> For the complete documentation index, see [llms.txt](https://quinck.gitbook.io/multijet/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://quinck.gitbook.io/multijet/getting-started/core-concepts/openapi.md).

# OpenAPI

The development flow of a Multijet project is based around the **OpenAPI definition file**, located in `configs/openapi.json`.

To know more about OpenAPI, head to the [official specification](https://spec.openapis.org/oas/v3.1.0).

{% hint style="warning" %}
Multijet only supports OpenAPI version 3.x
{% endhint %}

## Code generation

To generate all the required models from the OpenAPI file, simply run this command in the root of your project:

```bash
npm run openapi:generate
```

This script will generate all the Typescript interfaces and models based on the API definition, including:

* **Component schemas**
* **Path and query params**
* **Requests and responses body**
* **Routes**

The base schemas are generated in `libs/models` and can be imported from anywhere by just installing `@libs/models`. Everything else are `Fastify` specific types and located in `libs/fastify-utils/generated`.

The generated files are ignored by Git and should never be included in the repository.