diff --git a/src/db.ts b/src/db.ts
index e1039dc..2d6b4d7 100644
--- a/src/db.ts
+++ b/src/db.ts
@@ -14,6 +14,7 @@ interface DittoDB {
   unattached_media: UnattachedMediaRow;
   author_stats: AuthorStatsRow;
   event_stats: EventStatsRow;
+  pubkey_domains: PubkeyDomainRow;
 }
 
 interface AuthorStatsRow {
@@ -66,6 +67,11 @@ interface UnattachedMediaRow {
   uploaded_at: Date;
 }
 
+interface PubkeyDomainRow {
+  pubkey: string;
+  domain: string;
+}
+
 const sqliteWorker = new SqliteWorker();
 await sqliteWorker.open(Conf.dbPath);
 
diff --git a/src/db/migrations/015_add_pubkey_domains.ts b/src/db/migrations/015_add_pubkey_domains.ts
new file mode 100644
index 0000000..33bcc6c
--- /dev/null
+++ b/src/db/migrations/015_add_pubkey_domains.ts
@@ -0,0 +1,21 @@
+import { Kysely } from '@/deps.ts';
+
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .createTable('pubkey_domains')
+    .ifNotExists()
+    .addColumn('pubkey', 'text', (col) => col.primaryKey())
+    .addColumn('domain', 'text')
+    .execute();
+
+  await db.schema
+    .createIndex('pubkey_domains_domain_index')
+    .on('pubkey_domains')
+    .column('domain')
+    .ifNotExists()
+    .execute();
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema.dropTable('pubkey_domains').execute();
+}
diff --git a/src/pipeline.ts b/src/pipeline.ts
index 95c1a87..9d65b13 100644
--- a/src/pipeline.ts
+++ b/src/pipeline.ts
@@ -1,4 +1,6 @@
+import { NSchema as n } from '@soapbox/nspec';
 import { Conf } from '@/config.ts';
+import { db } from '@/db.ts';
 import { addRelays } from '@/db/relays.ts';
 import { deleteAttachedMedia } from '@/db/unattached-media.ts';
 import { Debug, LNURL, type NostrEvent } from '@/deps.ts';
@@ -15,6 +17,7 @@ import { TrendsWorker } from '@/workers/trends.ts';
 import { verifyEventWorker } from '@/workers/verify.ts';
 import { AdminSigner } from '@/signers/AdminSigner.ts';
 import { lnurlCache } from '@/utils/lnurl.ts';
+import { nip05Cache } from '@/utils/nip05.ts';
 
 const debug = Debug('ditto:pipeline');
 
@@ -30,6 +33,7 @@ async function handleEvent(event: DittoEvent, signal: AbortSignal): Promise<void
 
   await Promise.all([
     storeEvent(event, signal),
+    parseMetadata(event, signal),
     processDeletions(event, signal),
     trackRelays(event),
     trackHashtags(event),
@@ -74,6 +78,35 @@ async function storeEvent(event: DittoEvent, signal?: AbortSignal): Promise<void
   }
 }
 
+/** Parse kind 0 metadata and track indexes in the database. */
+async function parseMetadata(event: NostrEvent, signal: AbortSignal): Promise<void> {
+  if (event.kind !== 0) return;
+
+  // Parse metadata.
+  const metadata = n.json().pipe(n.metadata()).safeParse(event.content);
+  if (!metadata.success) return;
+
+  // Get nip05.
+  const { nip05 } = metadata.data;
+  if (!nip05) return;
+
+  // Fetch nip05.
+  const result = await nip05Cache.fetch(nip05, { signal }).catch(() => undefined);
+  if (!result) return;
+
+  // Ensure pubkey matches event.
+  const { pubkey } = result;
+  if (pubkey !== event.pubkey) return;
+
+  // Track pubkey domain.
+  const [, domain] = nip05.split('@');
+  await db
+    .insertInto('pubkey_domains')
+    .values({ pubkey, domain })
+    .execute()
+    .catch(debug);
+}
+
 /** Query to-be-deleted events, ensure their pubkey matches, then delete them from the database. */
 async function processDeletions(event: NostrEvent, signal: AbortSignal): Promise<void> {
   if (event.kind === 5) {