What is grepika CLAUDE.md?

A repository instruction file for grepika, a Rust server and command-line tool that searches source code using full-text search, regular expressions, and substring filtering. It also explains how to run it as an MCP server, which lets an AI tool communicate with it through structured messages.

Use it when building or testing grepika, indexing a codebase, searching files, retrieving line ranges, running its MCP server, or checking performance logs.

It gives agents the project overview and exact build, search, server, and test commands needed to work on the code-search tool correctly.

How adamthewilliam/grepika configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to adamthewilliam/grepika. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/adamthewilliam/grepika/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/adamthewilliam/grepika

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/adamthewilliam/grepika/claude-md/github.svg)](https://agentmods.dev/instructions/adamthewilliam/grepika/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/adamthewilliam/grepika/claude-md"><img src="https://agentmods.dev/badge/instructions/adamthewilliam/grepika/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/adamthewilliam/grepika/claude-md"><img src="https://agentmods.dev/badge/instructions/adamthewilliam/grepika/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,486 This file is loaded in full into every session.

When invoked 1,486 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 89% copy Near-identical to another mod in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.01486	$0.01486
Opus 5.5	$0.00594	$0.00594
Sonnet 5.5	$0.00297	$0.00297
Haiku 4.5	$0.00149	$0.00149

Measured 2mo ago against content hash 425462c0d6cf, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

grepika CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

89% identical to grepika AGENTS.md — 12 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

CLAUDE.md · 124 lines

How it starts

The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

grepika is a token-efficient MCP (Model Context Protocol) server for code search. It combines three search backends for high-quality results:

FTS5 - SQLite full-text search with BM25 ranking
Grep - Parallel regex search using ripgrep internals
Sparse n-gram prefilter - Fast substring candidate filtering, exposed through the legacy trigram naming in the code

The server communicates via JSON-RPC over stdin/stdout when running as an MCP server.

Build & Run Commands

# Build
cargo build --release

# Run MCP server — global mode (recommended, LLM calls add_workspace)
./target/release/grepika --mcp

# Run MCP server — single workspace mode
./target/release/grepika --mcp --root <path>

# CLI commands
grepika index                           # Index the codebase
grepika search <query> -l 20 -m combined  # Search (modes: combined, fts, grep)
grepika get <path> -s 1 -e 100          # Get file content with line range

# Run tests
cargo test

# Run single test
cargo test test_name

# Enable profiling logs
grepika --mcp --log-file /tmp/grepika.log

Architecture

MCP Server (rmcp)          ← JSON-RPC stdin/stdout
       │
Tool Router (server.rs)    ← search, structural_search, get, outline, toc, context, stats, refs, graph, index, diff, add_workspace
       │
Workspace                  ← Holds root + SearchService + Indexer (None in global mode)
       │
SearchService              ← spawn_blocking for async bridge
       │
┌──────┼──────┐
FTS5   Grep   Sparse n-gram ← Three lexical backends with weighted score merging
       │
SQLite + r2d2 pool         ← ~/.cache/grepika/<hash>.db by default

Key Design Decisions

spawn_blocking bridge: MCP handlers are async (rmcp), but search operations are CPU-bound. The run_tool helper in server.rs uses tokio::task::spawn_blocking to bridge this gap.

Read the full file on GitHub · 124 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 124 lines · 1,486 tokens per session scan A 425462c0d6cf

Subscribe to this mod's changes

grepika CLAUDE.md is an instructions file published in the GitHub repository adamthewilliam/grepika (138 stars, last pushed 2mo ago), licensed MIT. It adds 1,486 tokens to every session, about $0.0059 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 89% identical to grepika AGENTS.md, differing in 12 lines, and is treated as a copy.

grepika CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
grepika CLAUDE.mdadamthewilliam/grepika	Instructions file	138	2mo ago	MIT	A	1,486	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

grepika: Instructions file for Claude Code