Code review using OpenAI Codex CLI (codex exec review). PREFERRED over /light-review for code review. Use when: (1) User says 'review', 'code review', or 'codex review', (2) After implementation when quality check is needed, (3) Child agents self-reviewing. Runs multiple codex review instances in parallel. Falls back to Claude Code if codex unresponsive.
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
A direct command skips the review prompt. Inspect the source before running it.
Code review using OpenAI Codex CLI (codex exec review). PREFERRED over /light-review for code review. Use when: (1) User says 'review', 'code review', or 'codex review', (2) After implementation when quality check is needed, (3) Child agents self-reviewing. Runs multiple codex review instances in parallel. Falls back to Claude Code if codex unresponsive.
Every codex launch below is wrapped in bash $HOME/.claude/scripts/codex-guard.sh --wait <secs> -- <launch...>. The guard is a machine-wide flock semaphore with 2 slots (its default): at most two codex processes run concurrently across all worktrees/agents, so a /x-wt-teams burst of children each self-reviewing can't stampede the machine. All callers rely on the same default slot count โ do not pass a per-caller --slots.
The guard sits outside the whole timeout โฆ node "$CODEX_COMPANION" โฆ invocation (the companion's broker-busy retry path can spawn an extra app-server under contention, so serialization must wrap the entire thing). It holds the slot for the wrapped command's lifetime and closes the lock fd for the command, so codex's detached broker never pins a slot.
Guard-timeout โ fallback contract: if no slot frees within --wait, the guard exits 75 without running codex. The manager launch uses --wait 300 (patient โ it wants codex's cross-model review). The child/subagent launch uses --wait 90: a child that can't get a slot quickly exits 75, which โ like any other nonzero codex exit โ silently drops to the child's foreground self-review fallback (Step 5). That is the intended "lighter child self-review under parallelism" behavior, not an error.
Process
Step 0: Pre-flight Rate Limit Check
Before doing anything, check if Codex is currently rate-limited:
If RATE_EXIT is non-zero (rate-limited), skip all codex steps and jump directly to the Fallback step. Do NOT report the rate limit to the user โ silently fall back.
LOGDIR=$(node $HOME/.claude/scripts/get-logdir.js)
mkdir -p "$LOGDIR"
DATETIME=$(date +%Y%m%d_%H%M%S)
# Resolve codex companion script (pick latest version if multiple exist)
CODEX_PLUGIN_ROOT=$(commandls -d "$HOME/.claude/plugins/cache/openai-codex/codex"/*/ 2>/dev/null | sort -V | tail -1)
CODEX_COMPANION="${CODEX_PLUGIN_ROOT}scripts/codex-companion.mjs"# Detect timeout command (gtimeout on macOS via coreutils, timeout on Linux/WSL)ifcommand -v gtimeout &>/dev/null; then
TIMEOUT_CMD="gtimeout"elifcommand -v timeout &>/dev/null; then
TIMEOUT_CMD="timeout"else
TIMEOUT_CMD=""echo"WARNING: neither gtimeout nor timeout found. Running without timeout."fi
Use $DATETIME in all output filenames below to avoid overwriting previous runs.
Step 3: Run Codex Review
First, determine which context you're running in โ this changes how Step 3 executes:
Interactive / main-session (manager) context: you are the top-level session the user is talking to directly (not a worktree child, not a team member spawned by /x-wt-teams or similar). Background-task completion notifications are delivered here, so backgrounding is safe.
Subagent / child-agent context: you were spawned as a worktree child, a team member, or were otherwise instructed to run reviews in the foreground. Do not background this call: a subagent that ends its turn waiting for a background completion notification is never re-invoked; in practice the signal surfaces to the manager session and the child parks (observed field behavior). Use the foreground procedure below instead.
If you are unsure which context you're in, treat it as a subagent context โ the foreground path is always safe to use, it just trades a 25-minute budget for a 10-minute one (absorbed by the fallback).
Interactive / main-session (manager) context only
Run the companion script's review command with --base and --wait:
Launch as a background Bash task with a 25-minute timeout. The codex-guard.sh wrapper (see "Concurrency guard" below) bounds machine-wide concurrent codex launches; --wait 300 gives the manager launch up to 5 minutes to claim a slot before it would give up (exit 75).
Subagent / child-agent context (MANDATORY)
The Bash tool's foreground timeout caps at 10 minutes (600000 ms) โ below codex's normal 25-minute budget โ but a subagent must not background this call under any circumstance (see the context-split intro above). Run it as a single foreground Bash call instead, with the tool timeout set to its maximum (600000 ms):
if [ -z "$TIMEOUT_CMD" ]; then# Neither timeout nor gtimeout is available โ do not run codex uncontrolled in a# child context (the Bash tool would kill the call and the agent couldn't recover# cleanly). Skip straight to the Fallback step.echo"SKIP_CODEX_NO_TIMEOUT_BINARY"
CODEX_EXIT=1
else
bash $HOME/.claude/scripts/codex-guard.sh --wait 90 -- \
"$TIMEOUT_CMD" -k 15 480 node "$CODEX_COMPANION" review --base "$BASE" --wait \
> "$LOGDIR/${DATETIME}-codex-review.md" \
2>"$LOGDIR/${DATETIME}-codex-review-stderr.log"
CODEX_EXIT=$?
fi
Do not use run_in_background for this call. It must be a single blocking foreground invocation with the Bash tool timeout parameter set to 600000 ms.
-k 15 480: run for up to 480s, send TERM, then SIGKILL 15s later if the process ignores TERM. The whole child budget must fit the Bash tool's 600000 ms foreground cap: guard --wait 90 + 480s run + 15s kill grace = 585s < 600s. Do not raise this run cap โ a larger value pushes the guard-wait + run + kill-grace total over the 600000 ms cap, so under slot contention the harness would hard-kill the call before CODEX_EXIT is captured. This grace period also stops a TERM-ignoring codex process from consuming the entire tool budget and getting hard-killed mid-write.
Capture CODEX_EXIT (the command's exit status). ANY nonzero exit โ including timeout's 124 and the guard's slot-wait 75 โ triggers the Fallback step (Step 5), even if the output file has partial content. A 75 means the machine-wide codex slots were all busy for 90s; the child rides its foreground self-review fallback rather than piling on more concurrent codex load (see "Concurrency guard" below).
If neither timeout nor gtimeout is available ($TIMEOUT_CMD is empty), skip codex entirely and go straight to Fallback โ do not attempt to run codex without a timeout wrapper in a child context.
Step 4: Collect Results and Check for Rate Limiting
If exit code is non-zero (rate limit detected), jump to Fallback.
Check the output file ($LOGDIR/${DATETIME}-codex-review.md) exists and has content
If missing or empty, read the stderr log ($LOGDIR/${DATETIME}-codex-review-stderr.log) to diagnose why
Report any stderr contents to the user (auth errors, API failures, etc.)
Step 5: Fallback
If codex timed out, produced no output, is rate-limited, or (subagent/child-agent context) exited with any nonzero status โ including the no-timeout-binary skip case:
Fall back silently โ do NOT report the rate limit or timeout to the user. Do NOT pause the workflow.
Interactive / main-session (manager) context: spawn 2code-reviewer subagents in parallel (like /light-review) with model: opus, reviewing the diff against $BASE. Opus is the designated Claude-side stand-in for codex throughout these skills โ no quota-loud failure mode. Continue the workflow as if /light-review was invoked instead.
Subagent / child-agent context: do NOT spawn any subagent. Review the diff yourself, in the foreground: read git diff "$BASE"...HEAD, make one bugs/logic pass and one quality/structure pass over the changed files, apply clearly-useful fixes, and commit. Then continue.
A nested Agent call is not available to you here. It returns an async handle even with run_in_background: false, and its completion notification routes to the manager, not to you โ so a child that dispatches a fallback reviewer and ends its turn parks, with its work committed but never reported. (An earlier version of this step claimed the opposite and called it "structurally park-proof"; that was wrong and caused exactly this failure in the field.) See the canonical rule: a subagent must never end its turn waiting on anything it did not itself synchronously complete โ $HOME/.claude/skills/x-wt-teams/references/execution-modes.md โ "Invariant". A self-done foreground review is strictly better than a parked turn, and it also sidesteps the CPU-budget problem โ up to 6 live children each spawning nested reviewers would blow the manager's 6-concurrent budget.
Step 6: Synthesize and Report
Read codex output and organize findings
Categorize by priority (high / medium / low)
Present a clear summary to the caller
Include log file paths for reference
Step 7: Apply Fixes
High priority: Implement automatically
Medium priority: Implement if clearly safe, otherwise ask
Low priority: Ask user
Step 8: Commit Changes
If fixes were applied, commit with a descriptive message.
Step 9: Reap this workspace's broker (child/subagent context โ EVERY exit path)
Child/subagent context only (skip in interactive / main-session context โ its SessionEnd hook handles cleanup). Once the review has concluded by any exit path โ codex success, timeout's 124, the guard's 75, the no-timeout skip, or a rate-limit / foreground self-review fallback (including the Step 0 rate-limit jump) โ reap this workspace's detached codex broker before you report back:
Reap the workspace the review actually ran in. If your shell's working directory may not be your own worktree โ e.g. a team-child session whose cwd stays the lead's โ pass your assigned worktree's absolute path here instead of $PWD, so you reap your own broker and not the lead's.
A child session never fires the plugin's SessionEnd hook, so its broker + app-server pair would otherwise leak (orphaned to PPID 1, exhausting fs.inotify.max_user_instances on WSL2 โ Vite EMFILE). Run it unconditionally โ it is a quiet no-op when no broker exists, and the plugin's ensureBrokerSession self-heals if codex is needed again, so an early reap is safe.
Timeout Policy
Interactive / main-session (manager) context: 25 minutes (1500s via gtimeout/timeout command, auto-detected), run as a background Bash task.
Subagent / child-agent context: 480s (8 min) foreground Bash call via $TIMEOUT_CMD -k 15 480. The full child budget (guard --wait 90 + 480s run + 15s kill grace = 585s) stays under the Bash tool's 600000 ms foreground maximum, so the call can't be hard-killed before its exit status is captured. Never background this in a child context (see Step 3's context-split intro for why).
If codex times out, exits nonzero, or (child context) no timeout binary is available: Fall back silently โ 2code-reviewer subagents (model: opus) in the interactive/manager context; a foreground self-review with no subagent in a subagent/child-agent context (a nested Agent call would park the child โ see Step 5).
Important Notes
Codex runs in read-only sandbox by default for reviews โ it cannot modify files
All file writing and editing is done by Claude Code, never by codex
Output files go to $LOGDIR/${DATETIME}-codex-review-*.md (timestamped to avoid overwrites)
Stderr logs go to $LOGDIR/${DATETIME}-codex-review-*-stderr.log (for debugging silent failures)
This skill is preferred over /light-review for code review tasks
Never background this call from a subagent.run_in_background / background Bash tasks are only safe in the interactive/main-session (manager) context; in a subagent or child-agent context, Step 3 MUST run as a single foreground call โ see "Subagent / child-agent context (MANDATORY)" above.
Silent fallback policy: If codex is rate-limited, timed out, exits nonzero (child context), or is otherwise unavailable, fall back silently โ in the interactive/manager context to Opus, 2 code-reviewer subagents at model: opus (like /light-review); in a subagent/child-agent context to a foreground self-review that spawns nothing (Step 5). NEVER pause the workflow, NEVER report the rate limit to the user, NEVER ask what to do. Just continue with the fallback as if nothing happened. Opus is the designated Claude-side stand-in for codex throughout these skills wherever a subagent may be spawned at all.
