@fuin-labs/mcp-server

MCP (Model Context Protocol) server for Fuin — a programmable authorization layer on Solana. Lets AI agents manage delegate keys, check vault balances, and execute SOL transfers within on-chain policy constraints.

Quick Start

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "fuin": {
      "command": "npx",
      "args": ["-y", "@fuin-labs/mcp-server"],
      "env": {
        "DELEGATE_PRIVATE_KEY": "<base58-encoded-secret-key>"
      }
    }
  }
}

Cursor / VS Code

Add to .cursor/mcp.json or .vscode/mcp.json:

{
  "servers": {
    "fuin": {
      "command": "npx",
      "args": ["-y", "@fuin-labs/mcp-server"],
      "env": {
        "DELEGATE_PRIVATE_KEY": "<base58-encoded-secret-key>"
      }
    }
  }
}

Smithery

npx @smithery/cli install @fuin-labs/mcp-server

Tools

| Tool | Description | Hints | |------|-------------|-------| | get-balance | Get vault SOL balance, state, spending policy caps, and program allow/deny lists | Read-only | | get-delegate-info | Get delegate permissions, spending limits, usage count, expiry, status, and vault program policies | Read-only | | list-delegates | List all delegates issued to this agent's keypair, with vault info and program policies | Read-only | | transfer-sol | Execute a SOL transfer from a Fuin vault using delegate permissions. On-chain policy enforcement applies. | Destructive | | transfer-spl | Execute an SPL token transfer from a Fuin vault. Requires CAN_TRANSFER permission. Supports Pyth price feeds for USD valuation. | Destructive | | swap | Execute a token swap on Meteora DLMM from a Fuin vault. Requires CAN_SWAP permission and DLMM program in vault allow-list. | Destructive | | request-program | Request the guardian to add a program to the vault's allow-list. Creates a pending request for guardian review. | — |

Environment Variables

| Variable | Required | Default | Description | |----------|----------|---------|-------------| | DELEGATE_PRIVATE_KEY | Yes | — | Base58-encoded secret key of the delegate keypair | | SOLANA_RPC_URL | No | https://api.devnet.solana.com | Solana RPC endpoint |

How It Works

Fuin guardians create on-chain vaults (PDAs) and issue delegate keys with bitmask permissions, spending caps, and policy constraints. This MCP server allows AI agents to operate within those constraints — checking balances, inspecting delegate permissions, and executing transfers that are validated on-chain by the Fuin program.

License

MIT