array-parameter-serialization

October 16, 2025 · View on GitHub

Enforces the inclusion of style and explode fields for parameters with array type or parameters with a schema that includes items or prefixItems.

OASCompatibility
2.0❌
3.0✅
3.1✅
3.2✅
flowchart TD

Root ==> Paths --> PathItem --> Operation --> Parameter --enforces style and explode fields for array types--> Schema
PathItem --> Parameter
NamedParameters --> Parameter

Root ==> components

subgraph components
NamedParameters
end

style Parameter fill:#codaf9,stroke:#0044d4,stroke-width:5px
style Schema fill:#codaf9,stroke:#0044d4,stroke-width:5px

API design principles

Specifying serialization details consistently helps developers understand how to interact with the API effectively.

Configuration

OptionTypeDescription
severitystringPossible values: off, warn, error. Default off.
in[string]List of valid parameter locations where the rule should be enforced. By default the rule applies to parameters in all locations.

An example configuration:

rules:
  array-parameter-serialization:
    severity: error
    in:
      - query
      - header

Examples

Given this configuration:

rules:
  array-parameter-serialization:
    severity: error
    in:
      - query

Example of incorrect parameter:

paths:
  /example:
    get:
      parameters:
        - name: exampleArray
          in: query
          schema:
            type: array
            items:
              type: string

Example of correct parameter:

paths:
  /example:
    get:
      parameters:
        - name: exampleArray
          in: query
          style: form
          explode: true
          schema:
            type: array
            items:
              type: string

Resources