diff --git a/src/app/api/diag-mvtart/route.ts b/src/app/api/diag-mvtart/route.ts
new file mode 100644
index 0000000..0fbc955
--- /dev/null
+++ b/src/app/api/diag-mvtart/route.ts
@@ -0,0 +1,44 @@
+import { NextResponse } from "next/server";
+import { db } from "@/db";
+import { sql } from "drizzle-orm";
+
+export async function GET() {
+    try {
+        // Colonnes de mvtart
+        const cols = await db.execute(sql`
+            SELECT column_name, data_type
+            FROM information_schema.columns
+            WHERE table_name = 'mvtart'
+            ORDER BY ordinal_position
+        `);
+
+        // 5 ventes récentes avec tous les montants visibles
+        const sample = await db.execute(sql`
+            SELECT *
+            FROM mvtart
+            WHERE genremvt = 3 AND site IN ('292', '579')
+            ORDER BY datmvt DESC
+            LIMIT 5
+        `);
+
+        // CA mars 2025 par site via mntmvtttc — pour comparer avec le cube
+        const totaux = await db.execute(sql`
+            SELECT site,
+                   ABS(SUM(mntmvtttc))::float AS ca_mntmvtttc,
+                   COUNT(*) AS nb_lignes
+            FROM mvtart
+            WHERE genremvt = 3
+              AND TO_CHAR(datmvt, 'YYYY-MM') = '2025-03'
+              AND site IN ('292', '579')
+            GROUP BY site
+        `);
+
+        return NextResponse.json({
+            columns: cols.rows,
+            sample_ventes: sample.rows,
+            totaux_202503: totaux.rows,
+        });
+    } catch (e) {
+        return NextResponse.json({ error: String(e) }, { status: 500 });
+    }
+}