Mime Part Headers for multipart/mixed payload when using arrays

[jrihtarsic]

I would like to add body content with multipart/mixed payload, like this

"requestBody": {
"content": {
"multipart/mixed": {
"schema": {
"type": "object",
"properties": {
"payloads": {
"type": "array",
"items": {
"type": "string",
"format": "binary"
}
}
}
}
},

And I would also like define header "Part-Signature-Header" for each part in array
so that request body looks like this

-----------------------------37993639233119846881484177537
Content-Disposition: form-data; name="payloads"; filename="text-example1.txt"
Content-Type: text/plain
Part-Signature-Header: asdfsdf3223fsdfw...
Hello world text example 1. -----------------------------37993639233119846881484177537
Content-Disposition: form-data; name="payloads"; filename="text-example2.txt"
Content-Type: text/plain
Part-Signature-Header: asdfsd3345343fsdfw...
Hello world text example2. -----------------------------37993639233119846881484177537--

Is the correct encoding for this

"multipart/mixed": {
"schema": {
"type": "object",
"properties": {
"**payloads**": {
"type": "array",
"items": {
"type": "string",
"format": "binary"
}
}
}
},
"encoding": {
"**payloads**": {
"headers": {
"Part-Signature-Header": {
"$ref": "#/components/headers/Part-Signature-Header",
"required": true,
"style": "simple"
}
}
}
}
},

or should i use asterix or some other char to mark that this header must be on every part of Multipart/mixed
as example:

"multipart/mixed": {
"schema": {
"type": "object",
"properties": {
"payloads": {
"type": "array",
"items": {
"type": "string",
"format": "binary"
}
}
}
},
"encoding": {
"*": {
"headers": {
"Part-Signature-Header": {
"$ref": "#/components/headers/Part-Signature-Header",
"required": true,
"style": "simple"
}
}
}
}
},

[handrews]

The OpenAPI Specification does not explicitly support multipart/mixed, nor does JSON Schema define a mapping for it. So the answer is that if what you're doing works for you, with your tools, then it's as correct as it's going to get.

I've filed issue #3721 for adding multipart/mixed support because it comes up periodically and I thought we already had an issue for it. Closing this discussion in favor of the issue.