Lyre

Chrome Native Messaging implementation for .NET and .NET Core. Allows easy communication with a Chrome extension using Chrome Native Messaging protocol.

Install

Get it on NuGet: PM> Install-Package Lyre

Usage

using var host = new NativeMessagingHost();

try
{
    while (true)
    {
        var response = await host.Read<dynamic>();

        // Echo response
        await host.Write(new { value = $"You said {response.value} at {response.dateTime}", dateTime = DateTime.Now });
    }
}
catch (EndOfStreamException)
{
    // Disconnected
}

Example/Chrome Extension

See https://github.com/alexwiese/Lyre/tree/master/src/Lyre.ConsoleTest for an example of a Chrome extension communicating with a Native Messaging Host.

Customization

The NativeMessagingHost uses JSON.NET for serialization. This can be customized by passing in a JsonSerializerSettings object. The Encoding and Stream objects used for communications can also be passed into the constructor.

var host = new NativeMessagingHost(Console.OpenStandardInput(), Console.OpenStandardOutput(), Encoding.UTF8, new JsonSerializerSettings{ Formatting = Formatting.None});

Advanced Usage

// Using cancellation tokens for timeout support
using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(30));
var message = await host.Read<dynamic>(cts.Token);
await host.Write(response, cts.Token);

// Proper disposal pattern
using var host = new NativeMessagingHost(inputStream, outputStream, encoding, settings, ownsStreams: true);

Chrome Native Messaging Protocol Compliance

This library fully complies with the Chrome Native Messaging protocol:

• Message Size Limits: Enforces the 1MB message size limit as required by Chrome
• Proper Error Handling: Validates message formats and sizes
• Resource Management: Implements proper disposal patterns for stream cleanup
• Async Support: Full cancellation token support for timeout handling

Supressing Console Output

By default Chrome Native Messaging uses stdin and stdout to communicate. If any other code writes to the Console, for example by calling Console.WriteLine(string), then this would cause the Chrome Native Messaging pipe to fail due to unexpected output. Helper methods are provided by the NativeMessagingEnvironment class to supress or redirect the Console output.

Supress console output

// Redirects any calls to Console.Write() or Console.WriteLine() to TextWriter.Null
NativeMessagingEnvironment.SupressConsoleOutput();

Redirect to stderr

// This will redirect calls to Console.Write() and Console.WriteLine() to stderr
NativeMessagingEnvironment.RedirectConsoleOutputToErrorOutput();

Redirect to Debug output

// Redirects any calls to Console.Write() or Console.WriteLine() to the Debug output
NativeMessagingEnvironment.RedirectConsoleOutputToDebugStream();

Redirect to a TextWriter

// This will redirect calls to Console.Write() and Console.WriteLine() to a file
var writer = new StreamWriter(File.OpenWrite("console.out")) { AutoFlush = true };
NativeMessagingEnvironment.RedirectConsoleOutput(writer);

License