Implementation Peer Review

An independent reviewer runtime pressure-tests an implementation diff. This skill runs that cross-LLM review only on explicit user request after an implementation pass; its scope is the diff plus any --context files the user names, decoupled from any task-tracking system. Compozy is the review engine: each round is one compozy exec against a configurable runtime. The findings file the reviewer writes is the sole source of truth — treat compozy exec stdout/stderr and the event log as operational evidence only.

Bundled files

Resolve every scripts/<name> or references/<name> path relative to this SKILL.md's directory (<skill-dir>). All bundled files are read-only — read or run them, never edit them during a round.

Asking the user

When a step tells you to ask the user (which findings to incorporate, whether to run another round), use the runtime's interactive question tool — the one that presents a question and pauses until the user answers (e.g. AskUserQuestion). If the runtime has no such tool, present the question as the complete assistant message and stop; answer it yourself only after the user replies.

Inputs

All inputs are optional. Defaults make the common path impl-peer-review with no arguments.

• --files <p1,p2,...> — scope the review to explicit paths instead of the full branch diff.
• --context <p1,p2,...> — additional context files to feed the reviewer (a spec, ADR, design doc, RFC, README). The skill never assumes any of these exist.
• --base <git-ref> — base ref for the diff. Defaults to main. Use --base HEAD~N for a narrower scope.
• --staged — review staged changes only (git diff --staged) instead of a branch diff.
• --out <dir> — output directory for round artifacts. See Output Directory.
• --verify <cmd> — the verification command (build/tests) used as both the readiness gate and the post-remediation gate. When omitted, auto-detect per references/readiness-checks.md; if none resolves, ask the user.
• --ide <ide> (default claude): reviewer runtime, forwarded to compozy exec --ide. Accepted values mirror compozy exec: codex, claude, cursor-agent, droid, opencode, pi, gemini, copilot. On an invalid value, list the accepted values and ask the user to choose — do not fall back to claude.
• --model <name> (default opus): forwarded to compozy exec --model. Do not pre-validate; let compozy surface incompatibilities (see Step 3 for the stale-model response).
• --reasoning <effort> (default xhigh): forwarded to compozy exec --reasoning-effort. Accepted: low, medium, high, xhigh.

Output Directory

Resolve <out> in this order:

1. --out if provided.
2. Otherwise, if the repo exposes an unambiguous .compozy/tasks/<slug>/ layout for the current work, use that task's qa/ directory: .compozy/tasks/<slug>/qa/.
3. Otherwise, default to .peer-reviews/<UTC-timestamp-YYYYMMDDTHHMMSSZ>/ at the repository root.

Create the directory if it does not exist. Every artifact is versioned with -roundN; never overwrite a prior round — increment to the next round instead.

Findings Artifact

Each round has exactly one authoritative findings file: <out>/impl-review-findings-roundN.md. The reviewer writes that file and no other. If the target path is missing, ambiguous, unwritable, or outside <out>, the reviewer refuses and stops — no stdout fallback.

The findings format — frontmatter, section headings, and per-item fields — is defined in references/impl-review-prompt.md and enforced by scripts/validate-findings.sh.

Procedures

Step 0: Verify Compozy is available

Confirm the compozy binary is on PATH (e.g. command -v compozy). If missing, abort with a one-line message to install Compozy; the cross-LLM independence is the point, so require it rather than falling back to a harness-native subagent. This skill calls compozy exec directly — no --agent install is required.

Step 1: Validate Input and Compute Scope

1. Confirm the user has just completed (or paused) the implementation pass and explicitly asked to review the current state. Do not run review rounds during active editing.
2. Resolve the diff scope:
   • If --files is provided, verify each path exists and limit the diff to those paths.
   • If --staged is provided, use git diff --staged.
   • Otherwise run git diff <base>...HEAD --name-only (default <base> is main) to compute the changed file set. If the diff is empty, abort and tell the user there is nothing to review.
3. Resolve <out> (see Output Directory) and create it if needed.
4. Resolve the verification command (--verify, else auto-detect, else ask the user).
5. STOP. Read references/readiness-checks.md in full before running the review. Verify every readiness marker passes; the markers and their auto-detect order live in that file. If any marker fails, report the failed markers and abort — external review on a broken or incomplete change wastes credit and produces noise.
6. Determine the next review round number by listing existing <out>/impl-review-findings-round*.md and <out>/impl-review-summary-round*.md files. Start at round1 when none exist.

Step 2: Compose the Review Prompt

1. STOP. Read references/impl-review-prompt.md in full before composing the prompt. It is the canonical executable reviewer prompt template; substitute its placeholders verbatim and do not paraphrase it. The assembled prompt must start with the reviewer instructions, not with a Markdown wrapper describing the template.
2. Capture the diff payload:
   • Run git diff <base>...HEAD -- <changed-files> (or git diff --staged -- <changed-files> for --staged) and write the raw patch to <out>/impl-review-diff-roundN.patch.
   • Run git log --oneline <base>...HEAD -- <changed-files> and capture the commit list (empty string if --staged).
3. Define the round artifact paths under <out>/: impl-review-findings-roundN.md, impl-review-events-roundN.jsonl (event log), impl-review-result-roundN.err (stderr), impl-review-status-before-roundN.txt, impl-review-status-after-roundN.txt, and impl-review-validation-error-roundN.md (only when needed).
4. Discover existing project rule files to populate {project_rules}: root-level CLAUDE.md, AGENTS.md, .cursor/rules/*, .cursorrules, CONTRIBUTING.md; nested CLAUDE.md/AGENTS.md in the directories the diff touches; and any project memory/directive docs (e.g. docs/_memory/, standing directives, lessons indexes). Nested and memory rules hold the load-bearing invariants root-only discovery misses.
5. Substitute the placeholders in the prompt template:
   • {scope_summary} — one-paragraph description of what was implemented. Derive from the user's brief, the commit messages, or — if --context was passed — the linked spec/PRD.
   • {context_paths} — newline-separated repo-root paths from --context, or none. When the reviewed diff implements a task from a spec directory (e.g. .compozy/tasks/<slug>/, specs/<name>/, docs/rfcs/<name>/), also include that spec's contract-bearing sibling artifacts here even when the user passed no --context (see Guardrails: Contract parity).
   • {project_rules} — newline-separated discovered rule-file paths, or none.
   • {changed_files} — newline-separated repo-root paths.
   • {diff_path} — repo-root path to the patch file from step 2.
   • {commit_list} — captured git log --oneline output, or none if --staged.
   • {findings_path} — exact absolute path to <out>/impl-review-findings-roundN.md.
   • {round} — numeric review round N.
6. Write the assembled prompt to <out>/impl-review-prompt-roundN.md.

Step 3: Execute the Cross-LLM Review

1. Capture the pre-run status snapshot:

   git status --short > <out>/impl-review-status-before-roundN.txt
   

2. Run (substitute the resolved --ide/--model/--reasoning, defaults claude/opus/xhigh):

   compozy exec --ide <ide> --model <model> --reasoning-effort <reasoning> --format json --prompt-file <out>/impl-review-prompt-roundN.md > <out>/impl-review-events-roundN.jsonl 2> <out>/impl-review-result-roundN.err
   

3. Capture the post-run status snapshot:

   git status --short > <out>/impl-review-status-after-roundN.txt
   

4. If the command exits non-zero, fail loudly — no silent retry. If stderr shows The model 'X' does not exist, the runtime may be set to a stale name: surface the configured model and confirm with the user before rerunning; do not substitute a model yourself.

5. Require the findings target file to exist after the command exits. If missing, the round is invalid even when compozy exec exited 0 — write impl-review-validation-error-roundN.md and ask whether to rerun.

Step 4: Validate and Summarize Findings

1. Run the bundled read-only validator:

   bash <skill-dir>/scripts/validate-findings.sh --kind implementation --round N --path <out>/impl-review-findings-roundN.md
   

2. Manually inspect the findings file and verify the semantic contract:

   • every finding has a real file path/line or an explicit reason it is not applicable;
   • blockers include a rationale tied to project rules or architecture constraints;
   • no TBD, placeholder text, invented paths, or stdout-only findings;
   • when spec contract artifacts were passed in {context_paths}, the findings explicitly assess contract parity field by field (see Guardrails: Contract parity) — a SHIP verdict with no contract-parity assessment is an invalid round;
   • comparing the pre/post status snapshots shows no changes outside the expected review artifact/log paths.

3. If validation fails, write <out>/impl-review-validation-error-roundN.md with the failed checks, command, exit status, and artifact paths. Do not summarize the round as SHIP.

4. Write <out>/impl-review-summary-roundN.md from the validated findings file with: the verdict (SHIP / FIX_BEFORE_SHIP / REWORK); one-line rationale per blocker; the risks list; the nits list; files most likely affected by remediation; and the operational artifact paths.

5. Present a concise user-facing summary: verdict, blocker/risk/nit counts, main themes, and the artifact paths written for the round.

6. Hold all source, test, config, doc, and commit edits until Step 5.

Step 5: User-Directed Remediation

1. Ask the user which findings to incorporate:
   • A) all blockers
   • B) selected blockers/risks/nits
   • C) nothing — keep the review as a record only
   • D) manual edits before any remediation
2. Apply only the findings the user selected.
3. Re-run the resolved verification command after applying any code change. If it fails, fix the new failure or surface it back to the user before declaring remediation done.
4. Record the remediation decision in <out>/impl-review-remediation-roundN.md, listing: incorporated items with the new commit/diff range; deferred items; files changed; and the verification command and outcome with a timestamp.
5. Show the user what changed and what remains deferred. Commit or push only on explicit user instruction.

Step 6: Optional Additional Rounds

1. Ask whether the user wants another peer-review round against the updated code or wants to stop with the current state.
2. Run further rounds only when the user explicitly requests one: re-run from Step 2 against the new diff and create a fresh roundN+1 artifact set in the same <out> directory.

Guardrails

Contract parity. For a spec-workflow diff, engineering quality alone can never earn SHIP. When the diff implements a task from a spec directory (.compozy/tasks/<slug>/, specs/<name>/, docs/rfcs/<name>/), the reviewer must receive that spec's contract-bearing sibling artifacts — canonical example documents, input/schema tables, QA seeds, test contracts, parity maps — and assess the deliverable against them field by field. A round whose {context_paths} omitted those artifacts is invalid; a task-file paraphrase is never a sufficient contract source. Real incident: seven rounds reached SHIP on a deliverable that contradicted the spec's canonical example document because no round ever received it.

Credit once. compozy exec is the only place this skill spends external review credit. Run it once per round; rerun only when the round is explicitly invalid and the user asks for it.