CMS QPP specific express middleware to get version from Accept header and put it on the request object

Usage no npm install needed!

<script type="module">
  import cmsgovQppSharedApiVersioningNode from 'https://cdn.skypack.dev/@cmsgov/qpp-shared-api-versioning-node';



Build - PR

This package provides ExpressJS middleware that parses incoming HTTP headers to determine the type and version of the API to be consumed. It sets a apiVersion and format property on the req object.

The library will parse the version from the Accept header, expecting the following format:

Accept: application/vnd.qpp.cms.gov.v1+json


Accept: application/vnd.qpp.cms.gov.v123+xml


Accept: application/vnd.qpp.cms.gov.v123


node v10.15.x or higher


Set request version by 'Accept' header

const requestVersion = require('@cmsgov/qpp-shared-api-versioning-node');



const options = {
  defaultFormat: 'json'
  defaultVersion: 1,
  supportedVersions: [1, 2]

You can pass a defaultFormat to set a format if none are passed. Note: This will only be set if the format in the Accept header of the request matches xml or json.

You can pass in a defaultVersion value on options to set the default version if there is no version in the Accept header of the request:

app.use(requestVersion.setVersion({ defaultVersion: 1 }));

If you pass in a supportedVersions array on options the requested version does not exist in the array, then the defualt version will be set.


If you define a middleware after requestVersion then you can verify that the version is indeed set:

app.use((req, res, next) => {


npm install @cmsgov/qpp-shared-api-versioning-node


npm test

Project linting:

npm run lint


npm run test:coverage

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Public Domain

This project is in the public domain within the United States, and copyright and related rights in the work worldwide are waived through the CC0 1.0 Universal public domain dedication.

All contributions to this project will be released under the CC0 dedication. By submitting a pull request, you are agreeing to comply with this waiver of copyright interest.

See the formal LICENSE file.