// the find
eclipse-ditto/ditto
Eclipse Ditto™: Digital Twin framework of Eclipse IoT - main repository
Eclipse Ditto is a digital twin framework for IoT — it lets you model physical devices as JSON-based 'Things' and interact with them through a unified HTTP/WebSocket/MQTT API regardless of whether the physical device is online. It handles state persistence, live messaging, change notifications, and fine-grained policy-based access control. The target user is a team building an IoT platform that needs device state management without rolling their own persistence and protocol abstraction layer.
The policy model is genuinely well-designed — you can grant read/write access at the feature attribute level, not just per-device, which matters when multiple services need different slices of a twin's state. The connectivity service supports AMQP, MQTT, Kafka, and HTTP targets out of the box, so you're not locked into a single message broker. W3C Web of Things (WoT) integration means Thing models can be described with a standard TD (Thing Description), giving you interoperability with other WoT tooling. The event sourcing architecture (Akka-based, each Thing as a persistent actor) means you get an audit log and time-travel queries for free.
This is a Java monorepo requiring JDK 25 and Maven, built around Akka clustering — the operational complexity is substantial before you've done anything useful. MongoDB is the only supported persistence backend, which is a hard dependency you might not want in an existing PostgreSQL-heavy stack. The 894-star count reflects a real adoption ceiling: this is an Eclipse Foundation project with foundation overhead, and the community is small enough that you're likely filing issues into a slow queue. Horizontal scaling story requires Kubernetes and the provided Helm charts, which means a 'try it in production' path that isn't small-team-friendly.