Summary

On Linux, the Codex CLI agent toolbelt never appears when running codex inside a Warp terminal. The root cause is that codex is a Node.js shebang script (#!/usr/bin/env node), so the OS process name (/proc/PID/comm) is always node, not codex. Warp's agent detection matches against comm/argv[0], which resolves to node for any Node.js script — so the toolbelt is never triggered.

Problem

Warp detects CLI agents by observing the foreground process name in the terminal session. On Linux, /proc/PID/comm is initialised from the basename of the executable (i.e. node), not from argv[0] or the symlink name used to invoke the script. Because codex is installed as:

/usr/local/bin/codex -> ../lib/node_modules/@openai/codex/bin/codex.js

...and codex.js has the shebang #!/usr/bin/env node, the foreground process that Warp observes is:

• /proc/PID/comm = node
• argv[0] = node
• argv[1] = /usr/local/bin/codex

Warp never sees a process named codex, so the toolbelt does not activate. The issue does not reproduce on macOS where process naming for shebang scripts behaves differently.

Additionally, codex.js does not call process.title = 'codex' anywhere in its source, which is the Node.js mechanism that calls prctl(PR_SET_NAME, ...) on Linux and would update /proc/PID/comm to codex at runtime.

Expected behavior

The Codex agent toolbelt should appear at the bottom of the Warp pane when codex is launched inside a Warp terminal on Linux, matching the behaviour on macOS.

Actual behavior

The toolbelt never appears. All other settings are correctly configured:

• agents.third_party.should_render_cli_agent_toolbar = true
• agents.third_party.cli_agent_toolbar_enabled_commands.codex = "Codex"
• TERM_PROGRAM=WarpTerminal, WARP_CLI_AGENT_PROTOCOL_VERSION=1 are set in the shell environment
• Warp shell integration marker (SourcedRcFileForWarp) is present in ~/.bashrc

Reproduction steps

1. Install Warp Preview on Ubuntu Linux (apt, x86_64).
2. Install Codex CLI via npm install -g @openai/codex.
3. Open a new Warp terminal window.
4. Run codex in the foreground.
5. Observe that no agent toolbelt appears at the bottom of the pane.

To confirm the process name issue independently:

# Create a shebang script and symlink, identical to how codex is installed
TMPSCRIPT=$(mktemp /tmp/codex_sim_XXXXXX.js)
printf '#!/usr/bin/env node\nsetTimeout(()=>{}, 5000);\n' > "$TMPSCRIPT"
chmod +x "$TMPSCRIPT"
TMPSYM=$(mktemp -u /tmp/codex_XXXXXX)
ln -s "$TMPSCRIPT" "$TMPSYM"
"$TMPSYM" &
SIM_PID=$!
sleep 0.3
cat /proc/$SIM_PID/comm   # prints: node
tr '\0' ' ' < /proc/$SIM_PID/cmdline  # prints: node /tmp/codex_...
kill $SIM_PID

Artifacts

None attached.

Warp version

0.2026.04.27.15.33.preview.02 (Warp Preview, installed via apt from releases.warp.dev/linux/deb preview/main)

Operating system

Ubuntu Linux, kernel 7.0.0-14-generic, x86_64. Wayland (GNOME Shell). Node.js shebang scripts present this process-naming behaviour on all Linux distributions.

Possible source references

• Agent detection logic likely reads /proc/PID/comm or argv[0] to identify the foreground process. Extending the match to also check argv[1] (the script path) when argv[0] is node (or another JS/Python runtime) would cover this case.
• The cli_agent_toolbar_enabled_commands setting in settings.toml maps codex = "Codex", suggesting the detection key is the literal string codex — which will never match /proc/PID/comm for a Node.js script on Linux.
• Workaround: adding process.title = 'codex' to /usr/local/lib/node_modules/@openai/codex/bin/codex.js causes Node.js to call prctl(PR_SET_NAME, 'codex') on Linux, updating /proc/PID/comm to codex and unblocking detection. The correct fix is either in Warp's detection logic or upstream in the Codex CLI package.