Request URL is missing an 'http://' or 'https://' protocol.

[rhalai]

Type of issue

• Instructions in the learning path do not work.
• Spelling error in the learning path.
• Instructions in the learning path are hard to follow.
• Instructions to contribute a new learning path are not clear.
• Other

Describe the issue
I followed the instructions and get an error
https://learn.arm.com/learning-paths/cross-platform/mcp-ai-agent/
Deploy an MCP Server on Raspberry Pi 5 for AI Agent Interaction using OpenAI SDK

When I run the agent I get the error as per screenshot
| Traceback (most recent call last):
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 101, in map_httpcore_exceptions
| yield
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 394, in handle_async_request
| resp = await self._pool.handle_async_request(req)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpcore/_async/connection_pool.py", line 207, in handle_async_request
| raise UnsupportedProtocol(
| httpcore.UnsupportedProtocol: Request URL is missing an 'http://' or 'https://' protocol.
|
| The above exception was the direct cause of the following exception:
|
| Traceback (most recent call last):
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/mcp/client/sse.py", line 69, in sse_client
| async with aconnect_sse(
| File "/usr/lib/python3.11/contextlib.py", line 204, in aenter
| return await anext(self.gen)
| ^^^^^^^^^^^^^^^^^^^^^
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx_sse/_api.py", line 74, in aconnect_sse
| async with client.stream(method, url, headers=headers, **kwargs) as response:
| File "/usr/lib/python3.11/contextlib.py", line 204, in aenter
| return await anext(self.gen)
| ^^^^^^^^^^^^^^^^^^^^^
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_client.py", line 1583, in stream
| response = await self.send(
| ^^^^^^^^^^^^^^^^
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_client.py", line 1629, in send
| response = await self._send_handling_auth(
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_client.py", line 1657, in _send_handling_auth
| response = await self._send_handling_redirects(
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_client.py", line 1694, in _send_handling_redirects
| response = await self._send_single_request(request)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_client.py", line 1730, in _send_single_request
| response = await transport.handle_async_request(request)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 393, in handle_async_request
| with map_httpcore_exceptions():
| File "/usr/lib/python3.11/contextlib.py", line 155, in exit
| self.gen.throw(typ, value, traceback)
| File "/home/pi/mcp-agent/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 118, in map_httpcore_exceptions
| raise mapped_exc(message) from exc
| httpx.UnsupportedProtocol: Request URL is missing an 'http://' or 'https://' protocol.

To Reproduce
List the steps to reproduce the behavior:
server is running
ngrok is running
uv run main.py fails

Expected behavior
I do not get temperature readings

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• running on Raspberry PI
  uname -a
  Linux aipissd 6.12.62+rpt-rpi-2712 Template: Removed unused video-page template #1 SMP PREEMPT Debian 1:6.12.62-1+rpt1~bookworm (2026-01-19) aarch64 GNU/Linux
• Browser chrome
• Version 145.0.7632

Mobile (please complete the following information):
not using mobile

Additional context
I have not modified any of the code, its as per the instructions; I tried multiple times same result

[rhalai]

I found a missed step, I was supposed to add the grok URL; will try that and see if that fixes the issue

[rhalai]

New error - Failed to connect to MCP server 'RPI5 MCP Server': HTTP error 421 (Misdirected Request)

[rhalai]

I used ngrok http 8000 --host-header="localhost:8000" to get it working, turns out this is now deprecated

Flag --host-header has been deprecated, use traffic policy instead

Also I learned that I need to add credit to my openai account; due to the following error

openai.RateLimitError: Error code: 429 - {'error': {'message': 'You exceeded your current quota, please check your plan and billing details. For more information on this error, read the docs: https://platform.openai.com/docs/guides/error-codes/api-errors.', 'type': 'insufficient_quota', 'param': None, 'code': 'insufficient_quota'}}

uv run main.py
Running: What is the CPU temperature?
Response: The CPU temperature is 51.0°C.
Running: How is the weather in Cambridge?
Response: I'm currently unable to retrieve real-time weather data for Cambridge due to a technical issue. Would you like a general climate description of Cambridge or should I try again? If you need live weather, I recommend checking a weather website or app for the most accurate information.

From what I can tell, it didnt use any credit not sure what is occurring, no matter I am sure I can use the credit for something