codex-code-review

name	codex-code-review
description	Code review using Codex MCP. Use when: PR review, code audit, second opinion on changes. Not for: doc review (use doc-review), security audit (use security-review). Output: severity-grouped findings + merge gate.
allowed-tools	mcp__codex__codex, mcp__codex__codex-reply, Bash(git:*), Bash(yarn:*), Bash(npm:*), Bash(bash:*), Bash(node:*), Read, Grep, Glob, Task

Codex Code Review

Trigger

• Keywords: review, PR, code review, second opinion, audit, check

When NOT to Use

• Document review (use doc-review)
• Security-specific review (use security-review)
• Test coverage review (use test-review)
• Just want to understand code (use code-explore)

Variants

Variant	Command	Scope	Pre-checks
Fast	/codex-review-fast	Diff only	None
Full	/codex-review	Diff + local checks	lint:fix + build
Branch	/codex-review-branch	Full branch	None

Shared Workflow

Collect changes → [Pre-checks if Full] → Codex Review → Gate → Loop if Blocked

Dual dispatch adds a second reviewer, and is opt-in:

--dual:  … → Codex + Task in parallel → Merge findings in conversation → Gate → Loop if Blocked

Step 0: Reviewer Mode

Default: Codex alone. Do not launch a secondary reviewer. One reviewer, one verdict, noted in Step 4.5 — there is no mode field, no aggregate plane and no state machine behind this choice: which reviewers ran is a fact of the conversation, not of a store (hook-lightweighting § 3.3).

--dual (Branch variant only): adds a second reviewer in parallel, and the merge is yours to perform in conversation (Step 4). A second opinion for releases, security-sensitive changes and public API surfaces — nothing persists it, nothing blocks on it, and the next invocation starts single again unless the flag is passed again.

Variant	--dual accepted?
Fast (/codex-review-fast)	No — single only
Full (/codex-review)	No — single only
Branch (/codex-review-branch)	Yes, off unless passed

See @rules/auto-loop.md § Review Dispatch for why single is the default.

Step 1: Collect Change Metadata

Collect metadata only — Codex reads the actual diffs and file contents itself via sandbox access.

Variant	Collection Method
Fast	CHANGED_FILES: git diff --name-only HEAD + DIFF_STAT: git diff --stat HEAD
Full	Same as Fast
Branch	Same + CURRENT_BRANCH + BASE_BRANCH + COMMIT_COUNT

Codex independently reads full diffs and file contents via git diff HEAD -- <file> + cat (per research instructions).

Step 1.1: Resolve the tier (required before dispatch)

The gate is tier-derived, and the reviewer has to be told which severities block — otherwise it emits ✅ Ready / ⛔ Blocked against its own assumption, and that is the verdict you note in Step 4.5. Resolve the tier first, then bind TIER and BLOCKING into the prompt:

Tier	BLOCKING	Source
fast	P0	auto-loop-project.md ## Tier
standard (default)	P0/P1	unset, unrecognized, or explicit
thorough	P0/P1/P2	explicit, or the Branch variant, or a security / data-integrity change

The Branch variant is thorough by definition, so BLOCKING = P0/P1/P2 there regardless of project config — a P2 blocks a branch review. Escalation for a security or data-integrity change applies to every variant, and you say that you escalated.

Step 1.5: Feature Context & AC Detection (Spec-Driven Review)

Execute: bash scripts/resolve-feature.sh → parse JSON output.

Field	Use
has_requests	Gate: only proceed if true
docs_path	Glob for request docs
confidence	Require >= medium

If has_requests=true AND confidence in (high, medium):

1. Glob ${docs_path}/requests/*.md, sort descending, take latest
2. Read latest request doc
3. Extract ## Acceptance Criteria section (parse - [ ] / - [x] items)
4. Filter out quality-gate ACs matching: /codex-review-fast, /codex-review-doc, /codex-review, /precommit, /precommit-fast, /pr-review
5. Cap: max 20 ACs (truncate with "... and N more" note)
6. Build SPEC_CHECKLIST variable, set REQUEST_DOC_PATH

Graceful degradation: resolve-feature fails / no requests / no AC section / parse error → SPEC_CHECKLIST = null (skip silently).

Step 2: Pre-checks (Full variant only)

{LINT_FIX_COMMAND}
{BUILD_COMMAND}

These placeholders are resolved from the host project's CLAUDE.md or package.json scripts. Record results as LOCAL_CHECKS.

Step 3: Dispatch

Case A: First review (no --continue)

Dispatch Codex. Launch the secondary reviewer only when --dual was passed:

1. Codex MCP (primary): Use mcp__codex__codex with variant-specific prompt:

   Variant	Prompt Template
   Fast	references/codex-prompt-fast.md
   Full	references/codex-prompt-full.md
   Branch	references/codex-prompt-branch.md

   Config: sandbox: 'read-only', approval-policy: 'never'

   Save the returned threadId.

2. Secondary reviewer — --dual only, skip entirely otherwise: Use Task tool with reviewer selection cascade:

   Priority	Reviewer	subagent_type	Condition
   1	pr-review-toolkit:code-reviewer	pr-review-toolkit:code-reviewer	Default choice
   2	strict-reviewer	strict-reviewer	Priority 1 fails/times out
   3	Codex-only (degraded)	—	Both unavailable

   Selection: Try priority 1 first. If Task fails or times out (30s), try priority 2. If both unavailable, fall back to Codex-only (degraded mode — proceed with Codex results only, apply degradation matrix from references/review-common.md).

   Task prompt (provide changed file list + diff stats, request P0/P1/P2/Nit findings in standard output format):

   Review the code changes for correctness, security, performance, and maintainability issues.
   
   ## Changed Files
   <git diff --name-only output>
   
   ## Diff Stats
   <git diff --stat output>
   
   Read the actual diffs and file contents yourself to perform the review.
   
   Before reporting findings, independently verify each one:
   1. Evidence check: what specific code proves it's real? (file:line)
   2. Context check: did you read enough surrounding code?
   3. False positive check: could it be intentional design?
   4. Severity check: could it be more severe than initially assessed?
   5. Gap check: what related issues might you have overlooked?
   Only report findings that survive all 5 checks.
   
   Output findings in this format:
   - [P0/P1/P2/Nit] file:line issue description → fix recommendation
   
   Group by severity. Include a final gate: ✅ Ready (no finding at or above ${BLOCKING})
   or ⛔ Blocked (has one).
   

Case B: Loop review (has --continue)

• Codex: Use mcp__codex__codex-reply with re-review template from references/review-common.md
• Secondary (--dual only): re-dispatch in parallel, fresh context. Cycle resets on any code edit.

Step 3.5: Await Results

Single reviewer (default dispatch): await Codex. Its verdict is the gate for this dispatch. Go to Step 4.

If Codex itself is unavailable there is nothing to degrade to — the one reviewer is the gate. Emit ⛔ Blocked + ⚠️ Need Human and stop; do not silently substitute a subagent, because that would swap the reviewer the gate was defined against without the user having asked for it.

--dual: Codex is the blocking reviewer — await its result for the initial gate. Secondary runs in background (run_in_background: true) and is non-blocking:

Secondary Status	Action
Completed before Codex	Include in aggregation (Step 4)
Completed after Codex, before precommit	Reconcile at pre-precommit checkpoint
Still running at precommit	Proceed with Codex gate (authoritative); if the late result has a finding at or above ${BLOCKING}, re-open fix→re-review loop
Failed/timed out	Apply degradation matrix per references/review-common.md § Dual Reviewer Aggregation

Step 4: Consolidate Output

Single reviewer (default dispatch): Codex's findings are the output as-is. Sort P0 → P1 → P2 → Nit. Gate: any finding at or above the tier's blocking severity → BLOCKED, else READY (see references/review-common.md § Merge Gate; standard is the default and blocks on P0/P1). The [source: ...] tag is omitted — there is only one source.

--dual:

1. Normalize both sets of findings to unified format: [severity] file:line description → fix

   • Codex findings: already in standard format
   • toolkit findings: apply Severity Mapping (see references/review-common.md § Severity Mapping)
   • strict-reviewer findings: already use P0/P1/P2/Nit

2. Deduplicate using key = file + canonical_issue_text (ignore line ±5 difference)

   • Same key → keep highest severity (P0 > P1 > P2 > Nit)

3. Tag source: source = codex | toolkit | both

4. Sort: P0 → P1 → P2 → Nit

5. Gate decision: any finding at or above the tier's blocking severity → BLOCKED; else → READY

Output format includes source tag:

- [P0] file:line issue → fix [source: both]
- [P1] file:line issue → fix [source: codex]

Step 4.5: Output the gate and note the verdict

Output the standard gate sentinel:

• ✅ Ready — if READY (nothing at or above the tier's blocking severity)
• ⛔ Blocked — if BLOCKED

Then self-note the verdict — this is the declared-provenance record the reminder hooks read (hook-lightweighting § 3.2), and it is behaviour-layer: an attestation the conversation can audit, not a gate anything blocks on. Installed copy first:

CHECKER=".claude/scripts/review-state.js"; [ -f "$CHECKER" ] || CHECKER="scripts/review-state.js"
node "$CHECKER" note code_review pass   # on ✅ Ready
node "$CHECKER" note code_review fail   # on ⛔ Blocked — increments the rounds count

Note after every round's verdict, not only the terminal one: a fail note is what keeps the rounds fact honest across the fix → re-review loop, and a pass note resets it. The note binds to the current tree digest, so any later edit re-opens the plane by construction — there is no verdict to clear. A failed or unavailable note never fails the review: the checks are the job, the note is a courtesy for the reminders, and the missing-note cost is one redundant reminder line.

Shared Definitions

See references/review-common.md for:

• Severity levels (P0/P1/P2/Nit)
• Review dimensions
• Merge gate definitions
• Re-review prompt template
• Gate sentinels (behaviour-layer prose contracts)
• Dual Reviewer Aggregation (severity mapping, deduplication, degradation matrix, source attribution)

Review Loop

⚠️ @CLAUDE.md auto-loop: fix → re-review → ... → ✅ PASS ⚠️

Blocked → fix the blocking findings → /codex-review-fast --continue <threadId> → repeat until Ready. Ready with only sub-threshold findings → log and proceed to /precommit. No extra fix pass, no extra re-review — see @rules/auto-loop.md § Sub-Threshold Findings for what counts as sub-threshold at each tier.

Round cap comes from the tier — the table in @rules/auto-loop.md § Tiers owns the numbers, and restating them here is what let them drift last time. The cap is the backstop, not the stall detector: a stall (@rules/auto-loop.md § Stall Detection — three consecutive rounds that close nothing, counted by the model from the review reports) normally shows first. Same issue recurring at the cap → report blocker, request intervention.

This loop converges on the review result. Reaching Ready ends it — a stale reminder line from a hook is not a finding, and no further round addresses it; the Step 4.5 note is what retires the reminder.

Loop Behavior

Reviewer	Loop Behavior
Codex MCP	Stateful → mcp__codex__codex-reply(threadId) continues context
Secondary (--dual only)	Re-dispatched every iteration, fresh context

Any code edit resets the review cycle — the reviewer must re-run.

Pre-precommit Checkpoint (--dual only)

Before triggering /precommit, reconcile any pending secondary result:

Condition	Action
Task completed + has a finding at or above ${BLOCKING}	Re-emit BLOCKED → fix → re-review (Codex --continue + Secondary fresh)
Task completed + nothing at or above ${BLOCKING}	Union aggregate → proceed to precommit
Task still running	Proceed with Codex gate (authoritative); if the late result has a finding at or above ${BLOCKING}, re-open fix→re-review loop. Branch review is always thorough, so a late P2 counts

Verification

• Each issue tagged with severity (P0/P1/P2/Nit)
• Gate is clear (✅ Ready / ⛔ Blocked)
• Issues include: file:line, description, fix suggestion
• Codex performed independent project research
• Branch variant: dimension rating table included

References

• Shared definitions: references/review-common.md
• Fast prompt: references/codex-prompt-fast.md
• Full prompt: references/codex-prompt-full.md
• Branch prompt: references/codex-prompt-branch.md
• Research instructions: references/codex-research-instructions.md

Examples

Input: /codex-review-fast
Action: git diff → Codex → findings + Gate

Input: /codex-review --focus "auth"
Action: lint:fix → build → git diff → Codex (focus: auth) → findings + Gate

Input: /codex-review-branch origin/develop
Action: branch diff + history → Codex → Rating table + Findings + Gate

Input: /codex-review-branch origin/develop --dual
Action: branch diff + history → Codex + Task parallel → merge findings → Rating table + Findings + Gate → note verdict

Input: /codex-review-fast (Codex unavailable)
Action: ⛔ Blocked + ⚠️ Need Human — the single reviewer is the whole gate, so there is nothing to degrade to