Emitter

What it does

Deployment

Emitter can be deployed as a Docker container or built and run from source; the maker describes single-server and clustered deployment.checked 9 Oct 2026

Filtering and playback

Subscribers can filter messages, and messages can be stored for a period of time and delivered on demand.checked 9 Oct 2026

Limits

The pricing page lists 1 GB transfer and 50 unique devices on Start, and 15 GB transfer and 500 unique devices on Scale, with extra usage priced separately for Scale.checked 9 Oct 2026

Message size

The repository documentation lists a default maximum message size of 64 KB.checked 9 Oct 2026

Messaging

Publishers send messages to channels, and subscribers receive copies in real time.checked 9 Oct 2026

Open source

The download page says Emitter is free and open source under the AGPL license, and also offers a commercial license.checked 9 Oct 2026

Product

Emitter is a real-time publish-subscribe messaging service for connecting online devices.checked 9 Oct 2026

Protocols

Emitter supports MQTT and binary or text messages over WebSockets.checked 9 Oct 2026

Reliability

The maker describes the system as peer-to-peer with no master or slave nodes, designed to continue operating if a node fails.checked 9 Oct 2026

Security

The maker says Emitter supports per-channel authorization policies and SSL/TLS, encrypts network traffic, and does not inspect messages.checked 9 Oct 2026

Support

The maker offers support contracts and directs questions to [email protected] and GitHub issues.checked 9 Oct 2026

Use cases

The maker describes Emitter for gaming, IoT, web applications, dashboards, visual analytics, and mobile apps.checked 9 Oct 2026