415 Unsupported Media Type

Category: Status Codes & Responses

Description

Operations that accept request bodies should define a 415 Unsupported Media Type response to indicate when the client sends content in an unsupported format.

What It Checks

This rule checks POST, PUT, and PATCH operations that have a request body defined and verifies they include a 415 response definition.

• Only checks operations that can have request bodies (POST, PUT, PATCH)
• Verifies the operation has a requestBody defined
• Checks for explicit 415 response definition

Why It Matters

Documenting the 415 response is important for:

• Content Type Clarity: Developers know what content types are accepted
• Error Handling: Clients can handle format mismatches appropriately
• Debugging: Clear feedback when wrong content type is sent
• API Contract: Documents the expected input formats

Examples

Good

paths:
  /users:
    post:
      operationId: createUser
      requestBody:
        content:
          application/json:
            schema:
              type: object
      responses:
        '201':
          description: User created
        '415':
          description: Unsupported Media Type - Use application/json

Bad

paths:
  /users:
    post:
      operationId: createUser
      requestBody:
        content:
          application/json:
            schema:
              type: object
      responses:
        '201':
          description: User created
        # Missing 415 response

Exceptions

• GET, DELETE, and other operations that don't accept request bodies
• Operations without a requestBody definition

Configuration

This rule has no configuration options. It is either enabled or disabled.

Related Rules

• Rule 39: Content-Type Must Be Used - Content type requirements
• Rule 57: Common Status Codes - Common error responses