Skgen 0.0.10

What this package does

This is a source generator which finds Semantic Kernel plugins and generates helper static extension methods for calling them with all the right inputs.

Semantic Kernel plugins

Semantic Kernel plugins are stringly-typed, and it's easy to forget a variable or two when calling them:

A typical Semantic Kernel project defines its prompt-based plugins in a folder called Plugins:

.
├── Plugins/
│   ├── Summarize/
│   │   └── SummarizeText/
│   │       ├── config.json
│   │       └── skprompt.txt
│   └── Assistant/
│       └── GetResponse/
│           ├── config.json
│           └── skprompt.txt
└── Program.cs

A typical config.json file looks like this:

{
  "schema": 1,
  "type": "completion",
  "description": "Gives helpful responses using snippets of relevant information",
  "completion": {
    "max_tokens": 500,
    "temperature": 0.5,
    "top_p": 0.0,
    "presence_penalty": 0.0,
    "frequency_penalty": 0.0
  },
  "input": {
    "parameters": [
      {
        "name": "prompt",
        "description": "The user's prompt",
        "defaultValue": ""
      },
      {
        "name": "snippet0",
        "description": "The most relevant snippet found from documents",
        "defaultValue": ""
      },
      {
        "name": "snippet1",
        "description": "The second most relevant snippet found from documents",
        "defaultValue": ""
      },
      {
        "name": "snippet2",
        "description": "The third most relevant snippet found from documents",
        "defaultValue": ""
      }
    ]
  }
}

This source generator goes through and finds every file called config.json and generates static extension methods for Microsoft.SemanticKernel.Kernel that look like this:

// <auto-generated/>
using System;
using Microsoft.SemanticKernel;

namespace Skgen;

public static partial class KernelExtensionMethods
{
    
    public static async Task<FunctionResult> AssistantGetResponseAsync(this Kernel kernel, string prompt = "", string snippet0 = "", string snippet1 = "", string snippet2 = "", CancellationToken cancellationToken = default(CancellationToken))
    {
        var arguments = new KernelArguments();
        arguments["prompt"] = prompt;
		arguments["snippet0"] = snippet0;
		arguments["snippet1"] = snippet1;
		arguments["snippet2"] = snippet2;
    
        var answer = await kernel.InvokeAsync("Assistant", "GetResponse", arguments, cancellationToken);
        return answer;
    }

    public static async Task<FunctionResult> SummarizeSummarizeWithContextAsync(this Kernel kernel, string input = "", string fact1 = "", string fact2 = "", string fact3 = "", CancellationToken cancellationToken = default(CancellationToken))
    {
        var arguments = new KernelArguments();
        arguments["input"] = input;
		arguments["fact1"] = fact1;
		arguments["fact2"] = fact2;
		arguments["fact3"] = fact3;
    
        var answer = await kernel.InvokeAsync("Summarize", "SummarizeWithContext", arguments, cancellationToken);
        return answer;
    }
}

Getting started

Install the package

dotnet add package Skgen

Adjust your package's csproj

By default, the source generated code is not persisted to disk. In order to persist it to a file called Generated, you can add this to your csproj:

<PropertyGroup>
        <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
        <CompilerGeneratedFilesOutputPath>Generated</CompilerGeneratedFilesOutputPath>
</PropertyGroup>

<ItemGroup>
    <Compile Remove="$(CompilerGeneratedFilesOutputPath)/**/*.cs" />
</ItemGroup>

Thank you to Andrew Lock for describing this solution!

Reasoning

The point of <Compile Remove="$(CompilerGeneratedFilesOutputPath)/**/*.cs" /> is to avoid compiling the source generated files after they have been spit out to disk and hence double compiling the same thing and hitting errors like this `Error CS0111: Type 'KernelExtensionMethods' already defines a member called '' with the same parameters.

Drawbacks

Despite my best effort, I haven't gotten intellisense in Rider, Visual Studio or Visual Studio code to respect these new extension methods without removing <Compile Remove="$(CompilerGeneratedFilesOutputPath)/**/*.cs" /> and hence breaking compilation when you build the second time😔. If you figure this out, please let me know!