Skip to main content
Glama
mcollina

MCP Ripgrep Server

by mcollina

search

Search files for patterns using ripgrep to find text across your system. Specify search patterns and paths to locate matching content in files.

Instructions

Search files for patterns using ripgrep (rg)

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
patternYesThe search pattern (regex by default)
pathYesDirectory or file(s) to search.
caseSensitiveNoUse case sensitive search (default: auto)
filePatternNoFilter by file type or glob
maxResultsNoLimit the number of matching lines
contextNoShow N lines before and after each match
useColorsNoUse colors in output (default: false)

Implementation Reference

  • 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"]
      }
    },
  • 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"]
  • 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);
        });
      });
    }
  • 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, "'\"'\"'")}'`;
    }

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observed

TDQS

C2.9/5.0
Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden but only mentions using ripgrep. It lacks details on side effects, ownership, or output behavior, though search is inherently read-only.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is very concise with a single sentence, but it lacks structure or front-loading of critical information. Efficient but minimal.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given 7 parameters and no output schema or annotations, the description is insufficient. It does not cover return format, pagination, or limitations, leaving significant gaps for an AI agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description adds no extra parameter information beyond the schema, such as regex syntax or default values.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool uses ripgrep to search files, with a direct verb and resource. However, it does not explicitly differentiate from sibling tools like 'advanced-search', leaving some ambiguity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus siblings such as 'advanced-search' or 'count-matches'. The agent must infer usage from the name alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.