I have a service that can have two different kind of body parameters based on the Content-Type header.
E.g. for path /Pet:
If Content-Type: application/somecustom.resource+json is used, then POST can take up Pet as the body parameter.
If Content-Type: application/somecustom.function+json is used, then POST should take up some different body parameter to invoke a function and return a different response.
Any suggestion on how to manifest this in OpenAPI (Swagger)?
OpenAPI 3.0 supports different schemas per media type.
openapi: 3.0.0
...
paths:
/pet:
post:
requestBody:
required: true
content:
application/somecustom.resource+json:
schema:
$ref: '#/components/schemas/Pet'
application/somecustom.function+json:
schema:
$ref: '#/components/schemas/Foo'
No, it's not possible to define a two different body parameters for the same operation, in the same path item. The path item name are unique by virtue of being property names (and therefore "keys" in the JSON key-value map), and Swagger specification allows at most one body parameter in a given operation.
There are a few alternative approaches to address this need:
Create two separate path items
For example:
/pets/createFromDescription:
post:
summary: Create a pet from a basic description
operationId: createPetFromDescription
parameters:
- name: petDescription
in: body
required: true
schema:
$ref: "#/definitions/PetDescriptionObject"
responses:
200:
description: OK
/pets/createFromCatalog:
post:
summary: Create a pet from a standard catalog entry
operationId: createPetFromCatalogEntry
parameters:
- name: petCatalogEntry
in: body
required: true
schema:
$ref: "#/definitions/PetCatalogEntry"
responses:
200:
description: OK
Create subtypes, with a discriminator
Described in the Swagger–OpenAPI 2.0 specification here.
Example:
/pets:
post:
summary: Create a pet
operationId: createPet
parameters:
- name: petSource
in: body
description: Structured pet information, from which to create the object
required: true
schema:
$ref: "#/definitions/CreatePet_Request"
responses:
200:
description: OK
definitions:
CreatePet_Request:
type: object
properties:
requestVariant:
type: string
required:
- requestVariant
discriminator: requestVariant
PetDescriptionObject:
allOf:
- $ref: "#/definitions/CreatePet_Request"
- type: object
properties:
name:
type: string
description:
type: string
PetCatalogEntry:
allOf:
- $ref: "#/definitions/CreatePet_Request"
- type: object
properties:
SKU:
type: string
Breed:
type: string
Comments:
type: string
Neither of these methods is keyed to the media type of the request. While your request may accept multiple media types, if the use of a particular media type implies some requirement about the request body, you'd have to document that in the description property of the operation or body parameter.
requestBody which I do not see anywhere in your answer. I got here looking for an example of using a schema $ref on a requestBody since I cannot figure out where the name of the parameter goes in this case. The OpenAPI 3.0 spec does not seem to show this either, e.g. the definition of the PetBody schema.