Next, we need to specify what our endpoint can potentially respond with. This is a required field for all operation objects. The responses Object is a map of numeric HTTP status codes and a response object, which should contain two fields:

• description: A short description of the payload
• content (object): This specifies the valid MIME types (for example, application/json, text/plain) that are acceptable for this endpoint, as well as the expected structure of the payload:

paths:
  /salt:
    get:
      ...
      responses:
        '200':
          description: Salt Retrieved
          content:
            text/plain:
              schema:
                type: string
        '400':
          description: Email query parameter not specified
          content:
            application/json:
              schema:
                properties:
                  message:
                    description: Error message
                    type: string
        '500':
          description: Internal Server Error
          content:
            application/json:
              schema:
                properties:
                  message:
                    description: Error message
                    type: string

To make sure that we haven't forgotten any responses, we can check our request handler (src/handlers/auth/salt/retrieve/index.js), our middleware, as well as our E2E tests.

We have now defined the Get Salt endpoint with the OpenAPI specification language. Let's move on to a slightly more complicated endpoint—Create User—and see how we can specify payload bodies.