Foundry MCP Server

import { z } from "zod"; import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; import * as fs from "fs/promises"; import * as path from "path"; import { checkFoundryInstalled, executeCommand, FOUNDRY_PATHS, FOUNDRY_NOT_INSTALLED_ERROR } from "../../utils/command.js"; import { resolveRpcUrl } from "../../utils/rpc.js"; import { ensureWorkspaceInitialized } from "../../utils/workspace.js"; export function registerForgeScriptTool(server: McpServer): void { server.tool( "forge_script", "Run a Forge script from the workspace", { scriptPath: z.string().describe("Path to the script file (e.g., 'script/Deploy.s.sol')"), sig: z.string().optional().describe("Function signature to call (default: 'run()')"), rpcUrl: z.string().optional().describe("JSON-RPC URL (default: http://localhost:8545)"), broadcast: z.boolean().optional().describe("Broadcast the transactions"), verify: z.boolean().optional().describe("Verify the contract on Etherscan (needs API key)") }, async ({ scriptPath, sig = "run()", rpcUrl, broadcast = false, verify = false }) => { const installed = await checkFoundryInstalled(); if (!installed) { return { content: [{ type: "text", text: FOUNDRY_NOT_INSTALLED_ERROR }], isError: true }; } try { const workspace = await ensureWorkspaceInitialized(); // Check if script exists const scriptFullPath = path.join(workspace, scriptPath); const scriptExists = await fs.access(scriptFullPath).then(() => true).catch(() => false); if (!scriptExists) { return { content: [{ type: "text", text: `Script does not exist at ${scriptFullPath}` }], isError: true }; } const resolvedRpcUrl = await resolveRpcUrl(rpcUrl); let command = `cd ${workspace} && ${FOUNDRY_PATHS.forgePath} script ${scriptPath} --sig "${sig}"`; if (resolvedRpcUrl) { command += ` --rpc-url "${resolvedRpcUrl}"`; } if (broadcast) { command += ` --broadcast`; } if (verify) { command += ` --verify`; } const result = await executeCommand(command); return { content: [{ type: "text", text: result.success ? `Script executed successfully:\n${result.message}` : `Script execution failed: ${result.message}` }], isError: !result.success }; } catch (error) { return { content: [{ type: "text", text: `Error executing script: ${error instanceof Error ? error.message : String(error)}` }], isError: true }; } } ); }