Foundry MCP Server

import { z } from "zod"; import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; import { checkFoundryInstalled, executeCommand, FOUNDRY_PATHS, FOUNDRY_NOT_INSTALLED_ERROR } from "../../utils/command.js"; import { resolveRpcUrl } from "../../utils/rpc.js"; export function registerCastSendTool(server: McpServer): void { server.tool( "cast_send", "Send a transaction to a contract function", { contractAddress: z.string().describe("Address of the contract"), functionSignature: z.string().describe("Function signature (e.g., 'transfer(address,uint256)')"), args: z.array(z.string()).optional().describe("Function arguments"), from: z.string().optional().describe("Sender address or private key"), value: z.string().optional().describe("Ether value to send with the transaction (in wei)"), rpcUrl: z.string().optional().describe("JSON-RPC URL (default: http://localhost:8545)"), gasLimit: z.string().optional().describe("Gas limit for the transaction"), gasPrice: z.string().optional().describe("Gas price for the transaction (in wei)"), confirmations: z.number().optional().describe("Number of confirmations to wait for") }, async ({ contractAddress, functionSignature, args = [], from, value, rpcUrl, gasLimit, gasPrice, confirmations }) => { const installed = await checkFoundryInstalled(); if (!installed) { return { content: [{ type: "text", text: FOUNDRY_NOT_INSTALLED_ERROR }], isError: true }; } const resolvedRpcUrl = await resolveRpcUrl(rpcUrl); const privateKey = process.env.PRIVATE_KEY; let command = `${FOUNDRY_PATHS.castPath} send ${contractAddress} "${functionSignature}" --private-key ${[privateKey]}`; if (args.length > 0) { command += " " + args.join(" "); } if (from) { command += ` --from ${from}`; } if (value) { command += ` --value ${value}`; } if (resolvedRpcUrl) { command += ` --rpc-url "${resolvedRpcUrl}"`; } if (gasLimit) { command += ` --gas-limit ${gasLimit}`; } if (gasPrice) { command += ` --gas-price ${gasPrice}`; } if (confirmations) { command += ` --confirmations ${confirmations}`; } const result = await executeCommand(command); return { content: [{ type: "text", text: result.success ? `Transaction sent successfully:\n${result.message}` : `Transaction failed: ${result.message}` }], isError: !result.success }; } ); }