toonify is a Python library that implements TOON (Token-Oriented Object Notation), a compact and human-readable serialization format specifically designed for passing structured data to Large Language Models (LLMs). It addresses the challenge of reducing token consumption when working with LLM APIs while maintaining data structure and readability.
Describe features
Compact: Achieves 30-60% size reduction compared to JSON for structured data, significantly reducing LLM token costs
Human-readable: Clean, indentation-based syntax that's easy to read and understand
Structured: Preserves nested objects, arrays, and complex data hierarchies
Type-safe: Supports strings, numbers, booleans, and null values with proper type preservation
Flexible delimiters: Multiple delimiter options (comma, tab, pipe) for different data scenarios
Smart tabular format: Automatically formats uniform arrays in a CSV-like table structure with headers
CLI tool included: Command-line utility for converting between JSON and TOON formats
Bidirectional conversion: Encode Python objects to TOON and decode back to Python seamlessly
What's the difference between this Python project and similar ones?
Compared to existing serialization libraries in the list:
marshmallow: Focuses on object serialization/deserialization with schema validation; toonify focuses on token-efficient data representation for LLMs
pysimdjson / python-rapidjson / ultrajson: These libraries optimize JSON parsing speed; toonify creates a fundamentally different format optimized for token reduction (not just parsing performance)
Standard JSON: TOON achieves 30-60% token reduction while maintaining explicit structure, unlike JSON which is verbose with repetitive keys
CSV formats: TOON combines CSV-like compactness with JSON-like structure, supporting nested objects and arrays that CSV cannot handle
Unique value proposition: toonify is the only Python serialization library specifically designed to minimize LLM token usage while maintaining data structure integrity, making it ideal for AI applications where context window and API costs are critical concerns.
🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.
## 📋 Pull Request Information
**Original PR:** https://github.com/vinta/awesome-python/pull/2795
**Author:** [@VinciGit00](https://github.com/VinciGit00)
**Created:** 11/11/2025
**Status:** ✅ Merged
**Merged:** 11/17/2025
**Merged by:** [@vinta](https://github.com/vinta)
**Base:** `master` ← **Head:** `master`
---
### 📝 Commits (1)
- [`61ef122`](https://github.com/vinta/awesome-python/commit/61ef122791a199ae5fc8e5bff5f52020814e40ea) Update README.md
### 📊 Changes
**1 file changed** (+1 additions, -0 deletions)
<details>
<summary>View changed files</summary>
📝 `README.md` (+1 -0)
</details>
### 📄 Description
## What is this Python project?
**toonify** is a Python library that implements TOON (Token-Oriented Object Notation), a compact and human-readable serialization format specifically designed for passing structured data to Large Language Models (LLMs). It addresses the challenge of reducing token consumption when working with LLM APIs while maintaining data structure and readability.
## Describe features
- **Compact**: Achieves 30-60% size reduction compared to JSON for structured data, significantly reducing LLM token costs
- **Human-readable**: Clean, indentation-based syntax that's easy to read and understand
- **Structured**: Preserves nested objects, arrays, and complex data hierarchies
- **Type-safe**: Supports strings, numbers, booleans, and null values with proper type preservation
- **Flexible delimiters**: Multiple delimiter options (comma, tab, pipe) for different data scenarios
- **Smart tabular format**: Automatically formats uniform arrays in a CSV-like table structure with headers
- **Key folding**: Efficiently handles deeply nested objects by collapsing single-key chains
- **CLI tool included**: Command-line utility for converting between JSON and TOON formats
- **Bidirectional conversion**: Encode Python objects to TOON and decode back to Python seamlessly
## What's the difference between this Python project and similar ones?
**Compared to existing serialization libraries in the list:**
- **marshmallow**: Focuses on object serialization/deserialization with schema validation; toonify focuses on token-efficient data representation for LLMs
- **pysimdjson / python-rapidjson / ultrajson**: These libraries optimize JSON parsing speed; toonify creates a fundamentally different format optimized for token reduction (not just parsing performance)
- **Standard JSON**: TOON achieves 30-60% token reduction while maintaining explicit structure, unlike JSON which is verbose with repetitive keys
- **CSV formats**: TOON combines CSV-like compactness with JSON-like structure, supporting nested objects and arrays that CSV cannot handle
**Unique value proposition**: toonify is the only Python serialization library specifically designed to minimize LLM token usage while maintaining data structure integrity, making it ideal for AI applications where context window and API costs are critical concerns.
---
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<sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>
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📋 Pull Request Information
Original PR: https://github.com/vinta/awesome-python/pull/2795
Author: @VinciGit00
Created: 11/11/2025
Status: ✅ Merged
Merged: 11/17/2025
Merged by: @vinta
Base:
master← Head:master📝 Commits (1)
61ef122Update README.md📊 Changes
1 file changed (+1 additions, -0 deletions)
View changed files
📝
README.md(+1 -0)📄 Description
What is this Python project?
toonify is a Python library that implements TOON (Token-Oriented Object Notation), a compact and human-readable serialization format specifically designed for passing structured data to Large Language Models (LLMs). It addresses the challenge of reducing token consumption when working with LLM APIs while maintaining data structure and readability.
Describe features
What's the difference between this Python project and similar ones?
Compared to existing serialization libraries in the list:
Unique value proposition: toonify is the only Python serialization library specifically designed to minimize LLM token usage while maintaining data structure integrity, making it ideal for AI applications where context window and API costs are critical concerns.
🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.