RustAPI TOON

Token-Oriented Object Notation (TOON) support.

🤖 What is TOON?

TOON is an experimental, density-optimized data format designed for High-Volume LLM Interactions.

When building agents or APIs that consume massive amounts of structured data via LLMs (GPT-4, Claude), standard JSON is token-expensive due to repeated keys and syntax overhead. TOON eliminates this redundancy.

Comparison

JSON (Expensive)

[
  {"id": 1, "role": "admin", "active": true},
  {"id": 2, "role": "user",  "active": true},
  {"id": 3, "role": "user",  "active": false}
]

TOON (Optimized)

users[3]{id,role,active}:
  1,admin,true
  2,user,true
  3,user,false

Usage

RustAPI handles this transparently via content negotiation.

use rustapi_toon::Toon;

// Accepts explicit TOON or JSON automatically based on Content-Type
#[post("/ingest")]
async fn ingest(Toon(data): Toon<Vec<User>>) -> impl Responder {
    // ...
}