Best Practices

It is best to always provide a unique CallTreeId with every call.

You may generate that ID freely, probably a UUID. In case you encounter problems with the API, you can relay that to the METRO team, so as to enable them to analyze your issue.

Sample NodeJS code

Javascript
                      var request = require("request");

                        var options = { method: 'POST',
                          url: 'https://sandbox.metro-cc.com/webshop/v1/login/client',
                          headers: { CallTreeId: xxxxxxx }};

                        request(options, function (error, response, body) {
                          if (error) throw new Error(error);

                          console.log(body);
                        });