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Control protocol test utility

MIDI logging, OSC monitoring, and more...

Prokotol is a new utility by Hexler for the creator's toolbox: A lightweight, responsive console app for monitoring and logging control protocols.

Originally built as a MIDI monitor and Open Sound Control network checker, Protokol is designed to handle any complex message stream.

Protokol's Protocols

MIDI, OSC and Gamepad HID sources are all supported in the current version but anything is possible given sufficient demand. Contact us if you'd like to see additional protocols added: ArtNET / DMX? MQTT? Let us know.

Heavy Duty, Fast Response

All incoming data is rendered at 60 frames per second. With granular filtering of message and event types plus an optional timestamp, Protokol logs exactly what you need. This responsiveness and flexibility enables you to track down critical issues, conflicts, interrupts ... or just pretend you are Cypher observing the Matrix.

Cross Platform

Protokol installs on all platforms. Run a compact Raspberry Pi MIDI logger, or Linux based OSC monitor, or install on traditional Windows and macOS machines. Same interface, same speed, same accuracy. Download all versions here!

And we have not forgotten mobile. Android and iOS versions are currently in testing at Hexler HQ with a public release coming very soon.


We built Protokol as an in-house tool to test our own apps during development, and quickly found use for it in our home studios (troubleshooting MIDI hardware). A few of our music producer mates saw it running and bugged us for a copy ... we cleaned up the UI and started giving it away.

Protokol is currently beta software, so if you have any feature requests we'd love to hear them, and if you see a glitch or bug we are equally interested to know.



Work in progress documentation. Updated regularly.


A responsive heavy duty console for troubleshooting control protocols.

Mac Windows Linux

Download Protokol Beta

Click the buttons above to pop up links for your specific OS: Mac, Windows, and multiple versions of Linux (ARM, Raspberry Pi, x86 etc.)

DISCLAIMER: This is an early preview version and might not function as expected. Please use at your own risk.