Quickstart for the translation API

Language API is a single HTTPS endpoint. You post an array of strings and a target language; the translated strings come back in the same order. Nothing has to be installed, and there is no job queue or callback to wire up.

What you need

• An account with a verified e-mail address. Verification credits your team

with 100,000 characters, which is enough to work through this page and well beyond it without entering payment details.

• One API key, created in the dashboard under API keys.
• Any HTTP client. The examples below use curl and Node's built-in fetch.

Create an API key

Open the dashboard, choose API keys and create a key. The full key is displayed exactly once. Only a SHA-256 hash of it is stored on our side, so a lost key cannot be shown again — you revoke it and create another.

Keys have one of two prefixes:

Both prefixes translate for real and draw from the same character budget. The prefix exists so that your usage breakdown can separate staging from production; it does not switch on a sandbox.

Make the call

The request below translates two interface strings from English into Italian. The source language is omitted, so the engine detects it.

curl https://api.langapi.xyz/v1/translate \
  -X POST \
  -H "Authorization: Bearer la_test_xxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
        "text": ["Your order has been dispatched.", "Track the parcel"],
        "target_lang": "IT"
      }'

The same request from Node:

const reply = await fetch('https://api.langapi.xyz/v1/translate', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.LANGUAGE_API_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    text: ['Your order has been dispatched.', 'Track the parcel'],
    target_lang: 'IT',
  }),
});
const body = await reply.json();

Send Content-Type: application/json when the body is JSON. Without it, the body is parsed as a form and text is reported as missing.

Read the reply

{
  "translations": [
    { "detected_source_language": "EN", "text": "Il tuo ordine è stato spedito." },
    { "detected_source_language": "EN", "text": "Traccia il pacco" }
  ],
  "request_id": "01JAX0V3S2B8KQ9E4M7HZ6T1RD",
  "characters": 47,
  "engine": { "prompt_tokens": 63, "completion_tokens": 19, "total_tokens": 82 }
}

• translations[n] corresponds to text[n]. The order never changes.
• characters is the number of characters you were charged for. The response

header X-Characters-Billed carries the same value.

• request_id identifies this call in our logs. It is also sent as the

X-Request-Id header. Keep it if you ever need to ask about a request.

• engine reports token counts for transparency. They are not a billing unit;

see Tokens versus billed characters.

Check the remaining budget

curl https://api.langapi.xyz/v1/usage \
  -H "Authorization: Bearer la_test_xxxxxxxx"

{
  "character_count": 47,
  "character_limit": 100000,
  "billing": {
    "mode": "credit",
    "plan": "payg",
    "currency": "EUR",
    "period_end": null,
    "overage_characters": 0,
    "credit_balance": "1.499295"
  },
  "engine": { "prompt_tokens": 63, "completion_tokens": 19, "total_tokens": 82 }
}

The fields are explained on Usage and quota.

Limits that apply from the first request

Requests that fail are not charged.

Next steps

• API keys and authentication — header variants,

test keys and key rotation.

• POST /v1/translate reference — all parameters and

response fields.

• Error codes reference — what each code means and which

ones are safe to retry.