[Chat] Question about conversation history support in Symfony AI

[EfrosIonelu]

Hello,

I would like to ask whether Symfony AI currently provides built-in support for conversation history or persistent memory, similar to how LangChain/LangGraph implements memory graphs (for example: https://docs.langchain.com/oss/javascript/langgraph/memory
).

More specifically:

Is there any recommended way in Symfony AI to maintain conversational state across multiple user messages?

Is there support for memory persistence (e.g., storing previous messages, tool invocations, or intermediate steps)?

If not yet implemented, is this feature planned on the roadmap, or is there any recommended design pattern to achieve this behavior using the current Symfony AI components?

I am evaluating how best to implement stateful conversations in a Symfony-based application, and any guidance or examples would be greatly appreciated.

Thank you!

[lochmueller]

Hey @EfrosIonelu

structure: In general, there is the Chat Component, that handle the MessageBag of single conversations. There is a central interface https://github.com/symfony/ai/blob/main/src/chat/src/MessageStoreInterface.php that control the internal message store of one conversation. That means, it should be possible to create a unique marker and store multiple conversions on long terms (handled like the identifier in https://github.com/symfony/ai/blob/main/src/chat/src/Bridge/Local/InMemoryStore.php ) and store it in a database.

idea: If you implement such a PersitedMessageStore-Thing it is very individual. From my point of view, I would develop the Store-Integration by myself to handle all edge-cases of the env/project/app around the integration....

Regards,
Tim

[Guikingone]

Hi @EfrosIonelu 👋🏻

As said by @lochmueller, Chat is the main entrypoint, you can use stores that implements MessageStoreInterface and ManagedStoreInterface, the capability of storing multiple conversations in a single store is something that we've discussed for some months in #254, the "latest implementation" is under work in #821, this PR would allows to store and switch between multiple conversations without defining X stores (which is required for now).

Regarding the storage, everything that travel through messages (tools calls, images, videos and so on) is stored by default in stores thanks to MessageNormalizer.

[Guikingone]

Keep in mind that Langgraph (like Letta / Mem0 and more) is differentiating long and short term messages, for now, SfAI is not separating them in dedicated stores, if you want something that is not persisted, you can use the InMemoryStore, if you're using another message store, it's what we call "long term storage".

Regarding the storage approaches, you can mix them using a DelayedMessageStore (or something similar to "sleeping agents" in Letta), what I mean by that is that you can implement your own message store that receive both the InMemoryStore and a "persisted one" and implement a loop that trigger the persistence once a specific threshold is crossed, it's not supported "out of the box" by SfAI (feel free to submit a PR if you want to discuss about it).

Same approach goes for graph-based memories, for now, SfAI is not supporting them as it requires extra work from LLMs or local labelling (which is a real pain).