Write draft payment bud

BUD-08 returning NIP-94 file metadata tags

README.md

@@ -16,9 +16,10 @@ Blossom Servers expose four endpoints for managing blobs
 
 - `GET /<sha256>` (optional file `.ext`) [BUD-01](./buds/01.md#get-sha256---get-blob)
 - `HEAD /<sha256>` (optional file `.ext`) [BUD-01](./buds/01.md#head-sha256---has-blob)
-- `PUT /upload` [BUD-2](./buds/02.md#put-upload---upload-blob)
+- `PUT /upload` [BUD-02](./buds/02.md#put-upload---upload-blob)
   - `Authentication`: Signed [nostr event](./buds/02.md#upload-authorization-required)
   - Return a blob descriptor
+- `HEAD /upload` [BUD-06](./buds/06.md#head-upload---upload-requirements)
 - `GET /list/<pubkey>` [BUD-02](./buds/02.md#get-listpubkey---list-blobs)
   - Returns an array of blob descriptors
   - `Authentication` _(optional)_: Signed [nostr event](./buds/02.md#list-authorization-optional)
@@ -39,6 +40,9 @@ See the [BUDs](./buds) folder and specifically [BUD-01](./buds/01.md) and [BUD-0
 - [BUD-02: Blob upload and management](./buds/02.md)
 - [BUD-03: User Server List](./buds/03.md)
 - [BUD-04: Mirroring blobs](./buds/04.md)
+- [BUD-06: Upload requirements](./buds/06.md)
+- [BUD-07: Paid upload and download](./buds/07.md)
+- [BUD-08: Nostr File Metadata Tags](./buds/08.md)
 
 ## Event kinds
 

buds/02.md

@@ -12,13 +12,25 @@ Defines the `/upload`, `/list` and `DELETE /<sha256>` endpoints
 
 A blob descriptor is a JSON object containing `url`, `sha256`, `size`, `type`, and `uploaded` fields
 
-- `url` A public facing url this blob can retrieved from
+- `url` A publicly accessible URL to the [BUD-01](./01.md#get-sha256---get-blob) `GET /<sha256>` endpoint (optionally with a file extension)
 - `sha256` The sha256 hash of the blob
 - `size` The size of the blob in bytes
 - `type` (optional) The MIME type of the blob
 - `uploaded` The unix timestamp of when the blob was uploaded to the server
 
-Servers may include additional fields in the descriptor like `magnet`, `infohash`, or `ipfs` depending on other protocols they support
+Servers MAY include additional fields in the descriptor like `magnet`, `infohash`, or `ipfs` depending on other protocols they support
+
+Example:
+
+```json
+{
+  "url": "https://cdn.example.com/b1674191a88ec5cdd733e4240a81803105dc412d6c6708d53ab94fc248f4f553.pdf",
+  "sha256": "b1674191a88ec5cdd733e4240a81803105dc412d6c6708d53ab94fc248f4f553",
+  "size": 184292,
+  "type": "application/pdf",
+  "uploaded": 1725105921
+}
+```
 
 ## PUT /upload - Upload Blob
 

buds/06.md

@@ -0,0 +1,74 @@
+# BUD-06
+
+## Upload requirements
+
+`draft` `optional`
+
+Defines how clients can verify if the upload can be completed before sending the blob to the server. This mechanism helps prevent unnecessary traffic to other endpoints by rejecting files based on their hash, size, MIME type or other server-specific requirements.
+
+## HEAD /upload - Upload requirements
+
+The `HEAD /upload` endpoint `MUST` use the `X-SHA-256`, `X-Content-Type` and `X-Content-Length` headers sent by client to get the SHA-256 hash, MIME type and size of the blob that will be uploaded, returning a HTTP status code and a custom header `X-Upload-Message` to indicate some human readable message about the upload requirements.
+
+### Headers
+
+- `X-SHA-256`: A string that represents the blob's SHA-256 hash.
+- `X-Content-Length`: An integer that represents the blob size in bytes.
+- `X-Content-Type`: A string that specifies the blob's MIME type, like `application/pdf` or `image/png`.
+- `X-Upload-Message`: A human readable message that explains the reason why the upload cannot proceed.
+
+### Upload Authorization
+
+The `HEAD /upload` endpoint MAY accept an `upload` authorization event using the `Authorization` header similar to what is used in the [`PUT /upload`](./02.md#upload-authorization-required) endpoint
+
+If the server requires authorization to upload it may respond with the `401` status code, or if authorization was provided and is invalid or not permitted it may respond with `403` status code
+
+### Examples
+
+Example request from the client:
+
+```http
+X-Content-Type: application/pdf
+X-Content-Length: 184292
+X-SHA-256: 88a74d0b866c8ba79251a11fe5ac807839226870e77355f02eaf68b156522576
+```
+
+Example response from the server if the upload can be done:
+
+```http
+HTTP/1.1 200 OK
+```
+
+If the upload cannot proceed, the server `MUST` return an appropriate `4xx` HTTP status code and a custom header `X-Upload-Message` with a human readable error message.
+
+Some examples of error messages:
+
+```http
+HTTP/1.1 400 Bad Request
+X-Upload-Message: Invalid X-SHA-256 header format. Expected a string.
+```
+
+```http
+HTTP/1.1 401 Unauthorized
+X-Upload-Message: Authorization required for uploading video files.
+```
+
+```http
+HTTP/1.1 403 Forbidden
+X-Upload-Message: SHA-256 hash banned.
+```
+
+```http
+HTTP/1.1 411 Length Required
+X-Upload-Message: Missing X-Content-Length header.
+```
+
+```http
+HTTP/1.1 413 Content Too Large
+X-Upload-Message: File too large. Max allowed size is 100MB.
+```
+
+```http
+HTTP/1.1 415 Unsupported Media Type
+X-Upload-Message: Unsupported file type.
+```

buds/07.md

@@ -0,0 +1,36 @@
+BUD-07
+======
+
+Paid upload and download
+------------------------
+
+`draft` `optional`
+
+Cashu payments for uploads and downloads
+
+## Paid Upload
+
+The server may require payment for uploading blob by returning a `402` status code the `PUT /upload` endpoint (and `HEAD /upload` if [BUD-06](./06.md) is supported)
+
+## Paid Downloads
+
+The server may also require payment for downloads by responding with a `402` status code for `GET /<sha256` and `HEAD /<sha256>` endpoints
+
+## Payment Flow
+
+When the server is requesting payment for an endpoint it MUST respond with `402` and a `X-Cashu` header containing a base64 encoded json object (payment request)
+
+The payment request should contain an `amount`, `mints`, `unit`, and `pubkey` fields
+
+ - `amount` The amount of ecash being requested
+ - `mints` An array of mints that this server uses
+ - `unit` The cashu `unit` from the `mints`
+ - `pubkey` (optional) a 33 byte pubkey to lock the tokens too. see [NUT-11](https://github.com/cashubtc/nuts/blob/main/11.md)
+
+When the client receives a `402` response and with a `X-Cashu` header it may retry the request with a payment
+
+The payment should be a serialized cashu token according to [NUT-00](https://github.com/cashubtc/nuts/blob/main/00.md#v4-tokens)
+
+## Payment Checks
+
+Optionally a server may respond with `402` to the `HEAD /upload`, `HEAD /<sha156>` if it supports [BUD-06](./06.md)