Codex Code Review
<!-- Security note: Bash(bash:) is broader than ideal; cannot scope to specific script paths until Claude Code #9354 resolves ${CLAUDE_PLUGIN_ROOT} in command frontmatter. Only invoke bash for project scripts (scripts/). -->
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
Step 0 (PENDING) → Collect changes → [Pre-checks if Full] → Dual Review (Codex + Task) → Await Results → Aggregate → Emit Gate → Loop if Blocked
Step 0: Dual Review Init (Fail-closed)
Execute: bash scripts/emit-review-gate.sh PENDING
This sets review_mode=dual and aggregate_gate.executed=false in state file, ensuring fail-closed semantics — if the process crashes before Step 4.5, stop-guard blocks.
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 1.5: 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):
- Glob
${docs_path}/requests/*.md, sort descending, take latest - Read latest request doc
- Extract
## Acceptance Criteriasection (parse- [ ]/- [x]items) - Filter out quality-gate ACs matching:
/codex-review-fast,/codex-review-doc,/codex-review,/precommit,/precommit-fast,/pr-review - Cap: max 20 ACs (truncate with "... and N more" note)
- Build
SPEC_CHECKLISTvariable, setREQUEST_DOC_PATH
Graceful degradation: resolve-feature fails / no requests / no AC section / parse error → SPEC_CHECKLIST = null (skip silently).
Step 1.6: Deferred Finding Context
Prerequisite: Requires R4 (Nit History Persistence) hook-side write path. Until R4 is deployed, .claude_nit_history.json will not exist and this step is a no-op (graceful degradation).
Read .claude_nit_history.json (if exists):
- Filter
.deferred[]entries wherelast_seen + ttl_days> now - Sanitize each entry before injection (mandatory):
canonical_issue<= 120 chars (truncate)- Strip markdown control chars (
**, backticks,#,>,|) - No raw code snippets; only file:line references
- No secrets/tokens/passwords/API keys (per
rules/security.md) - Reject entries with shell metacharacters (
;,&,|, backtick,$() - Format as
<deferred_context>XML block (max 10 entries) - Store in
DEFERRED_CONTEXTvariable
Inject into all prompt variants after research instructions, before Review Dimensions:
${DEFERRED_CONTEXT ? DEFERRED_CONTEXT : ''}
Format:
<deferred_context>
Previously deferred (do not re-report without new evidence):
- [Nit] src/service.ts | naming convention (deferred 2x)
- [P2] src/utils.ts | error handling pattern (deferred 1x)
</deferred_context>
Graceful degradation: file missing / invalid JSON / no entries / sanitization failure → DEFERRED_CONTEXT = 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: Dual Review (Parallel Dispatch)
Case A: First review (no --continue)
Launch two reviewers in parallel (single message, multiple tool calls):
- Codex MCP (primary): Use
mcp__codex__codexwith 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.
- Secondary reviewer: Use
Tasktool 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:
- Evidence check: what specific code proves it's real? (file:line)
- Context check: did you read enough surrounding code?
- False positive check: could it be intentional design?
- Severity check: could it be more severe than initially assessed?
- 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 P0/P1) or ⛔ Blocked (has P0/P1). ```
Case B: Loop review (has --continue)
- Codex: Use
mcp__codex__codex-replywith re-review template fromreferences/review-common.md - Secondary: Re-dispatch in parallel (same mechanism as first pass, fresh context). Always dispatched in v1 — no skip exception. Cycle resets on any code edit.
Step 3.5: Await Codex + Reconcile Secondary
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 late result has P0/P1, re-open fix→re-review loop | | Failed/timed out | Apply degradation matrix per references/review-common.md § Dual Reviewer Aggregation |
Step 4: Consolidate Output (Dual Mode)
- 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
- Deduplicate using key =
file + canonical_issue_text(ignore line ±5 difference) - Same key → keep highest severity (P0 > P1 > P2 > Nit)
- **T