Foundry MCP Server

import { z } from "zod"; import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; import { executeCommand, FOUNDRY_PATHS } from "../../utils/command.js"; import { getHeimdallOutputDir, DEFAULT_RPC_URL, checkHeimdallOrError } from "./utils.js"; export function registerHeimdallDecodeTool(server: McpServer): void { server.tool( "heimdall_decode", "Decode raw calldata without requiring ABI using Heimdall", { target: z.string().describe("Transaction hash or string of bytes to decode"), rpcUrl: z.string().optional().describe(`EVM network RPC URL (default: ${DEFAULT_RPC_URL})`), openaiApiKey: z.string().optional().describe("OpenAI API key for explaining calldata"), explain: z.boolean().optional().describe("Explain the decoded calldata using OpenAI (default: false)"), useDefaults: z.boolean().optional().describe("Always select default values when prompted (default: false)"), truncateCalldata: z.boolean().optional().describe("Truncate nonstandard sized calldata (default: false)"), skipResolving: z.boolean().optional().describe("Skip resolving selectors and guess types (default: false)"), verbosity: z.enum(["quiet", "normal", "verbose"]).optional().describe("Output verbosity level (default: normal)"), outputDir: z.string().optional().describe("Not used (console output only)") }, async ({ target, rpcUrl, openaiApiKey, explain, useDefaults, truncateCalldata, skipResolving, verbosity, outputDir }) => { const installError = await checkHeimdallOrError(); if (installError) return installError; const finalOutputDir = getHeimdallOutputDir(outputDir); let command = `${FOUNDRY_PATHS.heimdallPath} decode "${target}"`; if (rpcUrl) { command += ` -r "${rpcUrl}"`; } if (openaiApiKey) { command += ` --openai-api-key "${openaiApiKey}"`; } if (explain) { command += " --explain"; } if (useDefaults) { command += " -d"; } if (truncateCalldata) { command += " --truncate-calldata"; } if (skipResolving) { command += " --skip-resolving"; } if (verbosity) { switch (verbosity) { case "quiet": command += " -q"; break; case "verbose": command += " -v"; break; } } // Results will be printed to console const result = await executeCommand(command); if (!result.success) { return { content: [{ type: "text", text: `Heimdall decode failed: ${result.message}` }], isError: true }; } const resultText = `Decoded calldata for ${target}:\n\n${result.message}`; return { content: [{ type: "text", text: resultText }] }; } ); }