MCP Crypto Wallet EVM

Instructions

Implementation Reference

• src/handlers/wallet.ts:319-343 (handler)

  The sendTransactionHandler function implements the core logic for the wallet_send_transaction tool. It validates input, retrieves the wallet, ensures a provider is set, sends the transaction via wallet.sendTransaction(input.transaction), and returns transaction details or an error.

  export const sendTransactionHandler = async (input: any): Promise<ToolResultSchema> => {
    try {
      if (!input.transaction) {
        return createErrorResponse("Transaction is required");
      }
  
      const wallet = await getWallet(input.wallet, input.password);
      if (!wallet.provider) {
        return createErrorResponse("Provider is required to send a transaction, please set the provider URL");
      }
  
      const tx = await wallet.sendTransaction(input.transaction);
  
      return createSuccessResponse(
      `Transaction sent successfully
        Hash: ${tx.hash}
        Nonce: ${tx.nonce.toString()}
        Gas limit: ${tx.gasLimit.toString()}
        Gas price: ${tx.gasPrice?.toString()}
        Data: ${tx.data}
      `);
    } catch (error) {
      return createErrorResponse(`Failed to send transaction: ${(error as Error).message}`);
    }
  };

• src/tools.ts:249-276 (schema)

  Defines the input schema and description for the wallet_send_transaction tool, specifying the required transaction object with fields like to, data, value, etc.

  {
    name: "wallet_send_transaction",
    description: "Send a transaction",
    inputSchema: {
      type: "object",
      properties: {
        wallet: { type: "string", description: "The wallet (private key, mnemonic, or JSON). If not provided, uses PRIVATE_KEY environment variable if set." },
        transaction: { 
          type: "object", 
          description: "The transaction to send",
          properties: {
            to: { type: "string" },
            from: { type: "string" },
            data: { type: "string" },
            value: { type: "string" },
            gasLimit: { type: "string" },
            gasPrice: { type: "string" },
            nonce: { type: "number" },
            type: { type: "number" },
            maxFeePerGas: { type: "string" },
            maxPriorityFeePerGas: { type: "string" }
          },
          required: ["to"]
        }
      },
      required: ["transaction"]
    }
  },

• src/tools.ts:579-579 (registration)

  Maps the tool name 'wallet_send_transaction' to its handler function sendTransactionHandler in the handlers dictionary.

  "wallet_send_transaction": sendTransactionHandler,