Versioning and deprecation policy

Stable integrations should use paths under /api/v1. Additive fields, new optional parameters, and new endpoints may ship within v1. Existing fields do not change meaning and required inputs are not added without a new major version. Legacy /api/me routes remain for installed clients but are not the preferred surface for new integrations.

If an operation is scheduled for retirement, txt will publish an RFC 9745 Deprecation response header containing the effective date, a Link with relation deprecation to migration guidance, and an RFC 8594 Sunset header no less than 180 days before removal when security or legal obligations do not require faster action. The OpenAPI operation will also be marked deprecated.

Current v1 operations are not deprecated, so they intentionally do not emit false Deprecation or Sunset dates. Every v1 response includes API-Version: v1. Agents should record that header, follow the published migration link when one appears, and avoid depending on undocumented response fields.