# App Builders

> Add Egon address validation to apps built with Lovable, v0, or Bolt: store your API key as a secret and paste a ready-made prompt.

Add Egon services to apps built with **Lovable, v0, or Bolt**.

## How It Works

App builders generate a whole app from a prompt. Give them the Egon documentation and the OpenAPI schema in the prompt, and they write the calls for you.

1. Store your API key as a secret named `EGON_API_KEY` in the builder's settings.
2. Copy a prompt from the [Prompt Library](https://documentation.egon.com/docs/build-with-ai/prompt-library.md) and paste it in the builder's chat. The prompts ask for a server-side function, because a key used in the browser is visible to anyone: keep that line when you adapt them (see [API Key Safety](https://documentation.egon.com/docs/build-with-ai/api-key-safety.md)).
3. Test the result with real addresses before you publish the app.