API Reference

Fast-VC provides streaming voice conversion, service status queries and saved session files. This reference covers service version 0.1.7.

1. Endpoints

Feature	Method and path	Description
Voice conversion	WebSocket /ws	Send PCM or Opus audio and receive converted PCM audio
Health check	GET /health	Check whether the API is reachable
Version	GET /version	Get the service version and build date
Session data	GET /tools/session/{session_id}	Retrieve saved recordings and timelines

WebSocket / is an alias for /ws. Voice conversion supports standard and simple protocols. New clients should use the standard protocol, which provides a ready acknowledgment; see the message flow.

2. Base URLs

Local examples use these addresses. Replace the host and port for your deployment:

Interface	URL
HTTP	http://localhost:8042
WebSocket	ws://localhost:8042/ws

Use https:// and wss:// when TLS is configured. After starting the service, visit /docs for interactive HTTP documentation or /openapi.json for the HTTP schema. See voice conversion for WebSocket message formats.

3. Authentication

The service does not implement full authentication. The standard protocol only checks that api_key is nonempty, the simple protocol requires no client-supplied key, and HTTP endpoints do not check keys. Configure authentication and access control through a gateway or reverse proxy; the session-data endpoint can return saved recordings.

4. Related documentation

• Quick start: installation, startup and a first conversion.
• Configuration and deployment: models, reference voices, recording settings and server options. The reference voice is configured at startup; there is no per-request reference-upload or model-switching endpoint.
• Design (Chinese): internal buffering, conversion and session management.