> ## Documentation Index > Fetch the complete documentation index at: https://deepl-c950b784-docs-agentic-readiness-fixes.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Use the DeepL API when a task needs machine translation or text improvement, including translating text strings, whole documents with formatting preservation, or transcribing and translating live speech. Preferred terminology and phrasing may be enforced using customizations (glossaries, style rules, and translation memories). Retrieve supported languages for each product from the `/v3/languages` endpoints. > Read the machine-readable API surface instead of inferring request shapes from prose: the REST spec is at https://developers.deepl.com/api-reference/openapi.yaml (also served as openapi.json) and the Voice WebSocket protocol is at https://developers.deepl.com/api-reference/voice/voice.asyncapi.yaml. These docs also expose an MCP server at https://developers.deepl.com/mcp (Streamable HTTP, no authentication). > Use https://api.deepl.com for Pro plans and https://api-free.deepl.com for the Free plan. Authenticate every request with the header `Authorization: DeepL-Auth-Key `. Never fabricate an API key: ask the user for one, or point them at https://developers.deepl.com/docs/getting-started/quickstart. > Errors use standard HTTP status codes with a JSON body containing a `message` field, plus a `code` field where available, and an `X-Trace-ID` response header that identifies the request in DeepL's logs. Log `X-Trace-ID` by default. Retry 429 and 5xx with exponential backoff. Do not retry 456, which means the account quota is exhausted, or 400, which means the request itself is invalid. # API Status Page > Monitor the operational status and availability of the DeepL API The [DeepL Status Page](https://status.deepl.com) provides a real-time, [API-specific view](https://status.deepl.com/?tab=api) of the operational status of the DeepL API. The same page also covers DeepL's other services, along with incident reports and upcoming maintenance. ## What you can check * **Current status** of all API services across all supported regions * **90-day availability** history per service group (Translation, Write, Document Translation, Glossaries, and more) * **Active and past incidents** affecting the API * **Pro and Free API tier** status separately ## When to check * If you're receiving HTTP 5xx errors from the API * If you're experiencing elevated latency or timeouts * Before investigating issues in your own integration — confirm the API is operational first Go to the API Status Page For the status of all DeepL services (including web, desktop apps, and non-API products), see [status.deepl.com](https://status.deepl.com).