MCP Ripgrep Server

Instructions

Implementation Reference

• src/index.ts:194-260 (handler)

  Handler for the 'search' tool: parses arguments, builds ripgrep command with options like case sensitivity, file pattern, max results, context, colors, executes it via exec(), processes output.
  case "search": { const pattern = String(args.pattern || ""); const path = String(args.path); const caseSensitive = typeof args.caseSensitive === 'boolean' ? args.caseSensitive : undefined; const filePattern = args.filePattern ? String(args.filePattern) : undefined; const maxResults = typeof args.maxResults === 'number' ? args.maxResults : undefined; const context = typeof args.context === 'number' ? args.context : undefined; const useColors = typeof args.useColors === 'boolean' ? args.useColors : false; if (!pattern) { return { isError: true, content: [{ type: "text", text: "Error: Pattern is required" }] }; } // Build the rg command with flags let command = "rg"; // Add case sensitivity flag if specified if (caseSensitive === true) { command += " -s"; // Case sensitive } else if (caseSensitive === false) { command += " -i"; // Case insensitive } // Add file pattern if specified if (filePattern) { command += ` -g ${escapeShellArg(filePattern)}`; } // Add max results if specified if (maxResults !== undefined && maxResults > 0) { command += ` -m ${maxResults}`; } // Add context lines if specified if (context !== undefined && context > 0) { command += ` -C ${context}`; } // Add line numbers command += " -n"; // Add color setting command += useColors ? " --color always" : " --color never"; // Add pattern and path command += ` ${escapeShellArg(pattern)} ${escapeShellArg(path)}`; console.error(`Executing: ${command}`); const { stdout, stderr } = await exec(command); // If there's anything in stderr, log it for debugging if (stderr) { console.error(`ripgrep stderr: ${stderr}`); } return { content: [ { type: "text", text: processOutput(stdout, useColors) || "No matches found" } ] }; }
• src/index.ts:98-113 (registration)

  Registration of the 'search' tool in the tools list, including name, description, and full input schema.
  name: "search", description: "Search files for patterns using ripgrep (rg)", inputSchema: { type: "object", properties: { pattern: { type: "string", description: "The search pattern (regex by default)" }, path: { type: "string", description: "Directory or file(s) to search." }, caseSensitive: { type: "boolean", description: "Use case sensitive search (default: auto)" }, filePattern: { type: "string", description: "Filter by file type or glob" }, maxResults: { type: "number", description: "Limit the number of matching lines" }, context: { type: "number", description: "Show N lines before and after each match" }, useColors: { type: "boolean", description: "Use colors in output (default: false)" } }, required: ["pattern", "path"] } },
• src/index.ts:100-111 (schema)

  Input schema for the 'search' tool defining parameters and requirements.
  inputSchema: { type: "object", properties: { pattern: { type: "string", description: "The search pattern (regex by default)" }, path: { type: "string", description: "Directory or file(s) to search." }, caseSensitive: { type: "boolean", description: "Use case sensitive search (default: auto)" }, filePattern: { type: "string", description: "Filter by file type or glob" }, maxResults: { type: "number", description: "Limit the number of matching lines" }, context: { type: "number", description: "Show N lines before and after each match" }, useColors: { type: "boolean", description: "Use colors in output (default: false)" } }, required: ["pattern", "path"]
• src/index.ts:51-91 (helper)

  Helper function to execute shell commands safely using spawn, capturing stdout/stderr, handling ripgrep exit codes.
  function exec(command: string): Promise<{ stdout: string; stderr: string }> { return new Promise((resolve, reject) => { const parts = command.split(" "); const program = parts[0]; const args = parts.slice(1).filter(arg => arg.length > 0); // Use spawn with explicit stdio control const child = spawn(program, args, { shell: true, // Use shell to handle quotes and escaping }); let stdout = ""; let stderr = ""; child.stdout.setEncoding("utf8"); child.stderr.setEncoding("utf8"); child.stdout.on("data", (data) => { stdout += data; }); child.stderr.on("data", (data) => { stderr += data; }); child.on("close", (code) => { if (code === 0 || code === 1) { // Code 1 is "no matches" for ripgrep resolve({ stdout, stderr }); } else { const error = new Error(`Command failed with exit code ${code}`); Object.assign(error, { code, stdout, stderr }); reject(error); } }); // Handle process errors child.on("error", (error) => { reject(error); }); }); }
• src/index.ts:41-45 (helper)

  Helper to escape shell arguments to prevent injection.
  function escapeShellArg(arg: string): string { // Replace all single quotes with the sequence: '"'"' // This ensures the argument is properly quoted in shell commands return `'${arg.replace(/'/g, "'\"'\"'")}'`; }