Your exclusive access to USPS APIs is protected using OAuth 2.0 industry standards.

All USPS APIs require an OAuth 2.0 access token to be conveyed in the 'Authorization' header, using the 'Bearer' token scheme.

Once you sign-in to the API developer portal, you may get the OAuth credentials you will need to register your application 'Add App'. See "Getting Started" for further information about: signing-in, registering your application, and additional USPS account credentials you will need to integrate your application with USPS APIs.

You are responsible for securing the application credentials once issued. Please contact USPS if your credentials have been disclosed to external parties and we will issue new credentials.