Api Server Simulator so you can mock api Rest services easily. Also, find an integrated Spy on api calls and an SMTP Server to catch emails.

Usage no npm install needed!

<script type="module">
  import apiServerSim from 'https://cdn.skypack.dev/api-server-sim';


API Server Simulator

Easily simulate requests and responses for a REST Api server as specified in an Excel file.

How to use the library

Next code will use the library and start an API server as specified in a list of Excel files located in your NodeJS project.

const ExcelServer = require("api-server-sim");
const sim = new ExcelServer({files: ['./endpoints.xslx'], port: 3000});

Find a sample Excel in the test_server folder.

Running and testing a sample server

Install the required libraries.

npm install

Running the sample server

Use the test_server/endpoints.xlsx as a reference to simulate GET, POST or PUT requests, and specify specific Urls and Query params. Responses can be specified with status and body.

npm run start

Running tests for sample server

After running the sample server provided in this library, run the sample Jasmine tests.

npm test



This project is licensed under the MIT License - see the license.txt file for details.


Feel free to report suggestions and issues! Thanks.


  • Contract testing
    • Validate simulation scenarios against a swagger file
  • Make your test automation aware of external dependencies:
    • Spy on calls made
    • SMTP Server and emails verification endpoints