> ## Documentation Index
> Fetch the complete documentation index at: https://developers.phrase.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Learn how to use the Phrase Language AI API to translate content automatically using the best available machine translation engine for your language pair.

export const DownloadOpenApiCard = ({url}) => {
  return <Card title="Full API Schema" href={url} target="_blank" horizontal>
      Explore the raw schema to see all endpoints in one place. Perfect for tools and integration setup.
    </Card>;
};

## Phrase Language AI API Reference 1.0.0

The Phrase Language AI API lets you translate content programmatically by automatically selecting the best available machine translation (MT) engine for each request. The selection is based on language pair, content type, and historical quality signals — you do not need to manage engine routing yourself.

### When to use this API

Use the Language AI API when you want to integrate MT into your own pipeline or application without building engine-selection logic. If you are already using the Phrase TMS API for project and job management, the Language AI API can be used independently for on-demand translation.

### Limits and constraints

* Requests are subject to per-account rate limits. Exceeding the limit returns a `429 Too Many Requests` response.
* Maximum input length per request is documented on each endpoint.
* Supported language pairs vary by underlying engine; unsupported pairs return a `422 Unprocessable Entity` response.

<DownloadOpenApiCard url="https://developers.phrase.com/public/assets/openapi/phrase-language-ai.json" />