Support @Tool/@P annotations from Lanchain4J

[jkschneider]

I think it could be nice if you supported the @Tool/@P annotations from Langchain4J in addition to @Tool/@ToolArg from Quarkus.

I had a codebase already that had many tools defined using the Langchain4J annotations and I could almost take those classes wholesale and plugin them into MCP server except for the annotation type changes.

Thanks!

[mkouba]

I'm not quite sure it's a good idea. First of all, we don't want to introduce a dependency on langchain4J. But more importantly, those annotations have different semantics, i.e. the annotated methods have different requirements, execution model, etc.

@geoand WDYT?

[geoand]

What if those annotations were extracted from LangChain4j into some API jar? Then we could avoid coupling to anything implementation specific to LangChain4j.

[mkouba]

What if those annotations were extracted from LangChain4j into some API jar? Then we could avoid coupling to anything implementation specific to LangChain4j.

Well, we could but I'm still not sure it would help significantly.

I could almost take those classes wholesale and plugin them into MCP server

The "almost" is important here. It could work for simple cases but I don't think you could just share the classes with an existing LangChain4j app.

Maybe we could write some annotation tranfromer like we do for Spring annotations for example?

BTW @P is a terrible name if you ask me ;-).

[geoand]

BTW @p is a terrible name if you ask me ;-).

I couldn't agree more.

[jkschneider]

First of all, we don't want to introduce a dependency on langchain4J

Sorry, I may have miscommunicated the intent. I'm not suggesting introducing a required dependency on langchain4J, but if one is present, simply be able to pick up these tools. There is no difference in the annotations other than the names.

[geoand]

That is an interesting idea and given how Quarkus works, that should be easy to do.

[geoand]

WDYT @mkouba ?