---
name: assert
description: TypeScript assertion function for runtime type narrowing with descriptive error messages. Based on tiny-invariant.
---

# Assertion Helper

To set up Assertion Helper, refer to the fullstackrecipes MCP server resource:

**Resource URI:** `recipe://fullstackrecipes.com/assert`

If the MCP server is not configured, fetch the recipe directly:

```bash
curl -H "Accept: text/plain" https://fullstackrecipes.com/api/recipes/assert
```