How do I register a custom URL protocol in Windows?

Question

How do I register a custom protocol with Windows so that when clicking a link in an email or on a web page my application is opened and the parameters from the URL are passed to it?

Answer 1

1. Go to Start and then in Find, type *regedit. It should open the Registry editor

2. Right-click on HKEY_CLASSES_ROOT and then `New* → Key

   

3. In the Key, enter the lowercase name by which you want URLs to be called (in my case, it will be testus://sdfsdfsdf). Then right-click on testus. Then New → String Value and add URL Protocol without value.

   

4. Then add more entries like you did with protocol (Right-click New → Key) and create a hierarchy like testus → shell → open → command. Inside command, change (Default) to the path where the .exe file you want to launch is. If you want to pass parameters to your EXE file, then wrap the path to the EXE file in "" and add "%1" to make it look like: "c:\testing\test.exe" "%1"

   

5. To test if it works, go to Internet Explorer (not Chrome or Firefox) and enter testus:have_you_seen_this_man. This should fire your .exe (it gives you some prompts that you want to do this; say Yes) and pass testus://have_you_seen_this_man into arguments.

Here's a sample console application to test:

using System;

namespace Testing
{
    class Program
    {
        static void Main(string[] args)
        {
            if (args!= null && args.Length > 0)
            Console.WriteLine(args[0]);
            Console.ReadKey();
        }
    }
}

Answer 2

[Obsolete - the MSDN information has been replaced by a new page which does address the security concerns]

The MSDN link is nice, but the security information there isn't complete. The handler registration should contain "%1", not %1. This is a security measure, because some URL sources incorrectly decode %20 before invoking your custom protocol handler.

PS. You'll get the entire URL, not just the URL parameters. But the URL might be subject to some mistreatment, besides the already mentioned %20->space conversion. It helps to be conservative in your URL syntax design. Don't throw in random // or you'll get into the mess that file:// is.

Answer 3

If anyone wants a .reg file for creating the association, see below:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\duck]
"URL Protocol"=""
[HKEY_CLASSES_ROOT\duck\shell]
[HKEY_CLASSES_ROOT\duck\shell\open]
[HKEY_CLASSES_ROOT\duck\shell\open\command] 
@="\"C:\\Users\\duck\\source\\repos\\ConsoleApp1\\ConsoleApp1\\bin\\Debug\\net6.0\\ConsoleApp1.exe\" \"%1\""

Pasted that into notepad, the file -> save as -> duck.reg, and then run it. After running it, when you type duck://arg-here into chrome, ConsoleApp1.exe will run with "arg-here" as an argument. Double slashes are required for the path to the exe and double quotes must be escaped.

Tested and working on Windows 11 with Edge (the chrome version) and Chrome

Answer 4

There is an npm module for this purpose.

link :https://www.npmjs.com/package/protocol-registry

So to do this in nodejs you just need to run the code below:

First Install it

npm i protocol-registry

Then use the code below to register you entry file.

const path = require('path');

const ProtocolRegistry = require('protocol-registry');

console.log('Registering...');
// Registers the Protocol
ProtocolRegistry.register({
    protocol: 'testproto', // sets protocol for your command , testproto://**
    command: `node ${path.join(__dirname, './index.js')} $_URL_`, // $_URL_ will the replaces by the url used to initiate it
    override: true, // Use this with caution as it will destroy all previous Registrations on this protocol
    terminal: true, // Use this to run your command inside a terminal
    script: false
}).then(async () => {
    console.log('Successfully registered');
});

Then suppose someone opens testproto://test then a new terminal will be launched executing :

node yourapp/index.js testproto://test

It also supports all other operating system.

Answer 5

To further the existing answers a bit more, the application invoked to handle the protocol does not have to be a compiled application. It can also be a script file.

For example, you could create a Windows batch file - such as that below to - handle the call. Let us assume you save that script to c:\temp\testprotocol-handler.bat.

REM just echo the passed argument
echo off
echo Hello from the custom protocol handling script.
echo script name: %0
echo script arg : %1
pause

Use the following registry configuration to map the script to the protocol testprotocol.

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\testprotocol]
"URL Protocol"=""
[HKEY_CLASSES_ROOT\testprotocol\shell]
[HKEY_CLASSES_ROOT\testprotocol\shell\open]
[HKEY_CLASSES_ROOT\testprotocol\shell\open\command] 
@="\"C:\\temp\\testprotocol-handler.bat\" \"%1\""

When the OS encounters the protocol it will execute the script - opening a command window and displaying the content of the echo statements in the script.

sample script executing

Answer 6

@echo off

setlocal

set "protocol_name=sugamprotocol"
set "application_path=C:\Users\%USERNAME%\Downloads\ping_execute.exe"

set "key_path=HKCU\SOFTWARE\Classes\%protocol_name%"
set "command_path=%key_path%\shell\open\command"

REM Create the registry key for the custom protocol handler
reg add "%key_path%" /ve /d "URL:Custom Protocol" /f > nul
reg add "%key_path%" /v "URL Protocol" /d "" /f > nul

REM Create the command key to specify the application to run
reg add "%command_path%" /ve /d "\"%application_path%\" \"%%1\"" /f > nul

echo Custom protocol handler registered successfully!

endlocal

1. To create the .bat file, open a text editor, copy the above code, and save the file with a .bat extension (e.g., register_protocol.bat). Make sure to adjust the protocol_name and application_path variables according to your requirements.

   When you run the .bat file, it will register the custom protocol handler by modifying the Windows registry. You should see the "Custom protocol handler registered successfully!" message if the registration is successful.

   Please note that modifying the Windows registry requires administrative privileges. Make sure to run the .bat file as an administrator.