I'm building a rails app and I want to have token authentication but I don't want to build a separate API, I want it to be all integrated into one rails app.
Is this possible? Every single tutorial about token authentication I can find is about APIs, and every API seems to need to be its own standalone entity running in parallel with the main app.
Is what I'm asking impossible, or stupid? If not, how do I do it?
For "classical" web applications you want to use session based authentication instead of tokens.
Token based authentication is stateless and requires the token to be sent along with every request. This is done via HTTP headers or by placing it in the request body. Which is how you use API's.
For a classical web application there is simply no practical way to send the token along on GET requests.
Session based authentication instead works by using cookies to store the authentication claim (usually a user id). While you could use a token and store it in the session its just an overly convoluted solution since it defeats the whole purpose of token based auth.