Add dynamic variable support to Assistant model and related components

- Introduce dynamic variable definitions in AssistantConfig and Assistant models, allowing for flexible prompt customization.
- Implement validation for dynamic variable names and types in the schema.
- Update backend services and routes to handle dynamic variables in assistant configurations and runtime processing.
- Enhance frontend components to support dynamic variable definitions, including a new editor for managing variables.
- Add tests to ensure proper functionality and validation of dynamic variables in various scenarios.

backend/services/pipecat/pipeline.py

@@ -308,6 +308,41 @@ class VisionCaptureProcessor(FrameProcessor):
         await self.push_frame(frame, direction)
 
 
+class RealtimeDynamicVariableProcessor(FrameProcessor):
+    """Keep realtime system turn/history variables current between responses."""
+
+    def __init__(self, brain: Brain, cfg: AssistantConfig, realtime):
+        super().__init__()
+        self._brain = brain
+        self._cfg = cfg
+        self._realtime = realtime
+
+    async def _refresh_instructions(self) -> None:
+        update = getattr(self._realtime, "update_instructions", None)
+        if callable(update):
+            await update(self._brain.system_prompt(self._cfg))
+
+    async def process_frame(self, frame, direction: FrameDirection):
+        await super().process_frame(frame, direction)
+        if isinstance(frame, OutputTransportMessageUrgentFrame):
+            message = frame.message
+            if isinstance(message, dict):
+                event_type = message.get("type")
+                if event_type == "transcript" and message.get("role") == "user":
+                    content = str(message.get("content") or "").strip()
+                    if content:
+                        self._brain.record_user_message(content)
+                        await self._refresh_instructions()
+                elif event_type == "assistant-text-end":
+                    await self._brain.on_assistant_text_end(
+                        str(message.get("turn_id") or ""),
+                        str(message.get("content") or ""),
+                        bool(message.get("interrupted", False)),
+                    )
+                    await self._refresh_instructions()
+        await self.push_frame(frame, direction)
+
+
 class RealtimeTextInputProcessor(FrameProcessor):
     """Route text input directly to a realtime service without cascade semantics."""
 
@@ -709,6 +744,7 @@ async def run_pipeline(
         assistant_name=cfg.name,
         channel=channel,
         runtime_mode=cfg.runtimeMode,
+        session_id=cfg.conversation_id or None,
     )
     pipeline = Pipeline(
         [
@@ -911,6 +947,7 @@ async def run_realtime_pipeline(
         instructions=brain.system_prompt(cfg),
     )
     text_input = RealtimeTextInputProcessor()
+    dynamic_variables = RealtimeDynamicVariableProcessor(brain, cfg, realtime)
     greeting = await brain.greeting(cfg)
 
     recorder = await ConversationRecorder.start(
@@ -918,12 +955,14 @@ async def run_realtime_pipeline(
         assistant_name=cfg.name,
         channel=channel,
         runtime_mode=cfg.runtimeMode,
+        session_id=cfg.conversation_id or None,
     )
     pipeline = Pipeline(
         [
             transport.input(),
             text_input,
             realtime,
+            dynamic_variables,
             ConversationHistoryProcessor(recorder),
             transport.output(),
         ]

backend/services/pipecat/stepfun_realtime.py

@@ -289,6 +289,12 @@ class StepFunRealtimeService(AIService):
             wait_until_ready=False,
         )
 
+    async def update_instructions(self, instructions: str) -> None:
+        """Refresh model instructions without rebuilding the realtime session."""
+        self._instructions = instructions
+        if self._session_ready.is_set():
+            await self._send_session_update()
+
     async def _send_event(
         self, payload: dict[str, Any], *, wait_until_ready: bool = True
     ) -> None: