📦 arc
Agentic skill package manager.
Install, discover, and share skills, tools, agents, and prompts
with capability-based trust and multi-source registries.
Claude Code skills are powerful but non-distributable. Each user's skill directory is a local collection with no mechanism for discovery, installation, or sharing between users.
arc is apt install for agentic skills. It manages the full lifecycle — search a registry, review capabilities, install with one command, audit what's running.
arc search doc # Find packages across all sources
arc install _DOC # Install with capability review
arc audit # See your total attack surfacearc handles all four artifact types:
| Type | Installed To | What It Is |
|---|---|---|
| Skill | ~/.claude/skills/{name}/ |
Directory with SKILL.md + workflows |
| Tool | ~/.claude/bin/{name} + PATH shim |
CLI command you can run directly |
| Agent | ~/.claude/agents/{name}.md |
Persona file — auto-discovered as subagent_type |
| Prompt | ~/.claude/commands/{name}.md |
Slash command template |
# Install arc
git clone https://github.com/the-metafactory/arc.git
cd arc && bun install && bun link
# Fetch the community registry
arc source update
# Search and install
arc search doc
arc install _DOCRequires Bun (v1.0+) and Git. Optional: GitHub CLI (gh) for release notes in arc info. See QUICKSTART.md for the full walkthrough.
arc install <name-or-url> # Install from registry or git URL
arc list # List installed packages
arc info <name> # Show details, capabilities, and release notes
arc audit # Audit capability surface (summary + cross-tier warnings)
arc audit --verbose # Full pairwise capability combination list
arc disable <name> # Disable (preserves repo)
arc enable <name> # Re-enable a disabled package
arc remove <name> # Completely uninstall
arc verify <name> # Verify manifest integrityarc upgrade --check # Check for available upgrades (compares against registry)
arc upgrade # Upgrade all packages
arc upgrade <name> # Upgrade a specific package
arc self-update # Update arc itself (git pull + bun install)
arc upgrade-core <version> # Upgrade core (symlink management)arc search <keyword> # Search all configured sourcesarc source list # Show configured registry sources
arc source add <n> <url> # Add a source (--tier official|community|custom)
arc source update # Refresh indexes from all sources (like apt update)
arc source remove <name> # Remove a sourceThe catalog is a local catalog.yaml tracking available artifacts (built-in skills, agents). It complements the registry — the registry is for community-published packages, the catalog is for known artifacts you may want to install.
arc catalog list # List catalog with install status
arc catalog search <keyword> # Search catalog by name or description
arc catalog add <name> # Add entry (--from-registry to pull from sources)
arc catalog remove <name> # Remove entry from catalog
arc catalog use <name> # Install from catalog (resolves deps)
arc catalog sync # Re-pull all installed catalog entries
arc catalog push <name> # Push local changes back to source
arc catalog push-catalog # Commit and push catalog.yaml to git remotearc init my-skill # Scaffold a new skill repo
arc init my-tool --type tool # Scaffold a tool
arc init my-agent --type agent
arc init my-prompt --type promptEach scaffold includes arc-manifest.yaml, package.json, README.md, .gitignore, and type-specific files (SKILL.md + workflows, agent persona, prompt template, or tool entry point).
sources.yaml Registry Sources arc Your Machine
──────────── ──────────────── ─────── ────────────
│ │ │ │
│ community hub │ │ │
│ personal (custom) │ │ │
│─────────────────────────►│ │ │
│ │ │ │
│ │ source update │ │
│ │ (fetch REGISTRY.yaml) │ │
│ │◄────────────────────────│ │
│ │ │ │
│ │ cached indexes │ │
│ │────────────────────────►│ search "doc" │
│ │ │ (queries cached files) │
│ │ │ │
│ │ │ install _DOC │
│ │ │ → git clone │
│ │ │─────────────────────────►
│ │ │ │
│ │ │ read arc-manifest.yaml │
│ │ │ display capabilities │
│ │ │ user confirms │
│ │ │ │
│ │ │ symlink → skills/ │
│ │ │ record in packages.db │
│ │ │─────────────────────────►
│ │ │ │
The flow:
arc source updatefetches REGISTRY.yaml from each source insources.yamland caches locallyarc searchqueries the cached indexes across all enabled sourcesarc installresolves the package from the registry, clones the source repo via git- Reads
arc-manifest.yaml— the capability declaration - Displays capabilities and risk level for user approval
- Creates symlinks to the appropriate Claude directory
- For tools: runs
bun installand creates CLI shim on PATH - Records metadata in SQLite (
packages.db)
No npm. No Docker. Just git clone, symlinks, and a manifest.
arc supports multiple registry sources, like apt's sources.list:
# ~/.config/metafactory/sources.yaml (auto-created on first run)
sources:
- name: community
url: https://raw.githubusercontent.com/mellanon/pai-collab/main/skills/REGISTRY.yaml
tier: community
enabled: trueAdd additional sources:
arc source add my-team https://raw.githubusercontent.com/my-org/registry/main/REGISTRY.yaml --tier community
arc source update # Fetch indexes from all sourcesSearch aggregates results across all enabled sources, showing the source name and trust tier for each match.
Trust flows from the source, not the package:
| Tier | Install Behavior | Example Source |
|---|---|---|
| official | Auto-approves, minimal display | Upstream maintained packages |
| community | Shows capabilities, requires confirmation | Community registries |
| custom | Risk warning, full capability review | Direct git URL installs |
Every package declares what it accesses in arc-manifest.yaml:
capabilities:
filesystem:
read: ["~/.claude/MEMORY/"]
write: ["~/.claude/MEMORY/WORK/"]
network:
- domain: "*.atlassian.net"
reason: "Jira REST API"
bash:
allowed: true
restricted_to: ["bun src/jira.ts *"]
secrets: ["JIRA_URL", "JIRA_API_TOKEN"]arc audit shows your total attack surface and detects dangerous capability compositions across installed packages:
- Summary mode (default): grouped composition stats + cross-tier warnings only
- Verbose mode (
--verbose): full pairwise list of all capability combination warnings
Cross-tier warnings surface when a community package's capabilities combine dangerously with your personal packages — the actually interesting signals. Same-tier combinations (your own skills) are summarized as expected.
A package is a git repo with arc-manifest.yaml at root:
arc-skill-example/
├── arc-manifest.yaml # Capability declaration (required)
├── skill/ # Skill directory (skills)
│ ├── SKILL.md
│ └── workflows/
├── agent/ # Agent directory (agents)
│ └── AgentName.md
├── prompt/ # Prompt directory (prompts)
│ └── prompt-name.md
├── src/ # Source code (tools, skills with CLI)
│ └── tool.ts
├── package.json # Bun dependencies (optional)
└── README.md
name: _DOC
version: 1.0.0
type: skill # skill | tool | agent | prompt
tier: community
author:
name: mellanon
github: mellanon
provides:
skill:
- trigger: "doc"
cli:
- command: "bun src/doc.ts"
name: "doc"
depends_on:
tools:
- name: bun
version: ">=1.0.0"
capabilities:
filesystem:
read: []
write: ["**/*.html"]
network: []
bash:
allowed: false
secrets: []bun test # All 180 tests
bun test:unit # Unit tests only
bun test:commands # Command tests
bun test:e2e # End-to-end lifecycle testsTests run in isolated temp directories — never touch real ~/.claude/ or ~/.config/.
Packages use semver. The canonical version lives in arc-manifest.yaml:
version: 1.2.0Convention: bump the version, tag the commit, create a GitHub Release:
# After updating arc-manifest.yaml version to 1.2.0
git tag v1.2.0
git push origin v1.2.0
gh release create v1.2.0 --title "v1.2.0" --notes "## What Changed
- Added new workflow for X
- Fixed Y bug in Z"Tags must match the manifest version (tag v1.2.0 ↔ manifest version: 1.2.0).
GitHub Releases are the changelog — no separate CHANGELOG.md needed. arc info fetches and displays release notes directly via the gh CLI.
Registry entries include a version field to advertise the latest available version. arc upgrade --check compares installed versions against registry versions. Pinned installs (arc install MySkill@1.2.0) are planned for a future release.
To add your package to a community registry, see the publishing guide.
Requirements:
- Public GitHub repo with
arc-manifest.yaml - All capabilities honestly declared
- License file (MIT, Apache-2.0, BSD-2-Clause, BSD-3-Clause)
- Git tag + GitHub Release matching the manifest version
- Open a PR adding your entry to the registry's
REGISTRY.yaml
- SkillSeal by Ian McCutcheon — Cryptographic signing framework for Claude Code skills (future integration)
- SpecFlow by Jens-Christian Fischer — The
arc-manifest.yamlcapability format is adapted from SpecFlow's manifest schema - Debian Project — The multi-tier trust model is inspired by Debian's main/contrib/non-free architecture
MIT