# The auth_key query parameter stops working

Calls to query parameter auth_key on api-free.deepl.com stopped working on January 15, 2026.

On January 15, 2026, the query parameter auth_key will stop working for calls to api-free.deepl.com. The deadline for this deprecation has been extended to January 15th, 2026. Any requests passing credentials using the query parameter auth_key after that date will fail.

## What to use instead

Send the key in the Authorization header instead, using Authorization: DeepL-Auth-Key [yourAuthKey].

- API: api-free.deepl.com (api-free.deepl.com)
- Kind: Endpoint removal
- Takes effect: January 15, 2026
- Calls after that day: fail
- Calls it hits: `query parameter auth_key`
- Source: [Announcement](https://developers.deepl.com/docs/resources/breaking-changes-change-notices/november-2025-deprecation-of-legacy-auth-methods)
- Verified: October 29, 2026, against api-free.deepl.com's own pages
- Page: https://www.okapi.bot/providers/api-free-deepl-com/breaking-changes/the-auth-key-query-parameter-stops-working/

## api-free.deepl.com's words

> Update: The deadline for this deprecation has been extended to January 15th, 2026.

Okapi finds the calls this change hits in your repo and opens the pull request with the fix: https://github.com/apps/okapi-agent