#nats #zenoh #pub-sub-client #mqtt

bin+lib mqcat

CLI pub/sub client (supports zenoh/nats/mqtt/centrifuge)

5 unstable releases

Uses new Rust 2024

new 0.3.0 Oct 14, 2025
0.2.1 Sep 30, 2025
0.2.0 Sep 29, 2025
0.1.3 Sep 28, 2025
0.1.2 Sep 28, 2025

#15 in #nats

Download history 61/week @ 2025-09-22 211/week @ 2025-09-29 15/week @ 2025-10-06 186/week @ 2025-10-13

473 downloads per month

MIT license

53KB
1K SLoC

mqcat

Command-line client for pub/sub messaging systems like zenoh, nats, mqtt, and centrifuge.

Why?

NATS has a great CLI tool, Zenoh is lacking one at the moment (python one is bit too slow), and Centrifugo doesn't have one at all.

I wanted to have the same experience as NATS CLI with other protocols/brokers, so I wrote this tool.

Installation

Option 1 - download new binary:

  • download the binary from the releases page

Option 2 - update existing binary:

  • run mqcat --upgrade to upgrade to the latest version

Option 3 - compile from source code:

  • run cargo install mqcat to install the latest version from source code (if you have Rust installed)

Usage

zenoh

# publish a message to zenoh
mqcat zenoh pub 'test' 'Hello, world!'

# subscribe to zenoh topics
mqcat zenoh sub '**'

# connect to specific zenoh server
mqcat zenoh+tcp/localhost:7447 sub 'test'

nats

# publish a message to nats
mqcat nats pub 'test' 'Hello, world!'

# subscribe to nats topics
mqcat nats sub '>'

# connect to specific nats server
mqcat nats://localhost:4222 sub 'test'

Dependencies

~10–32MB
~443K SLoC