# The access_token query parameter stops working

Calls to query parameter access_token on Marketo REST API stopped working on August 31, 2026.

Support for authentication using the access_token query parameter was removed on August 31, 2026. Requests relying on the query parameter access_token fail since that date across *.mktorest.com endpoints.

## What to use instead

Send the token in an Authorization: Bearer <access_token> header instead of the access_token query parameter.

- API: Marketo REST API (*.mktorest.com)
- Kind: Parameter removal
- Takes effect: August 31, 2026
- Calls after that day: fail
- Calls it hits: `query parameter access_token`
- Source: [Announcement](https://experienceleague.adobe.com/en/docs/marketo-developer/marketo/rest/authentication)
- Verified: November 6, 2026, against Marketo REST API's own pages
- Page: https://www.okapi.bot/providers/marketo-rest-api/breaking-changes/the-access-token-query-parameter-stops-working/

## Marketo REST API's words

> Support for authentication using the access_token query parameter was removed on August 31, 2026. New development should use the Authorization header exclusively.

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