Best practice about loading a session

[thezzisu]

Feedback on ACP Session Loading: Metadata Persistence and State Semantics

Hi everyone,

While implementing session loading as per the ACP Protocol Spec, I’ve encountered a few challenges regarding how agents handle the session/load RPC response. I’d love to get your thoughts on the following:

1. Missing Session Metadata in Responses

According to the spec, the agent can respond with result: null. However, I've noticed some ACP Agents fail to echo back the mode, model, and configOptions during the load process.

• The Problem: This behavior forces the client to persist all session options to a local disk just to ensure the UI can allow users to update these options after session/load.
• The Concern: Relying on client-side storage for this violates the "Single Source of Truth" principle. In my view, the Agent should be the authority on the current session state.

2. Inconsistent Config Options

I've observed some strange behavior in codex-acp 0.10.0 and codex-cli 0.117.0. When loading a session, the returned configurable options seem inconsistent with the expected session state.

• The Problem: It appears the implementation might be using merge semantics instead of replace semantics.
• The Expectation: According to the protocol, session/load should fully synchronize the state. Using merge leads to stale or orphaned configuration options.

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Questions for the Community:

1. Have you encountered similar issues where agents don't return full session metadata?
2. What is your preferred workaround? Do you stick to client-side persistence, or is there a more "ACP-native" approach?
3. Regarding the second issue—do you agree that session/load should strictly follow replace semantics?

Looking forward to your insights and seeing how others are handling these edge cases!

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transcript_session_new.json
transcript_session_load.json

JSONND Transcript files for issue 2

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Update: After upgraded codex to 0.117.0 issue 2 seems to be fixed. But still, I think there is improvement space for the session/load spec.

[WeekendSuperhero]

@thezzisu I totally have during the session if it is a session that was originally used through my app i use my app as the source of truth if it is a session i'm replaying that was not from my app I just inget all of the events, I figure all of the events with the exception of usage which I don't want two of are mostly harmless and I"m sure I'll have enough data to figure out how to de-dup them.