Deprecation of SOAP API and Access Token in Query Parameter for REST API

[Kenny_Elkington]

Two upcoming deprecations may impact your integration with Marketo Engage and may require action. 

The Marketo Engage SOAP API will be fully deprecated on October 31st 2025.  Please review if you are still using the SOAP API in one or more of your Marketo subscriptions. To avoid disruptions of service, you will need to retire or migrate any services using the SOAP API to the Marketo Engage REST API by October 31st, 2025.  Consult the Migration Guide for further information. 

On June 30th 2025, the Marketo Engage REST API will no longer accept access tokens for authentication and authorization via the ‘access_token’ query parameter.  Please check if one or more of your integrations uses this parameter to authenticate.  To avoid disruptions of service, any services using this parameter to authenticate will need to migrate to using header-based authentication using the ‘Authorization’ header, which is documented here. 

Please let us know in the comments section if you have any questions or concerns about this upcoming change.

[Jo_Pitts1]

@Kenny_Elkington, super useful post.  Maybe edit it so it doesn't refer to the statements about having used SOAP in the last 30 days, of having used a URL based based access token :).. Those references are clearly designed for messaging direct to an instance user, not for a blog post 🙂

[Miray]

Thank you @Kenny_Elkington This is very useful. 

[Ruchi_Lapran1]

Thanks for sharing @Kenny_Elkington