onlyoffice-nextcloud: editing Office documents inside Nextcloud

The app is the connector, the Document Server is the editor

The ONLYOFFICE app for Nextcloud is written in PHP and its job is to connect two things that do not know about each other.

On one side is Nextcloud, which stores the files. On the other is ONLYOFFICE Docs, packaged as Document Server, which is what actually renders and edits the document. The app enables users to edit office documents from Nextcloud using ONLYOFFICE Docs, allows multiple users to collaborate in real time, and saves those changes back to Nextcloud.

The description in the app's own package metadata puts it plainly: the app allows you to view, edit and collaborate on text documents, spreadsheets and presentations within Nextcloud, creates a new Edit in ONLYOFFICE action within the document library for Office documents, lets multiple users co-author documents in real time from the familiar web interface, and saves the changes back to the file storage.

The format list is where you find out what is actually supported. Viewing covers a wide set: the WORD group includes DOC, DOCX, ODT, RTF, EPUB, FB2, MD, HTML and PAGES among others, the CELL group includes XLS, XLSX, ODS, CSV, TSV and NUMBERS, the SLIDE group includes PPT, PPTX, ODP and KEY, PDF covers PDF, XPS and DJVU, and DIAGRAM covers the VSD and VST families.

Editing is a much shorter list, and this is the distinction to hold on to. Only DOCM, DOCX, DOTM and DOTX edit in the WORD group; XLSB, XLSM, XLSX, XLTM and XLTX in CELL; POTM, POTX, PPSM, PPSX, PPTM and PPTX in SLIDE; and PDF for PDF. So an ODT file in your Nextcloud can be opened and read, but it cannot be saved back in place.

Bidirectional reachability is the condition everything depends on

The installation section states the requirement plainly: you need an instance of ONLYOFFICE Docs (Document Server) that is resolvable and connectable both from Nextcloud and any end clients, and ONLYOFFICE Document Server must also be able to POST to Nextcloud directly.

That is the whole deployment constraint, and it is easy to get wrong in three ways.

The Document Server has to be reachable from the user's browser, since that is where the editor runs. It has to be reachable from the Nextcloud server, because the app calls it to open and save sessions. And the Nextcloud server has to be reachable from the Document Server, because that is how the editor fetches the file and pushes the result back. A reverse proxy in front of only one of the two will fail in a way that is hard to diagnose, and the documentation points to a separate article for running ONLYOFFICE behind a proxy.

There is a port collision to plan around. Document Server and Nextcloud can be installed on different computers or on the same machine, but if you use one machine you have to set up a custom port for Document Server, because by default both work on port 80.

The Document Server itself has an edition split that determines what you can run. The free Community version of ONLYOFFICE Docs is recommended for Docker installation, with separate instructions for Debian, Ubuntu and derivatives, while the Enterprise Edition has its own installation path and is described as scalable. The README links a comparison between the two editions. There is also a hosted option, ONLYOFFICE Docs Cloud, which requires no download or installation, and a pre-configured Docker installation that sets up Document Server and Nextcloud together with a couple of commands.

Installing the app from source with npm, composer and a chown

Most administrators will install the app from the in-built Nextcloud application market: go to the user name, select Apps, find ONLYOFFICE in the list of available applications and install it. The manual path exists for servers without internet access, and it is the one that says the most about the project.

The manual install starts by moving into the apps directory on the server:

    cd apps/

Then there are three ways to get the application. You can download the latest signed version from the official Nextcloud app store, or from the application release page on GitHub, or clone the source and compile it yourself:

    git clone https://github.com/ONLYOFFICE/onlyoffice-nextcloud.git onlyoffice
    cd onlyoffice
    git submodule update --init --recursive

The recursive submodule update matters, since the project uses `.gitmodules` and the checkout is incomplete without it. The build step for a cloned copy is:

    npm install
    npm run build

Composer dependencies are then installed, and the sequence includes two steps that are not obvious:

    composer install
    composer scope-dependencies
    rm -rf vendor/firebase
    composer dump-autoload

`composer scope-dependencies` prefixes the dependencies so several Nextcloud apps can coexist without clashing over vendor directories, and the removal of `vendor/firebase` is a workaround for a dependency that the scoped install pulls in but the app does not want. These two lines are the clearest sign that this app shares a server with other PHP apps, which is the normal Nextcloud deployment.

Finally the ownership is fixed so the web server can write to the app directory:

    chown -R www-data:www-data onlyoffice

The last step is not a shell command but a page. In Nextcloud, open the `~/settings/apps/disabled` page with Not enabled apps by administrator and click Enable for the ONLYOFFICE application. The page path is a detail worth noting, because the app does not appear in the app list until it is enabled there.

Three ways to point the app at a Document Server

Configuration is done from the Nextcloud admin panel, and the documentation says there are three ways to configure the ONLYOFFICE integration settings in Nextcloud, with the user interface being one of them.

In the UI, the administrator opens the `~/settings/admin/onlyoffice` page for the ONLYOFFICE section and enters the address of the Document Server:

https://<documentserver>/

The `documentserver` placeholder is the name of the server where ONLYOFFICE Document Server is installed. The address must be accessible to the user's browser and to the Nextcloud server, and the Nextcloud server address must also be accessible from ONLYOFFICE Document Server for correct work. That sentence is the network requirement in its most compact form, and it is the thing to check first when nothing loads.

The reason the address matters is structural. The editor runs in the browser, so the browser needs to reach the Document Server directly, not through Nextcloud. Nextcloud is in the middle only as a broker: it hands the Document Server the file to open and receives the edited file back. A reverse proxy or split DNS setup has to make that work for the browser, the Nextcloud server and the Document Server simultaneously, and the Document Server's own callback to Nextcloud has to survive whatever scheme and path prefix your Nextcloud sits behind.

Since the README section is cut off partway through discussing what to do when the network configuration does not allow the direct address, the remaining configuration routes, the command line and file based options, are documented elsewhere rather than in the README.

A PHP backend with a Vue frontend and a build pipeline

The repository layout shows what kind of app this is: a PHP Nextcloud app with a modern JavaScript front end, not a theme with a couple of templates.

The PHP side lives in `lib/`, with `appinfo/` holding the app metadata, `templates/` the server-rendered views, `l10n/` the translations, `css/` and `assets/` the styles and images, and `tests/` the PHP tests. The `composer.json` and `composer.lock` files manage the PHP dependencies, and `phpunit.xml` and `psalm.xml` cover the test runner and the static analysis configuration. There is a `ruleset.xml` for coding standard rules and a `scoper.inc.php` for the dependency scoping described earlier.

The JavaScript side is in `src/`, built with Vite. The `package.json` names the package `onlyoffice` at version 10.2.1, marks it private, and defines two scripts, a build running `vite build --mode production` and a dev script using development mode. The dependency list is almost entirely Nextcloud Vue libraries: `@nextcloud/vue` at 9.5.0 with Vue 3.5.28 underneath, plus `@nextcloud/dialogs`, `@nextcloud/files`, `@nextcloud/sharing`, `@nextcloud/axios`, `@nextcloud/auth`, `@nextcloud/initial-state`, `@nextcloud/l10n`, `@nextcloud/moment`, `@nextcloud/paths` and `@nextcloud/router`. There is also `npm-shrinkwrap.json` alongside `tsconfig.json`, `eslint.config.mjs`, `stylelint.config.js`, `.stylelintrc.json` and `vite.config.mjs`.

The presence of `playwright.config.ts` indicates browser-level testing alongside the PHPUnit suite, and `vendor-bin/` is where Composer tool dependencies are isolated.

One thing to note about the release numbering. The listed releases are v10.2.1 and v10.2.0 for the app, and v9.15.1 from the same day as v10.2.1, which reflects that the app version and the Nextcloud compatibility branch are tracked separately. The same day produced a patch on the older line and a new minor on the current one, so a Nextcloud administrator on the previous major version of the app is not left behind.

Co-editing modes, federation and AI assistants

The feature list is where the app's real value sits, and a few entries are worth unpacking.

Co-editing happens in real time with two modes, Fast and Strict, plus Track Changes, comments and built-in chat. The difference between Fast and Strict is the classic latency trade-off in collaborative editing, and the fact that both are offered is the point: a team that cares about seeing every keystroke immediately and a team that would rather not wait are served by different modes rather than one compromise.

The entry that matters most for a Nextcloud deployment is federation. Co-editing is available between several federated Nextcloud instances connected to one Document Server. In practice that means two organisations running their own Nextcloud servers can edit the same document in one session, with the Document Server as the meeting point, which is unusual for self-hosted software and directly addresses the case where a document has to be shared with a partner who runs their own server.

There are also PDF capabilities worth separating. The app can create and edit PDF forms and can edit PDF files, while PDF is listed as an editing format alongside the Office formats. Document protection with watermarks is available, as is sharing files to other users from within the editor.

The most recent addition in the list is AI assistants in the editors, and the parenthesis matters: it is possible to connect any AI provider. That is an open design rather than a vendor default, so the provider choice, and where the prompts and documents go, are decisions for the administrator rather than something baked into the app. The licence of the Document Server edition and the terms of the AI provider you connect are separate questions from the app's own licence.

Editorial conclusion

Adopt onlyoffice-nextcloud if you run Nextcloud for a group that needs to edit Word, Excel and PowerPoint files in the browser and you are willing to operate a Document Server alongside it. Do not adopt it as a single-package install, since the app alone cannot edit anything without the Document Server, and check first that the two servers can reach each other and that your users' browsers can reach the Document Server address, because that bidirectional reachability is the condition the documentation puts first.

Frequently asked questions

Official sources

1. Issues
2. License: AGPL-3.0
3. ONLYOFFICE/onlyoffice-nextcloud on GitHub
4. README
5. Releases