Sync-in

Sync‑in Server is a self‑hosted, enterprise‑grade file transfer and synchronization platform that emphasizes data sovereignty, fine‑grained access control, and real‑time collaboration. From a developer’s perspective it is designed to be modular, API‑centric, and easily integrated into existing workflows. The core of the system is a Node.js backend that exposes RESTful endpoints and WebSocket channels for real‑time updates, while the front end is a single‑page application built with React and TypeScript. The project follows a micro‑service inspired architecture, separating concerns such as authentication, storage orchestration, and collaboration into distinct modules that can be swapped or extended independently.

Key Features

• Collaborative Spaces & Shares – Users can create isolated “spaces” with role‑based permissions, and share individual files or entire directories via secure links. Permissions are encoded in JWTs that carry scopes, enabling fine‑grained checks on every request.
• Real‑time Collaboration – Integration with OnlyOffice is achieved through a WebSocket gateway that streams document changes and locks, allowing multiple users to edit the same file simultaneously without conflict.
• Full‑Text Search & Indexing – A background worker consumes change events and updates an Elasticsearch index. The search API supports fuzzy matching, file type filtering, and pagination, making it straightforward to build custom discovery tools.
• WebDAV & Desktop Clients – The server implements the WebDAV protocol, exposing a familiar file‑system interface. The accompanying Electron desktop client mounts Sync‑in as a network drive, enabling native OS sync and background uploads.

Technical Stack

The server is built as a single repository but follows the “service‑by‑module” pattern: authentication, file service, collaboration engine, and search are each isolated behind clear interfaces. This separation allows developers to replace MinIO with a cloud provider or swap Elasticsearch for Meilisearch without touching the core business logic.

Deployment & Infrastructure

Sync‑in ships with Docker images (syncin/server) that expose environment variables for database URLs, S3 credentials, and feature flags. For production, the recommended deployment is a multi‑pod Kubernetes cluster with an external PostgreSQL instance and a MinIO bucket for object storage. Horizontal scaling is achieved by running multiple API replicas behind an ingress controller; the WebSocket gateway uses Redis Pub/Sub to synchronize session state. The project also offers a lightweight NPM package that can be imported into custom Node.js applications, enabling developers to embed Sync‑in’s file management API directly into their services.

Integration & Extensibility

• Plugin System – The core exposes a hook registry (onFileUpload, beforeDelete, etc.) that third‑party modules can tap into. This is ideal for adding custom validation, virus scanning, or metadata enrichment.
• Webhooks – External services can subscribe to events (file created, shared, deleted) via HTTP callbacks, allowing integration with CI/CD pipelines or notification systems.
• SDKs & API Docs – The OpenAPI specification is auto‑generated from TypeScript types and published on the documentation site. Client libraries exist for JavaScript/TypeScript, Python, and Go, simplifying SDK consumption.
• Custom UI Themes – The React front end supports CSS variables and a theme context, enabling developers to brand the interface without modifying source code.

Developer Experience

The project places a strong emphasis on documentation: every endpoint is documented in the official docs, with example payloads and response schemas. The community is active on Discord and GitHub discussions, where feature requests and bug reports are triaged quickly. Licensing under AGPL‑v3 ensures that any derivative work remains open, which aligns with many enterprise compliance policies. Continuous integration pipelines run unit tests and linting across all modules, guaranteeing that new contributions do not break the existing contract.

Use Cases

1. Enterprise File Sharing – Deploy Sync‑in behind a corporate VPN to give teams secure, searchable access to documents while retaining full control over storage and permissions.
2. Regulated Industries – Leverage the granular audit logs, MFA support, and data‑at‑rest encryption to meet HIPAA or GDPR requirements.
3. Educational Institutions – Create class spaces where instructors can upload resources and students can collaborate in real time, all while keeping the data on campus servers.
4. Developer Tooling – Embed Sync‑in’s API into a CI/CD pipeline to store build artifacts, logs, or test results with fine‑grained access policies.

Advantages

• Performance & Scalability – Node.js event loop combined with Redis Pub/Sub allows the system to handle thousands of concurrent WebSocket connections, while PostgreSQL and Elasticsearch provide robust persistence and search.
• Flexibility – The modular architecture lets teams swap storage backends or add custom plugins without touching the core.
• Open‑Source Transparency – AGPL licensing and a transparent codebase mean there are no hidden dependencies or vendor lock‑in.
• Rich Feature Set – From MFA to OnlyOffice integration, Sync‑in bundles many enterprise capabilities that would otherwise require a stack of disparate tools.

In summary, Sync‑in Server offers developers