Transcription API

Quick start

1. 1 Buy any credit package once.
2. 2 Create an API key in Settings.
3. 3 Send your first request with one of the examples below.

What it does

• Speech to text for audio and video files, with the spoken language detected for you.
• Translations into up to 5 languages in the same call.
• One synchronous request: you get the answer as soon as the transcript is ready, for a voice message usually within seconds.
• The same file sent again is answered from the stored transcript, without waiting for a second transcription.

Authentication

Every request carries a personal API key as a Bearer token in the Authorization header. Create one in Settings under API keys. It is shown once, so store it where your code can read it, and never in a browser or an app you ship. A key only works for the endpoints on this page.

API keys are for paying accounts: an account that has bought credits at least once, or a premium account.

Authorization: Bearer YOUR_API_KEY

Pricing

Paid from your credit balance, per started minute of audio, after the transcript is ready. A call that fails costs nothing.

Example: a 77 second voice message counts as 2 minutes, so 20 credits, or 30 credits with one translation.

Asking for the language the recording is already in is not a translation and costs nothing.

Sending the same file twice is charged twice, because you receive the transcript twice. To retry safely after a timeout, send an Idempotency-Key header: a key you already used returns the first answer and charges nothing.

Endpoints

curl -X POST https://audiocap.app/api/v1/transcriptions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Idempotency-Key: 6f1c2b7e-voice-0001" \
  -F "file=@voice-message.ogg" \
  -F "translate=de"

import { openAsBlob } from 'node:fs';

const form = new FormData();
form.append('file', await openAsBlob('voice-message.ogg'), 'voice-message.ogg');
form.append('translate', 'de');

const res = await fetch('https://audiocap.app/api/v1/transcriptions', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer YOUR_API_KEY',
    'Idempotency-Key': '6f1c2b7e-voice-0001',
  },
  body: form,
});

console.log(await res.json());

import requests

res = requests.post(
    "https://audiocap.app/api/v1/transcriptions",
    headers={"Authorization": "Bearer YOUR_API_KEY", "Idempotency-Key": "6f1c2b7e-voice-0001"},
    files={"file": open("voice-message.ogg", "rb")},
    data={"translate": "de"},
)

print(res.json())

<?php

$client = new GuzzleHttp\Client();

$res = $client->request('POST', 'https://audiocap.app/api/v1/transcriptions', [
    'headers' => [
        'Authorization' => 'Bearer YOUR_API_KEY',
        'Idempotency-Key' => '6f1c2b7e-voice-0001',
    ],
    'multipart' => [
        ['name' => 'file', 'contents' => fopen('voice-message.ogg', 'r')],
        ['name' => 'translate', 'contents' => 'de'],
    ],
]);

echo $res->getBody();

{
    "data": {
        "id": 1234,
        "slug": "k3v9q2m7x1ab",
        "file": "voice-message.ogg",
        "status": "completed",
        "language": "en",
        "seconds": 6.4000000000000003552713678800500929355621337890625,
        "text": "Hi, it's me. I'm running ten minutes late, see you at the station.",
        "error": null,
        "translations": {
            "de": "Hallo, ich bin es. Ich komme zehn Minuten später, wir sehen uns am Bahnhof."
        }
    },
    "billing": {
        "credits_charged": 15,
        "minutes": 1,
        "transcription": 10,
        "translation": 5,
        "translated_languages": [
            "de"
        ],
        "balance": 485,
        "receipt_id": 42,
        "replayed": false
    }
}

curl https://audiocap.app/api/v1/transcriptions/1234 \
  -H "Authorization: Bearer YOUR_API_KEY"

const res = await fetch('https://audiocap.app/api/v1/transcriptions/1234', {
  method: 'GET',
  headers: {
    Authorization: 'Bearer YOUR_API_KEY',
  },
});

console.log(await res.json());

import requests

res = requests.get(
    "https://audiocap.app/api/v1/transcriptions/1234",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
)

print(res.json())

<?php

$client = new GuzzleHttp\Client();

$res = $client->request('GET', 'https://audiocap.app/api/v1/transcriptions/1234', [
    'headers' => [
        'Authorization' => 'Bearer YOUR_API_KEY',
    ],
]);

echo $res->getBody();

{
    "data": {
        "id": 1234,
        "slug": "k3v9q2m7x1ab",
        "file": "voice-message.ogg",
        "status": "completed",
        "language": "en",
        "seconds": 6.4000000000000003552713678800500929355621337890625,
        "text": "Hi, it's me. I'm running ten minutes late, see you at the station.",
        "error": null,
        "translations": {
            "de": "Hallo, ich bin es. Ich komme zehn Minuten später, wir sehen uns am Bahnhof."
        }
    }
}

Errors

Every error answers with JSON that has a stable error code and a readable message.

{
    "error": "payment_required",
    "message": "Not enough credits for this file. Top up and send it again; it will not be transcribed twice.",
    "reason": "insufficient_credits",
    "balance": 5,
    "cost": 20,
    "credits_per_minute": 10,
    "translation_per_minute": 5,
    "buy_url": "https://audiocap.app/developers?buy=credits"
}