Default starter for AssemblyScript

Get to know the Fastly Compute@Edge environment with a basic starter that demonstrates routing, simple synthetic responses and overriding caching rules.


Use this starter

Using the Fastly CLI, create a new project using this starter somewhere on your computer:

$ fastly compute init --from=


  • Add headers to an inbound request
  • Allow only requests with particular HTTP methods
  • Match request URL path and methods for routing
  • Build synthetic responses at the edge
  • Send requests to a backend
  • Override caching policy response headers

Understanding the code

This starter is intentionally lightweight, and requires no dependencies aside from the @fastly/as-compute package. It will help you understand the basics of processing requests at the edge using Fastly. This starter includes implementations of common patterns explained in our using Compute@Edge and VCL migration guides.

The path /backend will attempt to send a request to a backend called "backend_name". If the service you have installed this starter on doesn't have a backend defined, use the fastly backend create command to create one. Modify the following lines of the starter to use the name of the backend you created:

// The name of a backend server associated with this service.
// This should be changed to match the name of your own backend. See the the
// `Hosts` section of the Fastly Wasm service UI for more information.
const BACKEND_NAME = "backend_name";
/// The name of a second backend associated with this service.
const OTHER_BACKEND_NAME = "other_backend_name";

The starter uses two backends, so if you want to, go ahead and create two backends using the CLI and then modify both names here. You should now have a Fastly service running on Compute@Edge that can talk to your backends, and generate synthetic responses at the edge.

Next steps

Starters are a good way to bootstrap a project. For more specific use cases, and answers to common problems, try our library of code examples.