Amb relay duplicate filtering

LICENSE

@@ -1,4 +1,4 @@
-Copyright 2025 B310 Digital GmbH
+Copyright 2025-2026 B310 Digital GmbH
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

docker-compose.yml

@@ -75,6 +75,16 @@ services:
     depends_on:
       - amb-relay
 
+  # Crawl peertube and fill your local amb relay 
+  # peertube-to-amb:
+  #   build:
+  #     context: https://github.com/edufeed-org/nostr-activitypub-amb-bridge
+  #     dockerfile: Dockerfile
+  #   # volumes:
+  #   #   - ../nostr-activitypub-amb-bridge:/home/appuser/app
+  #   tty: true
+  #   stdin_open: true
+
   imgproxy:
     image: ghcr.io/imgproxy/imgproxy:latest
     # network_mode: host does not work on Windows/macOS, use port mapping instead

packages/oer-adapter-nostr-amb-relay/src/nostr-amb-relay.adapter.ts

@@ -321,16 +321,33 @@ function sanitizeKeywords(keywords: string): string {
     .trim();
 }
 
-function deduplicateEvents(events: readonly Event[]): Event[] {
-  return Array.from(
+/**
+ * Extracts the "d" tag value (resource URL) from a Nostr event,
+ * falling back to the Nostr event ID when no "d" tag exists.
+ */
+const getResourceKey = (event: Event): string =>
+  event.tags.find((tag) => tag[0] === 'd' && tag.length >= 2)?.[1] ?? event.id;
+
+/**
+ * Deduplicates events by resource identity (the "d" tag / resource URL).
+ *
+ * The same resource can appear with different Nostr event IDs when published
+ * by multiple relays or republished. For each unique resource URL, the newest
+ * event (highest `created_at`) is kept.
+ */
+const deduplicateEvents = (events: readonly Event[]): Event[] =>
+  Array.from(
     events
-      .reduce(
-        (seen, event) => (seen.has(event.id) ? seen : seen.set(event.id, event)),
-        new Map<string, Event>(),
-      )
+      .reduce((seen, event) => {
+        const key = getResourceKey(event);
+        const existing = seen.get(key);
+        if (!existing || event.created_at > existing.created_at) {
+          seen.set(key, event);
+        }
+        return seen;
+      }, new Map<string, Event>())
       .values(),
   );
-}
 
 function collectResults(
   settled: readonly PromiseSettledResult<Event[]>[],

packages/oer-adapter-nostr-amb-relay/test/nostr-amb-relay.adapter.spec.ts

@@ -334,7 +334,7 @@ describe('NostrAmbRelayAdapter multi-relay', () => {
     expect(result.items).toHaveLength(2);
   });
 
-  it('should deduplicate events with the same id from multiple relays', async () => {
+  it('should deduplicate events with the same event id from multiple relays', async () => {
     const sharedEvent = makeEvent('shared-event');
 
     (Relay.connect as jest.Mock)
@@ -348,6 +348,52 @@ describe('NostrAmbRelayAdapter multi-relay', () => {
     expect(result.items).toHaveLength(1);
   });
 
+  it('should deduplicate events with different event ids but same resource URL', async () => {
+    const resourceUrl = 'https://example.com/same-resource';
+    const event1 = {
+      ...makeEvent('event-id-1'),
+      created_at: 1000,
+      tags: [['d', resourceUrl]],
+    };
+    const event2 = {
+      ...makeEvent('event-id-2'),
+      created_at: 2000,
+      tags: [['d', resourceUrl]],
+    };
+
+    (Relay.connect as jest.Mock)
+      .mockResolvedValueOnce(makeMockRelay([event1]))
+      .mockResolvedValueOnce(makeMockRelay([event2]));
+
+    const adapter = createAdapter([RELAY_URL, RELAY_URL_2]);
+    const result = await adapter.search(baseQuery);
+
+    expect(result.total).toBe(1);
+  });
+
+  it('should keep the newest event when deduplicating by resource URL', async () => {
+    const resourceUrl = 'https://example.com/same-resource';
+    const olderEvent = {
+      ...makeEvent('old-event'),
+      created_at: 1000,
+      tags: [['d', resourceUrl]],
+    };
+    const newerEvent = {
+      ...makeEvent('new-event'),
+      created_at: 2000,
+      tags: [['d', resourceUrl]],
+    };
+
+    (Relay.connect as jest.Mock)
+      .mockResolvedValueOnce(makeMockRelay([olderEvent]))
+      .mockResolvedValueOnce(makeMockRelay([newerEvent]));
+
+    const adapter = createAdapter([RELAY_URL, RELAY_URL_2]);
+    const result = await adapter.search(baseQuery);
+
+    expect(result.items[0].amb.id).toBe(resourceUrl);
+  });
+
   it('should return results from successful relay when one relay fails', async () => {
     const event = makeEvent('event-1');
 

packages/oer-finder-plugin/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@edufeed-org/oer-finder-plugin",
-  "version": "0.2.4",
+  "version": "0.2.5",
   "description": "Web Components plugin for OER Proxy",
   "author": "B310 Digital GmbH",
   "license": "MIT",