Codex ACP: Allow for Session Management

[Sachin-Bhat]

Currently we are able to open new Codex CLI threads but from what I see, there is no way to return to previous threads once a new thread is open. Was wondering if it would be possible to have session management within Codex ACP.

[williamstein]

There’s an open PR for session persistence (zed-industries/codex-acp#66). I cherry‑picked it, rewired the flags to use Clap, and have that working in a fork I’m experimenting with: https://github.com/sagemathinc/codex-acp/commits/main/.

If anyone’s curious, that fork also:

• surfaces the remaining context size (see Emit token usage metadata in ACP notifications codex-acp#90)
• routes terminal requests through ACP so terminals could live remotely or use PTY mode
• applies patches via ACP’s read_text_file/write_text_file calls, so the client can mediate edits (e.g., for virtual files)

Those changes required a few tweaks to codex-core as well (https://github.com/sagemathinc/codex). I know the upstream project isn’t taking outside PRs right now, so I’m sharing this mostly as an example of what’s needed for deeper ACP integration. Hopefully it’s useful context for anyone exploring similar ideas.