# nextjs/tsc

> Has Next.js write its types, then type-checks the app with the strict compiler options.

Has Next.js write its types, then type-checks the app with the strict compiler options.

Part of the [`nextjs`](/reference/configurations/nextjs/) configuration, at the `recommended` [level](/start/concepts/#levels). It runs at the `push` [stage](/start/concepts/#stage), once per scope. It runs next.

## Why

A fresh clone holds no next-env.d.ts and no route types, so a plain tsc run fails on imports the framework resolves.

## What to do

Fix the first error tsc prints; later errors often come from the same mistake.

## Example

`const count: number = "one";` reports an incompatible assignment. Assign a number, such as `const count: number = 1;`.

## Turn it off

Turn it off for some files, with a reason:

```shell
gspot ignore nextjs/tsc --paths "<glob>" --reason "<why>"
```