Nitro 4.0 is a human translation API designed for AI agents to autonomously order and pay for professional translations without an API key.
What the product does and how it is positioned
Nitro 4.0 provides a programmatic interface for AI agents to access professional human translation services in over 80 languages. The platform is specifically engineered to support autonomous workflows where an agent can initiate a request, handle a payment challenge, and retrieve results without manual human intervention.
By utilizing native-speaker translators rather than machine engines, the service focuses on delivering cultural fluency and domain-specific accuracy for sensitive content. The API supports various developer environments and handles complex data structures to ensure that technical formatting remains intact during the translation process.
Source-supported ways to use the product
AI agents can independently localize marketing copy or product descriptions into multiple languages while ensuring cultural relevance.
Translating specialized legal, medical, or financial documents where machine translation may fail to capture precise terminology.
Processing iOS strings or JSON files for application localization while preserving the underlying code structure.
The documented workflow, where available
The AI agent sends a POST request to the translation endpoint with the source text and target languages.
The server returns a 402 Payment Required status along with a payment challenge header.
The agent obtains a payment token from a compatible MPP provider and builds a base64url credential.
The agent retries the original request including the payment credential in the Authorization header.
The agent polls the order endpoint periodically until the status changes from in-progress to done.
The core innovation of Nitro 4.0 is its ability to facilitate transactions between AI agents and human service providers without traditional authentication hurdles. By implementing a 402 Payment Required flow, the API allows agents to pay for services on-demand using MPP-compatible providers. This removes the need for developers to manage long-lived API keys or pre-fund accounts.
Security is maintained through strict request verification. When an agent retries a request after a payment challenge, the server performs a byte-for-byte comparison and SHA-256 hash check to ensure the payload has not been altered. This ensures that the payment is tied specifically to the original translation request.
Checks to run with your own material and workflow
What was checked and when
Answers based on the source-checked product record
No, Nitro 4.0 supports a no-auth flow where AI agents can use payment credentials instead of traditional API keys.
The service supports professional human translation in more than 80 different languages.
While not instant, the average turnaround time for translations is between 2 and 24 hours.
Yes, the service is designed to preserve markup and structure in formats such as HTML, JSON, XML, and iOS strings.
The current payment flow for the agentic no-auth system supports US-issued cards only.
