▲ Vercel AI SDK Integration with AssemblyAI

The AI SDK gives you a single, unified transcribe() API that works across speech-to-text providers. The @ai-sdk/assemblyai provider — maintained by Vercel in the vercel/ai repo — plugs AssemblyAI’s speech models into that API, so you can transcribe audio in any TypeScript or JavaScript project without calling the AssemblyAI API directly.

Quickstart

Install the AI SDK core package along with the AssemblyAI provider:

npm
yarn
pnpm
bun

npm install ai @ai-sdk/assemblyai

yarn add ai @ai-sdk/assemblyai

pnpm add ai @ai-sdk/assemblyai

bun add ai @ai-sdk/assemblyai

You’ll need an AssemblyAI account and an API key from your dashboard. The provider reads it from the ASSEMBLYAI_API_KEY environment variable:

export ASSEMBLYAI_API_KEY="<YOUR_API_KEY>"

Then transcribe a local file with transcribe():

import { transcribe } from 'ai';
import { assemblyai } from '@ai-sdk/assemblyai';
import { readFile } from 'node:fs/promises';

const result = await transcribe({
  model: assemblyai.transcription('universal-3-5-pro'),
  audio: await readFile('audio.mp3'),
});

console.log(result.text);

transcribe is a stable export as of AI SDK v7, which is what npm install ai installs today. The examples on this page target v7.

Using AI SDK v6? The examples on this page require v7. AI SDK v6 (and v5) export only experimental_transcribe — import { transcribe } from 'ai' throws on those versions — and the latest provider (@ai-sdk/assemblyai 3.x) is built for v7, so it won’t work against v6. If your project is on v6 (for example, an existing project or a registry policy that hasn’t picked up v7 yet), install the v6-compatible packages and alias the experimental export:

npm install ai@ai-v6 @ai-sdk/assemblyai@ai-v6

import { experimental_transcribe as transcribe } from 'ai';

Everything else on this page — the providerOptions, model IDs, and result shape — is the same.

Configuring the provider

The default assemblyai instance reads your key from ASSEMBLYAI_API_KEY. To pass the key explicitly — for example, from a secret manager or in a multi-tenant setup — or to add custom headers or a custom fetch implementation, create your own provider instance with createAssemblyAI:

import { createAssemblyAI } from '@ai-sdk/assemblyai';

const assemblyai = createAssemblyAI({
  apiKey: process.env.ASSEMBLYAI_API_KEY,
});

const result = await transcribe({
  model: assemblyai.transcription('universal-3-5-pro'),
  audio: await readFile('audio.mp3'),
});

Choosing a speech model

universal-3-5-pro is the recommended default. universal-2 is also supported. Pass the model ID to assemblyai.transcription():

const model = assemblyai.transcription('universal-3-5-pro');

For a breakdown of each model’s accuracy, latency, and language support, see Select the speech model.

Using AssemblyAI features

AssemblyAI’s diarization and audio-intelligence features are enabled through providerOptions.assemblyai. Option keys are the camelCase equivalents of the API’s snake_case parameters (for example, speaker_labels → speakerLabels, redact_pii → redactPii):

import { transcribe } from 'ai';
import {
  assemblyai,
  type AssemblyAITranscriptionModelOptions,
} from '@ai-sdk/assemblyai';
import { readFile } from 'node:fs/promises';

const result = await transcribe({
  model: assemblyai.transcription('universal-3-5-pro'),
  audio: await readFile('meeting.mp3'),
  providerOptions: {
    assemblyai: {
      speakerLabels: true,
      keytermsPrompt: ['AssemblyAI', 'Universal'],
      redactPii: true,
      redactPiiPolicies: ['person_name', 'email_address'],
    } satisfies AssemblyAITranscriptionModelOptions,
  },
});

Annotating the options object with satisfies AssemblyAITranscriptionModelOptions gives you editor autocomplete and type-checking for the full option set, so you don’t have to memorize parameter names or hunt through docs.

The table below reflects @ai-sdk/assemblyai 3.0.5. For the always-current list — including any options added in newer releases — see the @ai-sdk/assemblyai provider reference, which lives alongside the provider code and is the canonical source.

Transcription options

Every option below is optional and passed under providerOptions.assemblyai. Types and behavior follow the AssemblyAI transcription API.

Option	Type	Description
`audioEndAt`	number	End time of the audio, in milliseconds.
`audioStartFrom`	number	Start time of the audio, in milliseconds.
`autoChapters`	boolean	Automatically generate chapters for the transcript.
`autoHighlights`	boolean	Automatically generate highlights for the transcript.
`boostParam`	enum	Boost level for `wordBoost`. Allowed values: `low`, `default`, `high`. Deprecated — applies only to the deprecated `wordBoost`; use `keytermsPrompt` instead.
`contentSafety`	boolean	Enable content safety filtering.
`contentSafetyConfidence`	number	Confidence threshold for content safety filtering (25-100).
`customSpelling`	array of objects	Custom spelling rules. Each object has `from` (array of strings) and `to` (string).
`disfluencies`	boolean	Include disfluencies (um, uh, etc.) in the transcript.
`domain`	string	Enable a domain-specific model for specialized terminology. Currently supports `medical-v1` (Medical Mode).
`entityDetection`	boolean	Detect entities in the transcript.
`filterProfanity`	boolean	Filter profanity in the transcript.
`formatText`	boolean	Apply text formatting to the transcript.
`iabCategories`	boolean	Include IAB categories in the transcript.
`keytermsPrompt`	array of strings	Domain-specific keyterms to boost recognition for (max 6 words per phrase). Replaces `wordBoost` for newer models — supported by `universal-3-pro`, `universal-3-5-pro`, and `slam-1` (and `universal-2` when enabled).
`languageCode`	string	Language code for the audio. Supports numerous ISO-639-1 and ISO-639-3 codes.
`languageConfidenceThreshold`	number	Confidence threshold for language detection.
`languageDetection`	boolean	Enable automatic language detection.
`languageDetectionOptions`	object	Options for language detection: `expectedLanguages` (array of strings), `fallbackLanguage` (string), `codeSwitching` (boolean), `codeSwitchingConfidenceThreshold` (number, 0-1).
`multichannel`	boolean	Process multiple audio channels separately.
`prompt`	string	Natural-language context (up to 1,500 words) to steer the model. Only supported by `universal-3-pro`, `universal-3-5-pro`, and `slam-1`.
`punctuate`	boolean	Add punctuation to the transcript.
`redactPii`	boolean	Redact personally identifiable information (PII).
`redactPiiAudio`	boolean	Redact PII in the audio file.
`redactPiiAudioOptions`	object	Options for PII-redacted audio: `returnRedactedNoSpeechAudio` (boolean), `overrideAudioRedactionMethod` (`silence`). Requires `redactPiiAudio`.
`redactPiiAudioQuality`	enum	Quality of the redacted audio file. Allowed values: `mp3`, `wav`.
`redactPiiPolicies`	array of enums	Which types of information to redact (e.g. `person_name`, `phone_number`).
`redactPiiReturnUnredacted`	boolean	Return the original unredacted transcript alongside the redacted one. Requires `redactPii`.
`redactPiiSub`	enum	Substitution method for redacted PII. Allowed values: `entity_name`, `hash`.
`redactStaticEntities`	object	Map of user-defined labels to exact terms to redact, e.g. `{ INTERNAL_TOOL: ['Bearclaw'] }`. Applied on top of standard PII redaction. Requires `redactPii`.
`removeAudioTags`	enum	Remove inline annotations from rich transcripts. Allowed values: `all`, `speaker`. Universal-3 Pro models.
`sentimentAnalysis`	boolean	Perform sentiment analysis on the transcript.
`speakerLabels`	boolean	Label different speakers in the transcript (diarization).
`speakerOptions`	object	Diarization options: `minSpeakersExpected` (number), `maxSpeakersExpected` (number).
`speakersExpected`	number	Expected number of speakers in the audio.
`speechThreshold`	number	Threshold for speech detection (0-1).
`summarization`	boolean	Generate a summary of the transcript.
`summaryModel`	enum	Summarization model. Allowed values: `informative`, `conversational`, `catchy`.
`summaryType`	enum	Type of summary. Allowed values: `bullets`, `bullets_verbose`, `gist`, `headline`, `paragraph`.
`temperature`	number	Sampling temperature (0-1) controlling randomness. Universal-3 Pro models.
`webhookAuthHeaderName`	string	Name of the authentication header for webhook requests.
`webhookAuthHeaderValue`	string	Value of the authentication header for webhook requests.
`webhookUrl`	string	URL to send webhook notifications to.
`wordBoost`	array of strings	Words to boost in the transcript. Deprecated — rejected by `universal-3-pro`, `universal-3-5-pro`, and `slam-1` (works only on `universal-2`/`best`); use `keytermsPrompt` instead.

Getting the full results back

transcribe() returns a provider-agnostic result, but AssemblyAI’s richer output — utterances, entities, sentiment, and more — is preserved, so you don’t lose anything by going through the AI SDK:

Top-level fields like result.text, result.segments, and result.durationInSeconds are normalized across providers.
result.providerMetadata.assemblyai holds AssemblyAI-specific results such as utterances, entities, and sentimentAnalysisResults.
result.response.body is the complete, raw AssemblyAI transcript object.

const result = await transcribe({
  model: assemblyai.transcription('universal-3-5-pro'),
  audio: await readFile('meeting.mp3'),
  providerOptions: {
    assemblyai: { speakerLabels: true, sentimentAnalysis: true },
  },
});

// Normalized, provider-agnostic fields
console.log(result.text);
console.log(result.segments);

// AssemblyAI-specific results
const { utterances, sentimentAnalysisResults } =
  result.providerMetadata.assemblyai;

// The complete, raw AssemblyAI transcript
const rawTranscript = result.response.body;

Timestamps use different units depending on where you read them. The top-level result.segments are in seconds (the AI SDK’s normalized format), while every timing inside result.providerMetadata.assemblyai and result.response.body is in milliseconds (AssemblyAI’s native format). Convert accordingly when you combine the two.

Additional resources

AssemblyAI provider reference on ai-sdk.dev — the canonical, complete list of provider options
vercel/ai on GitHub — the AI SDK source and where the provider is maintained
AssemblyAI API reference — the underlying transcription API and every parameter it accepts

Getting started

Use cases & integrations

Trust & security

▲ Vercel AI SDK Integration with AssemblyAI

Quickstart

Configuring the provider

Choosing a speech model

Using AssemblyAI features

Transcription options

Getting the full results back

Additional resources

​Quickstart

​Configuring the provider

​Choosing a speech model

​Using AssemblyAI features

​Transcription options

​Getting the full results back

​Additional resources

Quickstart

Configuring the provider

Choosing a speech model

Using AssemblyAI features

Transcription options

Getting the full results back

Additional resources