Contact Cards

81.md

@@ -0,0 +1,76 @@
+NIP-81
+======
+
+Contact Cards
+-------------
+
+`draft` `optional`
+
+This NIP defines two event kinds (`30382` and `31382`) to document additional information about a contact.
+
+Both kinds offer public and private tags. Private tags are JSON-stringified, [NIP-44](44.md)-encrypted to the signer's keys and placed inside the `.content` of the event. 
+
+### Public Contact Cards
+
+Event kind `30382` is used when the relationship between two keys is public. The `d` tag contains the target public key in hex.
+
+```js
+{
+  "kind": 30382,
+  "tags": [
+    ["d", "e88a691e98d9987c964521dff60025f60700378a4879180dcbbb4a5027850411"],
+    ["n", "follow"],
+    ["n", "bitcoiner"],
+    ["n", "6064460175057025"]
+  ],
+  "content": nip44Encrypt(JSON.stringify([
+    ["petname", "NVK (Coldcard)"],
+    ["summary", "Owes me a beer"]
+  ])),
+  // ...other fields
+}
+```
+
+`petname` SHOULD be rendered instead of the person's display name in all interfaces when the signer of this event is logged in.
+
+### Contact Sets
+
+Optional `n` tags `["n", "<identifier>"]` add the contact to a set. This allows clients to query by `n` and download all members of a set. 
+
+The `<identifier>` can be human-readable and public or encoded and private. 
+
+For private cases, a new event kind named "Contact Set Names" (`kind:10008`) uses `map` tags to store the set name. 
+Clients SHOULD display the `name` instead of the `identifier` if the `identifier` is present in this event.
+
+```js
+{
+  "kind": 10008,
+  "content": nip44Encrypt(JSON.stringify([
+    ["map", "<identifier>", "<name>"],
+    ["map", "bitcoiner", "bitcoiner"], 
+    ["map", "6064460175057025", "debtor"]
+  ])),
+  // ...other fields
+}
+```
+
+### Private Contact Cards
+
+For contacts that must remain private (e.g, private follows, client lists, etc), the event kind `31382` uses a similar structure but with a hashed `d` tag using [NIP-44](44.md)'s `hkdf` function. 
+
+```js
+{
+  "kind": 31382,
+  "tags": [
+    ["d", sha256(hkdf(private_key, salt: 'nip81') || "<pubkey>")],
+    ["n", "6064460175057025"],
+  ],
+  "content": nip44Encrypt(JSON.stringify([
+    ["p", "<pubkey>", "<relay url>"],
+    ["n", "client-list"],
+    ["petname", "<My buddy>"],
+    ["summary", "<Summary of the relationship>"],
+  ])),
+  // ...other fields
+}
+```

README.md

@@ -91,6 +91,7 @@ They exist to document what may be implemented by [Nostr](https://github.com/nos
 - [NIP-77: Negentropy Syncing](77.md)
 - [NIP-78: Application-specific data](78.md)
 - [NIP-7D: Threads](7D.md)
+- [NIP-81: Contact Cards](81.md)
 - [NIP-84: Highlights](84.md)
 - [NIP-86: Relay Management API](86.md)
 - [NIP-87: Ecash Mint Discoverability](87.md)
@@ -192,6 +193,7 @@ They exist to document what may be implemented by [Nostr](https://github.com/nos
 | `10005`       | Public chats list               | [51](51.md)                            |
 | `10006`       | Blocked relays list             | [51](51.md)                            |
 | `10007`       | Search relays list              | [51](51.md)                            |
+| `10008`       | Event Set Names                 | [81](81.md)                            |
 | `10009`       | User groups                     | [51](51.md), [29](29.md)               |
 | `10012`       | Favorite relays list            | [51](51.md)                            |
 | `10013`       | Private event relay list        | [37](37.md)                            |
@@ -240,6 +242,7 @@ They exist to document what may be implemented by [Nostr](https://github.com/nos
 | `30312`       | Interactive Room                | [53](53.md)                            |
 | `30313`       | Conference Event                | [53](53.md)                            |
 | `30315`       | User Statuses                   | [38](38.md)                            |
+| `30382`       | Public Relationship Status      | [81](81.md)                            |
 | `30388`       | Slide Set                       | [Corny Chat][cornychat-slideset]       |
 | `30402`       | Classified Listing              | [99](99.md)                            |
 | `30403`       | Draft Classified Listing        | [99](99.md)                            |
@@ -248,6 +251,7 @@ They exist to document what may be implemented by [Nostr](https://github.com/nos
 | `30818`       | Wiki article                    | [54](54.md)                            |
 | `30819`       | Redirects                       | [54](54.md)                            |
 | `31234`       | Draft Event                     | [37](37.md)                            |
+| `31382`       | Private Contact Card            | [81](81.md)                            |
 | `31388`       | Link Set                        | [Corny Chat][cornychat-linkset]        |
 | `31890`       | Feed                            | [NUD: Custom Feeds][NUD: Custom Feeds] |
 | `31922`       | Date-Based Calendar Event       | [52](52.md)                            |