How to add a content-type on a POST request with no body in OpenAPI 3.0?

Question

I am trying to create an OpenAPI 3.0 definition for an existing API. It has a POST operation and takes header values as the input. Request body is empty. However the backend API was coded very poorly and is expecting request header Content-Type: application/json even though the body is empty.

How do I achieve this in OpenAPI 3.0? Looks like Content-Type is not accepted as a valid header parameter in OAS 3.0.

score 12 · Answer 1 · answered Nov 19 '19 at 07:53

12

You can add the requestBody with the application/json media type but no schema.

openapi: 3.0.2
...
paths:
  /something:
    post:
      parameters:
        ...
      requestBody:
        content:
          application/json: {}

answered Nov 19 '19 at 07:53

Helen

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i think we have a better way : requestBody: content: application/json: schema: # Request body contents type: object – saber tabatabaee yazdi Jun 20 '20 at 06:35
@sabertabatabaeeyazdi No. `type: object` means the request body is an object, and even an empty JSON object `{}` is not the same as empty request body. – Helen Jun 20 '20 at 08:13

score 3 · Answer 2 · answered Jun 20 '20 at 06:34

with Insomnia when use:

  requestBody:
    content:
      application/json: {}

result is this: (preview)

but if use this:

  requestBody:
    content:
      application/json:
        schema:      # Request body contents
          type: object

result is : (preview)

score 1 · Answer 3 · answered Sep 25 '22 at 17:47

Based on Open API 3 spec, your requestBody should be like the following:

   requestBody:
     required: true
       description: blabla.
         content:
            application/json:
                schema:
                   type: object
                   nullable: true

How to add a content-type on a POST request with no body in OpenAPI 3.0?

3 Answers3