json-to-types

What it does

The JSON to Types Converter handles the tedious task of manually defining data structures for API responses or JSON datasets. It recursively analyzes any JSON source—whether a local file or a raw string—and generates production-ready TypeScript interfaces or Python dataclasses.

Why use this skill

While you can ask a standard LLM to "convert this JSON," this skill provides a structured developer workflow that an LLM alone often misses. It auto-detects your project's language environment, handles singularization of array roots (e.g., turning users.json into a User interface), manages complex union types for mixed arrays, and follows language-specific best practices like snake_case conversion for Python and Record<string, unknown> for dynamic objects.

Supported tools

• TypeScript: Generates exported interfaces with optional property support and type aliases.
• Python: Generates @dataclass definitions using the typing module and __future__ annotations.
• Project Detection: Uses Glob to automatically check for tsconfig.json or pyproject.toml to choose the right language.

The Output

It generates a clean, well-commented types.ts or models.py file and provides a summary report of the inferred schema, including which fields were marked as optional based on property presence across array items.