title: JWT Token Validation using Mule
body: <p>I am trying to create an oAuth policy to protect an API using an JWT access token. That token can be validated by calling an external URL.</p>
  
  <p>I am using the following RAML for my Mule proxy.</p>
  
  <pre><code>#%RAML 1.0
  title: Custom API
  version: 1
  baseUri: http://localhost:8081
  securitySchemes:
    oauth_2_0:
      description: |
        This API supports OAuth 2.0 for authenticating all API requests.
      type: OAuth 2.0
      describedBy:
        headers:
          authorization:
            description: |
               Used to send a valid OAuth 2 access token. Do not use with the "access_token" query
               string parameter.
            type: string      
        responses:
          401:
            description: |
              Bad or expired token. This can happen if the user or the API revoked or expired an
              access token. To fix, you should re-authenticate the user.
          403:
            description: |
              Bad OAuth request (wrong consumer key, bad nonce, expired timestamp...). Unfortunately,
              re-authenticating the user won't help here.
  /hello:
    get:
    securedBy: [oauth_2_0]
  </code></pre>
  
  <p>However, mule is not able to send the Authorization header while validating against the external service.</p>