diff --git a/furumi-agent/src/db.rs b/furumi-agent/src/db.rs
index e7686ec..3600c78 100644
--- a/furumi-agent/src/db.rs
+++ b/furumi-agent/src/db.rs
@@ -690,91 +690,8 @@ pub async fn get_tracks_with_albums_for_artist(pool: &PgPool, artist_id: i64) ->
     ).bind(artist_id).fetch_all(pool).await
 }
 
-pub async fn rename_artist(pool: &PgPool, id: i64, new_name: &str) -> Result<(), sqlx::Error> {
-    sqlx::query("UPDATE artists SET name = $2 WHERE id = $1")
-        .bind(id).bind(new_name).execute(pool).await?;
-    Ok(())
-}
-
-pub async fn delete_artist(pool: &PgPool, id: i64) -> Result<(), sqlx::Error> {
-    sqlx::query("DELETE FROM artists WHERE id = $1")
-        .bind(id).execute(pool).await?;
-    Ok(())
-}
-
-pub async fn rename_album(pool: &PgPool, id: i64, new_name: &str) -> Result<(), sqlx::Error> {
-    sqlx::query("UPDATE albums SET name = $2 WHERE id = $1")
-        .bind(id).bind(new_name).execute(pool).await?;
-    Ok(())
-}
-
-pub async fn set_album_artist(pool: &PgPool, album_id: i64, artist_id: i64) -> Result<(), sqlx::Error> {
-    sqlx::query("UPDATE albums SET artist_id = $2 WHERE id = $1")
-        .bind(album_id).bind(artist_id).execute(pool).await?;
-    Ok(())
-}
-
-
-pub async fn move_track_artists(pool: &PgPool, from_artist_id: i64, to_artist_id: i64) -> Result<(), sqlx::Error> {
-    // Update, but avoid duplicate (track_id, artist_id, role) - delete first any conflicting rows
-    sqlx::query(
-        r#"DELETE FROM track_artists
-           WHERE artist_id = $2
-           AND (track_id, role) IN (
-               SELECT track_id, role FROM track_artists WHERE artist_id = $1
-           )"#
-    ).bind(from_artist_id).bind(to_artist_id).execute(pool).await?;
-    sqlx::query("UPDATE track_artists SET artist_id = $2 WHERE artist_id = $1")
-        .bind(from_artist_id).bind(to_artist_id).execute(pool).await?;
-    Ok(())
-}
-
-pub async fn get_duplicate_track_ids_in_albums(pool: &PgPool, source_album_id: i64, target_album_id: i64) -> Result<Vec<i64>, sqlx::Error> {
-    let rows: Vec<(i64,)> = sqlx::query_as(
-        r#"SELECT t1.id FROM tracks t1
-           JOIN tracks t2 ON t1.file_hash = t2.file_hash AND t2.album_id = $2
-           WHERE t1.album_id = $1"#
-    ).bind(source_album_id).bind(target_album_id).fetch_all(pool).await?;
-    Ok(rows.into_iter().map(|(id,)| id).collect())
-}
-
-pub async fn get_track_storage_path(pool: &PgPool, track_id: i64) -> Result<Option<String>, sqlx::Error> {
-    let row: Option<(String,)> = sqlx::query_as("SELECT storage_path FROM tracks WHERE id = $1")
-        .bind(track_id).fetch_optional(pool).await?;
-    Ok(row.map(|(p,)| p))
-}
-
-pub async fn delete_track(pool: &PgPool, track_id: i64) -> Result<(), sqlx::Error> {
-    sqlx::query("DELETE FROM track_artists WHERE track_id = $1").bind(track_id).execute(pool).await?;
-    sqlx::query("DELETE FROM tracks WHERE id = $1").bind(track_id).execute(pool).await?;
-    Ok(())
-}
-
-pub async fn move_tracks_to_album(pool: &PgPool, from_album_id: i64, to_album_id: i64) -> Result<(), sqlx::Error> {
-    sqlx::query("UPDATE tracks SET album_id = $2 WHERE album_id = $1")
-        .bind(from_album_id).bind(to_album_id).execute(pool).await?;
-    Ok(())
-}
-
-pub async fn delete_album(pool: &PgPool, id: i64) -> Result<(), sqlx::Error> {
-    sqlx::query("DELETE FROM albums WHERE id = $1")
-        .bind(id).execute(pool).await?;
-    Ok(())
-}
-
 pub async fn update_track_storage_path(pool: &PgPool, track_id: i64, new_path: &str) -> Result<(), sqlx::Error> {
     sqlx::query("UPDATE tracks SET storage_path = $2 WHERE id = $1")
         .bind(track_id).bind(new_path).execute(pool).await?;
     Ok(())
 }
-
-pub async fn get_albums_for_artist(pool: &PgPool, artist_id: i64) -> Result<Vec<Album>, sqlx::Error> {
-    sqlx::query_as::<_, Album>("SELECT * FROM albums WHERE artist_id = $1 ORDER BY year NULLS LAST, name")
-        .bind(artist_id).fetch_all(pool).await
-}
-
-pub async fn find_album_by_artist_id_and_name(pool: &PgPool, artist_id: i64, name: &str) -> Result<Option<i64>, sqlx::Error> {
-    let row: Option<(i64,)> = sqlx::query_as("SELECT id FROM albums WHERE artist_id = $1 AND name = $2")
-        .bind(artist_id).bind(name).fetch_optional(pool).await?;
-    Ok(row.map(|r| r.0))
-}
diff --git a/furumi-agent/src/merge.rs b/furumi-agent/src/merge.rs
index bd164b1..eec8105 100644
--- a/furumi-agent/src/merge.rs
+++ b/furumi-agent/src/merge.rs
@@ -96,49 +96,16 @@ pub async fn execute_merge(state: &Arc<AppState>, merge_id: Uuid) -> anyhow::Res
     let loser_ids: Vec<i64> = source_ids.iter().copied()
         .filter(|&id| id != proposal.winner_artist_id).collect();
 
-    // 1. Rename winner artist to canonical name
-    db::rename_artist(&state.pool, proposal.winner_artist_id, &proposal.canonical_artist_name).await?;
-
-    // 2. Process album mappings
-    for mapping in &proposal.album_mappings {
-        if let Some(target_id) = mapping.merge_into_album_id {
-            merge_albums_into(&state.pool, mapping.source_album_id, target_id).await?;
-        } else {
-            // Rename album, then move to winner — merging if winner already has same name
-            db::rename_album(&state.pool, mapping.source_album_id, &mapping.canonical_name).await?;
-            if let Some(existing_id) = db::find_album_by_artist_id_and_name(
-                &state.pool, proposal.winner_artist_id, &mapping.canonical_name,
-            ).await? {
-                if existing_id != mapping.source_album_id {
-                    merge_albums_into(&state.pool, mapping.source_album_id, existing_id).await?;
-                }
-                // else: source_album already belongs to winner with that name — nothing to do
-            } else {
-                db::set_album_artist(&state.pool, mapping.source_album_id, proposal.winner_artist_id).await?;
-            }
-        }
+    // Execute all DB mutations in a single atomic transaction.
+    // On error the transaction rolls back automatically (dropped without commit).
+    let mut tx = state.pool.begin().await?;
+    if let Err(e) = merge_db(&mut tx, &proposal, &loser_ids).await {
+        // tx is dropped here → auto-rollback
+        return Err(e);
     }
+    tx.commit().await?;
 
-    // 3. Move remaining albums from losers to winner, merging name conflicts
-    for &loser_id in &loser_ids {
-        let albums = db::get_albums_for_artist(&state.pool, loser_id).await?;
-        for album in albums {
-            if let Some(existing_id) = db::find_album_by_artist_id_and_name(
-                &state.pool, proposal.winner_artist_id, &album.name,
-            ).await? {
-                merge_albums_into(&state.pool, album.id, existing_id).await?;
-            } else {
-                db::set_album_artist(&state.pool, album.id, proposal.winner_artist_id).await?;
-            }
-        }
-    }
-
-    // 4. Move track_artists from losers to winner
-    for &loser_id in &loser_ids {
-        db::move_track_artists(&state.pool, loser_id, proposal.winner_artist_id).await?;
-    }
-
-    // 5. Move files on disk and update storage paths
+    // Move files after commit (best-effort; storage_path updated per file)
     let tracks = db::get_tracks_with_albums_for_artist(&state.pool, proposal.winner_artist_id).await?;
     for track in &tracks {
         let current = std::path::Path::new(&track.storage_path);
@@ -168,31 +135,180 @@ pub async fn execute_merge(state: &Arc<AppState>, merge_id: Uuid) -> anyhow::Res
         }
     }
 
-    // 6. Delete loser artists
-    for &loser_id in &loser_ids {
-        db::delete_artist(&state.pool, loser_id).await?;
-    }
-
-    // 7. Mark approved
     db::update_merge_status(&state.pool, merge_id, "approved", None).await?;
     tracing::info!(id = %merge_id, "Merge executed successfully");
     Ok(())
 }
 
-/// Merge source album into target: deduplicate tracks, move the rest, delete source.
-async fn merge_albums_into(pool: &sqlx::PgPool, source_id: i64, target_id: i64) -> anyhow::Result<()> {
-    let dup_ids = db::get_duplicate_track_ids_in_albums(pool, source_id, target_id).await?;
-    for dup_id in dup_ids {
-        if let Ok(Some(path)) = db::get_track_storage_path(pool, dup_id).await {
-            let p = std::path::Path::new(&path);
-            if p.exists() {
-                let _ = tokio::fs::remove_file(p).await;
+/// All DB mutations for a merge, executed inside a single transaction.
+/// `tx` is a `Transaction<'_, Postgres>` which derefs to `PgConnection`.
+async fn merge_db(
+    tx: &mut sqlx::Transaction<'_, sqlx::Postgres>,
+    proposal: &MergeProposal,
+    loser_ids: &[i64],
+) -> anyhow::Result<()> {
+    // 1. Rename winner artist to canonical name
+    sqlx::query("UPDATE artists SET name = $2 WHERE id = $1")
+        .bind(proposal.winner_artist_id)
+        .bind(&proposal.canonical_artist_name)
+        .execute(&mut **tx).await?;
+
+    // 2. Process album mappings from the proposal
+    for mapping in &proposal.album_mappings {
+        // Skip if source was already processed (idempotent retry support)
+        let src_exists: (bool,) = sqlx::query_as("SELECT EXISTS(SELECT 1 FROM albums WHERE id = $1)")
+            .bind(mapping.source_album_id)
+            .fetch_one(&mut **tx).await?;
+        if !src_exists.0 { continue; }
+
+        if let Some(target_id) = mapping.merge_into_album_id {
+            album_merge_into(tx, mapping.source_album_id, target_id).await?;
+        } else {
+            // Rename first
+            sqlx::query("UPDATE albums SET name = $2 WHERE id = $1")
+                .bind(mapping.source_album_id)
+                .bind(&mapping.canonical_name)
+                .execute(&mut **tx).await?;
+
+            // Check if winner already has an album with this canonical name (excluding self)
+            let conflict: Option<(i64,)> = sqlx::query_as(
+                "SELECT id FROM albums WHERE artist_id = $1 AND name = $2 AND id != $3"
+            )
+            .bind(proposal.winner_artist_id)
+            .bind(&mapping.canonical_name)
+            .bind(mapping.source_album_id)
+            .fetch_optional(&mut **tx).await?;
+
+            if let Some((existing_id,)) = conflict {
+                album_merge_into(tx, mapping.source_album_id, existing_id).await?;
+            } else {
+                // Just move to winner artist (only if not already there)
+                sqlx::query(
+                    "UPDATE albums SET artist_id = $2 WHERE id = $1 AND artist_id != $2"
+                )
+                .bind(mapping.source_album_id)
+                .bind(proposal.winner_artist_id)
+                .execute(&mut **tx).await?;
             }
         }
-        db::delete_track(pool, dup_id).await?;
     }
-    db::move_tracks_to_album(pool, source_id, target_id).await?;
-    db::delete_album(pool, source_id).await?;
+
+    // 3. Move all remaining albums from each loser to winner, merging name conflicts
+    for &loser_id in loser_ids {
+        loop {
+            // Fetch one album at a time; loop because merging changes the set
+            let album: Option<(i64, String)> = sqlx::query_as(
+                "SELECT id, name FROM albums WHERE artist_id = $1 LIMIT 1"
+            )
+            .bind(loser_id)
+            .fetch_optional(&mut **tx).await?;
+
+            let (album_id, album_name) = match album {
+                Some(a) => a,
+                None => break,
+            };
+
+            let conflict: Option<(i64,)> = sqlx::query_as(
+                "SELECT id FROM albums WHERE artist_id = $1 AND name = $2"
+            )
+            .bind(proposal.winner_artist_id)
+            .bind(&album_name)
+            .fetch_optional(&mut **tx).await?;
+
+            if let Some((existing_id,)) = conflict {
+                // Merge loser album into winner album
+                album_merge_into(tx, album_id, existing_id).await?;
+            } else {
+                sqlx::query("UPDATE albums SET artist_id = $2 WHERE id = $1")
+                    .bind(album_id)
+                    .bind(proposal.winner_artist_id)
+                    .execute(&mut **tx).await?;
+            }
+        }
+    }
+
+    // 4. Move track_artists from losers to winner
+    for &loser_id in loser_ids {
+        // Remove winner's entries that would conflict after the update
+        sqlx::query(
+            r#"DELETE FROM track_artists
+               WHERE artist_id = $2
+               AND (track_id, role) IN (
+                   SELECT track_id, role FROM track_artists WHERE artist_id = $1
+               )"#
+        )
+        .bind(loser_id)
+        .bind(proposal.winner_artist_id)
+        .execute(&mut **tx).await?;
+
+        sqlx::query("UPDATE track_artists SET artist_id = $2 WHERE artist_id = $1")
+            .bind(loser_id)
+            .bind(proposal.winner_artist_id)
+            .execute(&mut **tx).await?;
+    }
+
+    // 5. Delete loser artists (should be empty of albums/tracks by now)
+    for &loser_id in loser_ids {
+        sqlx::query("DELETE FROM artists WHERE id = $1")
+            .bind(loser_id)
+            .execute(&mut **tx).await?;
+    }
+
+    Ok(())
+}
+
+/// Merge source album into target within an open transaction:
+/// deduplicate by file_hash, move the rest, delete source.
+async fn album_merge_into(
+    tx: &mut sqlx::Transaction<'_, sqlx::Postgres>,
+    source_id: i64,
+    target_id: i64,
+) -> anyhow::Result<()> {
+    // Verify target exists
+    let target_ok: (bool,) = sqlx::query_as("SELECT EXISTS(SELECT 1 FROM albums WHERE id = $1)")
+        .bind(target_id)
+        .fetch_one(&mut **tx).await?;
+    if !target_ok.0 {
+        anyhow::bail!("Target album {} does not exist", target_id);
+    }
+
+    // Delete duplicate tracks from source (same file_hash already in target)
+    let dups: Vec<(i64,)> = sqlx::query_as(
+        r#"SELECT t1.id FROM tracks t1
+           JOIN tracks t2 ON t1.file_hash = t2.file_hash AND t2.album_id = $2
+           WHERE t1.album_id = $1"#
+    )
+    .bind(source_id)
+    .bind(target_id)
+    .fetch_all(&mut **tx).await?;
+
+    for (dup_id,) in dups {
+        // Retrieve path for later file deletion (non-fatal if missing)
+        let path: Option<(String,)> = sqlx::query_as("SELECT storage_path FROM tracks WHERE id = $1")
+            .bind(dup_id).fetch_optional(&mut **tx).await?;
+        if let Some((p,)) = path {
+            // Schedule physical deletion after commit — store in a side channel;
+            // here we do a best-effort remove outside the tx scope via tokio::spawn.
+            let p = p.clone();
+            tokio::spawn(async move {
+                let _ = tokio::fs::remove_file(&p).await;
+            });
+        }
+        sqlx::query("DELETE FROM track_artists WHERE track_id = $1").bind(dup_id).execute(&mut **tx).await?;
+        sqlx::query("DELETE FROM tracks WHERE id = $1").bind(dup_id).execute(&mut **tx).await?;
+    }
+
+    // Move remaining tracks from source to target
+    sqlx::query("UPDATE tracks SET album_id = $2 WHERE album_id = $1")
+        .bind(source_id)
+        .bind(target_id)
+        .execute(&mut **tx).await?;
+
+    // Delete the now-empty source album
+    sqlx::query("DELETE FROM albums WHERE id = $1")
+        .bind(source_id)
+        .execute(&mut **tx).await?;
+
     Ok(())
 }