Hi Tlstolz01,

Since vite build finishes successfully and the crash happens right after, I’d treat this as a Vercel post-build function detection/bundling issue, not a Vite/React bundle issue.

The quickest isolation test is to temporarily remove Vercel Functions from the deployment:

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mv api _api_disabled
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Deploy that test branch.

If the deployment succeeds, then the trigger is definitely inside /api. In that case, move the functions back one at a time until the failure returns.

A few things I’d check carefully in /api:

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- every real function file exports a valid default handler or supported method export
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- helper files are not living inside /api
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- files renamed with a leading underscore are actually ignored by Vercel
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- no generated/bundled file is unusually large or contains syntax Vercel’s function analyzer may parse differently
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- no api file imports browser-only code from the Vite app
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I’d move shared helpers outside the API folder, for example:

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api/send-message.js
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api/contact.js
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lib/rate-limit.js
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lib/supabase-server.js
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Then import from lib/ instead of keeping non-route helper files inside /api.

If disabling /api still fails, then I’d compare the local Vercel build step rather than plain Vite:

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npx vercel build --debug
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Plain npm run build only proves the Vite static build works; vercel build is closer to what Vercel runs when it also discovers and bundles Functions.

Can you share the /api file list and which one first makes the test deployment fail?