# Types

Herodot employs a generic, and recursive, type parser. It understands the type of all parameters in your API and can infer metadata from them.

TL;DR: Herodot understands types exactly the way you're used to writing them. Whenever a type is required (such as with parameters or responses), you can use primitives, generics, models or unions.

# Primitive types

Herodot has support for the following primitive types, which largely resembles PHP's primitives:

  • boolean
  • float
  • integer
  • null
  • string
  • array

Additionally, there's the special any type, which can be used in all places where a type isn't known or cannot be expressed as a union type.

# Union types

Herodot supports union types, that is, types composed out of one or more types. You can declare a union by joining two or more types with a pipe (|):


# Template types

Template types, or generics, are a kind of container for other types: Say, an array of numbers. It could be typed as array, but that would omit the additional information about the array content. Therefore, Herodot allows you to add that information to the type:


As that is pretty verbose, you can also write simple array types like the following:


Template types also support union types:


Herodot parses those types recursively, meaning you may nest the type syntax as much as you like:


# Model types

Herodot also supports model types, so you may use your model (or API resource) classes as types when annotating API responses, for example.