ptc-fs-mcp: Instructions file for Codex

AGENTS.md

ptc-fs-mcp AGENTS.md is an instructions file for Codex, OpenCode from andreasronge/ptc-fs-mcp. It costs 516 tokens per session, scanned A, original, MIT.

Repository instructions for a TypeScript filesystem MCP server that exposes files only inside a configured folder. It covers setup, build commands, tests, formatting, and project boundaries.

In plain words
What is it for?
Use it when developing, testing, formatting, or reviewing the ptc-fs-mcp project.
Why use it?
It gives an agent the repository's expected workflow and security constraints before changing code.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is andreasronge/ptc-fs-mcp's own configuration. It tells Codex and OpenCode how to work on ptc-fs-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ptc-fs-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to andreasronge/ptc-fs-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/andreasronge/ptc-fs-mcp/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/andreasronge/ptc-fs-mcp

Made for: Codex, OpenCode.

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.

agentmods badge for ptc-fs-mcp AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/andreasronge/ptc-fs-mcp/agents-md/github.svg)](https://agentmods.dev/instructions/andreasronge/ptc-fs-mcp/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/andreasronge/ptc-fs-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/andreasronge/ptc-fs-mcp/agents-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.

agentmods 80×15 button for ptc-fs-mcp AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/andreasronge/ptc-fs-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/andreasronge/ptc-fs-mcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 516 This file is loaded in full into every session.
When invoked 516 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00516 $0.00516
Opus 5 $0.00258 $0.00258
Sonnet 5 $0.00103 $0.00103
Haiku 4.5 $0.00052 $0.00052

Measured 8d ago against content hash ab167e60406c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

ptc-fs-mcp AGENTS.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 8d 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.

AGENTS.md · 47 lines

How it starts

The opening of the file, as written. The whole thing — 47 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Repository guidance

Project overview

ptc-fs-mcp is a small TypeScript filesystem MCP server and library. It exposes files only beneath one configured root and communicates over stdio. The package is demo software, but its confinement, cursor integrity, byte budgets, and protocol behavior are deliberate security and compatibility boundaries.

Setup and commands

  • Use a supported Node.js release from package.json (>=20.19.0) and install the locked dependency tree with pnpm install --frozen-lockfile. This repository uses pnpm, with its exact version pinned in package.json.
  • Run pnpm run build to compile src/ into the ignored dist/ directory.
  • Run pnpm test for the full integration suite. Tests exercise the built CLI over real stdio and create their own temporary filesystem roots.
  • Run pnpm run verify before proposing a change. It checks formatting and types, rebuilds, and runs the full test suite.
  • Use pnpm run format when repository files need Prettier formatting.

Repository conventions

  • Keep production code in src/ and tests in test/*.test.mjs. Add or update tests for observable behavior changes and bug fixes.
  • Do not commit dist/, node_modules/, coverage output, tarballs, or other generated artifacts.
  • Preserve ESM imports and the strict TypeScript settings in tsconfig.json.
  • Keep stdout reserved for MCP protocol messages. Send diagnostics to stderr, and keep user-facing errors short without stack traces or host paths.
  • Keep the server deterministic and self-contained: it must not spawn child processes, access the network, or depend on environment variables.
  • Treat path confinement, symlink handling, include/exclude rules, cursor validation, result-size limits, and UTF-8 handling as security-sensitive. Do not weaken them without explicit maintainer direction.
  • This server intentionally supports only the MCP protocol profile documented in README.md. Do not add negotiation or compatibility fallbacks unless the task explicitly calls for them.

Read the full file on GitHub · 47 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.

  1. 8d ago First seen · 47 lines · 516 tokens per session scan A ab167e60406c

Subscribe to this mod's changes

ptc-fs-mcp AGENTS.md is an instructions file published in the GitHub repository andreasronge/ptc-fs-mcp (0 stars, last pushed 4d ago), licensed MIT. It adds 516 tokens to every session, about $0.0026 per session on Opus 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 2026-09-04.

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