ASON - Aliased Serialization Object Notation

Token-optimized JSON compression format for LLMs

Original JSON

ASON Format

Tip: Hover over parts of the compressed format to see what each element represents.

How ASON Compresses Your Data

Document Structure

$def:

Definitions section where repeated objects and array schemas are declared once and referenced later.

$data:

Data section containing the actual compressed content using the definitions from above.

Uniform Arrays

Extract common keys to a header

// Instead of repeating keys:
[{id:1,name:"Alice"},{id:2,name:"Bob"}]
// ASON uses:
[2]@id,name
1,Alice
2,Bob

Value Dictionary

Deduplicate repeated values

// First occurrence:
email:user@example.com #0
// Subsequent uses:
shipping.email:#0

Object References

Reuse repeated structures

// Define once:
&obj0:{city:"SF",zip:"94102"}
// Reference everywhere:
billing:&obj0
shipping:&obj0

Path Flattening

Collapse nested single properties

// Instead of:
user:{profile:{settings:{theme:"dark"}}}
// ASON flattens to:
user.profile.settings.theme:dark
Complete Example: All Techniques Combined
JSON 384 tokens 
{
  "order": {
    "id": "ORD-2024-001",
    "customer": {
      "name": "Alice Johnson",
      "email": "alice@example.com"
    },
    "billing": {
      "street": "123 Main St",
      "city": "San Francisco",
      "zip": "94102"
    },
    "shipping": {
      "street": "123 Main St",
      "city": "San Francisco",
      "zip": "94102"
    },
    "items": [
      {"id": 1, "product": "Laptop", "price": 999},
      {"id": 2, "product": "Mouse", "price": 29}
    ]
  }
}
ASON 287 tokens (25% reduction) 
$def:
 &obj0:
  street:123 Main St
  city:San Francisco
  zip:94102
$data:
order.id:ORD-2024-001
order.customer.name:Alice Johnson #0
order.customer.email:alice@example.com
order.billing:&obj0
order.shipping:&obj0
order.items:[2]@id,product,price
 1,Laptop,999
 2,Mouse,29
Components: $def / $data - Sections [N]@keys - Arrays &obj0 - References a.b.c - Paths #0 - Values

Why Choose ASON?

Zero Configuration

No setup required. ASON automatically detects patterns and optimizes compression without any manual configuration.

Perfect Fidelity

Lossless round-trip guaranteed. Your data structure and values remain exactly as they were after decompression.

Proven Results

Up to 23% token reduction on uniform data with 4.94% average savings across diverse datasets. Consistently beats alternatives.

Universal Support

Full TypeScript definitions. Works seamlessly in Node.js and browsers. Available on NPM and all major CDNs.

Human Readable

Unlike binary formats, ASON output remains readable and debuggable while achieving significant compression ratios.

Smart Patterns

Combines multiple techniques: uniform arrays, object references, value dictionaries, and path flattening automatically.

Tools & Extensions

View all

MCP Server

Enable ASON in Claude Desktop, Cline, Continue, and other MCP-compatible AI assistants.

compress_json decompress_ason stats

VS Code Extension

Compress/decompress JSON with keyboard shortcuts, context menus, and GitHub Copilot integration.

Cmd+Alt+C Status bar MCP auto-config

Zed Extension

Rust-based ASON extension with slash commands and AI assistant integration for Zed editor.

/ason-compress Native Rust AI integration