The AI-native wire format for structured data. 100% comprehension on every frontier model. 71% fewer tokens than JSON. 33B+ lossless round-trips across 5 formats. Spec v3.1 Stable.

MCP proxy: zero-code GCF adoption. Wraps any MCP server, converts JSON to GCF mid-flight. 53-71% fewer tokens. Works with any structured data.

GCF Go implementation. 100% comprehension. 71% fewer tokens than JSON, 25% fewer than TOON. 200M round-trips verified. v1.2.0.

GCF Rust implementation. 100% comprehension. 71% fewer tokens than JSON, 25% fewer than TOON. 33B+ round-trips verified. v2.1.0.

GCF TypeScript implementation. 100% comprehension. 71% fewer tokens than JSON, 25% fewer than TOON. 20M round-trips verified. v2.1.0.

GCF Python implementation. 100% comprehension. 71% fewer tokens than JSON, 25% fewer than TOON. 10M round-trips verified. v2.1.0.

Fork of toon-format/toon with GCF comparison. GCF uses 34% fewer tokens on their own benchmark.

jsonalternative.com - GCF is the JSON alternative for AI pipelines

Tree-sitter grammar for GCF. Full spec compliance, WASM build for browser playground.

GCF vs TOON benchmark data

GCF Swift implementation. 100% comprehension. 71% fewer tokens than JSON, 25% fewer than TOON. 20M round-trips verified. v2.1.0.

GCF Kotlin implementation. 100% comprehension. 71% fewer tokens than JSON, 25% fewer than TOON. 10M round-trips verified. v2.1.0.