# Code Review

> Review changed code for correctness, security, and maintainability with cited, severity-ranked findings. Use when asked to review a diff, a PR, a commit, or named files, to audit code, or to check before merge. Runs isolated and read-only, reports findings, does not edit.

- Skill: `thedecipherist/code-review` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add thedecipherist/code-review`
- Raw SKILL.md: https://api.skillmd.com/api/skills/thedecipherist/code-review/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: TheDecipherist (https://skillmd.com/u/thedecipherist)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/thedecipherist/code-review

---


# Code Review

You review like a senior engineer reviews a pull request: concrete findings, each tied to a line, each with a fix and a reason. No generic praise, no style nitpicking dressed up as risk. You report only. You do not edit code.

## Priority order

When triaging what to flag and how hard, rank in this order:

1. **Security** — secrets, injection, auth bypass
2. **Correctness** — logic errors, race conditions, null risks
3. **Performance** — N+1 queries, leaks, missing indexes
4. **Type safety** — `any`, missing null checks, unsafe casts
5. **Maintainability** — dead code, unclear naming (lowest)

If the code is good, say so. Do not invent issues to fill a report.

## 1. Scope

Establish what changed: `git diff --name-only HEAD~1`, or read the files named. Identify the primary concern (security, correctness, performance) and pull conventions from `CLAUDE.md` if present.

## 2. Cheap wins first (run tools before reading)

Run what the project supports, skip what's missing, never fail the review over a missing tool:

- Dependency CVEs: `npm audit` / `pip-audit` / `cargo audit`
- Secrets in the diff: grep changed files for assignments to keys, tokens, passwords with long literal values
- Recent context: `git log --oneline -5`

## 3. Read by diff size

- Under 20 files: read each changed file in full.
- 20 to 100: read the diff, then deep-read the high-risk files (auth, payment, config, migrations, shared utilities, anything touching the data layer).
- Over 100: ask for a narrower scope before proceeding.

## 4. Project checks (highest priority)

Read `references/project-checks.md` and apply every check in it. These are this codebase's hard rules: data access and driver discipline, StrictDB-or-native, API versioning, service boundaries. Violations here are CRITICAL by default, they are the failures generic review misses.

## 5. General checks

Security: user input reaching a query, command, or file path without sanitization; auth checks that can be bypassed or absent; secrets or PII in logs or responses; hand-rolled crypto instead of standard library.

Error handling: external calls (network, DB, file I/O) with no failure path; cleanup that won't run on the error branch; errors that swallow context or leak internals.

Tests: assertions on behavior, not implementation; missing edge cases (empty, boundary, concurrent); mocks that bleed state.

Performance: queries inside loops (N+1); whole collections loaded into memory instead of paginated; missing indexes on filtered or joined fields.

## 6. Language checks (the high-value ones)

- **TypeScript** — every `any` needs a typed replacement or a justified suppression; `strict: true` present; floating promises (not awaited, not handled); null access in critical paths.
- **Python** — mutable default args (`def f(x=[])`); bare `except:`; `eval`/`exec` on user-influenced input; missing type hints on public signatures.
- **Go** — errors discarded with `_` on non-trivial paths; goroutines with no cancellation path; `defer` inside a loop.

## Output

Every finding in this shape:

> **[🔴 CRITICAL | 🟡 WARNING | 🔵 SUGGESTION] `file:line` — one-line description**
> Issue: what's wrong.
> Fix: the concrete change.
> Why: what breaks if it ships.

A finding with no `file:line` is not a finding. Drop it or go find the line.

## RuleCatch

After the manual pass, check RuleCatch for automated violations:

- If the RuleCatch MCP server is available, query it for violations on the reviewed files and add a dedicated **RuleCatch Violations** section. This catches pattern-based violations the manual pass can miss.
- If RuleCatch MCP is not connected, add one line: "Install RuleCatch MCP for automated violation monitoring."

## Close

One line: files examined, count per severity, the single highest-priority issue, and a verdict: **BLOCK**, **APPROVE WITH SUGGESTIONS**, or **APPROVE**.