mcp examples: check for env vars needed for examples

examples/foundational/39-mcp-stdio.py

@@ -200,6 +200,14 @@ async def bot(runner_args: RunnerArguments):
 
 
 if __name__ == "__main__":
+    if not os.getenv("NASA_API_KEY"):
+        logger.error(
+            f"Please set NASA_API_KEY environment variable for this example. See https://api.nasa.gov"
+        )
+        import sys
+
+        sys.exit(1)
+
     from pipecat.runner.run import main
 
     main()

examples/foundational/39a-mcp-run-sse.py

@@ -134,6 +134,14 @@ async def bot(runner_args: RunnerArguments):
 
 
 if __name__ == "__main__":
+    if not os.getenv("MCP_RUN_SSE_URL"):
+        logger.error(
+            f"Please set MCP_RUN_SSE_URL environment variable for this example. See https://mcp.run"
+        )
+        import sys
+
+        sys.exit(1)
+
     from pipecat.runner.run import main
 
     main()

examples/foundational/39b-multiple-mcp.py

@@ -213,6 +213,14 @@ async def bot(runner_args: RunnerArguments):
 
 
 if __name__ == "__main__":
+    if not os.getenv("NASA_API_KEY") or not os.getenv("MCP_RUN_SSE_URL"):
+        logger.error(
+            f"Please set NASA_API_KEY and MCP_RUN_SSE_URL environment variables. See https://api.nasa.gov and https://mcp.run"
+        )
+        import sys
+
+        sys.exit(1)
+
     from pipecat.runner.run import main
 
     main()

examples/foundational/39c-mcp-run-http.py

@@ -138,6 +138,14 @@ async def bot(runner_args: RunnerArguments):
 
 
 if __name__ == "__main__":
+    if not os.getenv("GITHUB_PERSONAL_ACCESS_TOKEN"):
+        logger.error(
+            f"Please set GITHUB_PERSONAL_ACCESS_TOKEN environment variable for this example."
+        )
+        import sys
+
+        sys.exit(1)
+
     from pipecat.runner.run import main
 
     main()