20-Params.md

title	description	excerpt
Params	Used for setting various WebSocket request-specific parameters such as headers, tags, etc.	Used for setting various WebSocket request-specific parameters such as headers, tags, etc.

Params is an object used by the WebSocket methods that generate WebSocket requests. Params contains request-specific options like headers that should be inserted into the request.

Name	Type	Description
Params.compression	string	Compression algorithm to be used by the WebSocket connection. The only supported algorithm currently is deflate. If the option is left unset or empty, it defaults to no compression.
Params.jar	http.CookieJar	The cookie jar that will be used when making the initial HTTP request to establish the WebSocket connection. If empty, the default VU cookie jar will be used.
Params.headers	object	Custom HTTP headers in key-value pairs that will be added to the initial HTTP request to establish the WebSocket connection. Keys are header names and values are header values.
Params.tags	object	Custom metric tags in key-value pairs where the keys are names of tags and the values are tag values. The WebSocket connection will generate metrics samples with these tags attached, allowing users to filter the results data or set thresholds on sub-metrics.

Example of custom metadata headers and tags

A k6 script that will make a WebSocket request with a custom header and tag results data with a specific tag

import ws from 'k6/ws';

export default function () {
  const url = 'ws://echo.websocket.org';
  const params = {
    headers: { 'X-MyHeader': 'k6test' },
    tags: { k6test: 'yes' },
  };
  const res = ws.connect(url, params, function (socket) {
    socket.on('open', function () {
      console.log('WebSocket connection established!');
      socket.close();
    });
  });
}