Crate gcf 

GCF (Graph Compact Format) encoder and decoder for Rust.

GCF is a compact, text-only, graph-native wire format designed for MCP tool responses. It exploits referential identity (local IDs), graph topology (edges as references), and hierarchical grouping (distance-based sections) to achieve significant token savings over JSON while remaining human-readable.

Specification: https://github.com/blackwell-systems/gcf

Quick Start

use gcf::{Payload, Symbol, Edge, encode, decode};

let p = Payload {
    tool: "context_for_task".to_string(),
    token_budget: 5000,
    tokens_used: 1847,
    pack_root: String::new(),
    symbols: vec![
        Symbol {
            qualified_name: "pkg.AuthMiddleware".to_string(),
            kind: "function".to_string(),
            score: 0.78,
            provenance: "lsp_resolved".to_string(),
            distance: 0,
            signature: String::new(),
            components: Default::default(),
        },
    ],
    edges: vec![],
};

let output = encode(&p);
let decoded = decode(&output).unwrap();
assert_eq!(decoded.tool, "context_for_task");

Re-exports

pub use decode::decode;

pub use decode::DecodeError;

pub use decode_generic::decode_generic;

pub use delta::encode_delta;

pub use encode::encode;

pub use generic::encode_generic;

pub use session::encode_with_session;

pub use session::Session;

pub use stream::StreamEncoder;

pub use stream::StreamOptions;

pub use stream_generic::GenericStreamEncoder;

pub use types::Components;

pub use types::DeltaPayload;

pub use types::Edge;

pub use types::Payload;

pub use types::Symbol;

Modules

decode

decode_generic

delta

encode

generic

session

stream

stream_generic

types

Functions

kind_abbrev

Returns the GCF abbreviation for a kind, or the original string if no abbreviation exists.

kind_expand

Returns the expanded kind for a GCF abbreviation, or the original string if not recognized.