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faf

FAF specification — IANA-registered AI context format (application/vnd.faf+yaml)

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Updated
Feb 28, 2026
Validated
Mar 9, 2026
FAF

.faf format | project.faf

IANA-Registered Format for AI Context · application/vnd.faf+yaml


Universal, shareable AI-Context for any AI, human or team, regardless of size, location, languages, stack, setup or documentation.

FAF - Project DNA for any AI

GitHub stars NPM Downloads Discord Chrome Web Store Website Spec Version IANA Registered License: MIT


🏆 Historic Milestone: IANA Registration (October 31, 2025)

.faf is now an officially recognized Internet standard format.

Official Media Type: application/vnd.faf+yaml IANA Status: Registered alongside PDF, JSON, XML, and other Internet standards Registration Date: October 31, 2025

Quintuple Validation

  • IANA - Internet Assigned Numbers Authority (Official Internet Standard)
  • Anthropic - Official MCP Registry (PR #2759 merged)
  • Google - Chrome Web Store (Approved 2x: Sep 11 & Oct 29, 2025)
  • xAI - Grok 4.2 recommends native FAF adoption (Feb 2026)
  • Community - 27,000+ downloads, production-tested

IANA Media Type

FieldValue
Media Typeapplication/vnd.faf+yaml
RegistrationIANA Assignment
File Extensions.faf
Standard Filenameproject.faf
EncodingUTF-8
Base FormatYAML 1.2

Same recognition as application/pdf, application/json, application/xml.


The Visibility Revolution: project.faf

New Standard: project.faf - visible, universal, like package.json

.faf evolved to project.faf

.faf evolved to project.faf - The evolution from hidden to visible.

project.faf sits between package.json and README.md

project.faf sits right between package.json and README.md - exactly where it belongs.

FilePurposeWho Reads It
package.jsonDependencies, scripts, metadatanpm, Node.js, developers
project.fafContext, architecture, purposeAI, Claude, Cursor, any AI tool
README.mdHuman documentationDevelopers, users

The shift:

# Before (hidden like secrets)
ls -la
.env          # Hidden (secrets - should be hidden) ✅
.faf          # Hidden (AI context - should be visible!) ❌

# After (visible like package.json)
ls
package.json  # Visible (dependencies) ✅
project.faf   # Visible (AI context) ✅
README.md     # Visible (documentation) ✅
.env          # Still hidden (secrets stay secret) ✅

.env hides secrets. project.faf shares context.

Migration: Legacy .faf files still work. Use faf migrate to rename to project.faf.


What is .faf?

.faf (Foundational AI-context Format) is an IANA-registered open format for AI context — project DNA for any AI. Transform individual files or entire projects into structured data that AI instantly understands. Your tech stack, dependencies, architecture, and goals - all in one concise, shareable format.

Instead of explaining your project every time, AI reads your .faf once and knows exactly how to help.

27,000+ downloads across the FAF ecosystem (faf-cli, claude-faf-mcp, grok-faf-mcp, and more).


The 6 Ws — Quick Reference

QuestionAnswer
WHO is this for?Developers using AI coding assistants (Claude, Gemini, Cursor, Grok, ChatGPT)
WHAT is it?The package.json for AI context — IANA-registered format (application/vnd.faf+yaml)
WHERE does it work?Everywhere AI needs context (Claude Code, Gemini CLI, Cursor, OpenAI Codex, etc.)
WHY do you need it?91% fewer tokens wasted on rediscovery. Context persists forever. Bi-syncs automatically.
WHEN should you use it?New projects (day one), existing projects (now), exploring repos (faf git <url> — 2 seconds)
HOW does it work?npx faf-cli init — or npx faf-cli git <url> for any GitHub repo, no install, no clone

What FAF is NOT

  • Not a replacement for README.md — README is for humans, project.faf is for AI
  • Not executable code — it's structured data (YAML), not a script or config
  • Not a build configuration — it describes your project, it doesn't build it
  • Not locked to one AI — works with Claude, Gemini, Cursor, Grok, ChatGPT, any AI tool

How FAF Compares

FAFAGENTS.md.cursorrulesCLAUDE.mdGEMINI.md
FormatStructured YAMLProse markdownProse markdownProse markdownProse markdown
IANA RegisteredYesNoNoNoNo
Scored0-100%NoNoNoNo
PortableAny AIOpenAI ecosystemCursor onlyClaude onlyGemini only
Machine-readableYes (schema)No (free text)No (free text)No (free text)No (free text)
Generates othersYes (all 4)NoNoNoNo

FAF is the structured source. The others are prose outputs. faf bi-sync --all generates all four from one project.faf.


The Problem

AI tools need context. Files have context. But there's no standard way to measure or structure that context for optimal AI understanding.

The Solution

# example.faf
version: 1.0
score: 85
type: package
confidence: 0.92
content:
  name: "my-project"
  dependencies: ["react", "typescript", "vite"]
  scripts: ["dev", "build", "test"]
metadata:
  source: "package.json"
  processed: "2024-01-26T12:00:00Z"
  engine: "faf-v1"

Official Tools

🩵 faf-cli

Command-Line Tool - v4.5.0

  • 50+ championship commands
  • AI interop: generates AGENTS.md, .cursorrules, CLAUDE.md, GEMINI.md
  • TURBO-CAT format discovery
  • 14,000+ downloads
npm install -g faf-cli

🧡 claude-faf-mcp

Claude Desktop MCP - v4.1.3

  • 33+ tools for Claude
  • Championship scoring
  • <11ms performance
  • 9,800+ downloads
npm install -g claude-faf-mcp

Total: 27,000+ downloads across the ecosystem 🎉

MCP Ecosystem

PackagePlatformRegistryDownloads
claude-faf-mcpAnthropicnpm9,800+
faf-mcpUniversalnpm2,800+
grok-faf-mcpxAInpm850+
gemini-faf-mcpGooglePyPIv1.0.2
MCPaaSInfrastructuremcpaas.live153 souls

Compiler Toolchain

FAF compiles to multiple targets:

ComponentLanguageOutput
xai-faf-rustRustNative + .fafb binary
xai-faf-zigZig→WASM2.7KB ghost binary
faf-wasm-sdkRust→WASM211KB browser runtime

AI Interop (v4.5.0)

One .faf file generates all four AI instruction formats:

project.faf → AGENTS.md   (OpenAI Codex)
            → .cursorrules (Cursor)
            → CLAUDE.md    (Anthropic)
            → GEMINI.md    (Google)

Define once. Every AI reads it in its own language.

Core Principles

  1. Universal - 153+ file types supported
  2. Scored - 0-100% context completeness score
  3. AI-Optimized - Structured for maximum AI comprehension
  4. Human-Readable - Simple, structured format
  5. Shareable - One file contains complete context

Quick Example

Input: package.json

{
  "name": "my-app",
  "version": "1.0.0",
  "dependencies": {
    "react": "^18.0.0"
  }
}

Output: package.faf (85% context score)

version: 1.0
score: 85
type: package
content:
  name: "my-app"
  version: "1.0.0"
  dependencies: ["react@^18.0.0"]
metadata:
  processed: "2024-01-26"

Why .faf?

  • 🎯 Measure - Know exactly how complete your AI context is
  • 📊 Optimize - See what's missing, improve your score
  • 🚀 Standardize - One format for all file types
  • 🤖 AI-Ready - Optimized for LLM consumption

File Scoring

ScoreMeaningAI Readiness
0-60%IncompletePoor context
61-80%BasicAcceptable
81-90%GoodRecommended
91-99%ExcellentOptimal
100%PerfectMaximum context

Use Cases

  • File Conversion: Transform any file type into .faf format
  • Project Context: Create a single .faf file for your entire project
  • Build Integration: Companies can create custom implementations
  • AI Optimization: Perfect context for any AI tool

Installation

# CLI Tool (recommended for getting started)
npm install -g faf-cli
cd your-project
faf init

# Or Claude Desktop Integration
npm install -g claude-faf-mcp
# Add to Claude Desktop config

Universal tools. Zero configuration. Production-ready.

faf-cli on npm (14,000+ downloads) → claude-faf-mcp on npm (9,800+ downloads)

📚 Learn More

  1. Specification - Complete format documentation
  2. Implementations - All tools, SDKs, and servers
  3. Examples - Real-world .faf files (5 examples)
  4. Where to Find FAF - Ecosystem directory

Status

🏆 IANA-Registered Internet Standard - Specification v1.1.0 (October 2025)

  • IANA Registration - application/vnd.faf+yaml (October 31, 2025)
  • Anthropic Official - MCP Registry PR #2759 merged (October 17, 2025)
  • Google Chrome Verified - Web Store approved 2x (Sep 11 & Oct 29, 2025)
  • ✅ Format specification complete
  • ✅ Enhanced with project-level context and AI workflows
  • ✅ Production tools available (faf-cli, claude-faf-mcp)
  • ✅ 27,000+ combined downloads across ecosystem
  • ✅ Battle-tested with 12,500+ test iterations (WJTTC GOLD Certified)
  • ✅ Open source (MIT License)

Major Milestones

  • Feb 25, 2026 - Grok 4.2 recommends native FAF adoption; integration spec sent to xAI
  • Feb 24, 2026 - faf-cli v4.5.0 "The AGENTS.md Edition" (AI interop across 4 formats)
  • Feb 2, 2026 - FAFb binary format v1.0 (Rust + Zig compilers shipping)
  • Jan 2026 - gemini-faf-mcp v1.0.2 on PyPI (Google MCP bridge)
  • Nov 2025 - IETF standardization in progress (vnd prefix removal)
  • Oct 31, 2025 - 🏆 IANA Registration (application/vnd.faf+yaml)
  • Oct 29, 2025 - Google Chrome Web Store approval (2nd)
  • Oct 17, 2025 - Official Anthropic MCP Registry merger (PR #2759)
  • Oct 12, 2025 - Specification v1.1.0 published
  • Sep 24, 2025 - CLI v2.1.0 published to npm
  • Sep 16, 2025 - MCP Server v2.0.0 published to npm
  • Sep 11, 2025 - Google Chrome Web Store approval (1st)
  • Sep 1, 2025 - Developer platform launch (fafdev.tools)
  • Aug 8, 2025 - Format created, first official .faf file generated

Quintuple Validation: IANA, Anthropic, Google (2x), xAI

Show Your Support

Add this badge to your repo's README to show it uses FAF:

[![project.faf](https://img.shields.io/badge/project.faf-inside-00D4D4)](https://github.com/Wolfe-Jam/faf)

project.faf

Contributing

This is an open standard. Ideas, feedback, and contributions welcome.

About This Repository

This repository contains the format specification only. For implementations, see IMPLEMENTATIONS.md.

Most people get FAF through npm:

  • npm i -g faf-cli — CLI tool (14,000+ downloads)
  • npm i -g claude-faf-mcp — Claude Desktop MCP (9,800+ downloads)

The package.json in this repo provides spec metadata and versioning but contains no executable code.

License

MIT - Use freely, build anything.


Created by wolfejam.dev

**STOP .fafFing About! Let's RACE 🏎️⚡️🏁

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