What is vfs AGENTS.md?

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.

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.

It gives agents consistent guidance for using the tool and explains that parsing happens locally without network access, telemetry, or stored source code.

How TrNgTien/vfs configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to TrNgTien/vfs. 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/TrNgTien/vfs/main/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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/trngtien/vfs/agents-md/github.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/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/trngtien/vfs/agents-md"><img src="https://agentmods.dev/badge/instructions/trngtien/vfs/agents-md.svg" alt="Reviewed on agentmods" width="80" 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. 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	$0.03334	$0.03334
Opus 5.5	$0.01334	$0.01334
Sonnet 5.5	$0.00667	$0.00667
Haiku 4.5	$0.00333	$0.00333

Measured 2mo ago against content hash 5fdc7c5a4352, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, 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 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.

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.

2mo 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 (144 stars, last pushed 2mo ago), licensed MIT. It adds 3,334 tokens to every session, about $0.0133 per session on Opus 5.5. 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.

ai-agents go vibe-coding

vfs AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
vfs AGENTS.mdTrNgTien/vfs	Instructions file	144	2mo ago	MIT	A	3,334	Codex, OpenCode
vibe-coding-prompt-template backend.instructions.mdKhazP/vibe-coding-prompt-template	Instructions file	3.2k	1mo ago	MIT	A	139	GitHub Copilot
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

vfs: Instructions file for Codex