@fastly/js-compute

@fastly/js-compute

JavaScript SDK and CLI for building JavaScript applications on Fastly's Compute@Edge.

Getting Started

We recommend using the Fastly CLI to create, build, and deploy JavaScript Compute@Edge services, as described on the Fastly Developer Hub.

Detailed documentation for JavaScript Compute@Edge services is also available on Fastly Developer Hub.

Usage

JavaScript Examples

The Fastly Developer Hub has a collection of example JavaScript applications.

Here is a small example application:

/// <reference types="@fastly/js-compute" />

async function app(event) {
    const request = event.request;
    return new Response(`You made a request to ${request.url}`)
}

addEventListener("fetch", event => {
  event.respondWith(app(event));
});

API documentation

The API documentation for the JavaScript SDK is located at https://js-compute-reference-docs.edgecompute.app.

Security

If you find any security issues, see the Fastly Security Reporting Page or send an email to: [e-mail]

We plan to disclose any found security vulnerabilities per the GitHub security vulnerability guidance. Note that communications related to security issues in Fastly-maintained OSS as described here are distinct from Fastly security advisories.

Changelog

The changelog can be found here.

License

Apache-2.0 WITH LLVM-exception

Changelog

3.0.0 (2023-07-08)

Changed

⚠ BREAKING CHANGE

• Rename SimpleCache.delete to SimpleCache.purge and require purge options to be supplied as the second parameter

We are renaming because "purge" is already a well-known and documented concept for removing content from Fastly's cache.

The new addition of a second argument allows the caller to decide what scope to purge the content from, currently they can choose to purge from all of Fastly ("global") or from the POP that contains the currently executing instance ("pop"). We do not provide a default option right now, in the future we may provide a default option, if we discover a common pattern is being used.

Here is an example of migrating an application using SimpleCache.delete to SimpleCache.purge with the same behaviour:

/// <reference types="@fastly/js-compute" />

import { SimpleCache } from 'fastly:cache';

addEventListener('fetch', event => event.respondWith(app(event)));

async function app(event) {
  const url = new URL(event.request.url);
  const path = url.pathname;
  if (url.searchParams.has('delete')) {
-    SimpleCache.delete(path);
+    SimpleCache.purge(path, { scope: "global" });
    return new Response(page, { status: 204 });
  }

  let page = SimpleCache.getOrSet(path, async () => {
    return {
      value: await render(path),
      // Store the page in the cache for 1 minute.
      ttl: 60
    }
  });
  return new Response(page, {
    headers: {
      'content-type': 'text/plain;charset=UTF-8'
    }
  });
}

async function render(path) {
  // expensive/slow function which constructs and returns the contents for a given path
  await new Promise(resolve => setTimeout(resolve, 10_000));
  return path;
}

Added

• add event.client.tlsCipherOpensslName (49b0c99)
• add event.client.tlsClientCertificate (cf93b62)
• add event.client.tlsClientHello (3d87cb2)
• add event.client.tlsJA3MD5 (2ecf4af)
• add event.client.tlsProtocol (4c91142)
• Rename SimpleCache.delete to SimpleCache.purge and require purge options to be supplied as the second parameter (20113c1)