What is emacs-mcp-server CLAUDE.md?

Instructions for connecting an AI coding agent to a running Emacs editor through an MCP server. Emacs is a programmable text editor, and Magit is its interface for reviewing Git changes.

Use them to open project files in Emacs, view Git changes in Magit, check whether Emacs is available, and discover the server’s tools.

They explain the required Emacs server setup and the available commands, making it easier to open files, inspect repository changes, and check the connection.

How toastynerd/emacs-mcp-server configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to toastynerd/emacs-mcp-server. 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/toastynerd/emacs-mcp-server/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/toastynerd/emacs-mcp-server

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/toastynerd/emacs-mcp-server/claude-md/github.svg)](https://agentmods.dev/instructions/toastynerd/emacs-mcp-server/claude-md)

Your own site

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

Per session 630 This file is loaded in full into every session.

When invoked 630 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	$0.00630	$0.00630
Opus 5.5	$0.00252	$0.00252
Sonnet 5.5	$0.00126	$0.00126
Haiku 4.5	$0.00063	$0.00063

Measured 2mo ago against content hash 989040659c44, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

emacs-mcp-server 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 · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Scope

Direct MCP tools that allow Claude Code to communicate with and control a running Emacs instance.

Prerequisites

Emacs with server mode enabled (M-x server-start)
emacsclient available in PATH
Node.js and npm (v14+)

MCP Tools

emacs-mcp-open - Opens the specified file in a new buffer in Emacs
- Required parameter: file_path (absolute path to file)
- Usage: For opening files directly in Emacs
emacs-mcp-magit - Opens Magit to show Git changes
- Optional parameter: repo_path (defaults to current directory)
- Usage: For viewing Git changes in the Magit interface
emacs-mcp-check - Checks if the Emacs server is running
- No parameters
- Usage: For verifying Emacs server status
emacs-mcp-list - Lists all available tools in this MCP server
- No parameters
- Usage: For discovering available tools and their parameters

Complementary Tools

git-mcp - For repository access and documentation exploration
- Usage: Allows Claude to read repository files and documentation
- Setup: claude mcp add --transport sse git-mcp https://gitmcp.io/idosal/git-mcp

Setup

To configure these MCP tools with Claude Code:

# Install dependencies
npm install

# Add the direct tools to Claude Code
claude mcp add emacs-mcp-open /Users/toasty/programming/emacs-mcp-server/src/direct-tool.js
claude mcp add emacs-mcp-magit /Users/toasty/programming/emacs-mcp-server/src/direct-tool.js
claude mcp add emacs-mcp-check /Users/toasty/programming/emacs-mcp-server/src/direct-tool.js
claude mcp add emacs-mcp-list /Users/toasty/programming/emacs-mcp-server/src/direct-tool.js

Replace the paths with the absolute path to your repository.

Usage in Claude Code

/mcp emacs-mcp-open file_path="/path/to/your/file.txt"
/mcp emacs-mcp-magit repo_path="/path/to/your/repo"
/mcp emacs-mcp-check
/mcp emacs-mcp-list

Logs and Debugging

Tool logs stored at: /tmp/emacs-mcp-direct.log
Claude MCP status: claude mcp list
Detailed MCP tool info: claude mcp get emacs-mcp-open

Read the full file on GitHub · 65 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 · 65 lines · 630 tokens per session scan A 989040659c44

Subscribe to this mod's changes

emacs-mcp-server CLAUDE.md is an instructions file published in the GitHub repository toastynerd/emacs-mcp-server (4 stars, last pushed 1y ago), licensed MIT. It adds 630 tokens to every session, about $0.0025 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 2026-08-31.

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emacs-mcp-server: Instructions file for Claude Code