# Moo Twitter Backend

Moo is a Spring Boot backend for a Twitter-style social network. It provides versioned REST APIs for users, posts, follows, likes, replies, hashtags, search, and JWT authentication.

- :material-rocket-launch: **Run Moo**

  Install the prerequisites and start the API locally or with Docker.

  [Get started](<https://subho.xyz/twitter-backend-java/getting-started/index.md>)
- :material-api: **Integrate with the API**

  Learn the JWT and CSRF flow, endpoint contracts, and response models.

  [Explore the API](<https://subho.xyz/twitter-backend-java/api/index.md>)
- :material-sitemap: **Understand the design**

  Follow requests through the application and inspect the persistence model.

  [Read the architecture](<https://subho.xyz/twitter-backend-java/architecture/index.md>)
- :material-source-pull: **Contribute**

  Find the focused workflow for issues, branches, tests, and pull requests.

  [Start contributing](<https://subho.xyz/twitter-backend-java/contributing/index.md>)

## At a glance

- Java 25 and Spring Boot 4.1
- Spring MVC, Spring Security, and Spring Data JPA
- MySQL in development and production; H2 for tests
- JWT access tokens with rotating refresh tokens
- CSRF double-submit protection for state-changing requests
- OpenAPI, Prometheus metrics, OpenTelemetry, JaCoCo, Sonar, and CodeQL

## Request flow

```
flowchart LR
    Client --> Security[Spring Security filters]
    Security --> Controller
    Controller --> Service
    Service --> Repository
    Repository --> Database[(MySQL / H2)]
```

The project keeps transport concerns in controllers, business rules in services, and persistence in repositories. API consumers receive model records, not JPA entities.

## Documentation map

| Section | What you will find |
| --- | --- |
| [Getting started](<https://subho.xyz/twitter-backend-java/getting-started/index.md>) | Installation, profiles, configuration, and local development |
| [Architecture](<https://subho.xyz/twitter-backend-java/architecture/index.md>) | Request flow, technology choices, security, and persistence |
| [API](<https://subho.xyz/twitter-backend-java/api/index.md>) | Authentication, endpoints, models, examples, and generated reference |
| [Quality](<https://subho.xyz/twitter-backend-java/quality/index.md>) | Tests, coverage, formatting, analysis, and CI |
| [Contributing](<https://subho.xyz/twitter-backend-java/contributing/index.md>) | Contribution workflow, issues, and reviews |
| [Project](<https://subho.xyz/twitter-backend-java/project/index.md>) | Planning, releases, support, and community resources |

## Useful links

- [Source repository](<https://github.com/ohbus/twitter-backend-java>)
- [Open issues](<https://github.com/ohbus/twitter-backend-java/issues>)
- [Contribution guidelines](<https://github.com/ohbus/twitter-backend-java/blob/master/CONTRIBUTING.md>)
- [Code of conduct](<https://github.com/ohbus/twitter-backend-java/blob/master/CODE_OF_CONDUCT.md>)
- [License](<https://github.com/ohbus/twitter-backend-java/blob/master/LICENSE>)