Quickstart: Setup the Document AI API

This guide provides all required setup steps to start using Document AI.

About the GCP Console

The Google Cloud Console is a web UI used to provision, configure, manage, and monitor systems that use GCP products. You use the Cloud Console to set up and manage Document AI resources.

Create a project

To use services provided by GCP, you must create a project.

A project organizes all your GCP resources. A project consists of the following components:

  • a set of collaborators
  • enabled APIs (and other resources)
  • monitoring tools
  • billing information
  • authentication and access controls

You can create one project, or you can create multiple projects. You can use your projects to organize your GCP resources in a resource hierarchy. For more information on projects, see the Resource Manager documentation.

In the Google Cloud Console, on the project selector page, select or create a Google Cloud project.

Go to project selector

Enable billing

A billing account defines who pays for a given set of resources. Billing accounts can be linked to one or more projects. Project usage is charged to the linked billing account. You configure billing when you create a project. For more information, see the Billing documentation.

Make sure that billing is enabled for your Cloud project. Learn how to confirm that billing is enabled for your project.

Enable the API

You must enable the Document AI API for your project. For more information on enabling APIs, see the Service Usage documentation.

Enable the Document AI API.

Enable the API

Set up authentication

Any client application that uses the API must be authenticated and granted access to the requested resources. This section describes important authentication concepts and provides steps for setting it up. For more information, see the GCP authentication overview.

About service accounts

There are multiple options for authentication, but it is recommended that you use service accounts for authentication and access control. A service account provides credentials for applications, as opposed to end-users. Projects own their service accounts. You can create many service accounts for a project. For more information, see Service accounts.

About roles

When calling an API, GCP requires the calling identity (any applicable person, entity, or process and their defined attributes) to have the appropriate permissions. You can grant permissions by granting roles to a service account. For more information, see the Identity and Access Management (IAM) documentation.

For the purpose of trying the Document AI API, you can use the Project > Owner role in steps below. The Project > Owner role grants the service account full permission to resources in your project. If your service account does not require full permissions, you specify a more restrictive role using the Cloud Console. For a list of roles and permissions, see IAM permissions reference. For information on managing permissions using IAM roles, see granting roles to service accounts.

About service account keys

Service accounts are associated with one or more public/private key pairs. When you create a new key pair, you download the private key. The Cloud SDK uses your private key to generate credentials when calling the API. You are responsible for security of the private key and other management operations, such as key rotation.

Create a service account and download the private key file

Create a service account:

  1. In the Cloud Console, go to the Create service account page.

    Go to Create service account
  2. Select a project.
  3. In the Service account name field, enter a name. The Cloud Console fills in the Service account ID field based on this name.

    In the Service account description field, enter a description. For example, Service account for quickstart.

  4. Click Create.
  5. Click the Select a role field.

    Under Quick access, click Basic, then click Owner.

  6. Click Continue.
  7. Click Done to finish creating the service account.

    Do not close your browser window. You will use it in the next step.

Create a service account key:

  1. In the Cloud Console, click the email address for the service account that you created.
  2. Click Keys.
  3. Click Add key, then click Create new key.
  4. Click Create. A JSON key file is downloaded to your computer.
  5. Click Close.

Use the service account key file in your environment

Provide authentication credentials to your application code by setting the environment variable GOOGLE_APPLICATION_CREDENTIALS. This variable only applies to your current shell session, so if you open a new session, set the variable again.

Linux or macOS

export GOOGLE_APPLICATION_CREDENTIALS="KEY_PATH"

Replace KEY_PATH with the path of the JSON file that contains your service account key.

For example:

export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/service-account-file.json"

Windows

For PowerShell:

$env:GOOGLE_APPLICATION_CREDENTIALS="KEY_PATH"

Replace KEY_PATH with the path of the JSON file that contains your service account key.

For example:

$env:GOOGLE_APPLICATION_CREDENTIALS="C:\Users\username\Downloads\service-account-file.json"

For command prompt:

set GOOGLE_APPLICATION_CREDENTIALS=KEY_PATH

Replace KEY_PATH with the path of the JSON file that contains your service account key.

Install and initialize the Cloud SDK

If you plan to use the Document AI API, you must install and initialize the Cloud SDK. Cloud SDK is a set of tools that you can use to manage resources and applications hosted on GCP. This includes the gcloud command line tool. The following link provides instructions:

Install and initialize the Cloud SDK.

Test the SDK and authentication

If you have set up authentication in previous steps, you can use the gcloud tool to test your authentication environment. Execute the following command and verify that no error occurs and that credentials are returned:

gcloud auth application-default print-access-token

That command is used by all Document AI API command line REST samples to authenticate API calls.

Install the Document AI API client library

You have three options for calling the Document AI API:

The client libraries are available for several popular languages. For information on installing the client libraries, see Document AI API Client Libraries.