Mattermost for Developers

<Eyebrow>Developers</Eyebrow>

Build with, on, and for Mattermost. Contribute to the platform, build plugins and integrations, and extend Mattermost into the rest of your operational stack.

Start here

<CardGrid columns={3} cards={[ { title: 'Contribute', icon: 'channels', to: '/developers/contribute', description: 'Set up the development environment, submit pull requests, run tests. The core path for engineers joining the project.', meta: 'Setup → review → ship' }, { title: 'Integrate & Extend', icon: 'channels', to: '/developers/integrate', description: 'Bots, slash commands, webhooks, OAuth apps, plugins, mobile clients. Build with the platform.', meta: 'Plugins · Apps · SDK' }, { title: 'API Reference', icon: 'channels', to: '/api', description: 'REST API v4 — every endpoint, generated from the canonical OpenAPI spec.', meta: '549 endpoints' } ]} />

What's covered here

• Contribute — onboarding, expectations, finding good first issues, the contribution workflow.
• Integrate & Extend — apps, plugins, slash commands, incoming + outgoing webhooks, OAuth, customization, the marketplace.
• Internal — Mattermost-engineering team docs (build process, infrastructure, QA).

Looking for something else?

<CardGrid columns={2} cards={[ { title: 'Documentation', icon: 'channels', to: '/', description: 'Operating, configuring, or using Mattermost? Admin and end-user guides.' }, { title: 'API Reference', icon: 'channels', to: '/api', description: 'Hit the REST API directly — every endpoint with request/response schemas and code samples.' } ]} />

<Note> Content migrated from the legacy `mattermost-developer-documentation` Hugo site. Some pages have unconverted Hugo shortcode placeholders (`` markers) that are scheduled for manual cleanup — see PLAN.md §11.2. </Note>