> For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt.

# maxConcurrency

- **Type:** `number`
- **Default:** `5`
- **CLI:** `--maxConcurrency=10`

A number limiting the number of test cases that are allowed to run at the same time when using `test.concurrent` or wrapped in `describe.concurrent`.

Any test above this limit will be queued and executed once a slot is released.


**CLI**

```bash
npx rstest --maxConcurrency=10
```


**rstest.config.ts**

```ts
import { defineConfig } from '@rstest/core';

export default defineConfig({
  maxConcurrency: 10,
});
```