Smallest AI

OverviewCopy Anchor Link

• SmallestSTTService: streams audio over a persistent WebSocket to Smallest AI's Pulse speech-to-text endpoint. Interim transcripts become InterimTranscriptionFrames; when the VAD sees the user stop, the service sends finalize and the final becomes a TranscriptionFrame.

InstallationCopy Anchor Link

bun add @pipedog/smallest

import { SmallestSTTService } from "@pipedog/smallest/stt";

PrerequisitesCopy Anchor Link

• A Smallest AI account and an API key from Smallest AI.
• Pass the key as apiKey. The examples read it from SMALLEST_API_KEY.

SmallestSTTServiceCopy Anchor Link

Connects to wss://api.smallest.ai/waves/v1/stt/live, with the key as a Bearer token on the handshake.

ConfigurationCopy Anchor Link

SettingsCopy Anchor Link

Runtime-updatable settings, passed as settings: new SmallestSTTService.Settings({...}) (SmallestSTTSettings). Any setting you leave out keeps the default below.

UsageCopy Anchor Link

import { Language } from "@pipedog/core/transcriptions/language";
import { SmallestSTTService } from "@pipedog/smallest/stt";

const stt = new SmallestSTTService({
  apiKey: process.env.SMALLEST_API_KEY ?? "",
  settings: new SmallestSTTService.Settings({ language: Language.EN, wordTimestamps: true }),
});

Pulse 2.0, English only:

const pulse2 = new SmallestSTTService({
  apiKey: process.env.SMALLEST_API_KEY ?? "",
  settings: new SmallestSTTService.Settings({ model: "pulse-2" }),
});

Change settings mid-call with an STTUpdateSettingsFrame:

import { STTUpdateSettingsFrame } from "@pipedog/core/frames/frames";

// Queue it on the worker, or push it from a processor upstream of the service.
const update = new STTUpdateSettingsFrame({
  delta: new SmallestSTTService.Settings({ redactPii: true }),
});

Event handlersCopy Anchor Link

NotesCopy Anchor Link

• encoding is "linear16" by default. sampleRate defaults to the pipeline's input rate.
• Settings are query parameters of the connection, so changing one reconnects.
• The same package has Smallest AI's LLM and text-to-speech services.

Generated from pipecat.runtimes and pipecat.compat in packages/smallest/package.json: ✅ means the compat smoke test passes on that runtime.

Runtime notesCopy Anchor Link

• The WebSocket goes through the core websocketConnect, with headers on the handshake.
• Upstream sets a keepalive interval without implementing the keepalive message, so an idle connection logs a warning every few seconds. The port behaves the same way.
• Tested against local WebSocket servers, as upstream's tests do, not against Smallest AI itself.