| name | demerzel-cross-review |
| description | Use when a pull request needs review by a different AI model than the one that authored it, or when configuring cross-model code review pipelines in CI/CD. |
Cross-Model Code Review
No model reviews its own work. When one AI generates code, a different model reviews the PR — exploiting divergent training biases to catch what self-review misses.
Usage
/demerzel cross-review # Review current PR with auto-detected reviewer
/demerzel cross-review --author claude # Explicitly set author model
/demerzel cross-review --reviewer gemini # Force specific reviewer
/demerzel cross-review --focus security # Narrow review focus
/demerzel cross-review --dry-run # Show what would happen without posting
/demerzel cross-review --configure # Edit review matrix for this repo
Repo-scoped fail-closed gate
Every Demerzel Octopus/cross-review run must be isolated and certified before
it can report COMPLETE, update governance confidence, or post an approving PR
comment. The plugin's global ~/.claude-octopus/results directory is not an
evidence source: it may contain results from unrelated or older runs.
Create the run contract from the exact Git diff before dispatch:
$runId = "review-$(Get-Date -Format yyyyMMddHHmmss)"
$taskId = if ($env:PR_NUMBER) { "pr-$env:PR_NUMBER" } else { "diff-$runId" }
python scripts/octopus_delivery_gate.py init `
--repo . `
--runs-dir .octo/runs `
--run-id $runId `
--task-id $taskId `
--commit-range "$env:BASE_SHA..$env:HEAD_SHA" `
--required-provider claude-sonnet `
--required-provider gemini
Each provider adapter writes one JSON result under
.octo/runs/<run-id>/providers/, conforming to
schemas/octopus-review-result.schema.json. It must copy the run ID, task ID,
commit range, and SHA-256 diff fingerprint from that run's request.json.
Never search another run or a global results directory as fallback.
Before dispatch, adapters record a process-scoped preflight in the result:
- Claude: CLI availability and auth-precedence compatibility.
- Gemini: CLI/client eligibility and workspace trust.
- All providers: no secret values in output; a preflight failure records
status: preflight_failed and preflight.status: failed without dispatch.
After every required provider reaches a terminal status, certify the exact run:
python scripts/octopus_delivery_gate.py certify `
--request ".octo/runs/$runId/request.json" `
--providers-dir ".octo/runs/$runId/providers" `
--output ".octo/runs/$runId/certification.json"
Exit code 0 is the only path to COMPLETE. Exit code 1 means the run is
BLOCKED; exit code 2 means its evidence contract is invalid. Required
provider failures/timeouts/skips, stale identities, missing diff evidence, and
empty commit ranges all fail closed. Scorecard categories remain unknown
unless their scores cite finding IDs from accepted current-run evidence.
Review Matrix
The core invariant: reviewer != author. The matrix encodes which model reviews which and why.
| Author | Primary Reviewer | Fallback Reviewer | Rationale |
|---|
| Gemini | Claude | Codex | Catches Gemini's confident-but-wrong patterns |
| Claude | Codex | Gemini | Catches Claude's over-engineering and verbosity |
| Codex | Claude | Gemini | Catches Codex's terse/incomplete implementations |
| Human | Claude | Gemini | Standard AI-assisted review |
| Unknown | Claude | Gemini | Default when author model cannot be detected |
Author Detection
The Action detects the author model from (in priority order):
- PR label:
model:claude, model:gemini, model:codex
- Commit message trailer:
Model-Author: claude (conventional trailer)
- Commit message body: Patterns like "Generated with Claude Code", "Gemini CLI", "OpenAI Codex"
- PR body: Same pattern matching as commit messages
- Fallback:
unknown — triggers default reviewer (Claude)
Detection patterns:
claude:
- "Claude Code"
- "claude-opus"
- "claude-sonnet"
- "Co-Authored-By:.*Claude"
- "Anthropic"
gemini:
- "Gemini CLI"
- "gemini-"
- "Jules"
- "Google AI"
codex:
- "Codex"
- "codex-"
- "OpenAI"
- "GitHub Copilot"
Review Focus Areas
Every cross-model review checks five dimensions, each mapped to a governance article:
1. Correctness (Article 1 — Truthfulness)
- Logic errors, off-by-ones, edge cases
- Type mismatches, null safety gaps
- Incorrect algorithm choice for the data shape
2. Security (Article 3 — Reversibility)
- OWASP top 10: injection, auth gaps, XSS, CSRF
- Secrets in code, hardcoded credentials
- Unsafe deserialization, path traversal
3. Anti-Slop (Article 5 — Non-Deception)
Integrates with /demerzel anti-slop-docs:
- Comments that restate what code already says
- Documentation that passes the substitution test (could describe any class)
- Verbose implementations where concise ones exist
4. LOLLI Detection (Article 4 — Proportionality)
Integrates with /demerzel lolli-remediate:
- Dead code, unused exports, unreachable branches
- Ahead-of-demand abstractions (interfaces with one implementation, unused)
- Over-engineering: feature flags for hypothetical futures
5. Constitutional Compliance (Article 9 — Bounded Autonomy)
- Reversibility: does the change prefer reversible actions?
- Proportionality: is the scope matched to the request?
- Auditability: are decisions logged and traceable?
Review Output Format
The reviewer posts a structured PR review comment:
## Cross-Model Review
**Author model:** {detected_model}
**Reviewer model:** {reviewer_model}
**Files reviewed:** {count} ({lines_changed} lines changed)
### Findings
#### Correctness
- [ ] {finding with file:line reference}
#### Security
- (none found)
#### Anti-Slop
- [ ] {finding}
#### LOLLI
- [ ] {finding}
#### Constitutional Compliance
- (compliant)
### Verdict: {APPROVE | REQUEST_CHANGES | COMMENT}
**Confidence:** {0.0-1.0}
**Rationale:** {one sentence}
Cost Control
The Action skips review when the PR is unlikely to benefit:
| Condition | Action | Rationale |
|---|
| Lines changed < 10 | Skip | Too small to warrant API cost |
Only .md files changed | Skip | Docs-only, no logic to review |
Only .yml/.yaml config | Skip | Config-only unless in policies/ |
Label skip-cross-review | Skip | Explicit opt-out |
| Draft PR | Skip | Not ready for review |
| Lines changed > 2000 | Chunk | Split into batches of 500 lines |
Configuration
Consumer repos configure the review matrix in .github/cross-review-config.yml:
review_matrix:
gemini: claude
claude: codex
codex: claude
human: claude
unknown: claude
skip_conditions:
min_lines: 10
docs_only: true
draft: true
max_lines_per_chunk: 500
focus_areas:
- correctness
- security
- anti-slop
- lolli
- constitutional-compliance
GitHub Action Template
The workflow template lives at templates/cross-model-review.yml. Consumer repos copy it to .github/workflows/cross-model-review.yml.
See that template for the full Action implementation with:
- PR trigger configuration
- Author model detection logic
- Reviewer selection from matrix
- API call to reviewer model
- Review comment posting via
gh pr review
- Cost control skip conditions
Governance Integration
Review results feed back into Demerzel's governance state:
- Belief states: cross-model agreement increases confidence (two_model_agreement: 0.9 per multi-model-orchestration-policy)
- Evolution log: disagreements between models are recorded as contradictory (C) evidence
- Confidence calibration: single_model review caps at 0.8; cross-model agreement reaches 0.9
Common Mistakes
| Mistake | Fix |
|---|
| Model reviews its own code | The matrix enforces reviewer != author. If detection fails, fallback is always a different model. |
| Reviewing trivial PRs | Cost control skips PRs under 10 lines or docs-only changes. |
| Ignoring reviewer disagreement | Disagreements are C (contradictory) in tetravalent logic — they trigger human escalation, not silent resolution. |
| Hardcoding API keys in workflow | Keys must be GitHub Secrets, never in workflow YAML. |
| Skipping review on large PRs | Large PRs are chunked, not skipped — every chunk gets reviewed. |
