With Mattermost’s rich RESTful web service API and OAuth 2.0 support it’s possible to build your own clients to embed Mattermost within any application of your choice.
Questions about embedding Mattermost? Ask in the Developer Toolkit channel on our Mattermost community instance.
Many modern browsers have support for extensions or add-ons that would allow you to build and embed a Mattermost client on web pages of your choice. Chrome has extensions, Firefox has add-ons, and IE/Edge have extensions.
We have an open-source demo Chrome extension that demonstrates how to get an access token for a user. You can use this demo extension as a starting point for building your embedded Mattermost client.