Anvil

Language-aware, role-aware skill system for Claude Code and OpenCode — hybrid CLI and plugin.

Important

Anvil is archived. It is complete and no longer developed. Its successor is Aegis: the same curated skill, agent, and template system rebuilt plugin-first, so hosts load it natively with no CLI, no build step, and no separate install. Start there.

Status: v0.18.0, final release. Skill system, layered model-and-effort routing, hook runtime, orchestration agents, and OpenCode plugin parity all shipped.

What it does

Anvil ships a complete skill system (79 universal skills + 54 language skills across 19 stacks) with intelligent skill selection, layered model-and-effort routing, 30 lifecycle hooks, and 18 orchestration agents. One source of truth, materialized to both Claude Code (.claude-plugin/) and OpenCode (.opencode/). (Canonical counts: anvil doctor --catalog.)

Installation

Prerequisites

Anvil requires Bun (preferred) or Node ≥ 20.

# Install Bun
curl -fsSL https://bun.sh/install | bash

Clone and install

git clone https://github.com/hyprtuna/anvil.git
cd anvil
bun install && bun run build

Run the installer from your project directory

# Default: user-scope Claude Code + OpenCode (no CLI on PATH)
./install.sh

# All four targets (cc-user, cc-project, oc-user, oc-project)
./install.sh --all

# Also put `anvil` on PATH at ~/.local/bin/anvil
./install.sh --cli

Uninstall

./uninstall.sh --all --purge

Verify

# If you used --cli:
anvil doctor

# Without --cli:
node ~/.anvil/bin/install.cjs doctor

What's included

• 79 universal skills — planning, development, test-driven-development, code-review, debugging, git-workflow, ultra-worker, orchestration, and more
• 54 language skills across 19 stacks — JavaScript, TypeScript, React, Next.js, PHP, Laravel, Python, Django, FastAPI, Go, Rust, Java, Spring, Kotlin, Ruby, Rails, C#, Swift, C++
• 18 agents — orchestrator, ultra-worker, code-explorer, code-architect, code-reviewer, doc-verifier, silent-failure-hunter, plan-verifier, and more
• 30 lifecycle hooks — session-start, session-end, user-prompt-submit, pre/post-tool-use, pre-commit, post-edit, pre-push, on-error, on-pr-open, pre-compact, and more
• 4 model presets — balanced (recommended), cost-optimised, max-quality, speed-first

CLI reference

anvil doctor          # verify installation
anvil models list     # show every skill's resolved model
anvil skill list      # list installed skills
anvil plan <goal>     # invoke planning
anvil review [target] # invoke code-review
anvil ultra <task>    # invoke autonomous ultra-worker

See docs/installation.md for the full command reference.

Docs

• Design spec: .anvil/specs/anvil-design.md
• Getting started: docs/getting-started.md
• Architecture: .anvil/specs/anvil-design.md
• Skill authoring: docs/skill-authoring.md
• Hook authoring: docs/hook-authoring.md
• Installation guide: docs/installation.md

Contributing

This is an AI-developed project. See CLAUDE.md and AGENTS.md at the root and in each folder for conventions.

License

MIT