## Step 11: Adversarial review (always-on)
Every diff gets adversarial review from both Claude and Codex. LOC is not a proxy for risk — a 5-line auth change can be critical.
**Detect diff size and tool availability:**
```bash
DIFF_BASE=$(git merge-base origin/ HEAD)
DIFF_INS=$(git diff "$DIFF_BASE" --stat | tail -1 | grep -oE '[0-9]+ insertion' | grep -oE '[0-9]+' || echo "0")
DIFF_DEL=$(git diff "$DIFF_BASE" --stat | tail -1 | grep -oE '[0-9]+ deletion' | grep -oE '[0-9]+' || echo "0")
DIFF_TOTAL=$((DIFF_INS + DIFF_DEL))
command -v codex >/dev/null 2>&1 && echo "CODEX_AVAILABLE" || echo "CODEX_NOT_AVAILABLE"
# Legacy opt-out — only gates Codex passes, Claude always runs
OLD_CFG=$(~/.claude/skills/gstack/bin/gstack-config get codex_reviews 2>/dev/null || true)
echo "DIFF_SIZE: $DIFF_TOTAL"
echo "OLD_CFG: ${OLD_CFG:-not_set}"
```
If `OLD_CFG` is `disabled`: skip Codex passes only. Claude adversarial subagent still runs (it's free and fast). Jump to the "Claude adversarial subagent" section.
**User override:** If the user explicitly requested "full review", "structured review", or "P1 gate", also run the Codex structured review regardless of diff size.
---
### Claude adversarial subagent (always runs)
Dispatch via the Agent tool. The subagent has fresh context — no checklist bias from the structured review. This genuine independence catches things the primary reviewer is blind to.
Subagent prompt:
"Read the diff for this branch with `DIFF_BASE=$(git merge-base origin/ HEAD) && git diff "$DIFF_BASE"`. Think like an attacker and a chaos engineer. Your job is to find ways this code will fail in production. Look for: edge cases, race conditions, security holes, resource leaks, failure modes, silent data corruption, logic errors that produce wrong results silently, error handling that swallows failures, and trust boundary violations. Be adversarial. Be thorough. No compliments — just the problems. For each finding, classify as FIXABLE (you know how to fix it) or INVESTIGATE (needs human judgment). After listing findings, end your output with ONE line in the canonical format `Recommendation: because ` — examples: `Recommendation: Fix the unbounded retry at queue.ts:78 because it'll DoS the worker pool under sustained 429s` or `Recommendation: Ship as-is because the strongest finding is a theoretical race that requires conditions we can't trigger in production`. The reason must point to a specific finding (or no-fix rationale). Generic reasons like 'because it's safer' do not qualify."
Present findings under an `ADVERSARIAL REVIEW (Claude subagent):` header. **FIXABLE findings** flow into the same Fix-First pipeline as the structured review. **INVESTIGATE findings** are presented as informational.
If the subagent fails or times out: "Claude adversarial subagent unavailable. Continuing."
---
### Codex adversarial challenge (always runs when available)
If Codex is available AND `OLD_CFG` is NOT `disabled`:
```bash
TMPERR_ADV=$(mktemp /tmp/codex-adv-XXXXXXXX)
_REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
codex exec "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the changes on this branch against the base branch. Run DIFF_BASE=$(git merge-base origin/ HEAD) && git diff "$DIFF_BASE" to see the diff. Your job is to find ways this code will fail in production. Think like an attacker and a chaos engineer. Find edge cases, race conditions, security holes, resource leaks, failure modes, and silent data corruption paths. Be adversarial. Be thorough. No compliments — just the problems. End your output with ONE line in the canonical format `Recommendation: because `. Generic reasons like 'because it's safer' do not qualify; the reason must point to a specific finding or no-fix rationale." -C "$_REPO_ROOT" -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR_ADV"
```
Set the Bash tool's `timeout` parameter to `300000` (5 minutes). Do NOT use the `timeout` shell command — it doesn't exist on macOS. After the command completes, read stderr:
```bash
cat "$TMPERR_ADV"
```
Present the full output verbatim. This is informational — it never blocks shipping.
**Error handling:** All errors are non-blocking — adversarial review is a quality enhancement, not a prerequisite.
- **Auth failure:** If stderr contains "auth", "login", "unauthorized", or "API key": "Codex authentication failed. Run \`codex login\` to authenticate."
- **Timeout:** "Codex timed out after 5 minutes."
- **Empty response:** "Codex returned no response. Stderr: ."
**Cleanup:** Run `rm -f "$TMPERR_ADV"` after processing.
If Codex is NOT available: "Codex CLI not found — running Claude adversarial only. Install Codex for cross-model coverage: `npm install -g @openai/codex`"
---
### Codex structured review (large diffs only, 200+ lines)
If `DIFF_TOTAL >= 200` AND Codex is available AND `OLD_CFG` is NOT `disabled`:
```bash
TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
_REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
cd "$_REPO_ROOT"
codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the changes on this branch against the base branch . Run git diff origin/...HEAD 2>/dev/null || git diff ...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
```
Set the Bash tool's `timeout` parameter to `300000` (5 minutes). Do NOT use the `timeout` shell command — it doesn't exist on macOS. Present output under `CODEX SAYS (code review):` header.
Check for `[P1]` markers: found → `GATE: FAIL`, not found → `GATE: PASS`.
If GATE is FAIL, use AskUserQuestion:
```
Codex found N critical issues in the diff.
A) Investigate and fix now (recommended)
B) Continue — review will still complete
```
If A: address the findings. After fixing, re-run tests (Step 5) since code has changed. Re-run `codex review` to verify.
Read stderr for errors (same error handling as Codex adversarial above).
After stderr: `rm -f "$TMPERR"`
If `DIFF_TOTAL < 200`: skip this section silently. The Claude + Codex adversarial passes provide sufficient coverage for smaller diffs.
---
### Persist the review result
After all passes complete, persist:
```bash
~/.claude/skills/gstack/bin/gstack-review-log '{"skill":"adversarial-review","timestamp":"'"$(date -u +%Y-%m-%dT%H:%M:%SZ)"'","status":"STATUS","source":"SOURCE","tier":"always","gate":"GATE","commit":"'"$(git rev-parse --short HEAD)"'"}'
```
Substitute: STATUS = "clean" if no findings across ALL passes, "issues_found" if any pass found issues. SOURCE = "both" if Codex ran, "claude" if only Claude subagent ran. GATE = the Codex structured review gate result ("pass"/"fail"), "skipped" if diff < 200, or "informational" if Codex was unavailable. If all passes failed, do NOT persist.
---
### Cross-model synthesis
After all passes complete, synthesize findings across all sources:
```
ADVERSARIAL REVIEW SYNTHESIS (always-on, N lines):
════════════════════════════════════════════════════════════
High confidence (found by multiple sources): [findings agreed on by >1 pass]
Unique to Claude structured review: [from earlier step]
Unique to Claude adversarial: [from subagent]
Unique to Codex: [from codex adversarial or code review, if ran]
Models used: Claude structured ✓ Claude adversarial ✓/✗ Codex ✓/✗
════════════════════════════════════════════════════════════
```
High-confidence findings (agreed on by multiple sources) should be prioritized for fixes.
---
## Capture Learnings
If you discovered a non-obvious pattern, pitfall, or architectural insight during
this session, log it for future sessions:
```bash
~/.claude/skills/gstack/bin/gstack-learnings-log '{"skill":"ship","type":"TYPE","key":"SHORT_KEY","insight":"DESCRIPTION","confidence":N,"source":"SOURCE","files":["path/to/relevant/file"]}'
```
**Types:** `pattern` (reusable approach), `pitfall` (what NOT to do), `preference`
(user stated), `architecture` (structural decision), `tool` (library/framework insight),
`operational` (project environment/CLI/workflow knowledge).
**Sources:** `observed` (you found this in the code), `user-stated` (user told you),
`inferred` (AI deduction), `cross-model` (both Claude and Codex agree).
**Confidence:** 1-10. Be honest. An observed pattern you verified in the code is 8-9.
An inference you're not sure about is 4-5. A user preference they explicitly stated is 10.
**files:** Include the specific file paths this learning references. This enables
staleness detection: if those files are later deleted, the learning can be flagged.
**Only log genuine discoveries.** Don't log obvious things. Don't log things the user
already knows. A good test: would this insight save time in a future session? If yes, log it.
### Refresh learnings for the headline feature on this branch
The top-of-skill learnings pull was keyed to "release ship" broadly. Before the VERSION/CHANGELOG step, re-pull learnings keyed to THIS branch's headline feature so any prior version-bump or CHANGELOG pitfalls for similar features surface.
Pick ONE keyword that names the headline feature you're shipping. The keyword should be a noun: the primary skill or module name, the central feature noun, or the binary you changed. The keyword MUST be alphanumeric or hyphen only — no quotes, slashes, dots, colons, or whitespace. If your candidate has any of those, simplify to just the alphanumeric stem.
Worked examples (ship-specific): good keywords are `learnings-search`, `pacing`, `worktree-ship`. Bad: `the branch headline`, `v1.31.1.0`, `feat: token-or search`.
```bash
~/.claude/skills/gstack/bin/gstack-learnings-search --query "" --limit 5 2>/dev/null || true
```
If any learnings come back, name which one applies to the version bump or CHANGELOG framing in one sentence. If none come back, continue without reference — the absence is itself useful information.