API cheat sheet

Create a key on the API Tokens page before running the authenticated examples below.

Hosts and authentication

What	Where
REST API (TTS, voices, coverage)	`https://users.rime.ai`
Coda WebSocket v1	`wss://api.rime.ai/coda/ws`
Older WebSocket endpoints	`wss://users-ws.rime.ai`
Text normalization	`https://optimize.rime.ai`
Docs (this site, plus `/llms.txt` and per-page `.md` exports)	`https://docs.rime.ai`

The HTTP examples below use users.rime.ai/v1/rime-tts. Coda WebSocket v1 uses api.rime.ai/coda/ws.
Authenticate with Authorization: Bearer YOUR_API_KEY. On WebSocket connections, send the same value as a connection header.
Keep the key on a server. Browser WebSocket objects cannot set the required header, so browser applications need a server-side bridge.
Use standard HTTP and WebSocket clients. The rime-api Python package supplies Protobuf message definitions for binary WebSocket clients; it does not manage connections.

Synthesize speech (HTTP)

POST /v1/rime-tts returns audio bytes in the format named by your Accept header (audio/mpeg, audio/wav, audio/webm;codecs=opus, audio/ogg;codecs=opus, audio/L16, audio/PCMU):

curl -X POST https://users.rime.ai/v1/rime-tts \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -H 'Accept: audio/mpeg' \
  --output hello.mp3 \
  -d '{"text": "Hello from Rime.", "speaker": "astra", "modelId": "coda"}'

Full parameters and streaming variants: Coda HTTP reference · Streaming guide

Stream Coda speech over WebSocket

Connect to wss://api.rime.ai/coda/ws with rime.v1.json and wait for ready. Send these messages separately to stream a sentence as PCM audio:

{"contextId":"turn-1","start":{"speaker":"lyra","language":"en","audioParameters":{"audioFormat":"audio/pcm","samplingRate":24000}}}
{"contextId":"turn-1","text":"Hello from Coda. "}
{"contextId":"turn-1","end":{}}

Decode base64 audio values as they arrive. Read until done, which leaves the socket open. To interrupt, stop playback and send {"contextId":"turn-1","cancel":{}}. Use the JSON quickstart for a runnable client and the Coda WebSocket API reference for parameters, events, and binary encoding. For Mist, use the model-specific WebSocket reference.

List voices

Both voice endpoints are public; no API key required.

# Voice names, keyed by modelId then ISO 639-2 language code
curl https://users.rime.ai/data/voices/all-v2.json

# Full metadata per voice (gender, age, dialect, language, flagship flag, …)
curl https://users.rime.ai/data/voices/voice_details.json

Choosing a voice: Voices guide · Reference: List All Voices · List Voice Details

Check vocabulary coverage (`/oov`)

Returns the input words that are not in Rime’s pronunciation dictionary:

curl -X POST https://users.rime.ai/oov \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"text": "hello kubectl blorbify"}'
# → ["kubectl","blorbify"]

Out-of-dictionary words still get a best-effort pronunciation; to control them, see Custom pronunciation. Reference: Vocabulary Coverage

Normalize text (`/textnorm`)

Preview exactly how numbers, dates, and phone numbers will be spoken. Note the host: optimize.rime.ai.

curl -X POST https://optimize.rime.ai/textnorm \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"text": "Call 1-800-444-4141 on 3/4/2026"}'
# → {"normalized":"Call one, eight hundred, four four four, four one four one on march fourth twenty twenty six"}

Guide: Text normalization · Reference: Text Normalization

Common parameters

Parameter	Values	Notes
`speaker`	See voices	Required. Must match the model and language.
`modelId`	`coda` (flagship), `mistv3`	Set it explicitly. Without one, `/ws3` serves only the Mist v3 voice catalog.
`text`	string	Up to 1,000 characters per request (HTTP returns `400` “text is too long” beyond that).
`lang`	`en`/`eng`, `es`/`spa`, `fr`/`fra`, `pt`/`por`, `de`/`ger`, `ja`/`jpn`, `ar`/`ara`, `hi`/`hin`	Must match the speaker’s language.
`audioFormat` (WS)	`wav`, `mp3`, `ogg`, `webm`, `pcm`, `mulaw`	HTTP uses the `Accept` header instead.
`segment` (WS)	`bySentence` (default), `immediate`, `never`	When synthesis triggers; see Segmentation.
`samplingRate`	`8000`–`96000`, default `24000`	Values above 24000 are upsampling.

Where to go deeper

API reference index: every endpoint across every model
WebSocket API overview: endpoint comparison, timestamps, interruption handling
Build a voice agent: complete apps in Next.js, Vite, Express, plain Node, and FastAPI
Rime CLI and the hosted MCP server: tooling around this same API

Overview

Quickstart

Voice agents

Voices & models

Customizing speech

Streaming & performance

Integrations

On-prem

Account & updates

Hosts and authentication

Synthesize speech (HTTP)

Stream Coda speech over WebSocket

List voices

Check vocabulary coverage (`/oov`)

Normalize text (`/textnorm`)

Common parameters

Where to go deeper

​Hosts and authentication

​Synthesize speech (HTTP)

​Stream Coda speech over WebSocket

​List voices

​Check vocabulary coverage (/oov)

​Normalize text (/textnorm)

​Common parameters

​Where to go deeper

Hosts and authentication

Synthesize speech (HTTP)

Stream Coda speech over WebSocket

List voices

Check vocabulary coverage (`/oov`)

Normalize text (`/textnorm`)

Common parameters

Where to go deeper