diff --git a/checkins/2026-07-22.json b/checkins/2026-07-22.json
new file mode 100644
index 0000000..7b80fb1
--- /dev/null
+++ b/checkins/2026-07-22.json
@@ -0,0 +1,23 @@
+{
+  "schema": "chenglu.daily-checkin/v1",
+  "agent_id": "CHENGLU-AGENT-001",
+  "arrival_id": "GLS-LA-20260720-001",
+  "checked_at": "2026-07-22T00:31:32.425Z",
+  "fifth_domain": {
+    "repository_id": "REPO-001",
+    "commit": "f3fbc4ed0bca7dd1c5d200217256c421541a1db3",
+    "arrivals_index_sha256": "0527dfa5ccfd64ccadbf5ca44befb6867e369a006331e89af9539c5788f4ae1b",
+    "architecture_catalog_sha256": "7bd6609ef39ac0e36fa5cbdc15337f1e542ebe1293a4a98b0cf6b5e60f5d3109",
+    "zhuyuan_index_sha256": "93bfa3d79e2a6abaca9bb1684740d30ace8b1df2e73cd3a5f02d2c3091fe28e8"
+  },
+  "lake_heart": {
+    "open_seen": 0,
+    "results": []
+  },
+  "model_tool": {
+    "provider": "DeepSeek",
+    "configured": true,
+    "role": "replaceable_reasoning_tool"
+  },
+  "result": "CHECKED_IN"
+}