--- title: AI Gateway Text to Speech product: vercel url: /docs/ai-gateway/modalities/text-to-speech canonical_url: "https://vercel.com/docs/ai-gateway/modalities/text-to-speech" last_updated: 2026-09-08 type: how-to prerequisites: - /docs/ai-gateway/modalities - /docs/ai-gateway related: - /docs/ai-gateway/modalities/realtime - /docs/ai-gateway/modalities/speech-to-text - /docs/ai-gateway/sdks-and-apis/ai-sdk-python summary: Generate spoken audio from text with speech models through Vercel AI Gateway. install_vercel_plugin: npx plugins add vercel/vercel-plugin --- # AI Gateway Text to Speech Generate spoken audio from text with speech models such as `openai/tts-1` and `openai/tts-1-hd`. Use this for voiceovers, audio versions of written content, or spoken responses in your app. ## Related pages > **For AI agents:** Follow these links to understand how this page connects to the rest of the Vercel ecosystem. For the full cross-link map (inbound, outbound, prerequisites, and semantic neighbors), see the .graph.md link below. - [Realtime voice, speech, and transcription now supported on AI Gateway](https://vercel.com/changelog/realtime-voice-speech-and-transcription-now-supported-on-ai-gateway?from=related&source_path=%2Fdocs%2Fai-gateway%2Fmodalities%2Ftext-to-speech&source_site=vercel-docs&relationship=related) - [Build realtime voice agents on AI Gateway](https://vercel.com/blog/realtime-voice-agents-on-ai-gateway?from=related&source_path=%2Fdocs%2Fai-gateway%2Fmodalities%2Ftext-to-speech&source_site=vercel-docs&relationship=related) - [AI Gateway Speech Quickstart: Transcription and TTS](https://vercel.com/docs/ai-gateway/getting-started/speech?from=related&source_path=%2Fdocs%2Fai-gateway%2Fmodalities%2Ftext-to-speech&source_site=vercel-docs&relationship=related) — Generate speech and transcribe it using AI Gateway. - [AI Gateway Text Generation Quickstart](https://vercel.com/docs/ai-gateway/getting-started/text?from=related&source_path=%2Fdocs%2Fai-gateway%2Fmodalities%2Ftext-to-speech&source_site=vercel-docs&relationship=related) — Generate and stream text responses using AI Gateway. - [OpenAI Responses Text Generation with AI Gateway](https://vercel.com/docs/ai-gateway/sdks-and-apis/responses/text-generation?from=related&source_path=%2Fdocs%2Fai-gateway%2Fmodalities%2Ftext-to-speech&source_site=vercel-docs&relationship=related) — Generate text responses with the OpenAI Responses API through AI Gateway. - [OpenResponses Text Generation with AI Gateway](https://vercel.com/docs/ai-gateway/sdks-and-apis/openresponses/text-generation?from=related&source_path=%2Fdocs%2Fai-gateway%2Fmodalities%2Ftext-to-speech&source_site=vercel-docs&relationship=related) — Generate text responses using the OpenResponses API through AI Gateway. - [AI SDK with AI Gateway](https://vercel.com/docs/ai-gateway/sdks-and-apis/ai-sdk?from=related&source_path=%2Fdocs%2Fai-gateway%2Fmodalities%2Ftext-to-speech&source_site=vercel-docs&relationship=related) — Build AI-powered TypeScript applications using the AI SDK with AI Gateway for unified access to 200+ models. Full cross-link map for this page: [/docs/ai-gateway/modalities/text-to-speech.graph.md](/docs/ai-gateway/modalities/text-to-speech.graph.md?from=related&source_path=%2Fdocs%2Fai-gateway%2Fmodalities%2Ftext-to-speech&source_site=vercel-docs&relationship=graph) Use this to turn text into spoken audio. For live, two-way voice, see [Realtime](/docs/ai-gateway/modalities/realtime); to transcribe recorded audio, see [Speech to Text](/docs/ai-gateway/modalities/speech-to-text). > **💡 Note:** Text to speech is in beta and access is rolling out gradually. Speech models > may not appear in the model catalog yet for your team. ## Generate speech with the AI SDK For SDK options and result types, see [AI SDK speech](https://ai-sdk.dev/docs/ai-sdk-core/speech) and [Python speech](https://ai-python.dev/docs/basics/model-operations#generate-speech). Use `generateSpeech` with a speech model from the AI Gateway provider: #### TypeScript ```typescript filename="generate-speech.ts" import { generateSpeech } from 'ai'; import { gateway } from '@ai-sdk/gateway'; import { writeFile } from 'node:fs/promises'; const result = await generateSpeech({ model: gateway.speechModel('openai/tts-1'), text: 'Hello! Thanks for trying out AI Gateway.', voice: 'alloy', outputFormat: 'mp3', }); await writeFile('greeting.mp3', result.audio.uint8Array); console.log("Saved greeting.mp3"); ``` #### Python (beta) ```python filename="generate-speech.py" import asyncio import ai import base64 from pathlib import Path async def main(): result = await ai.ops.generate_audio( ai.get_model('openai/tts-1'), 'Hello! Thanks for trying out AI Gateway.', params=ai.ops.AudioParams(voice="alloy", output_format="mp3"), ) audio = result.value[0] data = audio.data if isinstance(audio.data, bytes) else base64.b64decode(audio.data) Path("greeting.mp3").write_bytes(data) print("Saved greeting.mp3") asyncio.run(main()) ``` > **💡 Note:** Speech support ships in the stable AI SDK releases. Install it with `pnpm add > ai @ai-sdk/gateway`. The Python examples use the [AI SDK for Python beta](/docs/ai-gateway/sdks-and-apis/ai-sdk-python). These audio operations use dedicated AI Gateway endpoints. They are separate from Chat Completions, Messages, and Responses. See the [Python SDK setup](/docs/ai-gateway/sdks-and-apis/ai-sdk-python#installation) for installation requirements. ## Request options | Option | Description | | -------------- | ------------------------------------------------------------------------ | | `text` | The text to convert to speech. Required. | | `voice` | The voice to use, such as `alloy`. Available voices depend on the model. | | `outputFormat` | The audio format, such as `mp3` or `wav`. | | `instructions` | Directions for how the model should speak, such as tone or pacing. | | `speed` | Playback speed. Defaults to 1. | | `language` | The language of the input text. | Support for each option varies by model. Unsupported options are reported in `warnings` on the result instead of failing the request. ## Generate speech with the REST API You can also call the speech endpoint directly. Send a `POST` request with the model in the `ai-model-id` header. The response contains the audio as a base64-encoded string: #### TypeScript ```typescript filename="generate-speech-rest.ts" import { writeFile } from 'node:fs/promises'; const response = await fetch( 'https://ai-gateway.vercel.sh/v4/ai/speech-model', { method: 'POST', headers: { Authorization: `Bearer ${process.env.AI_GATEWAY_API_KEY}`, 'ai-gateway-protocol-version': '0.0.1', 'ai-speech-model-specification-version': '4', 'ai-model-id': 'openai/tts-1', 'Content-Type': 'application/json', }, body: JSON.stringify({ text: 'Hello! Thanks for trying out AI Gateway.', voice: 'alloy', outputFormat: 'mp3', }), }, ); const result = await response.json(); await writeFile('greeting.mp3', Buffer.from(result.audio, 'base64')); console.log("Saved greeting.mp3"); ``` #### Python ```python filename="request.py" import json import os import urllib.request request = urllib.request.Request( 'https://ai-gateway.vercel.sh/v4/ai/speech-model', data=json.dumps({'text': 'Hello! Thanks for trying out AI Gateway.', 'voice': 'alloy', 'outputFormat': 'mp3'}).encode(), headers={'Authorization': "Bearer " + os.environ["AI_GATEWAY_API_KEY"], 'ai-gateway-protocol-version': '0.0.1', 'ai-speech-model-specification-version': '4', 'ai-model-id': 'openai/tts-1', 'Content-Type': 'application/json'}, ) with urllib.request.urlopen(request) as response: print(json.load(response)) ``` #### cURL ```bash filename="generate-speech.sh" set -euo pipefail curl --fail-with-body -X POST https://ai-gateway.vercel.sh/v4/ai/speech-model \ -H "Authorization: Bearer $AI_GATEWAY_API_KEY" \ -H "ai-gateway-protocol-version: 0.0.1" \ -H "ai-speech-model-specification-version: 4" \ -H "ai-model-id: openai/tts-1" \ -H "Content-Type: application/json" \ -d '{ "text": "Hello! Thanks for trying out AI Gateway.", "voice": "alloy", "outputFormat": "mp3" }' | jq -r '.audio' | base64 -d > greeting.mp3 if [ -s greeting.mp3 ]; then echo "Saved greeting.mp3"; else exit 1; fi ``` The response is a JSON object with the base64-encoded audio: ```json filename="response.json" { "audio": "SUQzBAAAAAAA...", "warnings": [] } ``` ## Limitations - Audio returns base64-encoded in a JSON response. Streaming audio output is not supported. - Text to speech supports OpenAI speech models only. --- [View full sitemap](/docs/sitemap)