[zackify]

If only they would support the web and let you just issue a long running cookie....

I hacked the spec to pass through a cookie via the oauth handshake to do this without needing an oauth server.

Its really dumb they don't want to allow this.

If no cookie, open webpage.

If cookie set, close and persist.

I literally wrote an 80 page mini book on MCP yet it frustrates me to no end.

[dend]

Hey - one of the lead maintainers of the MCP project here. There are a lot of scenarios where this simply won't scale (both from a usability and security standpoint). Cookies were made for the browser. MCP servers and clients often operate in environments where that is not a guarantee.

[SkyPuncher]

I've been working on an MCP for creating semi-deterministic flows in Claude code (essentially skills, but broken down into pieces). In order to track execution and state, I have the LLM pass the MCP a unique "execution id" with every call. This lets me programmatically step it through skills and know exactly where execution progress is.

I've been considering a similar approach for the web. Essentially, do a short-lived, one-time use token exchange for every single call back and forth.

* LLM: "I'd like to interact with your site"

* Site: "Great, here's first token. I will exchange it for a new one on the next call. Do not share with with another site. You can authenticate in your browser with this link: [example.com]"

* Then you can go back and forth.

It'd be rather annoying to auth in the browser every time, but it would enable a low-touch flow.

Long term, it'd be ideal to have some sort of out-of-band credential store/tool available, but this would start proving the concept out. Don't use it for highly sensitive stuff, but it would enable a lot of agentic flows that are currently blocked by high-lift MCP setup.

[freakynit]

Agree.

Many times what the server returns is dictated by what kind of client software a user is using. Cookies are obviously used by browser based clients, with full browser capabilities. MCP doesn't have those capabilities. How will the server know what to return?

I have separated handling for token based calls vs cookie based in my non-mcp projects.. because it suffers from the same issue.

Most of the endpoints, assuming the client talks to server using api's, work fine with cookies, some, do not.

[Ferret7446]

You're just asking for your credentials to get stolen. Long lived creds are a huge liability.