Marketo REST API
access_token query parameter removal
Stopped workingSubscribe to Marketo REST APIShare
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.
Calls it hits
query parameter access_token
What to use instead of these calls
Send the token in an Authorization: Bearer <access_token> header instead of the access_token query parameter.
In 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.
Facts
- API
- Marketo REST API
*.mktorest.com - Kind
- Parameter removal
- Takes effect
- August 31, 2026
- Calls after that day
- Fail
- Source
- Announcement
- Last updated
- Verified
- , against Marketo REST API's own pages
Questions
When does this change take effect?
Calls to query parameter access_token on Marketo REST API stopped working on August 31, 2026.
What happens to calls after August 31, 2026?
They have failed since August 31, 2026.
How do I find the calls this hits in my code?
Okapi reads your repository, finds the calls this change hits and opens a pull request with the fix. It never commits to your branches: every change comes as a pull request you review.
You fixed this one by hand.
Okapi opens the pull request with the fix before the next breaking change reaches your code.