diff --git a/src/db/queries.rs b/src/db/queries.rs
index d4a093b..70eef61 100644
--- a/src/db/queries.rs
+++ b/src/db/queries.rs
@@ -406,6 +406,30 @@ pub async fn upsert_relay(pool: &SqlitePool, url: &str) -> anyhow::Result<()> {
     Ok(())
 }
 
+/// Sync the relays table to exactly match the configured relay list.
+/// Removes stale rows (old config), upserts current ones.
+pub async fn sync_relays(pool: &SqlitePool, urls: &[String]) -> anyhow::Result<()> {
+    // Delete rows not in the current config.
+    // SQLite doesn't support array binding, so build the IN clause manually.
+    if urls.is_empty() {
+        sqlx::query("DELETE FROM relays").execute(pool).await?;
+        return Ok(());
+    }
+    let placeholders = urls.iter().map(|_| "?").collect::<Vec<_>>().join(",");
+    let sql = format!("DELETE FROM relays WHERE url NOT IN ({placeholders})");
+    let mut q = sqlx::query(&sql);
+    for url in urls {
+        q = q.bind(url);
+    }
+    q.execute(pool).await?;
+
+    // Upsert current relays.
+    for url in urls {
+        upsert_relay(pool, url).await?;
+    }
+    Ok(())
+}
+
 pub async fn get_relay_last_event(pool: &SqlitePool, url: &str) -> anyhow::Result<Option<i64>> {
     let row: Option<(Option<i64>,)> =
         sqlx::query_as("SELECT last_event FROM relays WHERE url = ?")
diff --git a/src/main.rs b/src/main.rs
index 9b36fdd..cc1f9cd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -47,6 +47,8 @@ async fn main() -> anyhow::Result<()> {
     let pool = db::open(&cfg.database.path).await?;
     info!("database ready");
 
+    db::sync_relays(&pool, &cfg.relays).await?;
+
     let relay_count = Arc::new(AtomicI32::new(0));
     let cfg = Arc::new(cfg);