Add custom code-review Claude plugin

Author: codedmonkey

.claude/plugins/code-review/.claude-plugin/plugin.json

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+{
+  "name": "code-review",
+  "description": "Automated code review for pull requests using multiple specialized agents with confidence-based scoring",
+  "version": "1.0.0",
+  "author": {
+    "name": "Boris Cherny",
+    "email": "boris@anthropic.com"
+  }
+}
+

.claude/plugins/code-review/README.md

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+# Code Review Plugin
+
+**Stolen from https://github.com/anthropics/claude-code/tree/db8834ba1d72e9a26fba30ac85f3bc4316bb0689/plugins/code-review**
+
+Automated code review for pull requests using multiple specialized agents with confidence-based scoring to filter false positives.
+
+## Overview
+
+The Code Review Plugin automates pull request review by launching multiple agents in parallel to independently audit changes from different perspectives. It uses confidence scoring to filter out false positives, ensuring only high-quality, actionable feedback is posted.
+
+## Commands
+
+### `/code-review`
+
+Performs automated code review on a pull request using multiple specialized agents.
+
+**What it does:**
+1. Checks if review is needed (skips closed, draft, trivial, or already-reviewed PRs)
+2. Gathers relevant CLAUDE.md guideline files from the repository
+3. Summarizes the pull request changes
+4. Launches 4 parallel agents to independently review:
+   - **Agents #1 & #2**: Audit for CLAUDE.md compliance
+   - **Agent #3**: Scan for obvious bugs in changes
+   - **Agent #4**: Analyze git blame/history for context-based issues
+5. Scores each issue 0-100 for confidence level
+6. Filters out issues below 80 confidence threshold
+7. Outputs review (to terminal by default, or as PR comment with `--comment` flag)
+
+**Usage:**
+```bash
+/code-review [--comment]
+```
+
+**Options:**
+- `--comment`: Post the review as a comment on the pull request (default: outputs to terminal only)
+
+**Example workflow:**
+```bash
+# On a PR branch, run locally (outputs to terminal):
+/code-review
+
+# Post review as PR comment:
+/code-review --comment
+
+# Claude will:
+# - Launch 4 review agents in parallel
+# - Score each issue for confidence
+# - Output issues ≥80 confidence (to terminal or PR depending on flag)
+# - Skip if no high-confidence issues found
+```
+
+**Features:**
+- Multiple independent agents for comprehensive review
+- Confidence-based scoring reduces false positives (threshold: 80)
+- CLAUDE.md compliance checking with explicit guideline verification
+- Bug detection focused on changes (not pre-existing issues)
+- Historical context analysis via git blame
+- Automatic skipping of closed, draft, or already-reviewed PRs
+- Links directly to code with full SHA and line ranges
+
+**Review comment format:**
+```markdown
+## Code review
+
+Found 3 issues:
+
+1. Missing error handling for OAuth callback (CLAUDE.md says "Always handle OAuth errors")
+
+https://github.com/owner/repo/blob/abc123.../src/auth.ts#L67-L72
+
+2. Memory leak: OAuth state not cleaned up (bug due to missing cleanup in finally block)
+
+https://github.com/owner/repo/blob/abc123.../src/auth.ts#L88-L95
+
+3. Inconsistent naming pattern (src/conventions/CLAUDE.md says "Use camelCase for functions")
+
+https://github.com/owner/repo/blob/abc123.../src/utils.ts#L23-L28
+```
+
+**Confidence scoring:**
+- **0**: Not confident, false positive
+- **25**: Somewhat confident, might be real
+- **50**: Moderately confident, real but minor
+- **75**: Highly confident, real and important
+- **100**: Absolutely certain, definitely real
+
+**False positives filtered:**
+- Pre-existing issues not introduced in PR
+- Code that looks like a bug but isn't
+- Pedantic nitpicks
+- Issues linters will catch
+- General quality issues (unless in CLAUDE.md)
+- Issues with lint ignore comments
+
+## Installation
+
+This plugin is included in the Claude Code repository. The command is automatically available when using Claude Code.
+
+## Best Practices
+
+### Using `/code-review`
+- Maintain clear CLAUDE.md files for better compliance checking
+- Trust the 80+ confidence threshold - false positives are filtered
+- Run on all non-trivial pull requests
+- Review agent findings as a starting point for human review
+- Update CLAUDE.md based on recurring review patterns
+
+### When to use
+- All pull requests with meaningful changes
+- PRs touching critical code paths
+- PRs from multiple contributors
+- PRs where guideline compliance matters
+
+### When not to use
+- Closed or draft PRs (automatically skipped anyway)
+- Trivial automated PRs (automatically skipped)
+- Urgent hotfixes requiring immediate merge
+- PRs already reviewed (automatically skipped)
+
+## Workflow Integration
+
+### Standard PR review workflow:
+```bash
+# Create PR with changes
+# Run local review (outputs to terminal)
+/code-review
+
+# Review the automated feedback
+# Make any necessary fixes
+
+# Optionally post as PR comment
+/code-review --comment
+
+# Merge when ready
+```
+
+### As part of CI/CD:
+```bash
+# Trigger on PR creation or update
+# Use --comment flag to post review comments
+/code-review --comment
+# Skip if review already exists
+```
+
+## Requirements
+
+- Git repository with GitHub integration
+- GitHub CLI (`gh`) installed and authenticated
+- CLAUDE.md files (optional but recommended for guideline checking)
+
+## Troubleshooting
+
+### Review takes too long
+
+**Issue**: Agents are slow on large PRs
+
+**Solution**:
+- Normal for large changes - agents run in parallel
+- 4 independent agents ensure thoroughness
+- Consider splitting large PRs into smaller ones
+
+### Too many false positives
+
+**Issue**: Review flags issues that aren't real
+
+**Solution**:
+- Default threshold is 80 (already filters most false positives)
+- Make CLAUDE.md more specific about what matters
+- Consider if the flagged issue is actually valid
+
+### No review comment posted
+
+**Issue**: `/code-review` runs but no comment appears
+
+**Solution**:
+Check if:
+- PR is closed (reviews skipped)
+- PR is draft (reviews skipped)
+- PR is trivial/automated (reviews skipped)
+- PR already has review (reviews skipped)
+- No issues scored ≥80 (no comment needed)
+
+### Link formatting broken
+
+**Issue**: Code links don't render correctly in GitHub
+
+**Solution**:
+Links must follow this exact format:
+```
+https://github.com/owner/repo/blob/[full-sha]/path/file.ext#L[start]-L[end]
+```
+- Must use full SHA (not abbreviated)
+- Must use `#L` notation
+- Must include line range with at least 1 line of context
+
+### GitHub CLI not working
+
+**Issue**: `gh` commands fail
+
+**Solution**:
+- Install GitHub CLI: `brew install gh` (macOS) or see [GitHub CLI installation](https://cli.github.com/)
+- Authenticate: `gh auth login`
+- Verify repository has GitHub remote
+
+## Tips
+
+- **Write specific CLAUDE.md files**: Clear guidelines = better reviews
+- **Include context in PRs**: Helps agents understand intent
+- **Use confidence scores**: Issues ≥80 are usually correct
+- **Iterate on guidelines**: Update CLAUDE.md based on patterns
+- **Review automatically**: Set up as part of PR workflow
+- **Trust the filtering**: Threshold prevents noise
+
+## Configuration
+
+### Adjusting confidence threshold
+
+The default threshold is 80. To adjust, modify the command file at `commands/code-review.md`:
+```markdown
+Filter out any issues with a score less than 80.
+```
+
+Change `80` to your preferred threshold (0-100).
+
+### Customizing review focus
+
+Edit `commands/code-review.md` to add or modify agent tasks:
+- Add security-focused agents
+- Add performance analysis agents
+- Add accessibility checking agents
+- Add documentation quality checks
+
+## Technical Details
+
+### Agent architecture
+- **2x CLAUDE.md compliance agents**: Redundancy for guideline checks
+- **1x bug detector**: Focused on obvious bugs in changes only
+- **1x history analyzer**: Context from git blame and history
+- **Nx confidence scorers**: One per issue for independent scoring
+
+### Scoring system
+- Each issue independently scored 0-100
+- Scoring considers evidence strength and verification
+- Threshold (default 80) filters low-confidence issues
+- For CLAUDE.md issues: verifies guideline explicitly mentions it
+
+### GitHub integration
+Uses `gh` CLI for:
+- Viewing PR details and diffs
+- Fetching repository data
+- Reading git blame and history
+- Posting review comments
+
+## Author
+
+Boris Cherny (boris@anthropic.com)
+
+## Version
+
+1.0.0

.claude/plugins/code-review/commands/code-review.md

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+---
+allowed-tools: Bash(gh issue view:*), Bash(gh search:*), Bash(gh issue list:*), Bash(gh pr comment:*), Bash(gh pr diff:*), Bash(gh pr view:*), Bash(gh pr list:*), mcp__github_inline_comment__create_inline_comment
+description: Code review a pull request
+---
+
+Provide a code review for the given pull request.
+
+**Agent assumptions (applies to all agents and subagents):**
+- All tools are functional and will work without error. Do not test tools or make exploratory calls. Make sure this is clear to every subagent that is launched.
+- Only call a tool if it is required to complete the task. Every tool call should have a clear purpose.
+
+To do this, follow these steps precisely:
+
+1. Launch a haiku agent to check if any of the following are true:
+   - The pull request is closed
+   - The pull request is a draft
+   - The pull request does not need code review (e.g. automated PR, trivial change that is obviously correct)
+   - Claude has already commented on this PR (check `gh pr view <PR> --comments` for comments left by claude)
+
+   If any condition is true, stop and do not proceed.
+
+Note: Still review Claude generated PR's.
+
+2. Launch a haiku agent to return a list of file paths (not their contents) for all relevant CLAUDE.md files including:
+   - The root CLAUDE.md file, if it exists
+   - Any CLAUDE.md files in directories containing files modified by the pull request
+
+3. Launch a sonnet agent to view the pull request and return a summary of the changes
+
+4. Launch 4 agents in parallel to independently review the changes. Each agent should return the list of issues, where each issue includes a description and the reason it was flagged (e.g. "CLAUDE.md adherence", "bug"). The agents should do the following:
+
+   Agents 1 + 2: CLAUDE.md compliance sonnet agents
+   Audit changes for CLAUDE.md compliance in parallel. Note: When evaluating CLAUDE.md compliance for a file, you should only consider CLAUDE.md files that share a file path with the file or parents.
+
+   Agent 3: Opus bug agent (parallel subagent with agent 4)
+   Scan for obvious bugs. Focus only on the diff itself without reading extra context. Flag only significant bugs; ignore nitpicks and likely false positives. Do not flag issues that you cannot validate without looking at context outside of the git diff.
+
+   Agent 4: Opus bug agent (parallel subagent with agent 3)
+   Look for problems that exist in the introduced code. This could be security issues, incorrect logic, etc. Only look for issues that fall within the changed code.
+
+   **CRITICAL: We only want HIGH SIGNAL issues.** Flag issues where:
+   - The code will fail to compile or parse (syntax errors, type errors, missing imports, unresolved references)
+   - The code will definitely produce wrong results regardless of inputs (clear logic errors)
+   - Clear, unambiguous CLAUDE.md violations where you can quote the exact rule being broken
+
+   Do NOT flag:
+   - Code style or quality concerns
+   - Potential issues that depend on specific inputs or state
+   - Subjective suggestions or improvements
+
+   If you are not certain an issue is real, do not flag it. False positives erode trust and waste reviewer time.
+
+   In addition to the above, each subagent should be told the PR title and description. This will help provide context regarding the author's intent.
+
+5. For each issue found in the previous step by agents 3 and 4, launch parallel subagents to validate the issue. These subagents should get the PR title and description along with a description of the issue. The agent's job is to review the issue to validate that the stated issue is truly an issue with high confidence. For example, if an issue such as "variable is not defined" was flagged, the subagent's job would be to validate that is actually true in the code. Another example would be CLAUDE.md issues. The agent should validate that the CLAUDE.md rule that was violated is scoped for this file and is actually violated. Use Opus subagents for bugs and logic issues, and sonnet agents for CLAUDE.md violations.
+
+6. Filter out any issues that were not validated in step 5. This step will give us our list of high signal issues for our review.
+
+7. Output a summary of the review findings to the terminal:
+   - If issues were found, list each issue with a brief description.
+   - If no issues were found, state: "No issues found. Checked for bugs and CLAUDE.md compliance."
+
+   If `--comment` argument was NOT provided, stop here. Do not post any GitHub comments.
+
+   If `--comment` argument IS provided and NO issues were found, post a summary comment using `gh pr comment` and stop.
+
+   If `--comment` argument IS provided and issues were found, continue to step 8.
+
+8. Create a list of all comments that you plan on leaving. This is only for you to make sure you are comfortable with the comments. Do not post this list anywhere.
+
+9. Post inline comments for each issue using `mcp__github_inline_comment__create_inline_comment` with `confirmed: true`. For each comment:
+   - Provide a brief description of the issue
+   - For small, self-contained fixes, include a committable suggestion block
+   - For larger fixes (6+ lines, structural changes, or changes spanning multiple locations), describe the issue and suggested fix without a suggestion block
+   - Never post a committable suggestion UNLESS committing the suggestion fixes the issue entirely. If follow up steps are required, do not leave a committable suggestion.
+
+   **IMPORTANT: Only post ONE comment per unique issue. Do not post duplicate comments.**
+
+Use this list when evaluating issues in Steps 4 and 5 (these are false positives, do NOT flag):
+
+- Pre-existing issues
+- Something that appears to be a bug but is actually correct
+- Pedantic nitpicks that a senior engineer would not flag
+- Issues that a linter will catch (do not run the linter to verify)
+- General code quality concerns (e.g., lack of test coverage, general security issues) unless explicitly required in CLAUDE.md
+- Issues mentioned in CLAUDE.md but explicitly silenced in the code (e.g., via a lint ignore comment)
+
+Notes:
+
+- Use gh CLI to interact with GitHub (e.g., fetch pull requests, create comments). Do not use web fetch.
+- Create a todo list before starting.
+- You must cite and link each issue in inline comments (e.g., if referring to a CLAUDE.md, include a link to it).
+- If no issues are found and `--comment` argument is provided, post a comment with the following format:
+
+---
+
+## Code review
+
+No issues found. Checked for bugs and CLAUDE.md compliance.
+
+---
+
+- When linking to code in inline comments, follow the following format precisely, otherwise the Markdown preview won't render correctly: https://github.com/anthropics/claude-code/blob/c21d3c10bc8e898b7ac1a2d745bdc9bc4e423afe/package.json#L10-L15
+  - Requires full git sha
+  - You must provide the full sha. Commands like `https://github.com/owner/repo/blob/$(git rev-parse HEAD)/foo/bar` will not work, since your comment will be directly rendered in Markdown.
+  - Repo name must match the repo you're code reviewing
+  - # sign after the file name
+  - Line range format is L[start]-L[end]
+  - Provide at least 1 line of context before and after, centered on the line you are commenting about (eg. if you are commenting about lines 5-6, you should link to `L4-7`)