diff --git a/opax-mcp/policy/caller_context.py b/opax-mcp/policy/caller_context.py
index af19168..50180d1 100644
--- a/opax-mcp/policy/caller_context.py
+++ b/opax-mcp/policy/caller_context.py
@@ -2,7 +2,7 @@
 Derives a trusted CallerContext from a request.
 """
 from typing import Dict, Any
-from contracts.common import CallerContext, ToolRiskLevel
+from contracts.common import CallerContext
 
 # This is a placeholder for a future, more robust caller registry (e.g., Firestore).
 # The key would be the hash of the API key or the IAP-verified user email.
@@ -13,10 +13,10 @@ _CALLER_REGISTRY: Dict[str, Dict[str, Any]] = {
         "workspace_id": "ws:vauco",
         "allowed_tool_policy": {
             # This profile can read anything but requires approval for all writes
-            "default": ToolRiskLevel.REQUIRES_APPROVAL,
-            "read_only": ToolRiskLevel.READ_ONLY,
-            "propose_only": ToolRiskLevel.PROPOSE_ONLY,
-            "forbidden": ToolRiskLevel.FORBIDDEN,
+            "default": "requires_approval",
+            "read_only": "read_only",
+            "propose_only": "propose_only",
+            "forbidden": "forbidden",
         }
     },
     "user:chris.christiansen@vauco.no": {
@@ -25,9 +25,9 @@ _CALLER_REGISTRY: Dict[str, Dict[str, Any]] = {
         "workspace_id": "ws:vauco",
         "allowed_tool_policy": {
              # Admin can do safe writes directly, but needs high approval for destructive actions
-            "default": ToolRiskLevel.REQUIRES_HIGH_APPROVAL, 
-            "read_only": ToolRiskLevel.READ_ONLY,
-            "requires_approval": ToolRiskLevel.REQUIRES_APPROVAL, # Can do normal writes
+            "default": "requires_high_approval",
+            "read_only": "read_only",
+            "requires_approval": "requires_approval", # Can do normal writes
         }
     }
 }
@@ -38,7 +38,7 @@ _DEFAULT_CALLER_CONTEXT = CallerContext(
     profile="readonly",
     owner_id="system:public",
     workspace_id="ws:public",
-    allowed_tool_policy={"default": ToolRiskLevel.READ_ONLY}
+    allowed_tool_policy={"default": "read_only"}
 )
 
 def derive_caller_context(auth_identifier: str) -> CallerContext:
@@ -61,6 +61,6 @@ def derive_caller_context(auth_identifier: str) -> CallerContext:
 
     return CallerContext(
         caller_id=auth_identifier,
-        caller_type=auth_identifier.split(":")[0], # cheap trick
+        caller_type='human' if auth_identifier.startswith('user:') else auth_identifier.split(":")[0], # cheap trick
         **caller_data
     )