---
slug: /
title: Mattermost for Developers
description: Contribute to Mattermost, build plugins and integrations, and extend the platform.
sidebar_position: 1
sidebar_label: Welcome
---

<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/getting-started',
    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](/developers/contribute)** — onboarding, expectations, finding good first issues, the contribution workflow.
- **[Integrate & Extend](/developers/integrate/getting-started)** — apps, plugins, slash commands, incoming + outgoing webhooks, OAuth, customization, the marketplace.
- **[Internal](/developers/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 (`{/* TODO: unconverted Hugo shortcode … */}` markers) that are scheduled for manual cleanup — see PLAN.md §11.2.
</Note>