Every request your application sends to the Google App Engine Task Queue must include an authorization token. The token also identifies your application to Google.
About authorization protocols
We recommend using OAuth 2.0 to authorize requests.
If your application has certain unusual authorization requirements, such as logging in at the same time as requesting data access (hybrid) or domain-wide delegation of authority (2LO), then you cannot currently use OAuth 2.0 tokens. In such cases, you must instead use OAuth 1.0 tokens and an API key. To find your application's API key:
- Go to the Google Developers Console.
- Select a project.
- In the sidebar on the left, select APIs & auth. In the displayed list of APIs, make sure the Google App Engine Task Queue status is set to ON.
- In the sidebar on the left, select Credentials.
- Find the line or lines labeled API key. If there is no API key, then create one by selecting Create New Key. For more about API keys, see the Console help.
Authorizing requests with OAuth 2.0
All requests to the Google App Engine Task Queue must be authorized by an authenticated user.
The details of the authorization process, or "flow," for OAuth 2.0 vary somewhat depending on what kind of application you're writing. The following general process applies to all application types:
- When you create your application, you register it using the Google Developers Console. Google then provides information you'll need later, such as a client ID and a client secret.
- Activate the Google App Engine Task Queue in the Google Developers Console. (If the API isn't listed in the Developers Console, then skip this step.)
- When your application needs access to user data, it asks Google for a particular scope of access.
- Google displays a consent screen to the user, asking them to authorize your application to request some of their data.
- If the user approves, then Google gives your application a short-lived access token.
- Your application requests user data, attaching the access token to the request.
- If Google determines that your request and the token are valid, it returns the requested data.
Some flows include additional steps, such as using refresh tokens to acquire new access tokens. For detailed information about flows for various types of applications, see Google's OAuth 2.0 documentation.
Here's the OAuth 2.0 scope information for the Google App Engine Task Queue:
To request access using OAuth 2.0, your application needs the scope information, as well as information that Google supplies when you register your application (such as the client ID and the client secret).
Tip: The Google APIs client libraries can handle some of the authorization process for you. They are available for a variety of programming languages; check the page with libraries and samples for more details.