What is repl-mcp CLAUDE.md?

A set of instructions for working on repl-mcp, an MCP server for Clojure development. MCP is a way for an AI agent to use tools provided by another program, while a REPL is an interactive Clojure environment for trying code.

Use it when developing or maintaining Clojure code through repl-mcp. It covers interactive evaluation, project and code linting, test generation and execution, targeted tests and structural refactoring.

It defines a consistent workflow for evaluating code, reloading edits, linting, testing, debugging and refactoring. This helps developers get quick feedback while keeping the running REPL useful.

How simm-is/repl-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to simm-is/repl-mcp. 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/simm-is/repl-mcp/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/simm-is/repl-mcp

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/simm-is/repl-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/simm-is/repl-mcp/claude-md)

Your own site

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

Per session 2,355 This file is loaded in full into every session.

When invoked 2,355 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 original No closer match found 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	$0.02355	$0.02355
Opus 5.5	$0.00942	$0.00942
Sonnet 5.5	$0.00471	$0.00471
Haiku 4.5	$0.00235	$0.00235

Measured 2mo ago against content hash 4a3a3710cf9a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

repl-mcp 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.

CLAUDE.md · 303 lines

How it starts

The opening of the file, as written. The whole thing — 303 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.

Overview

This MCP server is built on mcp-toolkit providing a clean, simplified architecture with minimal dependencies. All 51 tools follow consistent patterns for reliability and ease of use.

Instructions

Interactive Development: Use the MCP tools for Clojure development in preference to default text editing. Start with eval to test code interactively before committing changes.
Code Quality: Use lint-code for immediate feedback during development, lint-project for comprehensive checks, and setup-clj-kondo to initialize linting in new projects.
File Management: When adding new code, use the standard Edit tool followed by load-file to reload changes into the REPL. This maintains REPL state while updating code.
Refactoring: Use structural editing tools for complex refactoring to maintain code integrity. Fall back to Edit + load-file if issues arise.
Testing: Use create-test-skeleton for comprehensive test generation, test-all for full test runs, and test-var-query for targeted testing.
Debugging: Apply direct fixes for obvious issues. For complex problems, use systematic investigation with appropriate tools.
Dependencies: Use add-libs for runtime dependency addition (Clojure 1.12+), sync-deps after updating deps.edn, and check-namespace to verify availability.

Workflow Philosophy

Simple, Direct, Effective: The mcp-toolkit foundation enables straightforward tool usage with consistent patterns and reliable error handling.

Tool Selection Principles:

Use the most direct tool for the task
All tools follow the same pattern: input → processing → structured output
Error handling is built-in - tools return clear error messages
No complex state management - each tool call is independent

Tool Categories

Evaluation (2 tools)

eval - Execute code in REPL with proper namespace context
load-file - Load files to update REPL state

Read the full file on GitHub · 303 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 · 303 lines · 2,355 tokens per session scan A 4a3a3710cf9a

Subscribe to this mod's changes

repl-mcp CLAUDE.md is an instructions file published in the GitHub repository simm-is/repl-mcp (44 stars, last pushed 10mo ago), licensed MIT. It adds 2,355 tokens to every session, about $0.0094 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Building agents

repl-mcp CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
repl-mcp CLAUDE.mdsimm-is/repl-mcp	Instructions file	44	10mo ago	MIT	A	2,355	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

repl-mcp: Instructions file for Claude Code