[BUG] claude.ai MT Newswires MCP connector — fetch returns HTTPStatusError.__init__() crash on all data requests

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

All calls to mcp__claude_ai_MT_Newswires__fetch fail with the error:

{"error": "Error getting dataset: HTTPStatusError.__init__() missing 2 required positional arguments: 'request' and 'response'", "status": "error"}

This happens regardless of dataset (mt_newswires_north_america or mt_newswires_global), symbol, date range, or whether parameters are included at all. The current_date and search tools work correctly — only fetch fails.

The same MT Newswires connector works in claude.ai web chat. The subscription is active and the connector has been disconnected and reconnected. The error is reproducible 100% of the time.

What Should Happen?

mcp__claude_ai_MT_Newswires__fetch should return news articles from the MT Newswires dataset. The connector works in claude.ai web chat, so the issue is specific to the Claude Code connector version.

Error Messages/Logs

{"error": "Error getting dataset: HTTPStatusError.__init__() missing 2 required keyword-only arguments: 'request' and 'response'", "status": "error"}

Steps to Reproduce

1. Connect the claude.ai MT Newswires MCP connector (via claude.ai Integrations settings)
2. Open Claude Code — connector appears active (mcp__claude_ai_MT_Newswires__current_date and search work)
3. Call fetch with any parameters, e.g.:

mcp__claude_ai_MT_Newswires__fetch(endpoint="data", product="edge", dataset_name="mt_newswires_north_america", symbols="NVDA", last=3)

1. Every fetch call returns the HTTPStatusError crash regardless of parameters

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.143 (Claude Code)

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

• mcp__claude_ai_MT_Newswires__current_date returns correct date — connector auth is working
• mcp__claude_ai_MT_Newswires__search returns dataset metadata correctly
• Only fetch (actual data retrieval) fails
• The error is a Python httpx library bug: newer versions of httpx require request and response as keyword args when raising HTTPStatusError, but the connector code calls it without them
• Same connector/subscription works fine in claude.ai web chat — this is specific to the Claude Code connector version
• Reproducible 100% of the time across all datasets, symbols, and date parameters