Capture beacon data from the browser, divert beacon request payloads to a log endpoint, and avoid putting load on your own infrastructure.
For more details about this and other starter kits for Compute@Edge, see the Fastly Developer Hub.
Beacons are HTTP requests, usually POSTs, sent from a web browser to record some analytics data. Browsers offer native support for beacons via the navigator.sendBeacon method, and via the Reporting API for out-of-band reports on browser-generated warnings like CSP and feature policy violations, deprecations, browser interventions, and network errors. Native apps will also often send beacon data back to base.
For an in-depth guide to beacon termination using VCL, see the Beacon Termination tutorial.
- Exposes a
POST /reportsendpoint to receive beacon reports (in batches) - Deserializes individual reports from JSON to Rust data structures, with optional type-checking (see Payload examples)
- Enriches the data with information available at the edge, e.g. by adding geo data
- Sends reports to a logging endpoint as individual JSON lines N.B.: Depending on which logging endpoint type is chosen, these lines may be batched.
- Responds with a synthetic 204
This starter kit allows an individual report to be any valid JSON value.
For optional type-checking, it also includes the data structures for some common report payloads. These structures can be imported from modules following the example_... naming convention:
- CSP Violations
mod example_csp_violation; use crate::example_csp_violation::ReportBody; - Network Errors
mod example_network_error_log; use crate::example_network_error_log::ReportBody; - Core Web Vitals
Tip: Use the web-vitals JavaScript library to measure all the Core Web Vitals.
mod example_core_web_vital; use crate::example_core_web_vital::ReportBody;
The following resources need to exist on your active Fastly service version for this starter kit to work:
- A logging endpoint called
reports.
Please see SECURITY.md for guidance on reporting security-related issues.