Create backend spec

backend/spec/robot.md

@@ -0,0 +1,26 @@
+# `pub struct Robot`
+
+Robot is a nostr identity which acts on behalf of the application.
+
+Members:
+
+- `secret: String` - a nostr secret key, from `ROBOT_SECRET`
+- `name: String` - the name of the bot, from `ROBOT_NAME`
+- `description: String` - the description of the bot, from `ROBOT_DESCRIPTION`
+- `picture: String` - the picture URL for the bot, from `ROBOT_PICTURE`
+- `outbox_relays: Vec<String>` - outbox relay URLs, from `ROBOT_OUTBOX_RELAYS`
+- `indexer_relays: Vec<String>` - indexer relay URLs, from `ROBOT_INDEXER_RELAYS`
+- `messaging_relays: Vec<String>` - messaging relay URLs, from `ROBOT_MESSAGING_RELAYS`
+- `client: nostr_sdk::Client`
+
+## `pub fn new() -> Self`
+
+- Reads environment and populates members
+- Publishes a `kind 0` nostr profile, a `kind 10002` relay list, and `kind 10050` relay selections using `client`
+
+## `pub async fn send_dm(&self, recipient: &str, message: &str) -> Result<()>`
+
+- Fetches recipient's outbox relays from `indexer_relays` (cached)
+- Fetches recipient's messaging relays from their outbox relays (cached)
+- Sends DM to recipient via their messaging relays
+- If no outbox/messaging relays are found, return an error