Office JavaScript APIs

The JavaScript API for Office enables you to create web applications that interact with the object models in Office host applications. Your application will reference the office.js library, which is a script loader. The office.js library loads the object models that are applicable to the Office application that is running the add-in.

The NPM package for Office.js is a copy of what gets published to the official "evergreen" Office.js CDN, at https://appsforoffice.microsoft.com/lib/1/hosted/office.js. The NPM also offers alpha and beta versions for faster-cadence beta-testing (relative to the slower-cadence official BETA endpoint).

Installing

To install "office-js" locally via the NPM package, run

npm install @microsoft/office-js --save

Once installed, the Office.js script reference can be used as

<script src="node_modules\@microsoft\office-js\dist\office.js"></script>

IntelliSense definitions

TypeScript definitions for Office.js are available.

• For latest RELEASE version of Office.js:
• DefinitelyTyped: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/office-js/index.d.ts
• @types: @types/office-js. (Acquire as npm install @types/office-js --save-dev)
• For any version (including RELEASE, BETA, custom etc.):
  • Inside of the NPM package, under dist/office.d.ts
  • In this repo: dist/office.d.ts

Visual Studio 2017+ can use these same TypeScript definitions, even for regular JavaScript. For JavaScript IntelliSense in earlier versions of Visual Studio, an office-vsdoc.js is available alongside the office.js file. As long as you have a Scripts/_references.js file in your VS project, and as long as you substitute the existing triple-slash reference (/// <reference path="https://.../office.js" />) with the new location (the -vsdoc part gets substituted automatically, so use it just as you would in a <script src=""> reference), you should have the corresponding JavaScript IntelliSense.

Accessing the NPM files via a CDN

In addition to downloading the files locally, you can also use them via an external service like https://unpkg.com, which provides best-effort (no uptime guarantees) CDN hosting for npm packages. This is especially useful for trying out alpha or beta builds. To do so, simply change the script reference to:

<script src="https://unpkg.com/@microsoft/office-js/dist/office.js"></script>

The different versions of the NPM package are listed in the dropdown on the top right at https://unpkg.com/@microsoft/office-js/.

To view the latest version numbers for each of the tags run the following command on the command-line:

npm view @microsoft/office-js dist-tags --json

When you have a version number, can use it as follows with https://unpkg.com: (appending @<version-#> right after office-js; e.g., .../office-js@1.1.2-custom.0/dist/...

<script src="https://unpkg.com/@microsoft/office-js@1.1.2-custom.0/dist/office.js"></script>

Production vs. Beta vs. Private versions

Office.js versioning is described in detail in https://dev.office.com/docs/add-ins/develop/office-js-versioning. Importantly, there is a large difference between what is in the JS files, versus what are the capabilities of a particular computer (i.e., older or slower-to-update versions of office).

The NPM package and the repo branches assume the following structure.

GitHub branch name	NPM tag name	Description
release	release (and also latest, a default NPM tag)	The latest of the released publicly-available APIs. Identical to a previous release on https://appsforoffice.microsoft.com/lib/1/hosted/office.js
beta	beta	Forthcoming APIs, not necessarily ready for public consumption yet (and may still change...), but likely available on Insider Fast (and maybe Insider Slow) builds. Identical to a previous release on https://appsforoffice.microsoft.com/lib/beta/hosted/office.js
custom	custom	A flavor of release deployed for a specific need (e.g., try out something experimental) or for a specific partner. Unlike other tags, successive versions of this tag are not necessarily cumulative updates; it is possible to have a 1.1.2-custom.1 that has the beta JS, and then a 1.1.2-custom.2 that only contains the publicly-available release APIs (with maybe some tweaks)

Using a specific version with Script Lab

To use a version of the NPM package with Script Lab, substitute the CDN reference and the @types/office-js reference with the NPM package name and version. [Note: Script Lab uses https://unpkg.com for resolving the package names, so it's very similar guidance as above].

For example, to use a 1.1.2-custom.0 version, use the following references:

@microsoft/office-js@1.1.2-custom.0/dist/office.js
@microsoft/office-js@1.1.2-custom.0/dist/office.d.ts

More info

For more information on Office Add-ins and the Office JavaScript APIs, see:

• Office Add-ins platform overview
• JavaScript API for Office reference