Message history not passed to ACP adapters on chat restoration

[gsalbuquerque-orb]

Hello, @ravitemer

Hope you're fine. I have to say I admire your work on this plugin and would like to open an issue regarding ACP adapter. This bug happens when retrieving the chat messages from a previous conversation, the chat doesn't 'remember' what have been discussed so far, since codecompanion.nvim filters messages marked as sent (_meta.sent == true). Thus the plugin isn't able to actually resume conversations.

The bug, however, doesn't seem to lie in codecompanion-history.nvim itself, which seems to handle correctly messages all the way to CodeCompanion.ACPAdapter.form_messages function. This function, by its turn, filters messages that the agent hasn't seen before.

I'd like to know if you're aware of this problem and if there's any work to prevent this or override default ACP Adapter behavior. I'd like to share some thoughts though, as this would either require changing codecompanion.nvim behavior (or API) or some workaround from our side (perhaps setting _meta.sent = false before sending it to form_messages?).

Thank you by the awesome work! Cheers and best regards =)

You may want to see this: https://github.com/olimorris/codecompanion.nvim/blob/3559fffb1410f86314fa1ed401c99e14b95482a7/lua/codecompanion/adapters/acp/helpers.lua#L17

[alexghergh]

I think the agent sessions are saved by the CLI tool (e.g. codex cli / zed's codex-acp saves agent sessions in ~/.codex/sessions). It's just about restoring the proper session_id in the initialization phase (e.g. see ACP init protocol overview, session/load). I think that's a better way to restore sessions compared to resending all the messages again, which creates a "new session".

Actually, code companion saves the session id in the acp/init.lua file, and checks if it exists in order to restore a session. However, code companion history (this plugin) doesn't correctly set this session_id, as it doesn't save it at all (it saves the actual chat history and other model / adapter settings). It makes sense that the plugin was built as an LLM history plugin first, but the approach doesn't work with ACP agents.

Edit: Just a quick test, modifying the session_id manually in code companion from a past conversation (i.e. ACP agent conversation in code companion, completely closed neovim and the CLI tool, and then reopened) correctly restores the agent's memory. It doesn't restore the past chat turns information, though, but you could use code companion history to actually see past messages.