foundry-mcp server fails to connect — missing auth in .mcp.json

[chashea]

Summary

The foundry-mcp MCP server defined in the azure@azure-skills plugin fails to connect with ✗ Failed to connect in claude mcp list.

Root Cause

The .mcp.json in the plugin cache (~/.claude/plugins/cache/azure-skills/azure/1.0.0/.mcp.json) configures the foundry server as a plain HTTP endpoint with no authentication:

"foundry-mcp": { 
  "type": "http", 
  "url": "https://mcp.ai.azure.com" 
}

The https://mcp.ai.azure.com endpoint returns 401 Unauthorized for all requests without a bearer token. Tested manually:

• GET / → 405 (server is reachable)
• POST / with az account get-access-token --resource https://management.azure.com → 401
• POST / with az account get-access-token --resource https://ai.azure.com → 401
• POST / with az account get-access-token --resource https://ml.azure.com → 401

The server config needs authentication headers (likely an Azure AD bearer token with the correct resource/audience).

Expected Behavior

The foundry-mcp server should authenticate automatically using the user's Azure CLI credentials (similar to how the azure server works via @azure/mcp).

Environment

• Claude Code (CLI)
• Plugin: azure@azure-skills v1.0.0
• macOS, az login active session

[fanyang-mono]

@tendau Can you comment on this please?

[github-actions]

Thanks for the detailed report, @chashea! 🙏

This has been labeled as a bug since the foundry-mcp server fails to connect due to missing authentication configuration. The auth label was applied because the root cause is the .mcp.json lacking bearer token support for (mcp.ai.azure.com/redacted), and the skills label was added since this affects the azure-skills plugin. A coding agent will be looking into the fix — the likely resolution is adding proper Azure AD bearer token configuration to the foundry-mcp entry in .mcp.json (similar to how the azure server handles auth via @azure/mcp).

Generated by Issue Triage for issue #1235

[tendau]

Hello. The foundry mcp has been removed from the mcp.json and is now being proxied through the azure MCP which should be handling auth at this point. Please pull latest and try again.