diff --git a/probe_keys.py b/probe_keys.py
new file mode 100644
index 00000000..ebaffae2
--- /dev/null
+++ b/probe_keys.py
@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+"""Probe actual checkpoint weight keys and shapes for DSV4-Pro NVFP4.
+Focus on layer 0 (HCA) and layer 2 (CSA) non-expert weights.
+"""
+import json, os
+from safetensors.torch import load_file
+from pathlib import Path
+
+CHECKPOINT_DIR = "/root/nvidia-meeting/DeepSeek-V4-Pro-NVFP4"
+cdir = Path(CHECKPOINT_DIR)
+
+with open(cdir / "model.safetensors.index.json") as f:
+    wmap = json.load(f)["weight_map"]
+
+# Find all keys for layer 0 and 2, excluding expert weights
+for li in [0, 2]:
+    pfx = f"model.layers.{li}."
+    keys = sorted([k for k in wmap if k.startswith(pfx) and 'experts.' not in k and 'shared_expert' not in k])
+    print(f"\n=== Layer {li} non-expert keys ({len(keys)}) ===")
+    for k in keys:
+        print(f"  {k}")
+
+# Global keys
+global_keys = sorted([k for k in wmap if not k.startswith("model.layers.")])
+print(f"\n=== Global keys ({len(global_keys)}) ===")
+for k in global_keys:
+    print(f"  {k}")
+
+# Load actual shapes for layer 0 and 2
+for li in [0, 2]:
+    pfx = f"model.layers.{li}."
+    keys = [k for k in wmap if k.startswith(pfx) and 'experts.' not in k and 'shared_expert' not in k]
+    shards = set(wmap[k] for k in keys)
+    print(f"\n=== Layer {li} shapes ===")
+    for sn in sorted(shards):
+        if not (cdir / sn).exists(): continue
+        w = load_file(str(cdir / sn))
+        for k in sorted(w.keys()):
+            if k.startswith(pfx) and 'experts.' not in k and 'shared_expert' not in k:
+                print(f"  {k}: {tuple(w[k].shape)} {w[k].dtype}")
+
+# Expert key pattern for layer 0 (just the first few)
+pfx0 = f"model.layers.0.mlp."
+expert_keys = sorted([k for k in wmap if k.startswith(pfx0) and 'experts.' in k])[:12]
+print(f"\n=== Layer 0 expert keys (sample) ===")
+for k in expert_keys:
+    print(f"  {k}")
+
+# Shared expert keys for layer 0
+shared_keys = sorted([k for k in wmap if k.startswith(pfx0) and 'shared_expert' in k])
+print(f"\n=== Layer 0 shared expert keys ===")
+for k in shared_keys:
+    print(f"  {k}")
+
+# Router/gate keys for layer 0
+gate_keys = sorted([k for k in wmap if k.startswith(pfx0) and ('gate' in k or 'e_score' in k or 'tid2eid' in k or 'router' in k)])
+print(f"\n=== Layer 0 gate/router keys ===")
+for k in gate_keys:
+    print(f"  {k}")