Mattermost

# MISSION: Scaffold "Mattermost" Production Architecture
You are an expert Senior Staff Software Architect and Full-Stack Engineer. Your mission is to scaffold and implement a production-grade, highly reliable, and modular codebase following the proven architecture of **Mattermost**.
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## 1. PROJECT SPECIFICATIONS & BENCHMARK
- **Reference Architecture**: Mattermost
- **What It Does**: Mattermost is an open-core, self-hosted collaboration platform combining chat, workflow automation, and AI integration, distributed as a single Go binary with a React web client and PostgreSQL as its database.
- **Domain & Category**: Team Collaboration Suite
- **Production Scale**: 20+ people
- **Development Mode**: CLASSIC
- **Architectural Rationale**: A single Go binary keeps the API, scheduler, and websocket hub in one deployable process backed by a required PostgreSQL database, while optional Redis, Elasticsearch, and OpenSearch clients let larger deployments add caching and full-text search without changing the core architecture.
- **Live Website Reference**: https://mattermost.com
- **Source Repository**: https://github.com/mattermost/mattermost
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## 2. PRODUCTION TECH STACK
- **Full Stack Array**: TypeScript, Go, React, PostgreSQL, Redis, Elasticsearch, OpenSearch, MinIO, Prometheus, Material UI, Tiptap, Docker
- **Primary Language(s)**: TypeScript, Go
- **License of the reference repo**: NOASSERTION
- **Frontend**: React — webapp/channels is the main React SPA; webapp/platform holds shared component libraries.; Material UI — Newer UI surfaces use MUI components alongside legacy Bootstrap markup.; Tiptap — Powers the rich-text message composer via its React bindings and table extensions.
- **Backend & APIs**: Go — server/ is the primary Go application; go.mod pins the module and Go toolchain version.
- **Data & persistence**: PostgreSQL — Required relational database, accessed via the lib/pq driver and sqlx.; Redis — Optional cache and pub-sub layer via the rueidis client for larger deployments.; Elasticsearch — Optional full-text search backend for channels and posts.; OpenSearch — Alternative search backend supported alongside Elasticsearch.; MinIO — S3-compatible client for storing uploaded files and compliance exports.
- **Infrastructure & deploy**: Docker — Packages the compiled Mattermost binary with a Postgres client for production images.; Prometheus — Exposes runtime metrics for monitoring deployments.; GitHub Actions — Dozens of workflows run server, webapp, and end-to-end tests plus Docker builds.
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## 3. KEY ARCHITECTURAL DECISIONS (audited from https://github.com/mattermost/mattermost @ de7a2dc)
1. **Mattermost ships as a single Go binary, not microservices**: server/go.mod defines one module (github.com/mattermost/mattermost/server/v8) that compiles into a single binary bundling the API, scheduler, plugin host, and websocket hub, matching the READMEs description of running as a single Linux binary.
2. **PostgreSQL is required; Redis, Elasticsearch, and OpenSearch are optional**: server/go.mod imports lib/pq for the required Postgres connection alongside optional clients for Redis (redis/rueidis), Elasticsearch (elastic/go-elasticsearch), and OpenSearch (opensearch-go), letting deployments add caching and search independently of the core database.
3. **Schema migrations run through Mattermost's own morph tool**: server/go.mod depends on github.com/mattermost/morph rather than a generic migration framework, giving the team control over Postgres migration ordering and rollback behavior across major versions.
4. **The webapp is a monorepo of React packages, not one flat app**: webapp/platform holds shared client, components, and eslint-plugin packages consumed by webapp/channels (the main SPA), letting the desktop app and plugins reuse the same @mattermost/client and @mattermost/types packages.
5. **File storage abstracts over S3-compatible object storage via a MinIO client**: server/go.mod's minio-go/v7 dependency lets Mattermost read and write uploaded files and exports against any S3-compatible backend, whether that is AWS S3, MinIO, or another provider, through one client library.
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## 4. NON-NEGOTIABLE ARCHITECTURAL GUARDRAILS
1. **Monorepo & Modular Separation**:
   - Structure as a Turborepo monorepo with strict package boundaries:
     - `apps/web`: Application UI, routing, layouts, and server endpoints.
     - `packages/ui`: Shared design tokens, CSS variables, and Radix UI primitive components.
     - `packages/db`: Database schemas, client singleton, declarative migrations, and seed scripts.
     - `packages/config`: Shared TypeScript, ESLint, and build configurations.
2. **Strict Type Safety & Zero `any` Policy**:
   - Enable `strict: true`, `noImplicitAny: true`, and `strictNullChecks: true`.
   - Validate ALL external inputs, API request bodies, and query parameters with **Zod** schemas before execution.
3. **Frontend & Rendering Guidelines**:
   - Isolate interactive UI state to leaf components. Keep core pages lightweight and performant.
4. **Design System & Aesthetics**:
   - Keep every color, radius, shadow and font in a single token file (CSS variables) and consume tokens everywhere; never hardcode hex values in components.
   - Prefer crisp 1px borders and one subtle shadow scale over blurry default shadows. Pair one sans-serif for body/headings with one monospace for tags, badges, metrics, and code.
5. **Data Layer & Reliability**:
   - Write declarative schema definitions with foreign keys, composite indexes on queried filters, and automated timestamp triggers.
   - Use connection pooling and prepared statements for serverless database execution.
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## 5. STEP-BY-STEP SCAFFOLDING ROADMAP
- **Phase 1: Workspace & Root Config**: Initialize package manager, monorepo configuration (`turbo.json`, `tsconfig.base.json`, `package.json`).
- **Phase 2: Database Schema & Client**: Set up the data layer (PostgreSQL, Redis, Elasticsearch, OpenSearch, MinIO): client, connection pool, models, and migration scripts.
- **Phase 3: Design Tokens & UI Primitives**: Build accessible `Button`, `Input`, `Card`, `Badge`, and layout wrappers inside `packages/ui`.
- **Phase 4: Core Application Routes & Handlers**: Implement primary authentication, user session handling, and application routes.
- **Phase 5: Quality Assurance & Build Verification**: Run `tsc --noEmit`, ESLint, Prettier, and smoke test suites to ensure zero compilation or runtime errors.
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## 6. EXECUTION INSTRUCTIONS
1. Review all specifications, architectural guardrails, and stack choices above.
2. Present the full monorepo directory tree structure.
3. Systematically generate the complete, production-ready codebase according to the 5-phase roadmap above — starting with the root workspace setup, followed by the database schema, UI design system package, and full-stack application routes until the repository is fully scaffolded and ready to run.