Fetch

This plugin allows you to capture fetch payloads and inspect them later on while replaying session recordings. This is very useful for understanding and fixing issues.

If you’d like to watch a Video Tutorial about the Fetch plugin, check out this YouTube video.

npm i @openreplay/tracker-fetch

Use the provided fetch method from the plugin instead of the one built-in.

If your website is a Single Page Application (SPA)

Section titled If your website is a Single Page Application (SPA)
import tracker from '@openreplay/tracker';
import trackerFetch from '@openreplay/tracker-fetch';

const tracker = new OpenReplay({
  projectKey: PROJECT_KEY
});
const fetch = tracker.use(trackerFetch(options)); // check list of available options below

tracker.start();

fetch('https://myapi.com/').then(response => console.log(response.json()));

If your web app is Server-Side-Rendered (SSR)

Section titled If your web app is Server-Side-Rendered (SSR)

Follow the below example if your app is SSR. Ensure tracker.start() is called once the app is started (in useEffect or componentDidMount).

import OpenReplay from '@openreplay/tracker/cjs';
import trackerFetch from '@openreplay/tracker-fetch/cjs';

const tracker = new OpenReplay({
  projectKey: PROJECT_KEY
});
const fetch = tracker.use(trackerFetch(options)); // check list of available options below

//...
function MyApp() {
  useEffect(() => { // use componentDidMount in case of React Class Component
    tracker.start();

    fetch('https://myapi.com/').then(response => console.log(response.json()));
  }, [])
//...
}
trackerFetch({
  overrideGlobal: boolean;
  failuresOnly: boolean;
  sessionTokenHeader: string;
  ignoreHeaders: Array<string> | boolean;
  sanitiser: (RequestResponseData) => RequestResponseData | null;
})
  • overrideGlobal: Overrides the default window.fetch. Default: false.
  • failuresOnly: Captures requests having 4xx-5xx HTTP status code. Default: false.
  • sessionTokenHeader: In case you have enabled some of our backend integrations (i.e. Sentry), you can use this option to specify the header name (i.e. ‘X-OpenReplay-SessionToken’). This latter gets appended automatically to each fetch request to contain the OpenReplay sessionToken’s value. Default: undefined.
  • ignoreHeaders: Helps define a list of headers you don’t wish to capture. Set its value to false to capture all of them (true if none). Default: ['Cookie', 'Set-Cookie', 'Authorization'] so sensitive headers won’t be captured.
  • sanitiser: Sanitise sensitive data from fetch request/response or ignore request comletely. You can redact fields on the request object by modifying then returning it from the function:
interface RequestData {
  body: BodyInit | null | undefined; // whatewer you've put in the init.body in fetch(url, init)
  headers: Record<string, string>;
}

interface ResponseData {
  body: string | Object | null;  // Object if response is of JSON type
  headers: Record<string, string>;
}

interface RequestResponseData {
  readonly status: number;
  readonly method: string;
  url: string;
  request: RequestData;
  response: ResponseData;
}

sanitiser: (data: RequestResponseData) => { // sanitise the body or headers
  if (data.url === "/auth") {
    data.request.body = null
  }

  if (data.request.headers['x-auth-token']) { // can also use ignoreHeaders option instead
    data.request.headers['x-auth-token'] = 'SANITISED';
  }

  // Sanitise response
  if (data.status < 400 && data.response.body.token) {
    data.response.body.token = "<TOKEN>"  
  }

  return data
}

// OR

sanitiser: data => { // ignore requests that start with /secure
  if (data.url.startsWith("/secure")) {
    return null
  }
  return data
}

// OR

sanitiser: data => { // sanitise request url: replace all numbers
  data.url = data.url.replace(/\d/g, "*")
  return data
}

If you’re looking for a practical example of how to use this plugin and how to sanitize data using it, check out our detailed tutorial over here.

Having trouble setting up this plugin? Please connect to our Slack and get help from our community.