AI42-MCP X402 Payment Server

Instructions

Implementation Reference

• src/index.ts:37-71 (handler)

  The handler function for the 'get-balance' tool. It creates a signer, connects to Solana devnet RPC, derives the public key from the private key in SOLANA_PRIVATE_KEY env var, fetches the balance, converts lamports to SOL, and returns formatted JSON or error.

  async () => {
    try {
      const signer = await createSigner("solana-devnet", process.env.SOLANA_PRIVATE_KEY || " ");
      const connection = new Connection("https://api.devnet.solana.com", "confirmed");
  
      const privateKeyBytes = bs58.decode(process.env.SOLANA_PRIVATE_KEY || "");
  
  
      const keypair = Keypair.fromSecretKey(privateKeyBytes);
      const publicKey = keypair.publicKey;
  
      const balance = await connection.getBalance(publicKey);
      const solBalance = balance / LAMPORTS_PER_SOL;
  
      return {
        content: [{
          type: "text",
          text: JSON.stringify({
            balance: solBalance,
            unit: "SOL",
            network: "devnet",
            address: publicKey
          }, null, 2)
        }]
      };
    } catch (err: any) {
      return {
        content: [{
          type: "text",
          text: `Error: ${err.message || "Failed to get balance"}`
        }],
        isError: true
      };
    }
  }

• src/index.ts:32-36 (schema)

  Schema definition for the 'get-balance' tool, including title, description, and empty input schema (no parameters required).

  {
    title: "Get Wallet Balance",
    description: "Check the current SOL balance in your wallet",
    inputSchema: {},
  },

• src/index.ts:30-72 (registration)

  Full registration of the 'get-balance' tool via server.registerTool, including name, schema, and inline handler function.

  server.registerTool(
    "get-balance",
    {
      title: "Get Wallet Balance",
      description: "Check the current SOL balance in your wallet",
      inputSchema: {},
    },
    async () => {
      try {
        const signer = await createSigner("solana-devnet", process.env.SOLANA_PRIVATE_KEY || " ");
        const connection = new Connection("https://api.devnet.solana.com", "confirmed");
  
        const privateKeyBytes = bs58.decode(process.env.SOLANA_PRIVATE_KEY || "");
   
  
        const keypair = Keypair.fromSecretKey(privateKeyBytes);
        const publicKey = keypair.publicKey;
  
        const balance = await connection.getBalance(publicKey);
        const solBalance = balance / LAMPORTS_PER_SOL;
  
        return {
          content: [{
            type: "text",
            text: JSON.stringify({
              balance: solBalance,
              unit: "SOL",
              network: "devnet",
              address: publicKey
            }, null, 2)
          }]
        };
      } catch (err: any) {
        return {
          content: [{
            type: "text",
            text: `Error: ${err.message || "Failed to get balance"}`
          }],
          isError: true
        };
      }
    }
  );