Circle Skills

Ship stablecoin apps faster with Circle Skills: best-practice guidance for USDC payments, crosschain transfers, wallets, and smart contracts, plus Circle's MCP server for real-time SDK and documentation context.

Installation

Claude Code

/plugin marketplace add circlefin/skills
/plugin install circle-skills@circle

Vercel Skills CLI

npx skills add circlefin/skills

Skills

Circle MCP

Skills contain stable patterns (architecture decisions, UX guidance, common mistakes). For ground-truth details that change frequently (e.g., SDK method signatures, contract addresses, chain IDs) use Circle's MCP server alongside skills.

Manual config for Cursor, Windsurf, and other JSON-based clients:

{
 "mcpServers": {
   "circle": {
     "url": "https://api.circle.com/v1/codegen/mcp"
   }
 }
}

Full setup guide: developers.circle.com/ai/mcp

How Skills Work

Skills provide context that help agents do specific things with greater accuracy:

• Decision frameworks: when to use CCTP vs Gateway, which wallet type fits your use case
• Correct patterns: USDC's 6-decimal rule, approve-then-deposit flows, passkey recovery
• Common mistakes: what breaks and why, so the agent avoids them upfront

Your agent reads the relevant SKILL.md while planning and generating code. You stay in control of what gets built.

Updating

Skills are local files. To get the latest versions:

# Vercel CLI
npx skills update

# Claude Code
/plugin marketplace update

Skills are designed around patterns with infrequent changes, so they remain useful even if slightly behind. For details that change often (contract addresses, SDK signatures), use Circle MCP which updates over the air.

Contributing

See CONTRIBUTING.md for guidelines.

FAQ

Do skills write code for me?
No. Skills are instructions and best-practice patterns that steer an agent's outputs. Your agent generates the code; skills guide it.

Do I need the MCP server?
No. Skills work standalone. MCP adds accuracy for SDK details that change between versions.

Resources

• Circle Developer Docs
• Arc Docs
• Circle MCP Server
• Testnet Faucet
• USDC Contract Addresses

Disclaimer

By using this skill, you acknowledge that any output generated in connection with the Skill may contain errors, omissions, outdated information, or fee configuration options, including options under which applicable fees may be directed to Circle Technology Services, LLC, and you are solely responsible for reviewing and validating all outputs and fee settings before taking any action. This skill is provided "as is," and Circle Technology Services, LLC disclaims liability for losses or damages arising from use of or reliance on output generated in connection with this skill; use of this skill is subject to the Circle Developer Terms and Conditions.

License

Apache 2.0 — see LICENSE for details.

{
  "name": "circle",
  "owner": {
    "name": "Circle Technology Services"
  },
  "metadata": {
    "description": "Circle's official skills and MCP integrations for AI agents",
    "version": "1.1.0"
  },
  "plugins": [
    {
      "name": "circle-skills",
      "source": "./plugins/circle",
      "description": "Ship stablecoin apps faster. Best-practice skills for USDC payments, cross-chain transfers, wallets, and smart contracts — plus Circle's MCP server for real-time SDK and documentation guidance."
    }
  ]
}