The Mailjet API is spread under 3 versions.

The Email API is available under v3 (URL: This includes all REST API resources (URL: and one transactional API resource -

Mailjet offers also a second transactional API under v3.1 (URL:, which includes advanced error management.

The SMS API is currently under v4 (URL:

One of the main differences between the v3 and v4 versions is a change in authentication:

  • v3s are using basic authentication with your public and secret API keys.
  • v4 leverages a token authentication (the token can be obtained through our user interface).
  • Separate applications under separate sub accounts

The URL paths for every API resource can be found in the API reference under the respective resource name.