Creating actions¶

Step 1: Define your mutation and associated types¶

Start with defining the mutation and the required types. These types will reflect in the GraphQL schema.

Console

CLI

Go to the Actions tab on the console and click on Create. This will take you to a page like this:

Define the action as follows in the Action Definition editor.

type Mutation {
  login (username: String!, password: String!): LoginResponse
}

In the above action, we called the returning object type to be LoginResponse. Define it in the New types definition as:

type LoginResponse {
  accessToken: String!
}

To create an action, run

hasura actions create login

This will open up an editor with metadata/actions.graphql. You can enter the action’s mutation definition and the required types in this file. For your login mutation, replace the content of this file with the following and save:

type Mutation {
  login (username: String!, password: String!): LoginResponse
}

type LoginResponse {
  accessToken: String!
}

The above definition means:

• This action will be available in your GraphQL schema as a mutation called login.
• It accepts two arguments called username and password of type String!.
• It returns an output type called LoginResponse.
• LoginResponse is a simple object type with a field called accessToken of type String!.

Step 2: Create the action handler¶

A handler is an HTTP webhook where you can perform the custom logic for the action.

In this case, we will just return an access token, but typically you would want to run all the business logic that the action demands. NodeJS/Express code for this handler would look something like:

const handler = (req, resp) => {
  // You can access their arguments input at req.body.input
  const { username, password } = req.body.input;

  // perform your custom business logic
  // check if the username and password are valid and login the user

  // return the response
  return resp.json({
    accessToken: "Ew8jkGCNDGAo7p35RV72e0Lk3RGJoJKB"
  })

};

You can deploy this code somewhere and get the URI. For getting started quickly, we also have this handler ready at https://hasura-actions-demo.glitch.me/login.

Set the handler

Now, set the handler for the action:

Step 3: Finish action creation¶

Finally, to save the action:

Step 4: Try it out¶

In the Hasura console, head to the GraphiQL tab and try out the new action.

mutation {
  login (username: "jondoe", password: "mysecretpassword") {
    accessToken
  }
}

And that’s it. You have extended your Hasura schema with a new mutation.

Step 1: Define your query and associated types¶

Start with defining the query and the required types. These types will reflect in the GraphQL schema.

Console

CLI

Go to the Actions tab on the console and click on Create. This will take you to a page like this:

Define the action as follows in the Action Definition editor.

type Query {
  addNumbers (numbers: [Int]): AddResult
}

In the above action, we called the returning object type to be AddResult. Define it in the New types definition as:

type AddResult {
  sum: Int
}

To create an action, run

hasura actions create addNumbers

This will open up an editor with metadata/actions.graphql. You can enter the action’s query definition and the required types in this file. For your addNumbers query, replace the content of this file with the following and save:

type Query {
  addNumbers (numbers: [Int]): AddResult
}

type AddResult {
  sum: Int
}

The above definition means:

• This action will be available in your GraphQL schema as a query called addNumbers
• It accepts an argument called numbers which is a list of integers.
• It returns an output type called AddResult.
• AddResult is a simple object type with a field called sum of type integer.

Step 2: Create the action handler¶

A handler is an HTTP webhook where you can perform the custom logic for the action.

In this case, it is the addition of the numbers. NodeJS/Express code for this handler would look something like:

const handler = (req, resp) => {
  // You can access their arguments input at req.body.input
  const { numbers } = req.body.input;

  // perform your custom business logic
  // return an error or response
  try {
    return resp.json({
      sum: numbers.reduce((s, n) => s + n, 0)
    });
  } catch(e) {
    console.error(e)
    return resp.status(500).json({
      message: 'unexpected'
    })
  }
};

You can deploy this code somewhere and get the URI. For getting started quickly, we also have this handler ready at https://hasura-actions-demo.glitch.me/addNumbers.

Set the handler

Now, set the handler for the action:

Step 3: Finish action creation¶

Finally, to save the action:

Step 4: Try it out¶

In the Hasura console, head to the GraphiQL tab and try out the new action.

query {
  addNumbers(numbers: [1, 2, 3, 4]) {
    sum
  }
}

And that’s it. You have extended your Hasura schema with a new query.