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

# API Changelog

> Changes to the public integration API and its OpenAPI contract

## Unreleased

* Added public reference catalogs for languages, interview modes, voice choices, and study-type planning templates, plus a versioned interview usage read. MCP resources and the usage tool now use these public routes.

* BYOP participant invitations accept a study-scoped `external_id` and bounded scalar `metadata` on creation. Participant reads return both fields, lists can filter by exact `external_id` with `study_id`, and PATCH can update or clear the customer ID or replace metadata.

* Interview and participant lists now default to 20 results per page, matching studies and feasibility requests. Set `page_size` explicitly to retain a different page size.

* `PATCH /api/public/v1/participants/{participant_id}` updates the participant email. The older `PUT` operation remains available but is deprecated; the MCP update tool now uses PATCH.

* The API host serves the curated public specification at `/.well-known/openapi.json` as well as `/openapi.json` in production.

* Interview summaries include `ended_at`, `interview_format`, and `language`. `language` is the study's current configured language, not a detected transcript language; older interviews may have used a previous setting. Unknown historical modes remain `null`.

* Transcript `messages` now have a typed public segment schema: `id`, `role`, `message`, and optional `text_offset`, `start_s`, and `end_s`. The response remains paged and bounded.

* `DELETE /api/public/v1/webhooks/` is deprecated. Use `DELETE /api/public/v1/webhooks/{webhook_id}`; the body-based route continues to work during migration.

* The OpenAPI Bearer security scheme no longer labels every credential as a JWT. It continues to accept both API keys and dashboard tokens.

See [versioning and deprecation](/api-reference/versioning-and-deprecation) for how to handle future changes.