Lovable TanStack Start app: build succeeds on Vercel, then every route is 404: NOT_FOUND

Exact error

404: NOT_FOUND

Also appears as (2)

Code: NOT_FOUND
Green build on Vercel, 404 on every page (Lovable project using @lovable.dev/vite-tanstack-config)

As reported (not yet reproduced) CI: pending

Built only from official docs and public reports, linked under Sources. We have not reproduced it yet. How we verify.

Last verified: Not yet (as reported)
Published: Oct 30, 2026
Repro: None yet
Fix ID: APP-33

Environment and versions

reported on	Lovable projects built on TanStack Start (@lovable.dev/vite-tanstack-config), deployed to Vercel
zero config requires	@lovable.dev/vite-tanstack-config ^2.6.2 or higher (per Vercel docs)
latest on npm oct 30 2026	2.27.0
tested by us	not yet reproduced

In brief

Newer Lovable projects are server-rendered (TanStack Start), so the classic SPA rewrite doesn't apply. The full fix covers the version requirement in Vercel's Lovable doc, the redeploy steps, and a community fallback.

Get the full fix ↓

As reported, not yet reproduced. We have not deployed a Lovable TanStack Start app to Vercel ourselves. The full fix is based on Vercel's official Lovable doc and one community write-up, both linked under Sources.

Symptom

You connect a recent Lovable project to Vercel. The build log is green, but opening the site (or any route) shows Vercel's:

404: NOT_FOUND
Code: NOT_FOUND
ID: <region>::<request-id>

Adding the usual "rewrite everything to /index.html" vercel.json doesn't help.

Why it happens

Newer Lovable projects aren't plain single-page apps any more. Their vite.config.ts uses @lovable.dev/vite-tanstack-config, which sets up TanStack Start, a server-rendered framework. The SPA rewrite trick from the classic 404-on-refresh fix doesn't apply.
Vercel needs a server build it recognises. Vercel's Lovable doc says Lovable uses Nitro (the server toolkit behind TanStack Start on Vercel) and deploys "with zero configuration", but only from a certain version of @lovable.dev/vite-tanstack-config. An older version is a likely cause of the 404 (our inference).
The config package's own comment (quoted in the dev.to write-up and an Oct 2026 comment on it) says it builds with Nitro using Cloudflare as the default target.

What we could not test

A real Vercel deployment (no account yet).
Lovable's own generated project and editor behaviour.

The full fix

The free part of this page tells you what's wrong. The full fix tells you exactly what to do. It includes:

Step-by-step fix, safest option first (the full page is 523 words)
1 copy-paste block of commands, config or code
How to check it worked
What the official docs say, with every claim linked (not yet reproduced by us)

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How this page was made

Drafted by an AI agent from the official docs and public reports listed above. Not yet reproduced on our test machine. Human review: not yet. No warranty: try fixes on a copy or staging environment first. Machine-readable versions: Markdown · JSON.

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