NIP-54 - Inline Resource Metadata

54.md

@@ -0,0 +1,54 @@
+NIP-54
+======
+
+Inline Resource Metadata
+------------------------
+
+Inline resource metadata is additional information associated with urls in notes that clients can optionally use to enhance resource loading.
+
+It uses [URI Fragment](https://en.wikipedia.org/wiki/URI_fragment) that agents (such as web browsers) never send to the server. Because of this, the url is fetched **without** the fragment parameters, unlike using query parameters.
+
+The URI fragment follows [media fragments structure](https://www.w3.org/TR/media-frags/#general-structure). For example, one could use `t=number_of_seconds` to start playing a video at the specified position along with an extra [percent-encoded](https://www.ietf.org/rfc/rfc3986.txt) name-value pair separated by `&` char like `https://xyz.com/a-video.mp4#t=24&a%20name=a%20value`. **Notice the usage of `#` instead of `?`.**
+
+The metadata can be appended to any url, like this [NIP-21](21.md) one: `nostr:nevent1qq...pm#a-metadata-name=a-metadata-value`.
+
+## NIP-94 File Fragments
+
+Besides available w3c and proprietary URI fragment usage, nostr uses existing [NIP-94](94.md) tags as file fragment name-value pairs. NIP-94 event `.content` is equivalent to `alt` fragment field. For example, one could join the following strings to form an image url with inline metadata:
+
+- `https://nostr.build/i/863321bb1ae68830ebcf9a343ca0a5e0ce2323d0a55b7fbe86f7a886cf61db8d.jpg`
+- `#`
+- `m=image%2Fjpeg`
+- `&`
+- `dim=3024x4032`
+- `&`
+- `alt=A%20scenic%20photo%20overlooking%20the%20coast%20of%20Costa%20Rica`
+- `&`
+- `blurhash=eVF%24%5EOI%3A%24%7BM%7Bo%23*0-nNFxakD-%3FxVM%7DWEWB%25iNKxvR-oetmo%23R-aen%24`
+
+Multiple array values use repeated names and are positioned in the same order of ocurrence in the tag array. For instance, `["aes-256-gcm", 'i-am-a-key', 'i-am-an-iv']` becomes `aes-256-gcm=i-am-a-key&aes-256-gcm=i-am-an-iv`.
+
+## Usage
+
+An url with added metadata can be used anywhere a normal url can, whether embedded in an event's `.content` field or as an event tag value.
+
+### Example:
+
+```js
+{
+  "kind": 1,
+  "content": "What a great place! https://xyz.com/filename#m=image%2Fjpeg&dim=1920x1080`",
+  // ... other event fields
+}
+```
+
+## Recommended client behavior
+
+When uploading images during a new post, clients can collect metadata
+after the image is uploaded and then include the url with inline metadata in the post.
+
+When pasting urls during post composition, the client could download the image
+and add some metadata before the post is sent.
+
+Clients can use `alt` value to add accessible text for people who prefer not to
+load images, visibility-impaired users, or text clients.

README.md

@@ -59,6 +59,7 @@ They exist to document what may be implemented by [Nostr](https://github.com/nos
 - [NIP-51: Lists](51.md)
 - [NIP-52: Calendar Events](52.md)
 - [NIP-53: Live Activities](53.md)
+- [NIP-54: Inline Resource Metadata](54.md)
 - [NIP-56: Reporting](56.md)
 - [NIP-57: Lightning Zaps](57.md)
 - [NIP-58: Badges](58.md)