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env

Functionin env@fastly/js-compute 4.0.0View source
env(name: string): string | undefined

Function to get the value for the provided environment variable name.

For a list of available environment variables, see the Fastly Developer Hub for Compute Environment Variables

Note: The environment variables can only be retrieved when processing requests, not during build-time initialization.

Parameters

name: string

The name of the environment variable

Returns

string | undefined

The value of the environment variable, or undefined if no such environment variable exists.

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<script async defer src="https://fiddle.fastly.dev/embed.js"></script>
In this example we log to stdout the environment variables `FASTLY_HOSTNAME` and `FASTLY_TRACE_ID`.


<script type="application/json+fiddle">
{
  "type": "javascript",
  "title": "Environment Variable Example",
  "origins": [
    "https://http-me.fastly.dev"
  ],
  "src": {
    "deps": "{\n  \"@fastly/js-compute\": \"^0.7.0\"\n}",
    "main": "/// <reference types=\"@fastly/js-compute\" />\nimport { env } from \"fastly:env\";\n\nfunction app(event) {\n  console.log(\"FASTLY_HOSTNAME:\", env(\"FASTLY_HOSTNAME\"));\n  console.log(\"FASTLY_TRACE_ID:\", env(\"FASTLY_TRACE_ID\"));\n\n  return new Response(\"\", {\n    status: 200\n  });\n}\n\naddEventListener(\"fetch\", event => event.respondWith(app(event)));\n"
  },
  "requests": [
    {
      "enableCluster": true,
      "enableShield": false,
      "enableWAF": false,
      "method": "GET",
      "path": "/status=200",
      "useFreshCache": false,
      "followRedirects": false,
      "tests": "",
      "delay": 0
    }
  ],
  "srcVersion": 26
}
</script>
<noscript>
```js
/// <reference types="@fastly/js-compute" />
import { env } from "fastly:env";


function app(event) {
  console.log("FASTLY_HOSTNAME:", env("FASTLY_HOSTNAME"));
  console.log("FASTLY_TRACE_ID:", env("FASTLY_TRACE_ID"));


  return new Response("", {
    status: 200
  });
}


addEventListener("fetch", event => event.respondWith(app(event)));
```
</noscript>
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