Agent Skill Cast

Cast your AI agent skills across your team.

English | 한국어 |

Why?

"I made a useful skill on the mobile branch, but I want to use it on main too... cherry-picking is such a pain..."

"Repo A and B are both React projects, and 90% of skills are identical. Managing copies is hell..."

Don't let skills be tied to branches or repos.

Agent Skill Cast lets you pick only the skills you need from a central repository and cast them into your project.

Features

| | | |---|---| | Selective Sync | Pick only the skills you need, not the entire repository | | Multi-Agent | Installs to existing Claude, Gemini, Codex folders | | Instant Updates | cast source sync attempts git updates and re-links active symlink skills | | Local & Remote | Supports both Git repos and local folders |

Installation

npm install -g agent-skill-cast

Requires Node.js 20+

Quick Start

Step 1. Initialize

cast init

Step 2. Register Source

# GitHub repository
cast source add https://github.com/my-team/shared-skills

# Or local folder
cast source add ~/my-personal-skills

Step 3. Cast Skills

cast use
# Interactive menu - select skill numbers (comma-separated for multiple)

# Or install every skill from a source at once
cast use my-skills --all

Step 4. Verify

cast list
# By default, symlinks are created in existing agent folders (.claude/.gemini/.codex)
# Use --copy for standalone local copies

Step 5. Sync (when source is updated)

cast source sync

Commands

Basic Commands

| Command | Description | |---------|-------------| | cast init | Initialize global configuration | | cast use | Select and install skills (interactive) | | cast use <source>/<skill> | Install a specific skill directly | | cast use <source> --all | Install all skills from a source | | cast use <source>/<skill> --copy | Install as standalone copies (no symlink) | | cast use <source> --all --copy | Install all skills from a source as standalone copies | | cast list | Show installed skills | | cast remove <skill> | Remove installed symlink skills (standalone --copy installs are not removed) |

Source Management

| Command | Description | |---------|-------------| | cast source | Source Management Menu (Interactive) | | cast source add <URL/Path> | Register a source | | cast source list | Show registered sources | | cast source remove <name> | Unregister a source | | cast source sync | Update git sources and refresh active symlink skills |

Legacy aliases (cast sync, cast ls, cast rm) are deprecated and will be removed in the next major version.

Options

| Option | Description | |--------|-------------| | --claude | Install only to .claude/skills | | --gemini | Install only to .gemini/skills | | --codex | Install only to .codex/skills | | --all | Install all skills from the specified source (cast use <source> --all) | | --copy | Copy skills instead of creating symlinks |

Configuration

cast config           # Configuration Menu (Interactive)
cast config lang ko   # 한국어
cast config lang en   # English

CI Mode (for AI Agents / Automation)

Use --ci flag for non-interactive execution (Claude Code, Codex, CI/CD pipelines). --json is supported across all commands and always returns { ok, data } or { ok, error, message }.

# CI mode is auto-activated when:
# - --ci flag is present
# - stdin is not a TTY

cast source list --ci --json     # JSON output
cast use my-skills/helper --ci   # Non-interactive install
cast use my-skills --all --ci    # Non-interactive install of all skills from one source
cast use my-skills/helper --copy --ci  # Non-interactive standalone copy install
cast list --ci --json            # JSON skill list

| Option | Description | |--------|-------------| | --ci | Non-interactive mode (no prompts, no colors) | | --json | Structured JSON output (all commands) |

See SKILL.md for the full agent interface specification.

How It Works

┌─────────────────────────────────────────────────────────┐
│  Skill Source Repository (GitHub / Local)               │
└─────────────────────────────────────────────────────────┘
                          │
                          ▼
┌─────────────────────────────────────────────────────────┐
│  ~/.asc_sources/                                        │
│  └── shared-skills/     ← git clone or symlink          │
│      ├── react-patterns/                                │
│      ├── testing-guide/                                 │
│      └── mobile-helper/                                 │
└─────────────────────────────────────────────────────────┘
                          │
          ┌───────────────┼───────────────┐
          ▼               ▼               ▼
     Project A       Project B       Project C
     .claude/        .claude/        .claude/
     skills/         skills/         skills/
       ↓               ↓               ↓
    [symlink]       [symlink]       [symlink]

• Zero Copy (Default): Symlinks save disk space
• Instant Reflect: Source updates can be re-linked in a project with cast source sync
• Independent Selection: Each project can have different skill combinations
• Standalone Mode: Use cast use <source>/<skill> --copy when you want independent local copies (cast remove does not remove these local copies)

Skill Structure

To identify a folder as a skill, it must contain a SKILL.md file. Agent Skill Cast searches for skills in the following locations within a source repository:

1. Root Directory: Any folder containing SKILL.md.
   • my-skill/SKILL.md → Identified as my-skill
2. Agent Specific Directories:
   • .claude/skills/my-skill/SKILL.md
   • .gemini/skills/my-skill/SKILL.md
   • .codex/skills/my-skill/SKILL.md

Note: Folders without SKILL.md are ignored.

Collaboration Scenarios

Situation: You made a skill on the mobile branch and want to use it on main.

# Register skill repository (once)
cast source add https://github.com/my-team/shared-skills

# Use from any branch
cast use shared-skills/mobile-helper

# Sync when updated
cast source sync

Situation: Repo A and B use the same frontend tech, 90% skills are identical.

# Both Repo A and B:
cast source add https://github.com/my-team/frontend-skills
cast use frontend-skills/react-patterns
cast use frontend-skills/testing-guide

Update the source once, cast source sync syncs all repos!

Situation: You want to quickly share a new skill with your team.

# 1. Push to skill repository
cd ~/shared-skills
mkdir new-skill && echo "..." > new-skill/SKILL.md
git add . && git commit -m "feat: add new skill" && git push

# 2. Tell teammates: "Run cast source sync!"

# 3. Teammates
cast source sync
cast use shared-skills/new-skill

License

MIT