Ditto provides two ways to interact with:
- A REST-like HTTP API with a sophisticated resource layout that allows to create, read, update and delete Things and the Thing’s data.
- A JSON-based WebSocket API implementing the Ditto Protocol.
HTTP API or WebSocket?
The two ways are almost equally powerful and allow the same operations to work with the Thing’s data, send messages to Things and receive messages from Things.
- The lightweight REST-like HTTP API can be used
- on less powerful devices lacking a Java runtime or supporting other (scripting) languages like JavaScript, Python, C/C++,
- and for developing Web-based user interfaces.
- The WebSocket API proves useful for
- gathering data streams from devices or massive data from another message broker,
- real-time device monitoring,
- event-driven Web applications,
- full duplex communication scenarios, etc.
Comparison by feature
| Feature | Ditto Protocol over WebSocket | REST-like HTTP API |
|---|---|---|
| Things management | ✓ | ✓ |
| Features management | ✓ | ✓ |
| Search Things | ✓ | ✓ |
| Count Things | no | ✓ |
| Messages | ✓ | ✓ |
| Change notifications | ✓ | ✓ (SSEs) |
| Access control via Policy | ✓ | ✓ (v2 only) |
Further aspects in which the interfaces differ
| Criteria | Ditto Protocol over WebSocket | REST-like HTTP API |
|---|---|---|
| Programming language | Almost any web-oriented programming language, e.g. Java, JavaScript, .NET | Almost any programming language, e.g. Java, JavaScript, NodeJS, .NET, Python, C/C++ |
| Connection paradigm | Connection-oriented with an always open and persistent connection with only one-time handshake overhead for lowest latency and highest throughput | Connectionless protocol with lower permanent resource allocation on sporadic transactions |
| Channel security | WSS: WebSocket over Transport Layer Security | HTTPS: HTTP over Transport Layer Security |
| Message exchange pattern | Non-blocking request - asynchronous response | Blocking request - response |
| Authentication mechanism | User authentication using: HTTP BASIC Authentication, JSON Web Token (JWT) issued OpenID connect provider | User authentication using: HTTP BASIC Authentication, JSON Web Token (JWT) issued OpenID connect provider |