Extending Google ADK: Building a Custom Session Service with Firestore

[mohan-ganesh]

Initially i opened this #497 (comment) thinking that i was in the right place for discussion but i was not..

Problem:

Google’s Java ADK (v0.3.0) is a powerful framework for building AI agents, but its default session services fall short when it comes to production readiness. While InMemorySessionService works for demos and local testing, it doesn’t persist state across restarts or scale across multiple instances. Meanwhile, VertexAiSessionService introduces unnecessary complexity, requiring an undocumented “Reasoning Engine.”

as i have started to use Java ADK 0.3.0 and production grade i had to write the custom session store service and since we were already with Google Eco System i did choose to go with Firestore as the choice for storing the session details, then suggestion was made would you like to contribute this to Java ADK.

This change does introduce one decent dependency for the Java ADK - Firestore

First i wanted get a feedback on would this depenanacy be reasonable to introduce for Java ADK.

This seems like major decision prior we can get to the details of looking in to the details of FirestoreSessionService

https://medium.com/google-cloud/extending-google-adk-building-a-custom-session-service-with-firestore-0fc4b74354bf

any thoughts?

[glaforge]

Regarding dependencies: ADK already has quite a few, so this is a good concern to have, thanks for raising it.
I can't make that call myself, but one approach could be to have a dedicated module (maybe in the contrib folder), to keep this integration as optional and without forcing users to have extra dependencies.
And should we have, say, a memory service backed by Firestore as well, it could live alongside this integration as well.

[mohan-ganesh]

Hi @glaforge

Just wanted to give you an update on this. Following your excellent suggestion which helped to promote the changes, I've moved all the Firestore integration work into a new, dedicated module: contrib/firestore-session-service.

This new module now includes:

A FirestoreSessionService for session management.
A FirestoreMemoryService that lives alongside it, just as you proposed.
I've also completed a full refactoring based on all the review feedback. The pull request (#578) now contains a single, clean commit and includes:

A full migration of the test suite from JUnit 4 to JUnit 5.
A significant increase in test coverage to over 80% for the module.
Fixes for resource leaks, performance optimizations for session deletion, and improved type safety.
The PR is now up-to-date with the main branch and ready for a final review. Thanks again for your guidance on this!

[glaforge]

Very nice!
I'm travelling this week, so won't have time in the next few days to look into it.
But I'll also ping the team to have a look too.

[mohan-ganesh]

thanks @glaforge , will look forward forward to the review.

[mohan-ganesh]

the changes are incorporated as a part of the contrib lib now. thanks again for your assistance with this @glaforge

[glaforge]

I'm super happy this is now integrated!
Thanks a lot for this awesome contribution!