Tools

A complete development methodology for coding agents: brainstorm to clarify requirements, write an implementation plan, then build with subagents, with red-green TDD, systematic debugging and code review throughout. In the official Claude Code and Codex marketplaces.

Anthropic's document skills, the implementation behind Claude's file features: create, edit and analyze Word, Excel, PowerPoint and PDF files, including tracked changes, comments, formulas and form filling. Source-available, not under an open-source license.

Orchestrates subagents in-session to map the architecture, build a threat model and hunt for vulnerabilities. Every finding is independently verified before it goes in the report, which also comes as SARIF, and optional patch files are left for you to apply. Official Anthropic plugin.

A complete harness for coding agents: dozens of subagents, nearly 300 skills, hooks, rules, memory and continuous learning, plus the AgentShield security scanner. Built mainly for Claude Code, with Codex support.

Official Claude Code plugin for the prompts.chat library: search prompts and Agent Skills from your coding assistant, fill in variables and improve prompts with AI. Includes commands, subagents and a remote MCP; saving your own prompts needs an API key.

Toolkit for building Claude Code plugins: 7 skills on plugin structure, hooks, MCP integration, commands, subagents and skill writing, a guided eight-phase create command, and subagents for agent generation, plugin validation and skill review. Maintained by Anthropic.

Learning mode: at key decision points such as business logic or error handling, asks you to write 5-10 lines of code yourself while explaining the trade-offs. Official Anthropic plugin built on a SessionStart hook; uses extra tokens.

Scaffolds a Claude Agent SDK project in Python or TypeScript interactively with /new-sdk-app, then a verifier agent checks dependencies, config and code against official best practices. Maintained by Anthropic.

Recreates the deprecated Explanatory output style with a SessionStart hook: adds Insight notes before and after code that explain implementation trade-offs and codebase conventions. Official Anthropic plugin; uses extra tokens.

UI/UX design knowledge base plugin with searchable UI styles, color palettes, font pairings, charts and guidelines for 20+ tech stacks; generates complete design system recommendations by product type. Needs Python 3 installed locally.

Job search system that runs in your local AI coding CLI: scans job portals, scores roles with a structured A-H evaluation and a 1-5 rating, flags fake listings, tailors ATS resumes and cover letters, and tracks applications. Never submits for you. Needs Node.js.

Multi-agent orchestration framework for Claude Code and Codex, formerly Claude Flow: swarm coordination, self-learning memory and cross-machine federated communication. The marketplace offers 30+ plugins; full features need npx ruflo init.

End-to-end academic paper plugin: deep research and literature review, writing, multi-perspective simulated peer review, revision and finalization, pausing for your approval at each stage, with built-in citation verification and integrity checks. Licensed CC BY-NC.

From Obsidian CEO Steph Ango (kepano): teaches agents to write Obsidian-flavored Markdown, Bases and Canvas files and work with vaults through the Obsidian CLI, plus skills like web page content extraction. Also installable into Codex and other agents via npx skills.

Official Anthropic plugin that solves competition math such as IMO and Putnam problems, with adversarial checks by an independent verifier that only sees the clean proof. Gives up explicitly rather than bluffing when unsure, and outputs LaTeX/PDF once verified.

Three layers of security checks on agent-written code: rule-based warnings on about 25 risky patterns during edits, a model review of the diff at turn end, and an agent tracing cross-file bugs like IDOR and SSRF at commit. Official Anthropic plugin; needs Python 3.8+ and model API access.

Connects Claude Code to the C# language server csharp-ls for code intelligence and diagnostics. Needs .NET SDK 6.0+; install csharp-ls first via dotnet tool or Homebrew. Official Anthropic plugin.

Official Anthropic plugin that reads local session logs in ~/.claude/projects and generates an interactive HTML usage report covering tokens, cache hit rate, subagents, skills and the most expensive prompts, with optimization tips. Needs Node.js.

Connects Claude Code to SourceKit-LSP so the agent can go to definitions, find references and inspect symbols in Swift code. Install the Swift toolchain or Xcode first. Official Anthropic plugin.

Creates or improves Agent Skills from scratch: writes eval cases to test them, runs benchmarks with variance analysis, and tunes descriptions for more accurate triggering. Maintained by Anthropic.

Connects Claude Code to JetBrains' Kotlin language server so the agent can go to definitions, find references and inspect symbols in .kt and .kts files. Install kotlin-lsp first (Homebrew works). Official Anthropic plugin.

Connects Upstash's hosted Context7 remote MCP to fetch current, version-specific docs and code examples for libraries on demand, reducing outdated or invented APIs. No local Node needed; works anonymously, and an API key raises limits. Maintained by Upstash.

Google's official Firebase plugin: starts the Firebase MCP via firebase-tools to manage projects, Firestore data, Auth users and security rules, and view Crashlytics and Cloud Functions logs. Needs Node.js and a Firebase CLI login.

Designs and builds MCP servers: first picks a deployment model among remote HTTP, MCPB bundles and local stdio, then guides tool design, auth and in-chat interactive components. Maintained by Anthropic.