Structured architecture analysis and strategic planning: extract decisions from conversations, write ADRs, audit agent codebases against 12-factor methodology, pressure-test concepts with PRFAQ, resolve spec gaps, and generate TDD implementation plans from finalized specs.
Use when you need to mine a conversation, session transcript, or design discussion for architectural decisions before writing ADRs. Identifies problem-solution pairs, trade-off debates, technology choices, and explicit "[ADR]" tags. Triggers on "what decisions did we make", "extract decisions from this chat", "find the choices in our discussion", or "summarize architectural decisions". Also useful after long planning sessions to capture decisions that were made implicitly. Does NOT write ADR documents — use adr-writing or write-adr for that.
Use when writing or formatting an ADR document using the MADR template, applying Definition of Done (E.C.A.D.R.) criteria, or verifying ADR completeness. Triggers on "write the ADR", "format as MADR", "check ADR quality", "mark gaps in ADR". Also triggers when a decision has been extracted and needs to become a document. Does NOT extract decisions from conversations (use adr-decision-extraction) or orchestrate the full extract-confirm-write workflow (use write-adr).
Use when auditing an agent codebase against the 12-Factor Agents methodology, reviewing LLM-powered system architecture, or assessing agentic app compliance. Triggers on "analyze agent architecture", "12-factor audit", "how compliant is this agent", or "evaluate this LLM app". Also applies when comparing frameworks or planning agent improvements. Not for quick checklists — this performs deep per-factor codebase analysis with file-level evidence.
Use when the user wants a cited, structured read of local documents and project knowledge. Triggers on: "analyze these docs", "scan my project for context", "read the docs folder", "summarize what's in .beagle/concepts/", "extract context from docs/", "what's in this folder", "go read everything in X and tell me what's there". Also invoked programmatically by other beagle skills (prfaq-beagle Ignition, brainstorm-beagle reference points, strategy-interview context grounding) via the companion contract. Does NOT trigger on codebase lookups ("find this function", "search the repo"), web research (use web-research), LLM-as-judge evaluation (use llm-judge), or document editing (use humanize-beagle). Produces a written scan plan, parallel-subagent findings, and a cited synthesis report on disk — never inline prose, never unsourced claims.
Use when the user has a fuzzy idea and wants to shape it into a concrete project spec before planning or building. Triggers on: "brainstorm this", "I have an idea for...", "help me think through this project", "what should I build", "spec this out". Also catches vague feature descriptions needing structured questioning to clarify scope. Does NOT write code, plan implementation, review strategy docs, or run strategy interviews — produces a WHAT/WHY spec through dialogue, not a HOW plan.
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Image: NASA, Public Domain. Source
Beagle is a Claude Code plugin marketplace with 145 skills across code review, documentation, testing, architectural analysis, and git workflows. Use it to review before you push, detect AI-generated artifacts, draft and improve docs, generate test plans, and analyze codebases — across Python, Go, Rust, Elixir, React, Remix v2, iOS/Swift, and AI frameworks.
Used with Amelia for agent-based workflows and Daydream for automated review-fix-test loops.
Prerequisites:
run-test-plan skill (optional)# Add the marketplace
claude plugin marketplace add https://github.com/existential-birds/beagle
# Install the plugins you need
claude plugin install beagle-core@existential-birds
claude plugin install beagle-python@existential-birds
claude plugin install beagle-react@existential-birds
Verify installation by opening a new Claude Code session and running /beagle-core:commit-push — if the skill loads, the plugin is active.
To update:
claude plugin marketplace update existential-birds && claude plugin update <plugin-name>
Troubleshooting:
~/.claude/plugins/known_marketplaces.json and restart Claude Code.claude plugin marketplace update existential-birds to refresh the marketplace.Use the skills CLI to install beagle skills for other AI agents:
npx skills add existential-birds/beagle
This downloads the skills and configures them for your agent.
Codex users: Link each plugin into ~/.agents/skills/ — see .codex/INSTALL.md for setup instructions.
| Plugin | Skills | Category |
|---|---|---|
| beagle-core | 20 | Shared workflows, verification, git |
| beagle-python | 7 | Python, FastAPI, SQLAlchemy, pytest |
| beagle-go | 13 | Go, BubbleTea, Wish SSH, Prometheus |
| beagle-elixir | 11 | Elixir, Phoenix, LiveView, ExUnit, ExDoc |
| beagle-ios | 16 | Swift, SwiftUI, SwiftData, iOS frameworks |
| beagle-react | 16 | React, React Flow, shadcn/ui, Tailwind |
| beagle-remix-v2 | 12 | Remix v2 route modules, loaders/actions, forms, sessions |
| beagle-rust | 12 | Rust, tokio, axum, sqlx, serde |
| beagle-ai | 13 | Pydantic AI, LangGraph, DeepAgents |
| beagle-docs | 10 | Documentation quality, AI writing detection (Diataxis) |
| beagle-analysis | 13 | Brainstorming, ADRs, strategy, LLM-as-judge, spec gap resolution, TDD plan writing |
| beagle-testing | 2 | Test plan generation and execution |
| Total | 145 | — |
These are the canonical skill entry points for Beagle.
| Skill | Description |
|---|---|
review-plan <path> | Review implementation plans |
review-llm-artifacts | Detect LLM coding artifacts |
verify-llm-artifacts | Confirm or reject review findings before deletes |
fix-llm-artifacts | Fix detected artifacts |
commit-push | Commit and push changes |
create-pr | Create PR with template |
gen-release-notes <tag> | Generate release notes |
receive-feedback <path> | Process review feedback |
fetch-pr-feedback | Fetch bot comments from PR |
respond-pr-feedback | Reply to bot comments |
subagent-prompt | Hand off the current session as an orchestrator-plus-subagents prompt for a fresh session |
skill-builder | Create new skills |
prompt-improver | Optimize prompts |
| Skill | Plugin | Description |
|---|---|---|
review-python | beagle-python | Python/FastAPI code review |
review-frontend | beagle-react | React/TypeScript code review |
review-go | beagle-go | Go code review |
review-tui | beagle-go | BubbleTea TUI code review |
review-ios | beagle-ios | iOS/SwiftUI code review |
review-elixir | beagle-elixir | Elixir/Phoenix code review |
review-rust | beagle-rust | Rust/tokio/axum code review |
review-remix-v2 | beagle-remix-v2 | Remix v2 code review (loaders, actions, forms, sessions) |
npx claudepluginhub existential-birds/beagle --plugin beagle-analysisRust code review and development skills covering ownership, lifetimes, error handling, async/tokio, serde, sqlx, axum, macros, FFI, unsafe, concurrency, and testing patterns.
React, React Flow, React Router, shadcn/ui, Tailwind v4, Vitest, and Zustand code review. Pairs with beagle-core for full workflow.
Python, FastAPI, SQLAlchemy, PostgreSQL, and pytest code review. Pairs with beagle-core for full workflow.
Pydantic AI, LangGraph, DeepAgents, and Vercel AI SDK skills for building and reviewing AI applications.
Swift, SwiftUI, SwiftData, iOS animation design/implementation/review, and framework code review (HealthKit, CloudKit, WidgetKit, watchOS, App Intents). Pairs with beagle-core for full workflow.
Architecture Deep Research — scan a repo, draft a PRD, run live deep research, get a cited handoff. Use when picking a topology, retrieval architecture, event bus, storage engine, auth pattern, or any system-design decision before code lands.
Verification-first engineering toolkit for Claude Code. 15 skills across a 5-phase spine (Investigate → Design → Implement → Verify → Ship), 8 specialist agents, an interactive setup wizard. Every skill has rationalizations + evidence requirements. Built for senior ICs and tech leads.
Pydantic AI, LangGraph, DeepAgents, and Vercel AI SDK skills for building and reviewing AI applications.
19 software engineering skills from Code Complete, APOSD, GoF, and Clean Architecture. Skills are internal (slash-invocable; injected via Read() — not auto-triggered). Research → plan → build workflow with Gate-field adaptive gates (Full | Standard | Minimal) and per-phase orchestrated commits.
[Beta] 6つの専門エージェントチームでコードベースのアーキテクチャを多角的に分析するスキル
Make your AI agent code with your project's architecture, rules, and decisions.