Configuring quotas

This page describes how to configure quotas for your API in Cloud Endpoints Frameworks. For an overview of the functionality provided by quotas, see About quotas.

Java

The following procedure assumes that you have already:

Written and annotated the code for your API.
Added API management.
Deployed your API.
Configured your API to use an API key. This is needed so that Endpoints Frameworks can identify the Google Cloud project that the calling application is associated with. See Sharing APIs protected by API key for more information.

To configure quotas on your API:

In the file that contains the API-scoped annotations, add the following to your @Api annotation:

limitDefinitions = {
      @ApiLimitMetric(
        name = "YOUR_METRIC_NAME",
        displayName = "YOUR_METRIC_DISPLAY_NAME",
        limit = YOUR_QUOTA_LIMIT)
}

Replace YOUR_METRIC_NAME with a name that describes the API requests counter.
Replace YOUR_METRIC_DISPLAY_NAME with the text that is displayed on Endpoints > Services > Quotas page to identify the quota.

Replace YOUR_QUOTA_LIMIT with an integer value. This is the number of requests that an application associated with a consumer's Google Cloud project can make in a minute. For example:

  @Api(
      name = "echo",
      version = "v1",
      namespace =
        @ApiNamespace(
          ownerDomain = "echo.example.com",
          ownerName = "echo.example.com",
          packagePath = ""
        ),
      limitDefinitions = {
        @ApiLimitMetric(
          name = "read-requests",
          displayName = "Read requests",
          limit = 1000),
        @ApiLimitMetric(
          name = "list-requests",
          displayName = "List requests",
          limit = 100),
        @ApiLimitMetric(
          name = "write-requests",
          displayName = "Write requests",
          limit = 50),
      }
  )

For each method that you want to apply a quota to, add the following to the @ApiMethod annotation:

metricCosts = {
             @ApiMetricCost(
               name ="YOUR_METRIC_NAME",
               cost = YOUR_COST)
}

Replace YOUR_METRIC_NAME with a name that you specified in the limitDefinitions parameter in the @Api annotation.

Replace YOUR_COST with an integer value that specifies the cost for each request.

For example:

  @ApiMethod(name = "echo",
             metricCosts = {
               @ApiMetricCost(
                 name = "read-requests",
                 cost = 1)
             })
  public Message echo(Message message, @Named("n") @Nullable Integer n) {
    // ...function code here...
  }

Deploy the API.

See the following for more information on the annotations used in quotas:

Python

The following procedure assumes that you have already:

Installed version 2.4.5 or later of the Endpoints Frameworks library.
Created your API.
Created a web server.
Added API management.
Deployed your API.
Configured your API to use an API key. This is needed so that Endpoints Frameworks can identify the Google Cloud project that the calling application is associated with. See Sharing APIs protected by API key for more information.

To configure quotas on your API:

In the file that contains the API decorator, create a list of LimitDefinition instances, similar to the following:
```
quota_limits = [
  endpoints.LimitDefinition(
    "YOUR_METRIC_NAME",
    "YOUR_METRIC_DISPLAY_NAME",
    limit)
]
```
- Replace YOUR_METRIC_NAME with a name that describes the API requests counter.
- Replace YOUR_METRIC_DISPLAY_NAME with the text that is displayed on Endpoints > Services > Quotas page to identify the quota.
- Replace limit with an integer value. This is the number of requests that an application associated with a consumer's Google Cloud project can make in a minute. For example:
```
  quota_limits = [
    endpoints.LimitDefinition('read-requests', 'Read Requests', 1000),
    endpoints.LimitDefinition('list-requests', 'List Requests', 100),
    endpoints.LimitDefinition('write-requests', 'Write Requests', 50),
  ]
```

Add your quota to the API decorator by assigning it to the limit_definitions argument. For example:

  @endpoints.api(name='bookstore',
                 version='v1',
                 limit_definitions=quota_limits)

For each method that you want to apply a quota to, assign a dictionary to the METRIC_COSTS argument of the method decorator. The key must be a name that you specified in the limit_definitions argument to the API decorator, and the value is an integer that specifies the cost for each request. For example:
```
  @endpoints.method(path='shelves/{shelf}',
                    http_method='GET',
                    metric_costs={'read-requests': 1})
  def get_shelf(self, request):
  # ...function code here...
```
Deploy the API.

See the following for more information on the decorators used in quotas: