[BUG] VSCode extension silently declines MCP URL elicitation requests

Summary

The Claude Code VSCode extension declares support for URL mode elicitation in its MCP client capabilities (per the 2025-11-25 MCP spec), but silently declines elicitation requests without surfacing them to the user. The CLI handles this correctly.

Steps to Reproduce

1. Configure an MCP server that requires OAuth authentication via URL elicitation (e.g., a GitHub MCP server).
2. In the VSCode extension, invoke a tool that triggers the MCP server to send a URL elicitation response.
3. Observe: the tool call fails silently — the URL is never shown, no dialog appears, and the user has no opportunity to approve or complete the OAuth flow.

Expected Behavior

When an MCP server sends a URL elicitation response, the VSCode extension should:

1. Display the URL to the user (e.g., as a notification or modal dialog).
2. Open the URL in a browser (or prompt the user to do so).
3. Wait for the user to complete the browser flow.
4. Return the result to the MCP server.

This is exactly what the Claude Code CLI does today — it shows the URL, prompts the user to confirm, and relays the result back. ✅

Actual Behavior

The VSCode extension declares URL elicitation support in its capabilities, causing the MCP server to send a URL elicitation response. The extension then silently declines the request without showing the URL or prompting the user. The tool call fails with no actionable feedback.

Environment

• Claude Code VSCode extension (latest)
• MCP spec version: 2025-11-25
• Elicitation type: URL mode

Impact

Any MCP server that requires browser-based authentication (OAuth, MFA, account linking) is unusable from within the VSCode extension, even though the same server works correctly with the Claude Code CLI. This creates a confusing inconsistency where the extension advertises a capability it does not actually implement.

Suggested Fix

Implement URL elicitation handling in the VSCode extension with:

• A UI component (notification, modal, or webview) to display the elicitation URL and context
• A mechanism to open the URL in the user's browser
• A way to capture user confirmation after completing the browser flow and relay it back to the MCP server

Alternatively, if full implementation is not feasible, the extension should not advertise URL elicitation support in its capabilities so MCP servers do not attempt to use it.

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🤖 Generated with Claude Code