feat: Improve FastAPI agentic template

helpers/env-variables.ts

@@ -13,6 +13,12 @@ import {
 
 import { TSYSTEMS_LLMHUB_API_URL } from "./providers/llmhub";
 
+const DEFAULT_SYSTEM_PROMPT =
+  "You are a helpful assistant who helps users with their questions.";
+
+const DATA_SOURCES_PROMPT =
+  "You have access to a knowledge base, use query engine tool to retrieve the facts to answer the user question.";
+
 export type EnvVar = {
   name?: string;
   description?: string;
@@ -449,9 +455,6 @@ const getSystemPromptEnv = (
   dataSources?: TemplateDataSource[],
   template?: TemplateType,
 ): EnvVar[] => {
-  const defaultSystemPrompt =
-    "You are a helpful assistant who helps users with their questions.";
-
   const systemPromptEnv: EnvVar[] = [];
   // build tool system prompt by merging all tool system prompts
   // multiagent template doesn't need system prompt
@@ -466,9 +469,12 @@ const getSystemPromptEnv = (
       }
     });
 
-    const systemPrompt = toolSystemPrompt
-      ? `\"${toolSystemPrompt}\"`
-      : defaultSystemPrompt;
+    const systemPrompt =
+      "'" +
+      DEFAULT_SYSTEM_PROMPT +
+      (dataSources?.length ? `\n${DATA_SOURCES_PROMPT}` : "") +
+      (toolSystemPrompt ? `\n${toolSystemPrompt}` : "") +
+      "'";
 
     systemPromptEnv.push({
       name: "SYSTEM_PROMPT",

templates/types/streaming/fastapi/app/api/routers/vercel_response.py

@@ -53,17 +53,27 @@ async def content_generator(
         # Merge the chat response generator and the event generator
         combine = stream.merge(chat_response_generator, event_generator)
         is_stream_started = False
-        async with combine.stream() as streamer:
-            async for output in streamer:
-                if not is_stream_started:
-                    is_stream_started = True
-                    # Stream a blank message to start displaying the response in the UI
-                    yield cls.convert_text("")
-
-                yield output
-
-                if await request.is_disconnected():
-                    break
+        try:
+            async with combine.stream() as streamer:
+                async for output in streamer:
+                    if await request.is_disconnected():
+                        break
+
+                    if not is_stream_started:
+                        is_stream_started = True
+                        # Stream a blank message to start displaying the response in the UI
+                        yield cls.convert_text("")
+
+                    yield output
+        except Exception:
+            logger.exception("Error in stream response")
+            error_message = (
+                "An error occurred while processing your request. Please try again."
+            )
+            yield cls.convert_text(error_message)
+        finally:
+            # Ensure event handler is marked as done even if connection breaks
+            event_handler.is_done = True
 
     @classmethod
     async def _event_generator(cls, event_handler: EventCallbackHandler):