[Feature Request] Custom MCP Server Access in Claude Code Web (Browser)

[Feature Request] Custom MCP Server Access in Claude Code Web (Browser)

Preflight Checklist

• [x] I have searched existing issues and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Related Issue

This is related to #11146 (MCP servers not accessible in web session mode via Desktop), but filed separately because:

• My entry point is Claude.ai in a browser (not the Desktop app)
• MCP servers are configured via Claude.ai Integrations/Connectors (not Desktop's local config)
• This is a feature request rather than a bug report — the ask is for Code Web to inherit the MCP context that's already working in standard chat

The root cause appears to be the same: the web container that powers Code sessions doesn't receive MCP server connections.

What I'd Love to See

It would be great if Claude Code Web (the browser-based code execution environment on claude.ai) could access custom MCP servers — just like standard Claude.ai chat already does!

What's Happening Now

I set up a custom MCP server on my own infrastructure, connected it to Claude.ai via Integrations, and confirmed it works perfectly in normal chat sessions. 🎉

However, when I switched over to Claude Code Web (the in-browser coding agent), the agent told me it couldn't see any of my custom MCP servers. Here's a quick summary:

| Environment | Custom MCP Access |
|---|---|
| Claude.ai (Web Chat) | ✅ Works great |
| Claude Code (Terminal CLI) | ✅ Works great |
| Claude Code Web (Browser) | ❌ Not available |

Steps to Reproduce

1. Host a custom MCP server (SSE transport) on your own infrastructure.
2. Connect it via Claude.ai settings (Integrations / Connectors).
3. Test in a standard Claude.ai chat → works fine.
4. Open a Claude Code Web session and try using the same MCP server → the agent says it can't see any custom MCP servers.

Why This Would Be Awesome

• Seamless workflow: Developers who set up custom MCP servers for their tools, databases, or internal APIs would be able to use them in Claude Code Web without switching to the terminal CLI.
• Consistency: All browser-based Claude interfaces sharing the same MCP configuration just makes sense — less confusion, fewer "wait, why doesn't this work here?" moments.
• MCP ecosystem growth: Lowering friction for custom MCP usage across all Claude surfaces encourages more people to build and share MCP servers.

Suggested Approach

Ideally, Claude Code Web sessions would simply inherit the MCP server connections already configured at the Claude.ai level. No extra setup needed on the user's side — if it works in chat, it should work in Code Web too.

The terminal-based Claude Code already supports MCP natively, so the protocol-level plumbing is there. It seems like it's just a matter of bridging that configuration into the browser-based Code environment.

Environment

• Platform: Claude.ai (Web / Browser)
• Product: Claude Code Web (browser-based code execution)
• MCP Server Type: Custom self-hosted (SSE transport)

Thanks for considering this! Really enjoying both Claude Code and the MCP ecosystem — this would make the experience even better. 🙏