Version: 1.0.0

Multipart Encoding Demo API

Demonstrates OAS encoding.contentType support for multipart/form-data parts.

Per the OAS spec, the encoding object lets you declare the Content-Type for individual form parts. Without this fix, all parts sent application/octet-stream regardless of the declared encoding.

Cases covered:

• File part with explicit contentType (e.g. text/plain, image/png)
• String/JSON part with explicit contentType: application/json
• Multiple parts with mixed encoding
• Parts without encoding (default browser behaviour)

📄️ File part with explicit contentType

Verifies that a binary file part declared with `encoding.contentType: text/plain`

📄️ JSON metadata part + binary file part

Verifies that:

📄️ File part with multiple selectable Content-Types

Verifies the Content-Type selector UI: when `encoding.contentType` is a

📄️ Mixed — some parts with encoding, some without

Verifies that parts without an `encoding` entry use the browser default