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  • About the ONLYOFFICE and Mattermost integration

    ONLYOFFICE offers an official connector to integrate ONLYOFFICE Docs with Mattermost to collaborate on office documents sent in private or group chats. You can download it from the official website or from GitHub. The application is distributed under the Apache license.

    To learn more about how it works and how to compile the ONLYOFFICE connector for Mattermost, please visit our API documentation.
    Main features
    • View and edit text documents, spreadsheets, and presentations using the Open file in ONLYOFFICE option.
    • Manage access rights (Edit or Read) from the context menu with the Change access rights option.
    • Co-editing documents in real-time: two co-editing modes (Fast and Strict).
    • View the file changes history.
    • JWT support to secure your traffic so no one besides the users with proper rights has access to your documents.
    Supported formats
    • For editing and viewing: DOCX, PPTX, XLSX
    What's new in version 1.1.1


    • Fixed work with s3 bucket
    • Fixed editor loader
    • Updated dependencies

    The full change log is available here.

    Connecting ONLYOFFICE Docs to Mattermost

    • ONLYOFFICE Document Server v6.4.0 (server or cloud version) or later

      You need an instance of ONLYOFFICE Docs that is resolvable and connectable both from Mattermost and any end clients. It must be able to POST to Mattermost directly.

      Please refer to the official documentation page to learn more about installing ONLYOFFICE Docs.
    • Mattermost v. 5.37.2 or later
    • ONLYOFFICE Connector v1.1.1 for Mattermost
    Installing the ONLYOFFICE connector for Mattermost

    To connect Mattermost, follow these steps:

    1. Get the Mattermost ONLYOFFICE integration app. There are several ways to do that:
      • Download the latest version from the application release page on GitHub.
      • Clone the application source code and compile it yourself:
        1. Clone the master branch.
        2. Go to the project root.
        3. Install the dependencies:
          npm install --legacy-peer-deps
          To build the plugin, you need to have Node.js v.15.14.0 installed on your machine.
        4. Run the following command:
          make dist
    2. Go to (your_mattermost_host)/admin_console/plugins/plugin_management
    3. Choose the downloaded tar.gz file or the compiled plugin from your dist folder and press Upload.
    Configuring the ONLYOFFICE Connector for Mattermost

    Go to System Console -> find the ONLYOFFICE plugin via search -> Configure. Enable the plugin in the corresponding field and specify the following parameters:

    1. Document Editing Service address - enter the URL address where ONLYOFFICE Docs is installed (e.g., https://documentserver).
      The address of ONLYOFFICE Docs must be accessible from Mattermost, as well as the address of Mattermost must be accessible from ONLYOFFICE Docs.
    2. Secret key - the document server JWT secret used to sign the data.
      Starting from ONLYOFFICE Docs v7.2, JWT is enabled by default and the secret key is generated automatically. You need to enable it on the Mattermost side as well: find your secret key in the ONLYOFFICE Docs configuration file, then specify the same secret key in the connector settings. For more details, see the Enabling JWT for the ONLYOFFICE and Mattermost integration section of this article.
    3. JWT Header - specify the JWT header.
      If JWT protection is enabled, it is necessary to specify a custom header name since the Mattermost security policy blocks external 'Authorization' Headers. This header should be specified in the ONLYOFFICE Docs signature settings as well (further information can be found here).
    4. JWT Prefix - specify the JWT prefix.
    Enabling JWT for the ONLYOFFICE and Mattermost integration

    To protect documents from unauthorized access, ONLYOFFICE editors use the JSON Web Token (JWT). The token is added in the configuration when the Document Editor is initialized and during the exchange of commands between inner ONLYOFFICE Docs services. The secret key is used to sign the JSON web token and validate the token upon the request to ONLYOFFICE Docs.

    Starting from ONLYOFFICE Docs v7.2, JWT is enabled by default and the secret key is generated automatically. You need to find your secret key in the ONLYOFFICE Docs configuration file, then specify the same secret key in the connector settings.

    Step 1: Find your secret key in the ONLYOFFICE Docs configuration file

    1. Open the local.json file with any available text editor.
      • For Linux - /etc/onlyoffice/documentserver/local.json
      • For Windows - %ProgramFiles%\ONLYOFFICE\DocumentServer\config\local.json
      • For Docker – enter the ONLYOFFICE Docs container using the docker exec -it <containerID> bash command and open /etc/onlyoffice/documentserver/local.json

        Alternatively, you can use the following command to find the default secret key without opening local.json:

        sudo docker exec <containerID> /var/www/onlyoffice/documentserver/npm/json -f /etc/onlyoffice/documentserver/local.json 'services.CoAuthoring.secret.session.string'

      The local.json file should look like this:

      {"services": {"CoAuthoring": {"token": {"enable": {"request": {"inbox": true,"outbox": true},"browser": true}},"secret": {"inbox": {"string": "yoursecret"},"outbox": {"string": "yoursecret"},"session": {"string": "yoursecret"}}}}}
    2. The true value is specified in three sections. It means that token validation is enabled.
      • services.CoAuthoring.token.enable.browser
      • services.CoAuthoring.token.enable.request.inbox
      • services.CoAuthoring.token.enable.request.outbox
    3. The automatically generated secret key is specified in three sections. You can replace the default secret value with your own secret key. The secret key must be the same in three sections.
      • services.CoAuthoring.secret.inbox.string
      • services.CoAuthoring.secret.outbox.string
      • services.CoAuthoring.secret.session.string
    4. If you make changes, save them and restart the services for the config changes to take effect.
      supervisorctl restart all

    Step 2: Specify the same secret key in the connector settings

    In the connector settings, specify the same secret in the Secret key field and save the settings.

    Start using ONLYOFFICE Docs within Mattermost

    Viewing and editing files
    • Click the More Actions button More Actions button next to a file sent in a Mattermost chat.
    • Choose the Open file in ONLYOFFICE option from the context menu.


    • Click the file name.
    • The file preview window will appear. To share the file with other users, click the Share button. To proceed with the editing, click the Edit in ONLYOFFICE button.

    The file will be opened in the corresponding ONLYOFFICE editor.

    Changing access rights

    The sender has editing access rights and the recipient has reading access rights by default. To change them, use the Change access rights option available in the file context menu. This option is available only for the sender.

    To co-edit a document, the authorized users should open the same file together.

    In a private chat:

    • Use the drop-down menu in the Access rights for @user field.

    In a group chat for all members:

    • Use the drop-down menu in the Default access rights for chat members field.

    In a group chat for a certain user:

    • Use the drop-down menu at the top, choose the required user, and click the Add button to the right.
    • The user will appear in the list below. Change their access rights via a drop-down menu on the right.
    Managing access rights will send a bot notification to the corresponding party.
    Viewing changes history

    All changes to the file will be sent as notifications containing the username.


    The notifications are available in a dedicated thread. To open the thread, click the arrow to the right of the file.


    Host ONLYOFFICE Docs on your own server or use it in the cloud