JSON to TypeScript Interface

WHAT IT DOES

JSON to TypeScript Interface generates TypeScript interfaces or types from JSON data, saving you time when working with API responses or complex data structures. Paste your JSON or upload a .json file, and the tool produces clean TypeScript code with proper type annotations. You can customize the output with options including interface or type alias, optional fields, comments, export keyword, and custom interface naming. The tool handles nested objects, arrays, union types, and automatically detects property types. A preview shows the generated TypeScript, and you can copy it to your clipboard or download it as a .ts file.

WHERE IT RUNS

The extension runs entirely within your browser's local environment using the BotGentz framework. All JSON parsing, type inference, and TypeScript generation occur on your machine without any network requests. No JSON data, TypeScript output, or user activity is ever transmitted, uploaded, or stored externally. The tool works on any website and respects the browser's security boundaries, operating within the isolated extension sandbox. Type generation uses pure JavaScript object traversal and type inference.

HOW TO USE

Click the extension toolbar icon to open the JSON to TypeScript Interface panel. Paste JSON data into the input area or click the file input to upload a .json file. Click "Generate" to create the TypeScript interfaces. The preview shows the generated TypeScript code with proper formatting. Click "Copy TypeScript" to copy the output to your clipboard. Click "Download .ts" to save the output as a .ts file. Enter an "Interface name" to set the root interface name. Toggle "Optional fields" to add a ? to all properties. Toggle "Use type alias" to generate type aliases instead of interfaces. Toggle "Include comments" to add JSDoc comments to each interface. Toggle "Export keyword" to add the export keyword before each interface. The tool updates automatically when you change settings.

THE TYPE GENERATION ENGINE — WHY IT WORKS

Most JSON-to-TypeScript generators use simple string templates that miss nested structures or produce inconsistent output. This tool uses a recursive type inference engine that traverses the JSON object tree and builds TypeScript types from the data. The engine detects property types (string, number, boolean, null, object, array) and generates appropriate TypeScript annotations. For arrays, it infers the element type and creates array types (e.g., string[]). For nested objects, it recursively generates interfaces and tracks them to avoid duplication. The engine also handles union types when arrays contain multiple different types. The optional fields option makes all properties optional with the ? modifier. The interface/type alias option controls the output syntax. The comments option adds JSDoc-style comments to each interface. This approach provides accurate, readable TypeScript type definitions that reflect the structure of your JSON data.

THE PANEL

The JSON to TypeScript Interface panel is fully draggable by its title bar and remembers its position on screen per website. It snaps to the edges of your browser window for clean alignment. Collapse the panel to a compact icon strip using the minimize button, restoring it with a single click. Resize the panel by dragging any edge or corner; the input area, output preview, and controls adjust proportionally. Press the Escape key to close the panel instantly. The panel maintains independent state for each browser tab, allowing you to generate TypeScript interfaces in multiple tabs simultaneously.

PLEASE NOTE

This extension requires the free BotGentz extension framework to be installed and enabled. The tool generates type definitions based on the provided JSON data; if the data is inconsistent, the generated types may be incomplete. The type inference is heuristic-based and may not produce perfect types for all edge cases. Large JSON objects with deeply nested structures may generate many interfaces. The generated TypeScript is intended as a starting point and may need manual adjustments. All data is processed locally and is never transmitted, logged, or shared. The extension requests no network permissions and functions entirely offline. The source code is fully auditable and available for review.