Our review

Understand a GitHub repository by analyzing its PR history, architecture, and evolution patterns.

Strengths

Provides a quick overview of repository stats and top contributors
Identifies high-signal PRs (most discussed, architectural, well-documented)
Enables deep dive into a specific PR with review summary and key changes
Reveals evolution of a specific code area through path filtering

Limitations

Requires GitHub CLI (gh) and proper authentication
Only considers merged PRs, ignoring branches or unmerged work
Theme categorization based on PR titles may be inaccurate

When to use it

Use this skill to quickly grok a repository's structure, contributors, and architectural decisions when onboarding or evaluating it.

When not to use it

Avoid using it for repositories with very limited PR history or when you need real-time analysis unrelated to PRs.

Examples

Repository overview

Analyze the repository facebook/react and give me an overview including stats, most active directories, top contributors, and recent activity themes.

List recent PRs

Show me the last 20 merged PRs in tensorflow/tensorflow as a table with number, title, author, files changed, comments, and merge date.

Find notable PRs

Find the most educational PRs in vercel/next.js by focusing on those with high comment counts, affecting many directories, or having long descriptions.

name: codebase description: "Understand a GitHub repository by analyzing its PR history, architecture, and evolution patterns." argument-hint: "<owner/repo> [prs|notable|<pr-number>|area:<path>]" allowed-tools: Bash, Read

Codebase

Understand a GitHub repository through its PR history and structure.

Arguments

Parse $ARGUMENTS to determine the command:

<owner/repo> alone → overview
<owner/repo> prs → list PRs
<owner/repo> notable → find high-signal PRs
<owner/repo> <number> → deep dive into PR
<owner/repo> area:<path> → PRs touching a path

Commands

Overview (default)

When only <owner/repo> is provided:

Fetch repo info:

gh repo view <repo> --json description,primaryLanguage,stargazerCount,forkCount

Fetch last 30 merged PRs:

gh pr list -R <repo> --state merged --limit 30 --json number,title,author,files,mergedAt

Analyze and report:
- Repository description and stats
- Most active directories (count file changes by directory)
- Top contributors (count PRs by author)
- Recent activity themes (categorize PR titles)

List PRs

When prs is specified:

gh pr list -R <repo> --state merged --limit 20 --json number,title,author,files,comments,mergedAt

Format as a table:

#     Title                              Author      Files  Comments  Merged
1234  Add user authentication            @alice      12     8         2d ago
1233  Fix memory leak in parser          @bob        3      2         3d ago

Notable PRs

When notable is specified:

gh pr list -R <repo> --state merged --limit 50 --json number,title,author,files,comments,body,mergedAt

Filter and rank by:

Comment count (most discussed)
Files touching 5+ directories (architectural)
Body length > 500 chars (well-documented)

Output the top 10 most educational PRs with brief explanations of why they're notable.

PR Deep Dive

When a PR number is specified:

gh pr view <number> -R <repo> --json title,body,author,files,comments,reviews,mergedAt

Extract and present:

Title and author
Problem: First paragraph of body (usually explains the why)
Key files: List files changed, grouped by directory
Discussion: Summarize review comments, focus on substantive feedback
Outcome: What was decided, any follow-up items mentioned

If the description is minimal, also fetch the diff to understand changes:

gh pr diff <number> -R <repo>

Area Focus

When area:<path> is specified:

gh pr list -R <repo> --state merged --limit 50 --json number,title,author,files,mergedAt

Filter PRs where any file path contains <path>. Show:

PRs that touched that area
When they were merged
What changed

This reveals the evolution of a specific part of the codebase.

Output Guidelines

Use tables for lists of PRs
Use headers to separate sections
Include PR numbers as #1234 for easy reference
For deep dives, quote notable review comments
Keep summaries concise but informative

GitHub Repository Analysis

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