diff --git a/src/verae_mcp_timestamping_server/global_client.py b/src/verae_mcp_timestamping_server/global_client.py
index 448ee30..30a4230 100644
--- a/src/verae_mcp_timestamping_server/global_client.py
+++ b/src/verae_mcp_timestamping_server/global_client.py
@@ -126,12 +126,30 @@ class GlobalClient:
         res = self.http.request(
             "POST",
             url,
-            payload={"data": digest, "hashAlg": "SHA256"},
+            payload={
+                "data": digest,
+                "digest": digest,
+                "hashAlg": "SHA256",
+                "restamp": False,
+            },
             headers=self._headers(),
         )
+        parsed = res.json() if hasattr(res, "json") else {}
+        if res.status_code == 200 and isinstance(parsed, dict):
+            cid = str(parsed.get("certificate") or parsed.get("jobId") or "")
+            if cid:
+                return Receipt(
+                    receipt_id=cid,
+                    hash=digest,
+                    scope="global",
+                    cube_id=cube_id,
+                    created_at=str(parsed.get("timestamp") or ""),
+                    merkle=str(parsed.get("blockHash") or ""),
+                )
         if res.status_code >= 300:
             raise ValueError(f"global timestamp HTTP {res.status_code}: {res.text}")
-        parsed = res.json()
+        if not isinstance(parsed, dict):
+            parsed = {}
         job_id = parsed.get("jobId") or parsed.get("blockHash") or ""
         if not job_id:
             raise ValueError("global timestamp response missing jobId")
diff --git a/tests/test_global_client.py b/tests/test_global_client.py
index 23239e2..4eae1db 100644
--- a/tests/test_global_client.py
+++ b/tests/test_global_client.py
@@ -60,7 +60,10 @@ async def test_global_stamp_posts_hash_sync_and_maps_receipt():
     method, url, payload, headers = http.calls[0]
     assert method == "POST"
     assert url == "https://api.veraetime.net/api/timestamp"
-    assert payload == {"data": SHA256_EMPTY, "hashAlg": "SHA256"}
+    assert payload["data"] == SHA256_EMPTY
+    assert payload["digest"] == SHA256_EMPTY
+    assert payload["hashAlg"] == "SHA256"
+    assert payload["restamp"] is False
     assert headers["Authorization"] == "Bearer secret"
     assert rec.scope == "global"
     assert rec.receipt_id == "job-1"