diff --git a/src/verae_mcp_timestamping_server/global_client.py b/src/verae_mcp_timestamping_server/global_client.py
index 89a3d1c..7a43f31 100644
--- a/src/verae_mcp_timestamping_server/global_client.py
+++ b/src/verae_mcp_timestamping_server/global_client.py
@@ -8,6 +8,7 @@ from __future__ import annotations
 
 import json
 import os
+import time
 import urllib.error
 import urllib.request
 from pathlib import Path
@@ -42,7 +43,7 @@ class UrllibHttp:
     def request(
         self, method: str, url: str, payload: dict[str, Any], headers: dict[str, str]
     ) -> _UrllibResp:
-        data = json.dumps(payload).encode()
+        data = None if method == "GET" else json.dumps(payload).encode()
         req = urllib.request.Request(url, data=data, method=method)
         for key, value in headers.items():
             req.add_header(key, value)
@@ -106,7 +107,7 @@ class GlobalClient:
         res = self.http.request(
             "POST",
             url,
-            payload={"hash": digest, "sync": True},
+            payload={"data": digest, "hashAlg": "SHA256"},
             headers=self._headers(),
         )
         if res.status_code >= 300:
@@ -115,13 +116,37 @@ class GlobalClient:
         job_id = parsed.get("jobId") or parsed.get("blockHash") or ""
         if not job_id:
             raise ValueError("global timestamp response missing jobId")
+        created = str(parsed.get("timestamp") or "")
+        merkle = str(parsed.get("blockHash") or "")
+        receipt_id = str(job_id)
+        status_url = f"{self.base_url}/api/status/{job_id}"
+        for _ in range(20):
+            st = self.http.request("GET", status_url, payload={}, headers=self._headers())
+            if st.status_code >= 300:
+                break
+            body = st.json() if hasattr(st, "json") else {}
+            if not isinstance(body, dict):
+                break
+            state = str(body.get("status") or "")
+            if state == "failed":
+                raise ValueError(str(body.get("error") or "global timestamp job failed"))
+            if state == "completed":
+                receipt_id = str(body.get("result") or body.get("id") or job_id)
+                meta = body.get("metadata") or {}
+                created = str(meta.get("timestamp") or body.get("completedAt") or created)
+                merkle = str(meta.get("blockIndex") or meta.get("blockHash") or merkle)
+                break
+            if state in ("pending", "running", ""):
+                time.sleep(0.25)
+                continue
+            break
         return Receipt(
-            receipt_id=str(job_id),
+            receipt_id=receipt_id,
             hash=digest,
             scope="global",
             cube_id=cube_id,
-            created_at=str(parsed.get("timestamp") or ""),
-            merkle=str(parsed.get("blockHash") or ""),
+            created_at=created,
+            merkle=merkle,
         )
 
     def verify_certificate(self, receipt_id: str) -> VerifyResult:
diff --git a/tests/test_global_client.py b/tests/test_global_client.py
index a46a87a..b1188b1 100644
--- a/tests/test_global_client.py
+++ b/tests/test_global_client.py
@@ -29,7 +29,7 @@ class FakeHttp:
                 200,
                 {
                     "jobId": "job-1",
-                    "hash": payload["hash"],
+                    "hash": payload.get("data") or payload.get("hash"),
                     "timestamp": "2026-08-15T00:00:00Z",
                     "blockHash": "0xdead",
                 },
@@ -38,6 +38,16 @@ class FakeHttp:
             if payload.get("certificate") == "job-1":
                 return _Resp(200, {"valid": True, "hash": SHA256_EMPTY})
             return _Resp(200, {"valid": False})
+        if "/api/status/" in url:
+            return _Resp(
+                200,
+                {
+                    "id": "job-1",
+                    "status": "completed",
+                    "result": "job-1",
+                    "metadata": {"timestamp": "2026-08-15T00:00:00Z", "blockHash": "0xdead"},
+                },
+            )
         return _Resp(404, {"error": "nope"})
 
 
@@ -49,7 +59,7 @@ 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 == {"hash": SHA256_EMPTY, "sync": True}
+    assert payload == {"data": SHA256_EMPTY, "hashAlg": "SHA256"}
     assert headers["Authorization"] == "Bearer secret"
     assert rec.scope == "global"
     assert rec.receipt_id == "job-1"
@@ -84,7 +94,7 @@ async def test_routing_sends_only_global_scope_to_central():
     [g] = await routed.stamp(SHA256_EMPTY, scope="global", cube_id="cube-1")
     assert g.scope == "global"
     assert g.receipt_id == "job-1"
-    assert len(http.calls) == 1
+    assert http.calls[0][1].endswith("/api/timestamp")
 
     cached = await routed.hash_report(SHA256_EMPTY, want_scope="global")
     assert cached[0].receipt_id == "job-1"