MOSQUITTO(7)

💅 MOSQUITTO(7) — conventions and miscellaneous, bestie edition

okay so you opened the mosquitto(7) page and that means you want the vibe tour of the whole project, not just one tool. buckle up 🎀

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✨ NAME ✨

mosquitto — project overview. that's it, that's the whole thing. it's the "hey, here's the family photo" page 🫶

🌸 DESCRIPTION 🌸

so the mosquitto project is this whole little ecosystem of MQTT related programs, and it's giving full ensemble cast ✨ it's made up of:

• the mosquitto broker itself
• applications that go with it
• command line clients
• and a whole client library for when you wanna build your own custom MQTT clients 💅

if you want a quick rundown of what MQTT even is, peep mqtt(7) — it's the lil primer 🔥

Mosquitto is an Eclipse Foundation project, part of the IoT top level project. very much main character energy in the IoT world, no cap 👑

the deets:

• project home page: mosquitto.org
• github project: github.com/eclipse-mosquitto/mosquitto
• and there's a public MQTT test broker literally just sitting there for you at test.mosquitto.org 🦋

development is driven by Cedalo, who also provide professional support and enterprise features for mosquitto. slay, sponsored by the pros 💖

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👑 MOSQUITTO BROKER 👑

the broker is the core of the project, periodt. everything orbits it 🌈

• how to start it, what MQTT support looks like, feature descriptions → mosquitto(8)
• the full tea on the configuration file format → mosquitto.conf(5)

bestie if you're configuring the broker without reading mosquitto.conf(5) you're lowkey just guessing. don't do that to yourself 😭

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🧚 MOSQUITTO BROKER APPLICATIONS 🧚

these command line apps directly support the running of the mosquitto broker. they're the backstage crew that keeps the show going 🎀

💜 mosquitto_ctrl

this one lets you interact with the broker MQTT APIs while the broker is running. it's got two modes and they're both iconic:

• batch mode — you provide all arguments on the command line
• interactive shell mode — available from version 2.1 onwards ✨

the batch mode is described in mosquitto_ctrl(1), and the Dynamic Security module gets its own page at mosquitto_ctrl_dynsec(1).

the interactive shell mode is described in mosquitto_ctrl_shell(1). iykyk 💅

🍓 mosquitto_passwd

this tool generates and modifies password files — the kind you use with the mosquitto_password_file plugin or the password_file configuration option. it's described in mosquitto_passwd(1) 🫶

⭐ mosquitto_signal

available from version 2.1.

this tool sends signals to the broker. on POSIX systems it does the same task as the kill command, but with named signals instead of numbers (much more readable, we love that 🌸). on Windows it's the only method of sending signals to the broker — literally the only one 👀

it's described in mosquitto_signal(1).

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🔥 MOSQUITTO MQTT COMMAND LINE CLIENTS 🔥

these are the MQTT clients that live on your command line — perfect for testing and automating tasks related to any MQTT broker, not just ours. equal opportunity icon behavior 💅

💖 mosquitto_pub

publishes messages to a broker. supports:

• sending simple messages straight from the command line
• reading from stdin
• sending files 📁

described at mosquitto_pub(1).

🦋 mosquitto_rr

request/response style, and the way that it works is: it sends a single message to the broker and waits for a response on another topic. very "text me back" energy 😭

request/response support is an MQTT v5.0 feature, but it's not required in most cases for this client. good to know, no cap.

described at mosquitto_rr(1).

🌈 mosquitto_sub

subscribes to topics on the broker and prints the messages it receives. and bestie, the output options? a wide variety. obsessed 💜

described at mosquitto_sub(1).

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🧚 MOSQUITTO CLIENT LIBRARY 🧚

the Mosquitto client library is described at libmosquitto(3). go build something cute 🎀

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💀 AUTHOR 💀

Roger Light <roger@atchoo.org>

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ok that's the whole tour, bestie. go forth and MQTT responsibly 🌸✨

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💖 Mosquitto Project · 02/09/2026 · MOSQUITTO(7) 💖

later babes, xoxo 🫶💅