Server should be accissible to tool handlers

[rnett]

Describe the bug

Currently, there is no way to access the server instances in tool handlers. This is important to have so that tools can sent elicitation requests and other notifications.

Currently, the only workaround is to re-crease the tool handler for each server instance, which can get expensive.

[rnett]

This is significantly worse with the introduction of server sessions. A tool call handler has no way of knowing which session the call originated from, and thus no way of knowing where to send elicitations, notifications, etc. This makes these features unusable.

@devcrocod should I create a new issue for this?

[devcrocod]

@rnett Do you mean this issue: #249 ?

[rnett]

No, I don't think so from that issue's description. My issue is around the API, not implementation. Inside of the handler you register a tool with (the suspend (CallToolRequest) -> CallToolResult lambda), there is no way to get the corresponding ServerSession instance to use to send notifications and messages back to the client. Unless I'm missing something obvious? I was able to work around this in previous versions by just using the server instance, since there was a single session, but that's not the case anymore, it's impossible to know which of the server's sessions a given tool invocation should send messages to.

[rnett]

@devcrocod are there any updates here? I see server session IDs have been added, but I don't see any way for a tool call handler to know its ID. Are there tests or examples for a tool call sending messages back (e.g. logging or notifications) that i could look at to see that it works? This is core functionality, so I would hope that it works.

[devcrocod]

yeap
We do have plans to include the sessionId in addTool in one of the next releases

[rnett]

Ok good, thanks. It's currently preventing me from updating, so it would be great if it was soon 🙂

[rnett]

Any updates here?

[rnett]

@devcrocod I'm happy to create a PR for this if it would speed things up. I would plan to do it along the lines of #144 (but with sessions, etc) unless I hear otherwise.