diff --git a/src/cleveragents/actor/config.py b/src/cleveragents/actor/config.py
index ad6a7f7a4..4e5f29a8f 100644
--- a/src/cleveragents/actor/config.py
+++ b/src/cleveragents/actor/config.py
@@ -11,6 +11,33 @@ from cleveragents.actor.yaml_loader import load_yaml_text
 #: v3 actor types that signal the ``ActorConfigSchema`` format.
 _V3_ACTOR_TYPES: frozenset[str] = frozenset({"llm", "graph", "tool"})
 
+def _parse_combined_actor(
+    value: Any,
+) -> tuple[str | None, str | None]:
+    """Parse a combined ``provider/model`` string into separate provider/model.
+
+    Accepts strings in the form ``"provider/model"`` (e.g.
+    ``"anthropic/claude-3.5-sonnet"``) at any nesting level.  Returns
+    ``(provider, model)`` where either may be ``None`` when the string
+    does not match the combined format.
+
+    Args:
+        value: A config value that might contain a combined actor string.
+
+    Returns:
+        An ``(provider, model)`` tuple on success, or ``(None, None)`` if
+        the value is not a valid combined-format string.
+    """
+    if not isinstance(value, str) or "/" not in value:
+        return None, None
+    parts = value.split("/", 1)
+    provider = parts[0].strip() if parts[0] else None
+    model = parts[1].strip() if parts[1] else None
+    if provider and model:
+        return provider, model
+    return None, None
+
+
 
 class ActorConfiguration(BaseModel):
     """Canonical actor configuration parsed from user-provided blobs."""
@@ -102,6 +129,20 @@ class ActorConfiguration(BaseModel):
             provider or data.get("provider") or data.get("provider_type") or v3_provider
         )
         resolved_model = model or data.get("model") or data.get("model_id") or v3_model
+
+        # Fall back to combined "provider/model" format from actor key at any
+        # nesting level. This handles configs that use ``actor: "provider/model"``
+        # instead of separate provider/model keys.
+        if not resolved_provider:
+            cp, _ = _parse_combined_actor(data.get("actor"))
+            if cp:
+                resolved_provider = cp
+
+        if not resolved_model:
+            _, cm = _parse_combined_actor(data.get("actor"))
+            if cm:
+                resolved_model = cm
+
         resolved_graph = (
             graph_descriptor
             or data.get("graph_descriptor")
@@ -205,10 +246,16 @@ class ActorConfiguration(BaseModel):
                         if isinstance(first_entry, dict):
                             config_block = first_entry.get("config")
                             if isinstance(config_block, dict):
+                                # 1. Try separate "model" key first
                                 mv = config_block.get("model")
                                 if isinstance(mv, str) and mv:
                                     model_value = mv
                                     break
+                                # 2. Fall back to combined "provider/model" format
+                                actor_combined = config_block.get("actor")
+                                cp, cm = _parse_combined_actor(actor_combined)
+                                if cm:
+                                    model_value = cm
                         break
             if not model_value:
                 if actor_type.lower() != "tool":
@@ -222,10 +269,16 @@ class ActorConfiguration(BaseModel):
                     if isinstance(first_entry, dict):
                         config_block = first_entry.get("config")
                         if isinstance(config_block, dict):
+                            # 1. Try separate "provider" key first
                             pv = config_block.get("provider")
                             if isinstance(pv, str) and pv:
                                 provider_value = pv
                                 break
+                            # 2. Fall back to combined "provider/model" format
+                            actor_combined = config_block.get("actor")
+                            cp, cm = _parse_combined_actor(actor_combined)
+                            if cp:
+                                provider_value = cp
                         break
 
         if not provider_value:
diff --git a/src/cleveragents/actor/v3_registry.py b/src/cleveragents/actor/v3_registry.py
index cca8fbbf7..5c3d291a1 100644
--- a/src/cleveragents/actor/v3_registry.py
+++ b/src/cleveragents/actor/v3_registry.py
@@ -108,11 +108,27 @@ def _extract_nested_v3_config(data: dict[str, Any]) -> None:
                 mv = config_block.get("model")
                 if isinstance(mv, str) and mv:
                     data["model"] = mv
+                else:
+                    # 2. Fall back to combined "provider/model" format
+                    actor_combined = config_block.get("actor")
+                    parts = actor_combined.split("/", 1) if (
+                        isinstance(actor_combined, str) and "/" in actor_combined
+                    ) else []
+                    if len(parts) == 2 and parts[1].strip():
+                        data["model"] = parts[1].strip()
 
             if "provider" not in data:
                 pv = config_block.get("provider")
                 if isinstance(pv, str) and pv:
                     data["provider"] = pv
+                else:
+                    # 2. Fall back to combined "provider/model" format
+                    actor_combined = config_block.get("actor")
+                    parts = actor_combined.split("/", 1) if (
+                        isinstance(actor_combined, str) and "/" in actor_combined
+                    ) else []
+                    if len(parts) == 2 and parts[0].strip():
+                        data["provider"] = parts[0].strip()
 
             if "name" not in data:
                 name_val = config_block.get("name")