Bearer token authentication for all but one method

[jcarlson]

I'm interesting in building a Consumer for an API that requires a Bearer token in the Authorization header in all but one endpoint. The same API also exposes an /access-token endpoint where you can exchange your refresh token for an access token.

Suppose the API endpoints are something like this:

• POST /access-token
• GET /api/widgets
• POST /api/widgets
• GET /api/widgets/:id
• PUT /api/widgets/:id
• DELETE /api/widgets/:id

Pretty standard RESTful API. All of the Widgets resource endpoints require a Bearer Token that can be obtained from the Access Token endpoint.

The Retrofit documentation talks about using a DelegatingHandler to implement that functionality. I'm not sure what the Uplink equivalent might be.

To add some additional context, this Consumer would be used in a CLI program, and I'm currently caching the access token externally in a secrets vault, like macOS Keychain. That makes the access token available not just across requests, but also across invocations of the CLI.

So I guess what I'm looking for is a way to annotate "this method requires an access token, and here's the method to call to obtain it dynamically". Ideally, I could annotate that on the class and not every method, and then have one annotation on the /access-token endpoint that says "skip access token authentication".

My best guess right now is that the /access-token endpoint should not be a part of my Consumer class, and would have to be implemented elsewhere. But that isn't entirely correct, since the /access-token endpoint is part of this API. Thoughts? Ideas?