[BUG] Claude code does not support MCP protocol version 2025-06-18 needed by Lens Studio and others

Resolved 💬 5 comments Opened Jan 9, 2026 by mspertus Closed Feb 28, 2026

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?

When I try to connect to Snap Lens Studio's MCP server from claude code, it fails to connect. After much debugging (with Claude code's assistance), we determined that the problem is that Lens Studio uses MCP protocol version 2025-06-18 while Claude Code apparently only goes up to MCP protocol version 2024-11-05.

What Should Happen?

Claude should be able to use MCP servers on protocol 2025-06-18. For example, the following curl statement works.

curl --location 'http://localhost:8732/mcp' \
--header 'Content-Type: appllication/json' \
--header 'Authorization: Bearer ...w37PVy' \
--data '  {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
      "protocolVersion": "2025-06-18",
      "capabilities": {},
      "clientInfo": {
        "name": "postman-test",
        "version": "1.0"
      }
    }
  }'

Error Messages/Logs

Steps to Reproduce

  1. Launch Lens Studio (or anything else on 2025-06-18)
  2. AI Assistant/MCP/Configure Server/Start Server
  3. Get config from AI Assistant/MCP/Copy MCP Configuration
  4. Install it in Claude Code
  5. Claude code will fail to connect

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.2

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_

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