While [budget alerts](https://firebase.google.com/docs/projects/billing/budget-alerts.md.txt) are a relatively easy way to receive billing updates, there may be times when you want to create more sophisticated alerts that include more customized logic. Here are two approaches to consider: - Use Cloud Monitoring to create more sophisticated and timely alerts - Use a billing Pub/Sub notification along with a corresponding Cloud Function to create custom behavior in response to changes in your spending While both of these techniques require more work on your part, they give you the power to control exactly what kinds of alerts you're receiving and how to respond to them. This page offers an overview for each of these approaches. > [!NOTE] > All Firebase projects are actually Google Cloud projects behind the scenes, which means billing is shared across Firebase and Google Cloud and you can view the same project in both the Firebase console and the Google Cloud console. > [!CAUTION] > When your project is on the Blaze pricing plan, [**set up budget alerts**](https://firebase.google.com/docs/projects/billing/budget-alerts.md.txt). You can use the [Blaze pricing plan calculator](https://firebase.google.com/pricing.md.txt#blaze-calculator) to estimate your monthly costs. > > Be aware that **budget alerts do *not* cap your usage or > charges** --- they are *alerts* about your costs so that you can > take action, if needed. For example, you might consider > [using budget notifications to programmatically disable > Cloud Billing on a project](https://cloud.google.com/billing/docs/how-to/disable-billing-with-notifications). > > > If you use Firebase AI Logic, Firebase App Hosting, Cloud Functions for Firebase, and Firebase Extensions, we strongly recommend that you > also > [**set up spend caps**](https://firebase.google.com/docs/projects/billing/spend-caps.md.txt), > which will pause any new usage of the applicable service if your project > reaches the budget set for that service. ## Create more sophisticated alerts with Cloud Monitoring Simple budget alert emails let you know when your overall billing has reached certain thresholds. However, you might also be interested in knowing whether individual services are increasing unexpectedly --- before they've had a chance to significantly affect your budget. For more sophisticated use cases like this, we recommend learning about Cloud Monitoring, which is a Google Cloud tool available for your Firebase project. Cloud Monitoring is useful for several different types of alerts: - If a resource that your project relies upon is unavailable (for both Firebase and Google Cloud services, but even for external services, like AWS) - If services like Cloud Functions are taking longer than expected to respond - If your Cloud Storage bucket, Realtime Database instance, or Cloud Firestore instance is rejecting too many requests (an indication that your Firebase Security Rules might be incorrect). - If the amount of resources used by some of your Firebase products have increased above a certain threshold Alerts created through Cloud Monitoring are usually sent more quickly than basic budget alert emails, which are typically sent once per day. Alerts can take the form of SMS messages, Slack channel messages, PagerDuty notifications, webhooks, and more. These options enable you to send alerts with higher and more actionable levels of visibility. ### Using Cloud Monitoring To get started with Cloud Monitoring, we recommend starting with the [Metrics Explorer](https://docs.cloud.google.com/monitoring/charts/metrics-explorer), which lets you create graphs of custom metrics within your Firebase/Google Cloud project and visualize their usage. Specifically, you can look at resources such as your Cloud Firestore, Realtime Database, or Cloud Function instances. You can view usage information about these products (like number of document reads, bytes sent, or function invocations) that would have an effect on your billing. After you're comfortable visualizing your resource usage in the Metrics Explorer, we recommend creating an [alerting policy](https://docs.cloud.google.com/monitoring/alerts) on the metrics you care about most. Here are some example alerting policies: - If the number of document reads in a 30-minute time period is greater than a particular value - If the usage of a specific resource (like a function invocation) seems to be increasing too quickly in a certain timeframe ## Create additional billing logic Budget alerts send out emails automatically when your budget reaches certain thresholds, but for more sophisticated alerting or programmatic reactions to spending increases, you might consider setting up additional custom logic based on Google Cloud Pub/Sub messages. For example, you can send alerts to Slack channels or via text message, or you make programmatic changes to your app or project depending on spend levels. Pub/Sub is a message-passing service that allows other services to send messages --- usually in the form of JSON data --- in an asynchronous manner through channels known as Pub/Sub topics. You can set up authorized services, like Cloud Functions, to listen to messages in these topics and act on the data appropriately. Note that Pub/Sub notifications for billing are sent about once every 20 minutes whether or not your billing usage has changed, and they are stateless (meaning that they provide no context as to what preceded them). If you want to keep track of unusual increases in spending over time, or compare your spending to the previous cycle, you will need to manage that historical data yourself using a database like Cloud Firestore or the Realtime Database. ### Using Pub/Sub topics with Cloud Functions You can set up a Pub/Sub topic for your billing data by visiting the budget associated with your Firebase project in the Google Cloud console (under *Billing* \> *Budgets and alerts* ), then clicking the checkbox for **Connect a Pub/Sub topic to this budget** . This will create a Pub/Sub topic that you can listen to later. For detailed steps, see the [full documentation](https://docs.cloud.google.com/billing/docs/how-to/budgets-programmatic-notifications). After you've created your Pub/Sub billing topic, you can write a Cloud Function to listen to the billing topic and act on the data accordingly. The data is sent as JSON data and includes helpful information like the amount you've spent so far, your budget amount, and the start date of your current billing cycle. The Google Cloud documentation has full details on how to receive this data using a Cloud Function. However, if you're using Cloud Functions for Firebase to deploy your functions, the general process is a little simpler (check out the [Firebase documentation](https://firebase.google.com/docs/functions/pubsub-events.md.txt)). You can also refer to [this video](https://www.youtube.com/watch?v=NWrZwXK92IM) for a sample walkthrough of the process. Once you've received this data, there are a number of different ways you can respond to it. Here are some options: - Send alerts to [Slack channels](https://docs.cloud.google.com/billing/docs/how-to/send-notifications-to-slack), Discord channels, or by text messages when your spending has reached a certain threshold. - Analyze your spending compared to historical data and alert you if anything seems out of the ordinary. - [Make changes to your app using Remote Config](https://firebase.google.com/docs/remote-config/automate-rc.md.txt) if billing levels have gotten too high. - Disable your Firebase project entirely by [programmatically removing your billing service](https://docs.cloud.google.com/billing/docs/how-to/disable-billing-with-notifications) from your account.