Nitro API — Human Translation API for AI Agents

Nitro API is a human translation API designed specifically for AI agents, enabling autonomous requests without requiring API keys or account setup. It connects AI agents directly with professional native-speaker translators across 80+ languages, delivering publication-ready translations with cultural fluency and domain expertise. The API supports complex content formats and offers a fully automated payment and order management flow.

• Your AI agent sends a POST request to /translate with source and target languages and the content to be translated.
• Initially, the request returns a 402 Payment Required response with a payment challenge.
• Obtain a payment token from your MPP-compatible payment provider (outside Nitro API).
• Retry the POST request with the same body and include the payment credential in the Authorization header.
• Poll the /orders/{id} endpoint every ~10 seconds to check the translation status until it is marked DONE.
• Retrieve the translated text from the order response.
• The payment flow currently supports US-issued cards only.
• Ensure the retry request body is byte-for-byte identical to the original (verified via SHA-256 hash).

What is Nitro API?

Nitro API is a human translation service API designed for AI agents to autonomously request professional native-speaker translations without needing API keys or account setup.

How does Nitro API work for AI agents?

AI agents send a translation request, receive a payment challenge, obtain a payment token from an MPP provider, retry the request with payment authorization, and then poll for translation results until completion.

What languages does Nitro API support?

Nitro API supports translation in over 80 languages, covering a wide range of global language needs.

How does Nitro API ensure translation quality?

Translations are performed by professional native speakers who provide cultural fluency, domain expertise, and preserve brand voice and complex content formats.

Can Nitro API be used without an API key?

Yes, Nitro API allows AI agents to call the translation service autonomously without any API key or account registration.

What types of content formats does Nitro API support?

Nitro API supports complex formats such as HTML, JSON, XML, and iOS strings, preserving markup and structure during translation.

Price data is not explicitly provided on the website. Users can retrieve current rates per 1,000 characters via the GET /rates endpoint or estimate prices using POST /calculate. Pricing is pay-per-order with no minimum order size.

1. Nitro API offers a unique and streamlined approach for AI agents to access professional human translation services without the friction of API key management or account setup, which is a significant advantage for autonomous AI workflows.
2. The support for over 80 languages and complex content formats makes it versatile for diverse translation needs, including specialized domains like legal, medical, and marketing content.
3. The payment flow integration with MPP providers enables secure and flexible payment handling, although currently limited to US-issued cards, which may restrict international users.
4. The turnaround time of 2 to 24 hours balances quality and speed, suitable for production workflows requiring human-level accuracy.
5. The lack of publicly available pricing details may require potential users to explore the API endpoints or contact support for cost transparency.
6. While the API design is developer-friendly and supports full automation, the requirement for byte-for-byte identical retry requests may add complexity to implementation.
7. Overall, Nitro API fills a niche for AI-driven applications needing high-quality human translations with minimal setup, though expanding payment options and clearer pricing could enhance its accessibility and adoption.