Quickstart

This is the fastest path from zero to a working API call. If you are an AI coding agent: copy the Python or cURL block exactly; only replace YOUR_API_KEY and the audio file path.

Prerequisites

You need three things before calling the API:

1. An account on the Theta One API Console — see Sign Up.
2. Credits on the account — see Top Up Prepaid Credits. The Free plan starts with $0.20, which is enough for ~8 minutes of STT.
3. An API key beginning with sk-theta- — see API Keys.

Make your first call

cURL

curl -X POST \
  'https://stt.thetaone-ai.com/transcribe' \
  -H 'accept: application/json' \
  -H 'x-api-key: YOUR_API_KEY' \
  -H 'Content-Type: multipart/form-data' \
  -F 'file=@audio.wav;type=audio/wav'

Python

import requests

url = "https://stt.thetaone-ai.com/transcribe"
headers = {"x-api-key": "YOUR_API_KEY"}

with open("audio.wav", "rb") as f:
    files = {"file": ("audio.wav", f, "audio/wav")}
    response = requests.post(url, headers=headers, files=files, timeout=30)

response.raise_for_status()
result = response.json()
print(result["text"])

Node.js

import fs from "node:fs";

const form = new FormData();
form.append(
  "file",
  new Blob([fs.readFileSync("audio.wav")], { type: "audio/wav" }),
  "audio.wav"
);

const res = await fetch("https://stt.thetaone-ai.com/transcribe", {
  method: "POST",
  headers: { "x-api-key": "YOUR_API_KEY" },
  body: form,
});

if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);
const data = await res.json();
console.log(data.text);

A successful response looks like:

{
  "text": "Welcome to Theta One AI!",
  "text_type": "en",
  "metadata": {},
  "response_time_in_sec": 0.42
}

What to do next

Decide your integration path:

• Transcription only → stay on /transcribe. Add options via STT additional features.
• Pronunciation scoring → follow Choosing an API to pick between /pronunciation (with native reference) and /pronunciation-simple (text-only).

Before going to production, read:

• API Reference Overview
• Error Reference
• Rate Limits & Retries

Troubleshooting

Symptom	Likely cause	Fix
401 Unauthorized	Key missing / wrong / deactivated	Check x-api-key and that the key is active in the console
402 PAYMENT_REQUIRED	Out of credits, or plan doesn't include the endpoint	Top up or upgrade — see Pricing
429 RATE_LIMIT_EXCEEDED	Exceeded per-key RPM	Retry with backoff — see Rate Limits
400 Bad Request with pronunciation	options not a JSON string, or NotAllWordsSpokenError	See Error Reference