# What changed in supertonic

> 15 changes in supertonic 1 from its official release notes, upgrade guides and advisories: 2 breaking, 1 security, 9 new APIs and options. Each one cited. Sources checked 2026-10-28. HTML: https://unstale.sh/pypi/supertonic/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## supertonic 1

### Breaking changes

- Pre-flight middleware rejects POST /v1/styles/import requests exceeding 1 MiB before buffering the body. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- The residual numpy<2.0 pin was removed from requirements.txt, making it consistent with the package specification. (1.2.3) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#123--2026-05-15)

### Security

- Starts a loopback-only local HTTP server for TTS; binding beyond loopback is opt-in and emits a stderr warning. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)

### New APIs and options

- Adds a health endpoint that returns readiness and loaded model information. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- Adds an endpoint to retrieve built-in and imported custom voices. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- Adds an OpenAI Audio Speech-compatible alias for speech synthesis. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- Adds an endpoint that accepts multipart or JSON uploads of Voice Builder style JSON and persists them per model. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- Adds an endpoint for native synthesis with the full parameter set. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- Adds batch synthesis for up to 64 items in one JSON request, returning base64-encoded audio. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- The server supports wav, flac, and ogg (Vorbis) response formats; MP3, AAC, and Opus are not shipped. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- Overrides per-model custom-voice storage with a single shared directory. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)
- Adds a Python package for mounting the FastAPI app inside a larger ASGI service. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)

### Behavior and default changes

- The environment variable now overrides the cache directory on every code path, and late-set values are honored through call-time resolution. (1.3.1) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#131--2026-05-18)

### Tooling

- The `[serve]` extra installs the dependencies needed for the local HTTP server. (1.3.0) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#130--2026-05-18)

### Fixes and other changes

- Python 3.13 is officially supported, expanding the supported Python range. (1.3.1) — [release notes](https://github.com/supertone-inc/supertonic-py/blob/47c8d3436bcbe4ecf6b127550883e2c8d62e9f02/CHANGELOG.md#131--2026-05-18)