mcp-code-search

name

mcp-code-search

description

Use the MCP grep server (`grep_searchGitHub`) for code search and GitHub code lookups instead of `web_search` or `code_search`. The `code_search` tool triggers an SSH passphrase prompt which blocks the workflow. The MCP grep tool searches literal code patterns across millions of public GitHub repos. Use whenever the user asks to find code examples, search GitHub repos, look up API usage patterns, or understand how libraries are used in real projects.

MCP Code Search

IMPORTANT: Tool Preference

When the user asks you to search for code, find GitHub examples, look up API usage patterns, or research how libraries are used in the wild:

1. Always prefer the mcp tool with grep_searchGitHub over web_search or code_search
2. Only fall back to web_search if the MCP grep server returns a 500 error or is unavailable
3. Never use the built-in code_search tool — it triggers an SSH passphrase prompt and blocks the workflow

How to Use the MCP Grep Tool

The grep_searchGitHub tool searches for literal code patterns (like grep), not keywords. Search for actual code that would appear in files.

Basic Usage

mcp({
  tool: "grep_searchGitHub",
  args: {
    query: "literal code pattern to search",
    language: ["TypeScript"],
  }
})

Search Examples

Goal	Query	Notes
Find React imports	"import React from"	Literal string
Find async functions	"async function"	Literal string
Find useState patterns	"useState("	Literal string
Find multi-line patterns	"(?s)try {.*await"	Use useRegexp: true
Find specific repo patterns	"createAgentSession"	Use repo: "earendil-works/pi"

Filter Parameters

• query (string, required) — The literal code pattern to search for
• repo (string) — Filter by repository, e.g. "facebook/react", "vercel/", "microsoft/"
• path (string) — Filter by file path, e.g. "src/components/Button.tsx", "/route.ts"
• language (array) — Filter by language, e.g. ["TypeScript", "TSX"], ["Python"], ["Rust"]
• matchCase (boolean) — Case-sensitive search (default: false)
• matchWholeWords (boolean) — Whole word matching (default: false)
• useRegexp (boolean) — Interpret query as regex (default: false). Prefix with (?s) for multi-line matching

Good vs Bad Queries

✅ Good (literal code that appears in files):

• "useState("
• "import React from"
• "async function"
• "export default function"
• "(?s)try {.*await" (with useRegexp: true)

❌ Bad (keywords, not code):

• "react tutorial"
• "best practices"
• "how to use"
• "authentication in Next.js"

Fallback

If grep_searchGitHub returns an error (500, timeout, etc.), use web_search as a fallback to find what the user needs. Never use code_search.