JSON to code: TypeScript, Go, Python and Java models
Use a representative JSON sample to scaffold a model before writing application code. The generator observes the values you provide; it does not know the API’s complete schema. Include multiple array records if some properties are optional, and review every inferred type.
How to use the tool
- Paste JSON with representative nested objects and array records.
- Choose TypeScript, Go, Python or Java, then set a valid root type name.
- Choose one file or multiple files and generate code. Switching file mode after generation rebuilds the result.
- Inspect each file. Copy one file or all code as text, save actual files to a selected directory when supported, or download and extract ZIP.
An example to test
{"user_id":10086,"profile":{"name":"Alex"},"items":[{"id":1},{"id":2,"note":null}]}Language conventions and inferred types
TypeScript keeps JSON property names and uses interfaces and unions. Go uses exported fields, familiar initialisms such as ID, and original JSON tags. Python uses snake_case dataclasses with modern type annotations. Java uses private fields, a no-argument constructor and getters/setters. Empty arrays have unknown element types; mixed Go and Java values use any or Object.
Single-file and multi-file output
Java single-file output uses static nested classes; multi-file output creates separate public Bean classes. TypeScript and Python multi-file output adds references between model files. Go files share package model. Renamed Python keys are stored in field metadata, which standard dataclasses do not automatically use for JSON mapping; renamed Java keys are recorded in comments and need serializer configuration.
Frequently asked questions
Why can copied code not be pasted into Finder as files?
Copy all code writes text with filename separators, not filesystem file references. Download ZIP and extract it to create actual files, or use Save to folder in a browser that supports it.
Does a generated nullable type prove a field is optional?
No. Null and absence are different observations, and a sample cannot establish a full API contract. Review the model against the actual API specification.