Struct tags

Tag	Effect
json:"name"	JSON field name. Use "-" to exclude. A pointer field (*T) becomes nullable.
doc:"text"	description in the schema / parameter
example:"val"	example in the schema / parameter
default:"val"	default in the schema
validate:"..."	go-playground/validator rules mapped to JSON-Schema constraints (see Validation)
path:"name"	Path parameter; matches {name} in the URL
query:"name"	Query parameter
header:"name"	Header parameter (e.g. X-Currency, Authorization)

Parameter routing

Tag / condition	OpenAPI location
path:"name"	parameters[in=path], always required
query:"name"	parameters[in=query]
header:"name"	parameters[in=header]
Remaining fields on GET	implicit query parameters
Remaining fields on POST/PUT/PATCH	JSON request body

A non-GET request type whose fields are all path/query/header parameters emits no request body.

Enums

apiary detects named types with const values and adds enum automatically; no annotation needed. Works with string and integer base types.

type ProductCategory string

const (
    CategoryElectronics ProductCategory = "electronics"
    CategoryClothing    ProductCategory = "clothing"
    CategoryFood        ProductCategory = "food"
)