The AI-native wire format for structured data. 100% comprehension on every frontier model. 50-92% fewer tokens than JSON. 43B+ lossless round-trips across 17 formats. Spec v3.5.1 Stable.
README
[!IMPORTANT] Graph Compact Format (GCF): A Token-Efficient Wire Format for LLM Tool Interactions Dayna Blackwell, 2026. DOI: 10.5281/zenodo.20579817
100% comprehension on every frontier model tested. 25.5% fewer tokens than TOON, 53% fewer than JSON across 15 datasets. 90.7% on structurally complex code graphs (vs TOON 68.5%, JSON 53.6%). Proven lossless: decode(encode(value)) == value for every structured value, verified across 33,000,000,000+ round-trips in 5 formats (JSON, YAML, TOML, CSV, MessagePack). Zero training required.
Encode any structured data as GCF before sending it to an LLM. JSON, YAML, TOML, CSV, MessagePack: GCF encodes them all. The model reads it natively with zero format instructions. decode() converts back to any format when a human needs to see it. Your existing schemas and validators work on the decoded output unchanged.
pip install gcf-python # Python
npm install @blackwell-systems/gcf # TypeScript
go get github.com/blackwell-systems/gcf-go # Go