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I’m using contentful with the latest Angular version 10.0.5 and I have errors in the dev console.


 contentful: {
    space: 'MY_SPACE',
    accessToken: 'MY_TOKEN',


  providedIn: 'root'
export class ContentfulService {
  private cdaClient = createClient(environment.contentful);

  constructor(private localStorageService: LocalStorageService) {

  private getNewsList(query?: ContentfulQuery): Promise<Entry<ContNewsFieldItem>[]> {
    return this.cdaClient.getEntries<ContNewsFieldItem>(Object.assign({
      content_type: 'SOME_CONTENT_TYPE'
    }, query))
      .then((res: EntryCollection<ContNewsFieldItem>) => res.items);

Each time when I call contentfulService.getNewsList({limit: 6}) I get a list of news but in the dev console I see 2 errors:

xhr.js:126 Refused to set unsafe header "user-agent"
xhr.js:126 Refused to set unsafe header "Accept-Encoding"

How can I fix it or it’s your bug?

Issue Analytics

  • State:open
  • Created 3 years ago
  • Reactions:4
  • Comments:10 (1 by maintainers)

github_iconTop GitHub Comments

ankhuvecommented, Feb 28, 2022

Experiencing the same issue with v9.1.12. I dug into the stack trace and found out that the reason I’m getting this message is because of Contentful’s isNode function:

function isNode() {
   * Polyfills of 'process' might set process.browser === true
   * See:
  return typeof process !== 'undefined' && !process.browser;

When this function evaluates to true, the user-agent and Accept-Enconding headers are set.

Normally, this shouldn’t be a problem, however in edge cases you might have your client side JS polyfilled to use node-only packages. For my case, it’s because we’re using aws-amplify which unfortunately requires node packages. If using a bundler like Vite which doesn’t automatically polyfill these things, you have to add the process global variable into your code, for instance with something like:

    // Need this for aws-amplify to not throw errors
    const isBrowser = () => typeof window !== 'undefined';
    const isGlobal = () => typeof global !== 'undefined';
    var exports = {};
    if (!isGlobal() && isBrowser()) {
        var global = window;
        var process = process || {
            env: { DEBUG: undefined },
            version: [],
            // browser property added because Contentful thinks it's running in a node environment otherwise
            browser: true,

The issue was solved on my end by adding the browser: true line, since the isNode function looks for it in order to decide if it’s running in a browser or node.

Hopefully this helps someone, and perhaps it’s a good thing to put into the docs for cases where you’re using polyfilled client side code.

robertsinecommented, Oct 28, 2021

Updating contentful to latest version didn’t help. Also seeing these errors.

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