import * as fs from "fs"; const clientId = "####-####-####-####-####"; const secret = "##################"; const wordsApi = new WordsApi(clientId, secret); const requestTemplate = fs.createReadStream("template.doc"); const requestData = fs.createReadStream("TestPostDocumentExecuteMailMerge.txt"); const mailMergeRequest = new model.ExecuteMailMergeOnlineRequest({ template: requestTemplate, data: requestData, documentFileName: "Out_PostDocumentExecuteMailMergeWithHTMLData.docx" }); wordsApi.executeMailMergeOnline(mailMergeRequest) .then((mailMergeRequestResult) => { // tslint:disable-next-line:no-console console.log("Result of mailMergeRequest: ", mailMergeRequestResult); });