diff --git a/packages/api/src/routes/procurement.ts b/packages/api/src/routes/procurement.ts
index 0f58743..bc02418 100644
--- a/packages/api/src/routes/procurement.ts
+++ b/packages/api/src/routes/procurement.ts
@@ -781,6 +781,100 @@ procurementRouter.get("/dead-stock-revival", async (_req: Request, res: Response
 });
 
 // ─── C: GET /api/procurement/supply-squeeze ──────────────────────────────────
+
+// ─── GET /api/procurement/availability ───────────────────────────────────────
+// Data-grounded supply-availability per speed tier. Derived from real supplier
+// diversity (distinct source vendors offering it) + stock coverage. Surfaces the
+// 400G/800G/1.6T supply tightening that exists in the data but was not shown.
+procurementRouter.get("/availability", async (_req: Request, res: Response) => {
+  const client = await pool.connect();
+  try {
+    // Disable parallel workers for this aggregate — Docker /dev/shm (64MB) is too
+    // small for parallel hash and the query is fast enough single-threaded.
+    await client.query('BEGIN');
+    await client.query('SET LOCAL max_parallel_workers_per_gather = 0');
+    const result = await client.query(`
+      WITH sup AS (
+        SELECT t.speed_gbps,
+          COUNT(DISTINCT po.source_vendor_id) FILTER (WHERE po.time > NOW() - INTERVAL '45 days') AS suppliers,
+          COUNT(DISTINCT po.source_vendor_id) FILTER (WHERE po.time <= NOW() - INTERVAL '45 days') AS suppliers_prior
+        FROM price_observations po
+        JOIN transceivers t ON t.id = po.transceiver_id
+        WHERE t.speed_gbps IN (100,200,400,800,1600) AND po.time > NOW() - INTERVAL '90 days'
+        GROUP BY t.speed_gbps
+      ),
+      sk AS (
+        SELECT speed_gbps, COUNT(*) AS sku_count
+        FROM transceivers WHERE speed_gbps IN (100,200,400,800,1600)
+        GROUP BY speed_gbps HAVING COUNT(*) >= 3
+      ),
+      st AS (
+        SELECT t.speed_gbps,
+          COUNT(*) FILTER (WHERE s.in_stock IS TRUE) AS skus_in_stock,
+          COUNT(*) AS skus_with_stock
+        FROM transceivers t
+        JOIN LATERAL (
+          SELECT in_stock FROM stock_observations so
+          WHERE so.transceiver_id = t.id ORDER BY so.time DESC LIMIT 1
+        ) s ON true
+        WHERE t.speed_gbps IN (100,200,400,800,1600)
+        GROUP BY t.speed_gbps
+      )
+      SELECT
+        sk.speed_gbps,
+        sk.sku_count::int,
+        COALESCE(sup.suppliers,0)::int       AS suppliers,
+        COALESCE(sup.suppliers_prior,0)::int AS suppliers_prior,
+        COALESCE(st.skus_in_stock,0)::int    AS skus_in_stock,
+        COALESCE(st.skus_with_stock,0)::int  AS skus_with_stock,
+        CASE WHEN COALESCE(st.skus_with_stock,0) > 0
+          THEN ROUND(100.0 * st.skus_in_stock / st.skus_with_stock)::int ELSE NULL END AS in_stock_pct
+      FROM sk
+      LEFT JOIN sup ON sup.speed_gbps = sk.speed_gbps
+      LEFT JOIN st  ON st.speed_gbps  = sk.speed_gbps
+      ORDER BY sk.speed_gbps DESC
+    `);
+
+    type Row = { speed_gbps: string; sku_count: number; suppliers: number; suppliers_prior: number; skus_in_stock: number; skus_with_stock: number; in_stock_pct: number | null };
+    const tiers = (result.rows as Row[]).map((r) => {
+      const sup = r.suppliers ?? 0;
+      const inStockPct = r.in_stock_pct ?? null;
+      // availability class from supplier diversity + stock coverage
+      let availability: "scarce" | "constrained" | "moderate" | "abundant";
+      if (sup <= 3 || (inStockPct !== null && inStockPct < 20)) availability = "scarce";
+      else if (sup <= 6 || (inStockPct !== null && inStockPct < 45)) availability = "constrained";
+      else if (sup <= 9) availability = "moderate";
+      else availability = "abundant";
+      // tightening trend: supplier diversity dropped vs prior window
+      const trend = r.suppliers_prior > 0
+        ? (sup < r.suppliers_prior ? "tightening" : sup > r.suppliers_prior ? "loosening" : "stable")
+        : "stable";
+      const drivers: string[] = [`${sup} active suppliers`];
+      if (inStockPct !== null) drivers.push(`${inStockPct}% of tracked SKUs in stock`);
+      drivers.push(`${r.sku_count} SKUs`);
+      if (trend === "tightening") drivers.push(`supplier base shrinking (${r.suppliers_prior}→${sup})`);
+      return {
+        speed_gbps: parseFloat(r.speed_gbps),
+        sku_count: r.sku_count,
+        suppliers: sup,
+        in_stock_pct: inStockPct,
+        availability,
+        trend,
+        drivers,
+      };
+    });
+
+    res.json({ success: true, tiers });
+  } catch (err) {
+    try { await client.query('ROLLBACK'); } catch { /* ignore */ }
+    console.error("availability error:", err);
+    res.status(500).json({ success: false, error: String(err) });
+  } finally {
+    client.release();
+  }
+});
+
+
 // Multi-signal supply constraint detector
 procurementRouter.get("/supply-squeeze", async (_req: Request, res: Response) => {
   try {