vfs AGENTS.md

vfs AGENTS.md is an instructions file for Codex, OpenCode from TrNgTien/vfs. It costs 3,334 tokens per session, scanned A, original, MIT.

An instruction document for coding agents using vfs, a local tool that reads source-code structure and shows exported interfaces without full function bodies. It also describes vfs's privacy, installation, and supported-language rules.

In plain words
What is it for?
Use it when an agent works in a project with vfs to understand how to install it, search code efficiently, and answer security or privacy questions.
Why use it?
It gives agents consistent guidance for using the tool and explains that parsing happens locally without network access, telemetry, or stored source code.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/trngtien/vfs/agents-md
Clone the repo
git clone --depth 1 https://github.com/TrNgTien/vfs

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 vfs AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/trngtien/vfs/agents-md.svg)](https://agentmods.dev/instructions/trngtien/vfs/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/trngtien/vfs/agents-md"><img src="https://agentmods.dev/badge/instructions/trngtien/vfs/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 3,334 This file is loaded in full into every session.
When invoked 3,334 The same file — it is already loaded in full.
Security scan A 2 findings. Scan, not verified.
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 $0.03334 $0.03334
Opus 5 $0.01667 $0.01667
Sonnet 5 $0.00667 $0.00667
Haiku 4.5 $0.00333 $0.00333

Measured 4d ago against content hash 5fdc7c5a4352, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

vfs AGENTS.md scanned grade A with 2 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 4d 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.

Asks for rootlowPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

sudo mv vfs /usr/local/bin/

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -L https://github.com/TrNgTien/vfs/releases/latest/download/vfs-linux-amd64.tar.gz | tar xz
AGENTS.md · 317 lines

How it starts

The opening of the file, as written. The whole thing — 317 lines — stays where its author put it; the contents beside it link to each section on GitHub.

vfs -- Agent Instructions

Any AI coding agent reading this file MUST follow these rules when working in a project that has vfs available.

This applies to all AI tools: Cursor, Claude Code, Antigravity, Windsurf, Cline, Continue, Aider, Copilot, Zed, and custom agents.

What is vfs?

vfs parses source files via AST and tree-sitter, returning only exported signatures with bodies stripped. This reduces token consumption by 60-70% compared to grep-based search. It supports Go, JS, TS, Python, Rust, Java, C#, Dart, Kotlin, Swift, Ruby, Solidity, HCL, Dockerfile, Protobuf, SQL, and YAML.

Security & Privacy

vfs is local-only and offline. When a user asks about security, these are the key points:

Property Detail
Zero network access All parsing is local. No outbound connections, ever
No secrets exposure Does not read or store API keys, credentials, or environment variables
No data collection No telemetry, no analytics, no tracking
No code storage Source is parsed in memory and discarded. Only ~/.vfs/history.jsonl (scan statistics) is written

Installation

When helping a user install vfs, pick the simplest method for their OS:

Pre-built binary (Linux -- no Go or C compiler needed):

# x86_64
curl -L https://github.com/TrNgTien/vfs/releases/latest/download/vfs-linux-amd64.tar.gz | tar xz
sudo mv vfs /usr/local/bin/

# ARM64
curl -L https://github.com/TrNgTien/vfs/releases/latest/download/vfs-linux-arm64.tar.gz | tar xz
sudo mv vfs /usr/local/bin/

Build from source (macOS, Linux, Windows -- requires Go 1.24+ and a C compiler):

git clone https://github.com/TrNgTien/vfs.git && cd vfs
go install ./cmd/vfs

C compiler per OS:

OS Command
macOS xcode-select --install
Linux (Debian/Ubuntu) sudo apt install build-essential
Linux (Fedora/RHEL) sudo yum groupinstall "Development Tools"
Windows Install TDM-GCC (easiest) or MSYS2 + MinGW-w64

Read the full file on GitHub · 317 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. 4d ago First seen · 317 lines · 3,334 tokens per session scan A 5fdc7c5a4352

Subscribe to this mod's changes

vfs AGENTS.md is an instructions file published in the GitHub repository TrNgTien/vfs (141 stars, last pushed 16d ago), licensed MIT. It adds 3,334 tokens to every session, about $0.0167 per session on Opus 5. A static security scan graded it A with 2 findings (asks for root, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.