Using Deepgram Conversational STT / Flux (JavaScript / TypeScript SDK)

Turn-aware streaming STT via /v2/listen for conversational audio and explicit turn events.

When to use this product

• You need turn-aware transcription, not just a word stream.
• You want Flux-style events like TurnInfo and Connected.
• You are building a conversational interface but do not want the full Voice Agent runtime.

Use a different skill when:

• You want general v1 transcription or prerecorded REST → deepgram-js-speech-to-text.
• You want a hosted assistant with think + speak built in → deepgram-js-voice-agent.
• You want analytics overlays like sentiment and summaries → deepgram-js-audio-intelligence.

Authentication

require("dotenv").config();

const { DeepgramClient } = require("@deepgram/sdk");

const deepgramClient = new DeepgramClient({
  apiKey: process.env.DEEPGRAM_API_KEY,
});

Quick start

From examples/26-transcription-live-websocket-v2.ts:

const deepgramConnection = await deepgramClient.listen.v2.createConnection({
  model: "flux-general-en",
});

deepgramConnection.on("message", (data) => {
  if (data.type === "Connected") {
    console.log("Connected:", data);
  } else if (data.type === "TurnInfo") {
    console.log("Turn Info:", data);
  } else if (data.type === "FatalError") {
    deepgramConnection.close();
  }
});

deepgramConnection.connect();
await deepgramConnection.waitForOpen();

// Swap this for a live mic capture in real apps; the repo example uses
// `createReadStream` over a sample file.
const { createReadStream } = require("node:fs");
const audioStream = createReadStream("samples/spacewalk.wav");

audioStream.on("data", (chunk) => {
  deepgramConnection.sendMedia(chunk);
});

audioStream.on("end", () => {
  deepgramConnection.sendCloseStream({ type: "CloseStream" });
});

Key parameters / API surface

• Connect args from src/api/resources/listen/resources/v2/client/Client.ts: model, encoding, samplerate, eagereotthreshold, eotthreshold, eottimeoutms, keyterm, tag, mipoptout.
• Socket methods from src/api/resources/listen/resources/v2/client/Socket.ts: sendMedia(...), sendCloseStream(...), sendListenV2Configure(...), waitForOpen().
• Custom wrapper additions from src/CustomClient.ts: createConnection(...) alias and Node-only ping(...) helper.

Limitations

• The current generated ListenV2Model type only exposes "flux-general-en".
• Product docs mention broader Flux capabilities, but flux-general-multi / language_hint are not surfaced in this repo's generated types today.

API reference (layered)

1. In-repo reference: reference.md does not currently document listen.v2; use src/CustomClient.ts and src/api/resources/listen/resources/v2/client/{Client,Socket}.ts as the in-repo source of truth.
2. Canonical OpenAPI (REST): https://developers.deepgram.com/openapi.yaml
3. Canonical AsyncAPI (WSS): https://developers.deepgram.com/asyncapi.yaml
4. Context7: library ID /llmstxt/developersdeepgramllms_txt
5. Product docs:

- https://developers.deepgram.com/reference/speech-to-text/listen-flux - https://developers.deepgram.com/docs/flux/quickstart - https://developers.deepgram.com/docs/flux/language-prompting

Gotchas

1. There is no REST path here. This skill is /v2/listen WebSocket only.
2. Current repo typing only allows flux-general-en. Treat multilingual Flux support as a product capability not yet reflected in this SDK surface.
3. Close with sendCloseStream, not sendFinalize. Finalize is the v1 pattern.
4. ping() is Node-only. src/CustomClient.ts throws in browsers because browser WS ping frames are not user-exposed.
5. createConnection() is lazy. Call connect() after registering handlers.
6. The example explicitly warns about access/availability. A 400 may mean your account or endpoint is not enabled yet, not that your socket code is wrong.
7. Omit encoding for containerized audio. Keep it for raw PCM/Opus streams.

Example files in this repo

• examples/26-transcription-live-websocket-v2.ts
• examples/27-deepgram-session-header.ts

Central product skills

For cross-language Deepgram product knowledge — the consolidated API reference, documentation finder, focused runnable recipes, third-party integration examples, and MCP setup — install the central skills:

npx skills add deepgram/skills

This SDK ships language-idiomatic code skills; deepgram/skills ships cross-language product knowledge (see api, docs, recipes, examples, starters, setup-mcp).