# Page Not Found

The URL `building-apps/data-processing/function-extensions` does not exist.

You might be looking for one of these pages:
- [Extensions](https://docs.heisenware.com/app-builder/build-backend/functions-library/extensions.md)
- [Functions](https://docs.heisenware.com/app-builder/build-backend/functions.md)
- [Connect an External MQTT Client](https://docs.heisenware.com/tutorials/integration-guides/connect-an-external-mqtt-client.md)
- [Integrations (Inbound Connections)](https://docs.heisenware.com/app-manager/app-manager-overview/integrations-inbound-connections.md)
- [Functions library](https://docs.heisenware.com/app-builder/build-backend/functions-library.md)

## How to find the correct page

1. **Browse the full index**: [/sitemap.md](https://docs.heisenware.com/sitemap.md) - Complete documentation index
2. **View the full content**: [/llms-full.txt](https://docs.heisenware.com/llms-full.txt) - Full content export

## Tips for requesting documentation

- For markdown responses, append `.md` to URLs (e.g., `/app-builder/build-backend/functions-library/extensions.md`)
- Use `Accept: text/markdown` header for content negotiation