Deprecation or Sunset header will be sent only when it describes an announced change. Their absence today means no retirement has been announced.

## Retries

Public reads do not create orders or change records. Use ETag / If-None-Match for catalog descriptions; public profile reads are private/no-store. The read-only profile batch optionally accepts Idempotency-Key with 120-second per-instance replay retention, not durable or global exactly-once processing. Retry temporary failures with backoff. No payment, bulk export or private-data entitlement is provided.

- [Public reader OpenAPI](https://altss.com/api/v1/public/openapi.json)
- [Complete public OpenAPI](https://altss.com/openapi.json)
- [Anonymous access walkthrough](https://altss.com/auth.md)
- [Developer reference](https://altss.com/developers)