Bug: "Try TanStack MCP" button freezes the entire site

[Kyujenius]

Description

Clicking or even hovering over the "Try TanStack MCP" button in the navbar causes the entire site to freeze/become unresponsive. This is a critical UX bug affecting all visitors.

Steps to Reproduce

1. Go to https://tanstack.com
2. Hover over the "Try TanStack MCP" button in the navbar (top right, green button with "Alpha" badge)
3. Expected: Navigate to MCP landing page
4. Actual: Page freezes and becomes unresponsive

Video

2026-01-25.mov

Root Cause Analysis

This regression was introduced in commit 1889db30 ("builder alpha.2" - Jan 21, 2026).

Timeline:

• a71ea35 (Jan 11): MCP library added with its own landing page (McpLanding.tsx) and docs (docs/mcp/)
• 1889db3 (Jan 21): handleRedirects added to MCP config, redirecting all /mcp paths to /cli/latest/docs/mcp/*

(There is no PR Link because It's all done by Maintainer 😄 )

What went wrong:

1. handleRedirects in libraries.ts throws redirect() for any /mcp or /mcp/latest path
2. TanStack Router's Link component preloads routes on hover
3. During preload, beforeLoad in $version.tsx calls library.handleRedirects()
4. throw redirect() during preload causes an unhandled exception → page freeze

Additionally:

• McpLanding component exists but was never registered in landingComponents in $version.index.tsx
• MCP has its own docs in docs/mcp/ but handleRedirects tries to redirect to CLI docs

Suggested Fix

1. Remove handleRedirects from MCP config (MCP has its own docs)
2. Add mcp to landingComponents in $version.index.tsx

PR #678 by @jakebodea addresses this issue.

Environment

• Browser: All browsers
• Route: Any page with navbar visible
• Trigger: Hover or click on "Try TanStack MCP" button

[PrathamGhaywat]

I am also having the same issue.
Details of Device:
Surface Pro 9 on Brave Browser

[tannerlinsley]

Resolved

…

On Jan 28, 2026 at 1:00 AM -0700, Pratham ***@***.***>, wrote: PrathamGhaywat left a comment (TanStack/tanstack.com#681) I am also having the same issue — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[Kyujenius]

Thanks for the fix! Excited to try out the new CLI features.

[PrathamGhaywat]

Thx