Faf Crate

faf

Persistent Project Context for Rust. cargo add faf and you're in.

FAF defines. MD instructs. AI codes.

One crate, full ecosystem. Parse, validate, compile, and broadcast .faf files in Rust.

FAF (Foundational AI-context Format) is the IANA-registered format for persistent AI project context (application/vnd.faf+yaml). This meta-crate re-exports everything you need.

Install

cargo add faf

With Radio Protocol + Axum middleware:

cargo add faf --features radio,axum

Quick Start

use faf::{parse, binary};

let yaml = std::fs::read_to_string("project.faf")?;

// Parse
let doc = parse(&yaml)?;
println!("{} — {}% AI-ready", doc.project_name(), doc.score().unwrap_or(0));

// Compile to FAFb binary
let fafb = binary::compile(&yaml)?;
println!("{} bytes YAML → {} bytes FAFb", yaml.len(), fafb.len());

Feature Flags

| Feature | Default | Crate | What you get | |---------|---------|-------|--------------| | sdk | yes | faf-rust-sdk | Parse, validate, compile, FAFb binary format | | radio | no | faf-radio-rust | Radio Protocol — broadcast AI context via WebSocket | | axum | no | faf-rust-sdk/axum | FafContext extractor + FafLayer middleware |

Radio Protocol

Broadcast AI context once, every tool receives:

use faf::faf_radio_rust::{RadioClient, RadioConfig};

let mut client = RadioClient::new(RadioConfig::grok());
client.connect().await?;
client.tune(vec!["91.0".into()]).await?;

// Broadcast metadata on a frequency
client.broadcast("91.0", serde_json::json!({
    "type": "fafb",
    "project": "my-app",
    "size": 220,
})).await?;

Axum Middleware

Inject .faf project context into every request:

use faf::{FafLayer, FafContext};

let app = Router::new()
    .route("/", get(handler))
    .layer(FafLayer::discover());

async fn handler(faf: FafContext) -> String {
    format!("Project: {}", faf.project_name())
}

Ecosystem

| Crate | Version | What | |-------|---------|------| | faf | 0.3.0 | This meta-crate | | faf-rust-sdk | 1.3.0 | Core SDK — parse, validate, compile, FAFb | | faf-radio-rust | 0.2.0 | Radio Protocol client | | rust-faf-mcp | 0.1.0 | MCP server for .faf |

Also available in TypeScript, Python, and Zig.

If faf has been useful, consider starring the repo — it helps others find it.

Links

• Website: faf.one
• IANA: application/vnd.faf+yaml
• Docs: docs.rs/faf
• Platform: mcpaas.live

License

MIT

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Built by Wolfe James | faf.one

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Wolfe-Jam
• Source: Wolfe-Jam/faf-crate
• License: MIT
• Homepage: https://faf.one

Install and usage instructions live in the source repository linked above.