Counters

Counters are integer-based values defined in the Backstack dashboard to store account based statistics, such as tracking how often a feature is used.

INFO

Counters are set up in the Backstack dashboard and managed in your codebase.

Counter transactions

Counter transactions are managed in your codebase, and the current app/session account.counters contains an aggregate of their values.

The API endpoint syntax to update a counter is as follows. Where :value is a positive or negative integer to add to the existing counter integer.

POST https://api.backstack.com/account/counters/:counter_id/:value

The API updates the accounts counter value.

Codebase implementation

Initiate a transaction on counters you want to track for future assessment.

// pseudocode

if (session.account.counters.foo_downloads === 10)
    <button>Get More Foos</button>
else
    <button onClick="downloadFoo()">Download Foo</button>

function downloadFoo() {
    const result = processDownload('foo_downloads');
    if (result.success) {
        updateFooDownloads(1);
    }
}

In the pseudocode above, the updateFooDownloads() function would update the foo_downloads counter using the following endpoint.

POST https://api.backstack.com/account/counters/foo_downloads/1

The app/session is updated with the counters total value.

// session object
{
  ...
  "account": {
    "counters": {
      "foo_downloads": 1,
      ...
    }
    ...
  }
}

Subtracting values

Use negative integers to offset existing counter values.

POST https://api.backstack.com/account/counters/foo_downloads/-1

The app/session is updated with the counters total value.

Resetting counters

Submit a delete request to reset the counter to zero.

DELETE https://api.backstack.com/account/counters/foo_downloads

The app/session is updated with the counters total value.

Monetizing counters

You can use counters to track feature use and invoice accounts based on their usage. For example, you can track the number of API calls an account makes and bill them accordingly.

POST https://api.backstack.com/account/counters/api_calls/1

After a certain threshold, create an invoice item for the account.

POST https://api.backstack.com/account/invoice-items
{
  "amount": 500, // cents
  "description": "API calls over 1000",
}

Reset the counter after creating the invoice item.

DELETE https://api.backstack.com/account/counters/api_calls