My understanding from this change modelcontextprotocol/python-sdk#1177 is that the signature has changed on how the client is passed.

If streamable_http_client is imported instead of streamablehttp_client, I think this will break because the new implementation will use a default http_client which will not have the headers, auth etc here set up.

Yes, good catch! I had wrongly assumed that we would be using the version > 1.24.0 always,

In this case, how do you suggest we determine whether we are on a new version or old version ?

One option is we can use the packaging dependency and do something like

from importlib.metadata import version
  from packaging.version import Version

  # Check version at import time
  _MCP_VERSION = Version(version('mcp'))
  _NEW_API_AVAILABLE = _MCP_VERSION >= Version('1.24.0')

  if _NEW_API_AVAILABLE:
      from mcp.client.streamable_http import streamable_http_client as _streamable_http_client_new
  else:
      from mcp.client.streamable_http import streamablehttp_client as _streamablehttp_client_old

Or we can directly check the method signature at runtime and determine that ?

import inspect

  _NEW_API_AVAILABLE = False
  _streamable_http_client_new = None
  _streamablehttp_client_old = None

  try:
      from mcp.client.streamable_http import streamable_http_client as _candidate

      sig = inspect.signature(_candidate)
      # New API has 'http_client' param, old API has 'auth' param
      if 'http_client' in sig.parameters and 'auth' not in sig.parameters:
          _NEW_API_AVAILABLE = True
          _streamable_http_client_new = _candidate
  except (ImportError, ValueError):
      pass

  if not _NEW_API_AVAILABLE:
      try:
          from mcp.client.streamable_http import streamablehttp_client as _streamablehttp_client_old
      except ImportError:
          from mcp.client.streamable_http import streamable_http_client as _streamablehttp_client_old

Actually, the only way we get rid of the DeprecationWarning is if we update the version. I talked to @wzxxing on any problems with upgrading. Copying his reply here:

The fastmcp v2.14.1 introduced some incompatible change that changes the signature of the the httpx client factory.
The fix should be just to add kw args to this function.

mcp-proxy-for-aws/mcp_proxy_for_aws/utils.py

Line 60 in 1bea695

**kw,

3:28

@ps06756 would you be willing to include this change and upgrade the dependency?

If not, then please comment in the linked issue and we will prioritise the fix and update.