> ## Documentation Index
> Fetch the complete documentation index at: https://vendo-mintlify-24213046.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# E-CFG-004

> A Next.js host's next.config does not list @vendoai/vendo in serverExternalPackages, so every generated screen fails its checks.

```text config/next-externals theme={null}
broken: next.config.ts does not list @vendoai/vendo in serverExternalPackages
```

`check: config/next-externals` · `error_code: E-CFG-004` · `doctor exits: 1`

## What you're seeing

The app builds, the pages render, the agent answers — and every screen a user
asks for comes back failed. Nothing else looks wrong.

## Why

Vendo syntax-checks each generated screen with `esbuild`, imported at runtime
through a variable specifier behind bundler-ignore comments. Without
`serverExternalPackages`, Next bundles `@vendoai/vendo` into the server chunk, so
that import becomes a bare resolve from your app root instead — and under pnpm's
strict `node_modules`, esbuild was never hoisted there (it lives only under
`node_modules/.pnpm/@vendoai+apps…`). The checker cannot load, so every screen
fails the checks floor.

**Listing `"esbuild"` on its own does not fix this.** There is no static
`"esbuild"` request in the bundle for Next to match against the list — the
specifier is a variable. `@vendoai/vendo` is the entry that matters: externalize
the package and the import stays inside it, where esbuild is a declared
dependency.

PGlite and `@vendoai/vendo` — which holds the store that loads it — are on the
same list for a different reason: PGlite's Emscripten module breaks under
production chunking.

## The fix

Add the line inside your config object.

```ts next.config.ts focus={2} theme={null}
const nextConfig = {
  serverExternalPackages: ["esbuild", "@electric-sql/pglite"],
};

export default nextConfig;
```

On Next 14 the key is `experimental.serverComponentsExternalPackages` — same
list, old name and location (renamed in Next 15).

`npx vendo init` writes this line for you. It falls back to printing it when
your config is one it cannot read as an object literal — a function of `phase`,
for instance — because it never rewrites a file whose shape it is not sure of.

## Related errors

* [E-CFG-001](/production/troubleshooting/e-cfg-001): a required `.vendo/` file is missing
* [E-CFG-003](/production/troubleshooting/e-cfg-003): a different config disagreement, the OpenAPI mount