How to Generate Go Structs from JSON

Struct fields and JSON tags

Exported Go field names map to JSON property names through struct tags. Tags preserve names such as snake_case while keeping Go identifiers idiomatic.

type User struct {
    UserID string `json:"user_id"`
}

Choose optionality deliberately

A zero value does not distinguish a missing field from an explicitly supplied zero. Use pointers, nullable wrappers or custom types when that distinction matters.

Be careful with numbers

JSON has one number syntax, while Go has many integer and floating types. Large identifiers should often remain strings, and generic decoding may use float64 unless configured otherwise.

Test real payload variations

Unmarshal multiple production-like examples, including missing fields, nulls, empty arrays and large numeric values before relying on generated structs.