[Server] Prepare server for integrated events

[EdouardCourty]

Hi!

I've been working with Symfony's integration of this SDK through symfony/mcp-bundle.

I think it lacks event support (like a ToolCallErrorEvent, ToolCallResponseEvent, ToolCallRequestEvent... you get the point).

These events would greatly improve observability on the MCP servers, for example to have custom logging or logic triggered by the developers who use the MCP Server.

Of course, I thought about implementing this only on the Symfony bundle's side, but then I thought it could be great for the official SDK to have support for a callback logic when something happens; making it easier for implementations of the SDK to introduce events in their ecosystem (EventDispatcher with Symfony as an example).

Is this something that can we want to do on the SDK's side?

I would be willing to provide an implementation if this issue would be validated.

[chr-hertel]

I'd be up for something like that - I guess it makes sense. It always has the risk of people working around missing feature themselves instead of reporting that issue to us, but still I usually value that kind of flexibility and extension points myself. we have the psr/event-dispatcher also as a dependency around already.

[EdouardCourty]

Alright, thank you for your feedback, I will work on an implementation then :)

Edit: here is the PR
#175