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Version: 4.0.0

Using the OPTIONS method


Due to the built-in CORS middleware, the usage of the OPTIONS method in routes requires some additional configuration.

Mocks Server adds by default a middleware to enable CORS automatically in all routes. It also enables CORS pre-flight responses, so it will respond with a 204 status to all requests using the OPTIONS method to any route. This means that the OPTIONS method can't be used in routes until this middleware is disabled, because the built-in CORS pre-flight middleware would send the request response before your route is executed.

Disabling CORS pre-flight response

If you want to handle all OPTIONS requests by yourself, you can enable the preflightContinue option of the cors middleware using the configuration file:

module.exports = {
server: {
cors: {
options: {
preflightContinue: true

Read the configuration chapter for further info.

Enabling CORS pre-flight response only for some paths

Mocks Server uses the cors npm package under the hood to enable CORS, so you could still enable it only for your desired routes using the same package even if you disabled it globally.

To do that, you should install cors and create a route adding the cors middleware to the correspondent path.

npm i --save-dev cors
const cors = require("cors");

module.exports = [
"id": "cors",
"url": "/api/users/*", // paths to enable cors
"method": ["GET", "HEAD", "PUT", "PATCH", "POST", "DELETE", "OPTIONS"], // HTTP methodS
"variants": [
"id": "enabled",
"type": "middleware",
"options": {
"middleware": cors(),

Then, remember to add your route to the beginning of your "base" collection:

"id": "base", // collection from which the others extend
"routes": ["cors", "get-users:all", "get-user:id-1"] // add cors middleware to the beggining of the routes array

Read how to use middleware variants for further info.