Beagle: Claude Code's 145-Skill Plugin Marketplace for Building Professional Code Review Workflows

The beagle project on GitHub is a plugin marketplace designed specifically for Claude Code, offering 145 cross-language code review skills covering dimensions like code review, documentation generation, test planning, and architecture analysis. It particularly focuses on AI-generated code detection, helping resolve code smells and compliance issues in AI-assisted programming to improve code quality. The project is maintained by existential-birds and was released on May 26, 2026.

After the popularization of AI-assisted programming, code review has become more critical—AI-generated code tends to introduce "code smells" or patterns that do not comply with team norms. The name Beagle is inspired by Snoopy, the mascot of NASA's Apollo 10 mission, symbolizing accompanying developers to explore codebases and discover potential issues.

Beagle includes 13 plugin packages with a total of 145 skills. The core plugin (beagle-core) provides general skills to form a complete review workflow; language-specific plugins are deeply customized for Python, Go, Rust, etc.; it also supports review for front-end frameworks (React, Remix v2) and AI frameworks. Additionally, it collaborates with tools like Amelia (workflow orchestration) and Daydream (review-fix-test cycle).

Beagle's review-llm-artifacts and verify-llm-artifacts skills can detect "Artifacts" in AI-generated code (such as over-annotation, inconsistent style, unnecessary defensive programming, etc.). Typical scenarios include: pre-commit code review, post-processing of AI-generated code, automatic PR creation, release note generation, architecture decision records, documentation maintenance, etc.

Prerequisites: Claude Code CLI must be installed; agent-browser is optional. Installation steps:

1. Add the plugin marketplace: claude plugin marketplace add https://github.com/existential-birds/beagle
2. Install required plugins (e.g., beagle-core, beagle-python)
3. Verify: Run /beagle-core:commit-push in a Claude Code session Update plugins: claude plugin marketplace update existential-birds && claude plugin update <plugin-name> It can also be installed to other AI Agents via npx skills add existential-birds/beagle, and OpenAI Codex users can link it to a specified directory.

Beagle represents the evolution of AI-assisted development tools from code generation to a complete quality management ecosystem. Its 145 skills cover all aspects of modern development, and the AI-generated code detection in particular reflects mature thinking. For Claude Code users, it can improve review efficiency, help teams establish consistent quality standards, and keep codebases healthy and maintainable.

It is recommended that Claude Code users try the Beagle plugin to improve code review efficiency using its skills; create custom review rules via the skill-builder skill to adapt to different project needs; and combine with collaboration tools to implement more complex automated workflows.