Implement config-driven models (Phase 1): graph MODELS dict, instantiate applies, per-request overrides

- Graph definitions (v3, v4) now declare MODELS mapping role → model string
- engine.py extracts MODELS and applies to nodes during instantiation
- frame_engine.process_message() accepts model_overrides for per-request swaps
  (restored via try/finally after processing)
- 11/11 engine tests green

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

agent/engine.py

@@ -63,6 +63,7 @@ def _graph_from_module(mod) -> dict:
         "conditions": getattr(mod, "CONDITIONS", {}),
         "audit": getattr(mod, "AUDIT", {}),
         "engine": getattr(mod, "ENGINE", "imperative"),
+        "models": getattr(mod, "MODELS", {}),
     }
 
 
@@ -79,6 +80,12 @@ def instantiate_nodes(graph: dict, send_hud, process_manager: ProcessManager = N
             nodes[role] = cls(send_hud=send_hud, process_manager=process_manager)
         else:
             nodes[role] = cls(send_hud=send_hud)
+        # Apply model from graph config (overrides class default)
+        model = graph.get("models", {}).get(role)
+        if model and hasattr(nodes[role], "model"):
+            nodes[role].model = model
+            log.info(f"[engine] {role} = {impl_name} ({cls.__name__}) model={model}")
+        else:
             log.info(f"[engine] {role} = {impl_name} ({cls.__name__})")
     return nodes
 

agent/frame_engine.py

@@ -173,10 +173,23 @@ class FrameEngine:
 
     # --- Main entry point ---
 
-    async def process_message(self, text: str, dashboard: list = None) -> dict:
+    async def process_message(self, text: str, dashboard: list = None,
+                              model_overrides: dict = None) -> dict:
         """Process a message through the frame pipeline.
-        Returns {response, controls, memorizer, frames, trace}."""
+        Returns {response, controls, memorizer, frames, trace}.
 
+        model_overrides: optional {role: model} to override node models for this request only.
+        """
+        # Apply per-request model overrides (restored after processing)
+        saved_models = {}
+        if model_overrides:
+            for role, model in model_overrides.items():
+                node = self.nodes.get(role)
+                if node and hasattr(node, "model"):
+                    saved_models[role] = node.model
+                    node.model = model
+
+        try:
             self._begin_trace(text)
 
             # Handle ACTION: prefix
@@ -224,6 +237,12 @@ class FrameEngine:
                 return await self._run_director_pipeline(command, mem_ctx, dashboard)
             else:
                 return await self._run_thinker_pipeline(command, mem_ctx, dashboard)
+        finally:
+            # Restore original models after per-request overrides
+            for role, original_model in saved_models.items():
+                node = self.nodes.get(role)
+                if node:
+                    node.model = original_model
 
     # --- Pipeline variants ---
 

agent/graphs/v3_framed.py

@@ -62,4 +62,13 @@ CONDITIONS = {
     "has_tool_output": "thinker.tool_used is not empty",
 }
 
+MODELS = {
+    "input":       "google/gemini-2.0-flash-001",
+    "director":    "anthropic/claude-haiku-4.5",
+    "thinker":     "google/gemini-2.0-flash-001",
+    "interpreter": "google/gemini-2.0-flash-001",
+    "output":      "google/gemini-2.0-flash-001",
+    "memorizer":   "google/gemini-2.0-flash-001",
+}
+
 AUDIT = {}

agent/graphs/v4_eras.py

@@ -68,4 +68,13 @@ CONDITIONS = {
     "has_tool_output": "expert.tool_used is not empty",
 }
 
+MODELS = {
+    "input":        "google/gemini-2.0-flash-001",
+    "pa":           "anthropic/claude-haiku-4.5",
+    "expert_eras":  "google/gemini-2.0-flash-001",
+    "interpreter":  "google/gemini-2.0-flash-001",
+    "output":       "google/gemini-2.0-flash-001",
+    "memorizer":    "google/gemini-2.0-flash-001",
+}
+
 AUDIT = {}