Send global stamps as a verae-meta-git/1 history.

Optional metadata or restamp builds the same commit history as node-red. A call that omits both stays digest-only with restamp false. Local and shared stamps reject metadata.

tests/test_global_client.py

@@ -380,3 +380,36 @@ async def test_global_hash_report_uses_api_hash():
     assert methods_urls[0] == ("GET", f"https://api.veraetime.net/api/hash/{SHA256_EMPTY}")
     assert methods_urls[1][0] == "POST"
     assert methods_urls[1][1].endswith("/api/verify")
+
+
+async def test_restamp_sends_verae_meta_git_history():
+    class HistoryHttp(FakeHttp):
+        def request(self, method, url, payload, headers):
+            self.calls.append((method, url, payload, headers))
+            if url.endswith(f"/api/hash/{SHA256_EMPTY}"):
+                return _Resp(200, {"receipts": [{"jobId": "job-old", "certificate": "QmOld"}]})
+            if url.endswith("/api/status/job-old"):
+                return _Resp(200, {"status": "completed", "metadata": {"title": "deed", "tags": ["a"]}})
+            if url.endswith("/api/timestamp"):
+                return _Resp(202, {"jobId": "job-new"})
+            if url.endswith("/api/status/job-new"):
+                return _Resp(200, {"status": "completed", "result": "QmNew", "metadata": {"schema": "verae-meta-git/1"}})
+            raise AssertionError(f"unexpected {method} {url}")
+
+    http = HistoryHttp()
+    client = GlobalClient("https://api.veraetime.net", token="secret", http=http)
+    rec = client.submit(
+        SHA256_EMPTY,
+        metadata={"place": "office"},
+        restamp=True,
+        message="add the place",
+        at="2026-10-11T02:00:00.000Z",
+    )
+    post = next(call for call in http.calls if call[1].endswith("/api/timestamp"))
+    body = post[2]
+    assert body["restamp"] is True
+    assert body["metadata"]["schema"] == "verae-meta-git/1"
+    assert body["metadata"]["snapshot"]["title"] == "deed"
+    assert body["metadata"]["snapshot"]["place"] == "office"
+    assert body["metadata"]["snapshot"]["tags"] == ["a"]
+    assert rec.receipt_id == "QmNew"

tests/test_metadata_history.py

@@ -0,0 +1,59 @@
+"""Golden verae-meta-git/1 ids shared with node-red-contrib-verae."""
+
+from verae_mcp_timestamping_server.metadata_history import append_metadata
+
+HEAD_1 = "161ff3344ba776ae7201b73914c0e7500116ac9dde02e1967a761b7089c41fa7"
+HEAD_2 = "c606e41ccbf4c0f9f653b21759df83ecda25262621075db3a153b592270fd918"
+
+
+def test_append_matches_node_reference():
+    first = append_metadata(
+        None,
+        {"title": "deed", "tags": ["a"]},
+        restamp=False,
+        at="2026-10-11T01:00:00.000Z",
+        message="stamp",
+    )
+    assert first["head"] == HEAD_1
+    second = append_metadata(
+        first,
+        {"title": "deed-2", "tags": ["b"], "place": "office"},
+        restamp=True,
+        at="2026-10-11T02:00:00.000Z",
+        message="correct the title",
+    )
+    assert second["head"] == HEAD_2
+    assert second["snapshot"] == {"title": "deed-2", "tags": ["a", "b"], "place": "office"}
+    assert second["commits"][1]["parent"] == HEAD_1
+    assert "removed" not in second["commits"][1]["changes"]
+
+
+def test_blank_restamp_keeps_snapshot():
+    nxt = append_metadata(
+        {"title": "deed", "note": "keep", "tags": ["a"]},
+        {"title": "", "note": None, "tags": []},
+        restamp=True,
+        at="2026-10-11T01:47:00.000Z",
+        prior_at="2026-10-11T01:00:00.000Z",
+    )
+    assert nxt["snapshot"]["title"] == "deed"
+    assert nxt["snapshot"]["note"] == "keep"
+    assert nxt["snapshot"]["tags"] == ["a"]
+    assert len(nxt["commits"]) == 2
+
+
+def test_omit_when_empty():
+    assert append_metadata(None, None, restamp=False, at="2026-10-11T01:00:00.000Z") is None
+    assert append_metadata(None, {}, restamp=False, at="2026-10-11T01:00:00.000Z") is None
+
+
+def test_history_document_is_not_rewritten_by_append_of_itself():
+    first = append_metadata(
+        None,
+        {"title": "deed", "tags": ["a"]},
+        restamp=False,
+        at="2026-10-11T01:00:00.000Z",
+        message="stamp",
+    )
+    assert first["schema"] == "verae-meta-git/1"
+    assert first["commits"][0]["parent"] is None