API version pinning with Speechify-Version

The API now supports date-based version pinning with the Speechify-Version request header.

  • Current version: 2026-06-25
  • Header format: YYYY-MM-DD
  • Resolution order: request header, workspace default, oldest supported version
  • Migration path: official SDKs pin their build-date version automatically; raw HTTP callers should send Speechify-Version explicitly.

No existing TTS response shape changed in this release. Future breaking wire-format changes will publish a dated changelog entry with the legacy shape, the new shape, and the sunset date.