Mainly just taking these notes down for my own future reference. Hope it helps some others out. For my use case I wanted to isolate a github runner so it couldn't access my home network but still had a clear path out to the greater internet. Protects against supply chain related vectors in case the runner is ever compromised.
David Cheeseman nuvious
nuvious
/ custom-protocol-handler.py
Created
January 15, 2026 18:16
Custom Windows Protocol Handler Registration with Python (No Admin Required)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| """ | |
| This registers a simple echo protocol handler so that echo://anything_here will | |
| open a command prompt and echo the full URL. | |
| This does not require admin privileges as it writes to HKEY_CURRENT_USER. | |
| Built from the following reference: | |
| https://stackoverflow.com/questions/3964152/how-do-i-create-a-custom-protocol-and-map-it-to-an-application/3964401#3964401 | |
| """ |
OlderNewer