Coral

Coral is a full‑stack, self‑hosted commenting platform designed for modern web publishers and community sites. At its core it provides a rich comment thread UI, real‑time moderation, and advanced engagement features such as user identity verification, notification handling, and content discovery. The system is built to be data‑centric: all comment metadata, user profiles, and moderation actions are persisted in a relational database, while the front‑end communicates via GraphQL for fine‑grained data access and mutation.

Architecture

Coral follows a monorepo structure (GitHub: coralproject/talk) that splits the codebase into several npm packages. The main stack consists of:

• Node.js / Express for the API layer, exposing a GraphQL endpoint (/graphql) and RESTful hooks for legacy integration.
• React with a component library that renders the comment UI on the client. The React bundle is served as static assets but can be embedded via a simple <script> tag or an iframe.
• PostgreSQL as the primary datastore, with a schema that supports user accounts, comment trees, moderation logs, and site configuration. An optional Redis cache can be used for session storage or rate‑limiting.
• Docker Compose is the recommended deployment method; a single docker-compose.yml can bring up all services (API, UI, database, Redis) in a reproducible environment.

The platform is event‑driven: actions such as comment creation, moderation decisions, or user mentions trigger asynchronous jobs (via a background worker written in Node) that handle email notifications, webhook calls, or analytics events.

Core Capabilities

Developers have a wealth of hooks and APIs:

• GraphQL API: Full CRUD for comments, users, moderation actions, and site settings. Supports pagination, filtering, and real‑time subscriptions via WebSockets.
• RESTful webhooks: External services can subscribe to events (e.g., new comment, moderation update) and receive JSON payloads.
• Plugin SDK: Coral exposes a plugin interface that allows injecting custom UI components, middleware, or data processors. Plugins are written in JavaScript and bundled with the front‑end.
• OAuth & SSO Integration: Built‑in adapters for Google, GitHub, and custom OIDC providers; developers can extend authentication by adding new strategies.

Deployment & Infrastructure

Coral is designed for cloud‑native deployment:

• Docker images are available on Docker Hub (coralproject/talk), with tags for the latest stable release and LTS versions. Images are lightweight (~400 MB) and include both API and UI layers.
• Kubernetes: The repo ships with Helm charts that configure deployments, services, and persistent volumes. Horizontal Pod Autoscaling can be enabled for the API pods.
• Scalability: The stateless API layer can scale horizontally; PostgreSQL should be backed by a managed instance (e.g., RDS) for high availability. Redis can be sharded if needed.
• CI/CD: The project uses GitHub Actions to run tests and build Docker images automatically, ensuring that every commit is validated.

Integration & Extensibility

Coral’s open‑source nature encourages deep customization:

• Theming: CSS variables and a theming API let you match the comment UI to your brand without touching core code.
• Custom registration flows: By hooking into the authentication middleware, you can replace or augment the default user creation logic with your own database or LDAP integration.
• AI moderation: The platform ships with a pluggable moderation engine; developers can swap in external services (e.g., Perspective API) or implement custom machine‑learning models.
• Data export: GraphQL introspection and a CLI tool allow bulk extraction of comments for archival or migration purposes.

Developer Experience

• Documentation: The official docs (docs.coralproject.net) cover setup, API reference, and plugin development. Inline code comments and a well‑structured README make onboarding fast.
• Community: Coral has an active GitHub community with issue triage, pull‑request reviews, and a Slack channel for real‑time support. The Apache‑2.0 license removes licensing friction.
• Testing: Jest and Cypress tests are bundled with the repo, enabling developers to run unit and end‑to‑end tests locally or in CI.

Use Cases

1. Newsrooms – Embed Coral on articles to provide threaded discussions while keeping moderation under editorial control.
2. E‑commerce – Use Coral as a review and Q&A system, leveraging its moderation tools to filter spam.
3. Educational platforms – Integrate with LMS authentication and use Coral for discussion forums or peer review.
4. Open‑source projects – Host community discussions on project pages without third‑party ad networks.

Advantages

• Performance: Real‑time updates via WebSockets and efficient GraphQL queries keep latency low even on high traffic sites.
• Flexibility: Full access to the source code and a plugin SDK allow tailoring the platform to niche workflows.
• Privacy: No embedded trackers or ad scripts; data remains on your own infrastructure.
• Scalability: Containerized deployment and support for Kubernetes make it trivial to grow with traffic spikes.
• Open‑source & Licensing: Apache‑2.0 ensures no vendor lock‑in and encourages community contributions.

Coral gives developers a powerful, self‑hosted foundation for building engaging, moderated comment ecosystems while maintaining full control over data and user experience.