Skip to main content

Getting Started

Let's set up Exograph and create a simple application to ensure everything works as expected.

Setting up​

Install Prerequisites​

Install either Postgres or Docker. We need one of these to enable the "yolo" mode during development.

Install Exograph​

curl -fsSL https://raw.githubusercontent.com/exograph/exograph/main/installer/install.sh | sh

Install the VS Code extension​

Click here to install the Exograph VS Code extension.

Creating a simple application​

Let's create a simple application to get a taste of working with Exograph. Later, we will develop a more fully featured application with access control, performance monitoring, and more.

Creating the model​

We will follow the well-worn tradition and create an API server for a Todo app.

Execute the following command:

exo new todo-app

This command will create a new directory named todo-app with the following structure:

todo-app
├── src
│   └── index.exo
├── tests
│   ├── basic-query.exotest
│   └── init.gql
├── .gitignore

Now change into the todo-app directory and check the contents of the index.exo file:

cd todo-app
cat src/index.exo

You will see the following (to see syntax highlighting, open the file in VS Code after installing the Exograph VS Code Extension):

src/index.exo
@postgres
module TodoDatabase {
  @access(true)
  type Todo {
    @pk id: Int = autoIncrement()
    title: String
    completed: Boolean
  }
}

Launching the server​

Now we can launch the server.

exo yolo

The yolo mode is a simple way to start the server during development without requiring a database. Exograph will create a temporary database in this mode and apply migrations whenever the model changes.

You should see the output in the console that the server is running.

Launching PostgreSQL locally...
Watching the src directory for changes...
Starting with a temporary database (will be wiped out when the server exits)...
Postgres URL: postgres://exo@%2Fvar%2Ffolders%2F8g%2Fttrcklpj7879w6fbk26dgrbh0000gn%2FT%2F.tmpcYt5yp/yolo
Generated JWT secret: c1d22ndtjjxlxni
Applying migrations...
Started server on localhost:9876 in 6.14 ms
- Playground hosted at:
        http://localhost:9876/playground
- Endpoint hosted at:
        http://localhost:9876/graphql

Using the GraphiQL interface​

Visit the playground at http://localhost:9876/playground.

Exograph GraphiQL interfaceExograph GraphiQL interface

Performing GraphQL mutations​

Let's create a couple of todo items.

Paste the following code in the GraphiQL interface to create a todo titled "Install". Since that task is complete, we will set the completed property to true.

mutation {
  createTodo(data: { title: "Install", completed: true }) {
    id
  }
}

And hit the "Execute Query" button. You should see the following output:

{
  "data": {
    "createTodo": {
      "id": 1
    }
  }
}

Let's create another todo titled "Create Simple App". Since we are working on that task, we will set the completed property to false. You can query back any fields you want, so let's query the title and completed fields in addition to id.

mutation {
  createTodo(data: { title: "Create Simple App", completed: false }) {
    id
    title
    completed
  }
}

You should see the following output:

{
  "data": {
    "createTodo": {
      "id": 2,
      "title": "Create Simple App",
      "completed": false
    }
  }
}

Performing GraphQL queries​

Now we can query the todos.

First, let's get all of the todos. Execute the following query in the GraphiQL interface:

query {
  todos {
    id
    title
    completed
  }
}

You should see the following output:

{
  "data": {
    "todos": [
      {
        "id": 1,
        "title": "Install",
        "completed": true
      },
      {
        "id": 2,
        "title": "Create Simple App",
        "completed": false
      }
    ]
  }
}

You can do much more: getting a todo by id or some filtering criteria, updating and deleting todos, etc. We will leave all those details for later.