What is mcp-telnet CLAUDE.md?

Repository instructions for an MCP server, a standard way for AI tools to use external services, through telnet connections to text-based systems such as MUDs, older systems, and network equipment.

Building or watching the TypeScript server and understanding its connection, command, session-log, and memory components.

They explain how the project is organised and how to build it, while making clear that no automated test suite is configured.

How distantorigin/mcp-telnet configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to distantorigin/mcp-telnet. 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/distantorigin/mcp-telnet/master/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/distantorigin/mcp-telnet

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/distantorigin/mcp-telnet/claude-md/github.svg)](https://agentmods.dev/instructions/distantorigin/mcp-telnet/claude-md)

Your own site

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

Per session 719 This file is loaded in full into every session.

When invoked 719 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	$0.00719	$0.00719
Opus 5.5	$0.00288	$0.00288
Sonnet 5.5	$0.00144	$0.00144
Haiku 4.5	$0.00072	$0.00072

Measured 2mo ago against content hash 7eea7aa661a3, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcp-telnet 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 · 77 lines

How it starts

The opening of the file, as written. The whole thing — 77 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.

Build Commands

npm run build - Compiles TypeScript to JavaScript, makes scripts executable, and updates version
npm run prepare - Runs build (executed automatically on npm install)
npm run watch - Watches TypeScript files for changes and recompiles

No test suite is configured in this project.

Architecture Overview

This is an MCP (Model Context Protocol) server that enables LLMs to interact with telnet-based services like MUDs, legacy systems, and network equipment.

Core Components

MCP Server Layer (src/server.ts, src/index.ts)

Entry point that initializes the MCP server using the @modelcontextprotocol/sdk
Registers tools, handles identity management, and manages stdio transport
Starts both the MCP server and interactive CLI concurrently

Tool System (src/tools/)

All MCP tools are registered in src/tools/index.ts with schema definitions
Each tool handler is in separate modules (connect, command, status, etc.)
Tools include connection management, command sending, session logging, and memory storage

Connection Management (src/connection/)

telnet.ts - Core telnet client implementation with protocol handling
state.ts - Connection state management and response buffering
Supports automatic reconnection, keep-alive, and MTTS identification

Configuration System (src/config/)

loader.ts - Loads configurations and saved connections from ~/.mcp-telnet/
identity.ts - Manages LLM identity for access control
types.ts - TypeScript types for configuration objects

CLI Interface (src/cli/)

Separate interactive CLI that runs on port 9000 for direct telnet management
Allows manual login and credential entry outside of LLM context

Key Design Patterns

Identity-Based Access Control

LLM must identify itself using set_llm_identity before telnet connections are allowed
Prevents unauthorized access and provides audit trails

Read the full file on GitHub · 77 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 · 77 lines · 719 tokens per session scan A 7eea7aa661a3

Subscribe to this mod's changes

mcp-telnet CLAUDE.md is an instructions file published in the GitHub repository distantorigin/mcp-telnet (12 stars, last pushed 2d ago), licensed MIT. It adds 719 tokens to every session, about $0.0029 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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mcp-telnet: Instructions file for Claude Code