@abelcaptain/cctp-mcp

MCP server for cross-chain USDC bridging via Circle CCTP V2. Works with Claude Code, Cursor, and any MCP-compatible host.

Supported Chains (18)

Ethereum, Avalanche, Optimism, Arbitrum, Solana, Base, Polygon, Unichain, Linea, Codex, Sonic, World Chain, Monad, Sei, XDC, HyperEVM, Ink, Plume

Quick Start (Zero Config)

No environment variables required. Public RPCs are built-in for all 18 chains.

Claude Code

claude mcp add cctp-bridge -- npx -y @abelcaptain/cctp-mcp

Cursor

Add to ~/.cursor/mcp.json (global) or <project>/.cursor/mcp.json (project-level):

{
  "mcpServers": {
    "cctp-bridge": {
      "command": "npx",
      "args": ["-y", "@abelcaptain/cctp-mcp"]
    }
  }
}

Other MCP Hosts

Check your host's documentation for how to register an MCP server. The command is npx -y @abelcaptain/cctp-mcp.

Restart your host and try: "Check USDC balance for 0xYourAddress on Base"

This gives you all read-only tools — balance checks, bridge quotes, transfer status, attestation lookups, etc.

Optional: Enable Auto-Signing

To sign and broadcast transactions automatically, pass your private key(s) as environment variables.

Claude Code

claude mcp add cctp-bridge \
  --env CCTP_PRIVATE_KEY=0xYourEvmPrivateKey \
  -- npx -y @abelcaptain/cctp-mcp

Add Solana signing:

claude mcp add cctp-bridge \
  --env CCTP_PRIVATE_KEY=0xYourEvmPrivateKey \
  --env CCTP_SOLANA_PRIVATE_KEY=YourSolanaBase58Key \
  -- npx -y @abelcaptain/cctp-mcp

Cursor

Add env to your ~/.cursor/mcp.json or <project>/.cursor/mcp.json:

{
  "mcpServers": {
    "cctp-bridge": {
      "command": "npx",
      "args": ["-y", "@abelcaptain/cctp-mcp"],
      "env": {
        "CCTP_PRIVATE_KEY": "0xYourEvmPrivateKey",
        "CCTP_SOLANA_PRIVATE_KEY": "YourSolanaBase58Key"
      }
    }
  }
}

Or export them in your shell (~/.zshrc) and omit the env block entirely.

Optional: Better RPCs

Public fallback RPCs work but may be rate-limited. For production use, add an Alchemy key:

claude mcp add cctp-bridge \
  --env CCTP_ALCHEMY_API_KEY=YourAlchemyApiKey \
  -- npx -y @abelcaptain/cctp-mcp

Free tier at dashboard.alchemy.com covers Ethereum, Polygon, Arbitrum, Optimism, Base, Solana, Linea, World Chain.

Environment Variables (All Optional)

| Variable | Description | |----------|-------------| | CCTP_PRIVATE_KEY | EVM private key (0x...) — enables auto-signing | | CCTP_SOLANA_PRIVATE_KEY | Solana private key (base58 or JSON array) — enables auto-signing | | CCTP_ALCHEMY_API_KEY | Alchemy API key for better RPC reliability | | CCTP_SOLANA_RPC_URL | Custom Solana RPC for reliable broadcasting | | CCTP_WALLET_ADDRESS | Default wallet address for read-only tools | | CCTP_{CHAIN}_RPC_URL | Per-chain RPC override (e.g. CCTP_ETHEREUM_RPC_URL) |

Gotchas

• Do not put empty strings in .mcp.json env values — they override system variables.
• This package does not load .env files automatically.

Install AI Skill (Optional)

Gives Claude Code detailed guidance on bridge workflows and error recovery:

mkdir -p .claude/skills/bridge-usdc
npx -y @abelcaptain/cctp-mcp --print-skill > .claude/skills/bridge-usdc/SKILL.md

Available Tools (15)

| Tool | Description | Annotation | |------|-------------|------------| | check-config | Check wallet, signing, and RPC configuration | read-only | | get-supported-chains | List all 18 supported chains | read-only | | get-bridge-quote | Get fee quote and estimated time | read-only | | check-usdc-balance | Check USDC balance on any chain | read-only | | check-usdc-allowance | Check ERC20 approval status (EVM) | read-only | | check-attestation | Check Circle attestation status | read-only | | get-transfer-status | Full transfer status check | read-only | | get-fast-transfer-allowance | Check Fast Transfer capacity | read-only | | get-message-by-nonce | Recover transfer by message nonce | read-only | | prepare-approve-tx | Build unsigned ERC20 approve transaction | read-only | | prepare-burn-tx | Build unsigned burn/deposit transaction | read-only | | prepare-claim-tx | Build unsigned claim transaction | read-only | | sign-and-send-evm | Sign and broadcast EVM transaction | destructive | | sign-and-send-solana | Sign and broadcast Solana transaction | destructive | | reattest-message | Re-attest an expired Fast Transfer | write |

Security

• NEVER paste private keys in chat. Always use --env flags or shell exports.
• Private keys are only used locally for transaction signing and never transmitted beyond the target blockchain RPC.
• Use check-config to verify your setup without exposing sensitive data.

License

MIT