codexrpc — Discord Rich Presence for OpenAI Codex

A live Discord activity banner for OpenAI Codex — both the CLI and the desktop app. Codex exposes no hook system covering both clients, so codex-rpc.exe attaches to a process you pick (by PID) and derives a coarse state from its CPU activity, labeling the banner with the process's window title (what Task Manager shows), tracked live.

Download: grab codex-rpc-win64.zip from Releases — no Python needed. Unzip, keep the EXE next to its _internal folder, double-click.

Sibling project: clauderpc does the same for Claude Code via its hook system.

How it works

• codex-rpc.exe (double-click) — UI: process picker (filter defaults to codex), Attach & start (writes %TEMP%\codex_rpc_target.json atomically and starts the daemon if needed), Detach, Stop daemon, live status card, daemon log tail.
• codex-rpc.exe daemon — owns the Discord RPC connection (default app ID baked in; override with CODEX_DISCORD_APP_ID). Samples the attached process tree every 5 s.

Window titles as labels: the picker shows each process's window title, and the Discord details line tracks it live — rename the window, the banner follows within ~5 s. Console apps like the Codex CLI have no window of their own, so the title is resolved through the process's children and parent chain (i.e. the hosting terminal's title, which Codex/Claude Code set per task). Leading spinner glyphs (⠋, ✳…) are stripped so an animating title doesn't spam presence updates, and title renames don't reset the elapsed timer — only state changes do. Processes with no window anywhere fall back to "Codex CLI"/"Codex" labels.

States (honest process-activity semantics, not Codex internals):

• Attached — just attached, no delta sample yet, or the process denies CPU access (some sandboxed codex processes do)
• Active — process-tree CPU above threshold, 2 consecutive samples to flip
• Idle — below threshold, 2 consecutive samples to flip

Threshold: Codex is network-bound — measured, a live turn peaks around 1.4% of one core and idle is ~0.0% — so the default threshold is 0.5% (CODEX_RPC_CPU_THRESHOLD env var, in percent, to tune).

PID safety: the target file stores PID + exe path + process creation time; a recycled PID is never trusted. If the target exits, presence is cleared. With auto-reattach checked (default), the daemon adopts the newest process with the same exe path when one appears.

Attaching to CLI vs desktop app

• Codex CLI (npm): processes named codex.exe under ...\npm\node_modules\@openai\codex\....
• Codex desktop app (Microsoft Store): processes under the OpenAI.Codex_... WindowsApps package (its Electron processes are named ChatGPT.exe) or agent processes under AppData\Local\OpenAI\Codex\bin\.

Re-attach any time from the UI; the daemon follows within 5 s without restarting.

Setup

1. Create a Discord application at https://discord.com/developers/applications — its name is the banner title (e.g. "Codex"). Upload a 512×512 PNG asset named exactly codex under Rich Presence → Art Assets. Enter the Application ID in the UI's Application ID field and hit Save (stored in %APPDATA%\codex-rpc.json; a running daemon restarts automatically). The CODEX_DISCORD_APP_ID env var overrides the saved value if set.
2. Build (Windows, Python 3.11+):

py -m pip install pypresence psutil pyinstaller
py -m PyInstaller --onedir --noconsole --icon codex-rpc.ico --add-data "codex-rpc.ico;." --name codex-rpc --noconfirm codex_rpc.py

--icon sets the EXE's file icon; --add-data ships the same .ico inside the bundle so the app window and taskbar entry use it too. To regenerate the icon from other artwork: py make_icons.py <source-image> codex-rpc.ico preview.png --tile (the --tile flag puts monochrome art on a white rounded tile — without it, black artwork is invisible on a dark taskbar).

3. Double-click dist\codex-rpc\codex-rpc.exe, pick your Codex process, Attach & start. Tick Start at login to have the daemon come up automatically (a Startup-folder shortcut, no admin rights needed).

Checking your setup

Click "Check my setup" for a read-only diagnostic covering every way this can silently do nothing:

• Application ID present, and whether it came from the env var, your saved value, or the built-in default
• The Discord app exists (a wrong ID reports "Discord doesn't recognise this" instead of failing silently), its name — which is the banner's title line — and whether the codex art asset is actually uploaded, since a missing asset quietly falls back to your app icon and looks fine
• Daemon running and connected to Discord
• A process is attached, still alive, and what state it's in
• Whether clauderpc is also connected, since one Discord client only shows one activity

Only the Discord-app checks need internet; presence itself is entirely local.

Files: %TEMP%\codex_rpc_target.json (attachment), %TEMP%\codex_rpc_daemon.json (heartbeat), %TEMP%\codex_rpc_daemon.log (log).

Showing this and clauderpc at once

One Discord client displays only one local RPC activity — with two daemons on the same client, only one card shows (and which one can flip when a daemon reconnects). Discord merges activities across clients, though: run a second Discord client (PTB/Canary) logged into the same account and each client carries one banner. codex-rpc automatically prefers the second client's IPC pipe (discord-ipc-1) and falls back to the first; pin an exact pipe with CODEX_RPC_PIPE.