Speech

Turns text into spoken audio in the OpenAI Speech format. Speech models are paid models from providers: each one's price per million characters is on its page at freetheai.org/models.

POSThttps://api.freetheai.org/v1/audio/speech

Request

curl

curl https://api.freetheai.org/v1/audio/speech \
  -H "Authorization: Bearer $FTAI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "MODEL_ID", "input": "Hello from FreeTheAI!", "voice": "alloy"}' \
  -o speech.mp3

Python

import os
from openai import OpenAI

client = OpenAI(base_url="https://api.freetheai.org/v1", api_key=os.environ["FTAI_KEY"])

audio = client.audio.speech.create(model="MODEL_ID", input="Hello from FreeTheAI!", voice="alloy")
audio.write_to_file("speech.mp3")

TypeScript

import { writeFile } from 'node:fs/promises'
import OpenAI from 'openai'

const client = new OpenAI({ baseURL: 'https://api.freetheai.org/v1', apiKey: process.env.FTAI_KEY })

const audio = await client.audio.speech.create({ model: 'MODEL_ID', input: 'Hello from FreeTheAI!', voice: 'alloy' })
await writeFile('speech.mp3', Buffer.from(await audio.arrayBuffer()))

Field	Type	Description
model	string	A speech model ID from GET /v1/models ("type": "speech").
input	string	The text to speak, at most 4,096 characters.
voice	string	The voice. Names depend on the model; see its page.
instructions	string	Optional. How to speak (tone, pace), for models that support it.
response_format	string	Optional. mp3 (default), opus, aac, flac, wav, or pcm.
speed	number	Optional. Speaking speed, for models that support it.

Response

The audio file itself, with a matching Content-Type (for example audio/mpeg). You are charged for the characters in input.

Errors

Status	Meaning
400	input must be at most 4096 characters, or another field has a value the endpoint does not take. Split long text into several requests.
401	Missing or invalid API key.
402	Not enough wallet balance, or the key's budget is used (paid usage errors).
404	No model has that ID, or none of the providers you follow serve it.
502 / 503	The provider failed or is busy. Retry; a failed request is not charged.