The Mutual TLS security scheme in OpenAPI

Mutual TLS (mTLS) is a security protocol that enhances the security of API communication by requiring both the client and server to authenticate each other using digital certificates. This two-way authentication ensures that only trusted parties can establish a connection, providing an additional layer of security.

OpenAPI lets you define a Mutual TLS security scheme using the mutualTLS type.

Defining a Mutual TLS security scheme

Define a Mutual TLS security scheme in OpenAPI using the following structure:

The mutualTLS type requires no additional fields, as its primary purpose is to indicate that the API requires mutual TLS authentication. However, you can use the description field to provide API users with additional information about how to obtain a certificate.

Learn more about mutual TLS in the OpenAPI Specification  or the Cloudflare Learning Center .