Implement Agent Skills plugin for BotSharp

Directory.Packages.props

@@ -62,6 +62,7 @@
     <PackageVersion Include="Qdrant.Client" Version="1.15.1" />
     <PackageVersion Include="Selenium.WebDriver" Version="4.27.0" />
     <PackageVersion Include="HtmlAgilityPack" Version="1.12.4" />
+    <PackageVersion Include="YamlDotNet" Version="16.3.0" />
     <PackageVersion Include="Microsoft.SemanticKernel.Abstractions" Version="1.67.1" />
     <PackageVersion Include="Microsoft.SemanticKernel.Plugins.Memory" Version="1.16.0-alpha" />
     <PackageVersion Include="Microsoft.VisualStudio.Validation" Version="17.13.22" />

src/Plugins/BotSharp.Plugin.AgentSkills/AgentSkillsPlugin.cs

@@ -0,0 +1,40 @@
+using BotSharp.Abstraction.Agents;
+using BotSharp.Abstraction.Settings;
+using BotSharp.Plugin.AgentSkills.Functions;
+using Microsoft.Extensions.Configuration;
+
+namespace BotSharp.Plugin.AgentSkills;
+
+/// <summary>
+/// Agent Skills plugin for BotSharp.
+/// Enables AI agents to leverage reusable skills following the Agent Skills specification.
+/// </summary>
+public class AgentSkillsPlugin : IBotSharpPlugin
+{
+    public string Id => "a5b3e8c1-7d2f-4a9e-b6c4-8f5d1e2a3b4c";
+    public string Name => "Agent Skills";
+    public string Description => "Enables AI agents to leverage reusable skills following the Agent Skills specification (https://agentskills.io).";
+    public string IconUrl => "https://raw.githubusercontent.com/SciSharp/BotSharp/master/docs/static/logos/BotSharp.png";
+    public string[] AgentIds => [];
+
+    public void RegisterDI(IServiceCollection services, IConfiguration config)
+    {
+        // Register settings
+        services.AddScoped(provider =>
+        {
+            var settingService = provider.GetRequiredService<ISettingService>();
+            return settingService.Bind<AgentSkillsSettings>("AgentSkills");
+        });
+
+        // Register skill loader
+        services.AddScoped<SkillLoader>();
+
+        // Register hooks
+        services.AddScoped<IAgentUtilityHook, AgentSkillsUtilityHook>();
+
+        // Register function callbacks
+        services.AddScoped<IFunctionCallback, ReadSkillFn>();
+        services.AddScoped<IFunctionCallback, ReadSkillFileFn>();
+        services.AddScoped<IFunctionCallback, ListSkillDirectoryFn>();
+    }
+}

src/Plugins/BotSharp.Plugin.AgentSkills/BotSharp.Plugin.AgentSkills.csproj

@@ -0,0 +1,57 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>$(TargetFramework)</TargetFramework>
+    <Nullable>enable</Nullable>
+    <LangVersion>$(LangVersion)</LangVersion>
+    <VersionPrefix>$(BotSharpVersion)</VersionPrefix>
+    <GeneratePackageOnBuild>$(GeneratePackageOnBuild)</GeneratePackageOnBuild>
+    <GenerateDocumentationFile>$(GenerateDocumentationFile)</GenerateDocumentationFile>
+    <OutputPath>$(SolutionDir)packages</OutputPath>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <None Remove="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\functions\skill-read_skill.json" />
+    <None Remove="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\functions\skill-read_skill_file.json" />
+    <None Remove="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\functions\skill-list_skill_directory.json" />
+    <None Remove="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\templates\skill-read_skill.fn.liquid" />
+    <None Remove="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\templates\skill-read_skill_file.fn.liquid" />
+    <None Remove="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\templates\skill-list_skill_directory.fn.liquid" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Include="data\agents\471ca181-375f-b16f-7134-5f868ecd31c6\agent.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="data\agents\471ca181-375f-b16f-7134-5f868ecd31c6\instructions\instruction.liquid">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\functions\skill-read_skill.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\functions\skill-read_skill_file.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\functions\skill-list_skill_directory.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\templates\skill-read_skill.fn.liquid">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\templates\skill-read_skill_file.fn.liquid">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="data\agents\6745151e-6d46-4a02-8de4-1c4f21c7da95\templates\skill-list_skill_directory.fn.liquid">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="YamlDotNet" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\Infrastructure\BotSharp.Core\BotSharp.Core.csproj" />
+  </ItemGroup>
+
+</Project>

src/Plugins/BotSharp.Plugin.AgentSkills/Enums/UtilityName.cs

@@ -0,0 +1,9 @@
+namespace BotSharp.Plugin.AgentSkills.Enums;
+
+/// <summary>
+/// Utility name constants for Agent Skills plugin.
+/// </summary>
+public class UtilityName
+{
+    public const string AgentSkills = "agent-skills";
+}

src/Plugins/BotSharp.Plugin.AgentSkills/Functions/ListSkillDirectoryFn.cs

@@ -0,0 +1,107 @@
+namespace BotSharp.Plugin.AgentSkills.Functions;
+
+/// <summary>
+/// Function that lists contents of a skill's directory.
+/// </summary>
+public class ListSkillDirectoryFn : IFunctionCallback
+{
+    public string Name => "skill-list_skill_directory";
+    public string Indication => "Listing skill directory...";
+
+    private readonly IServiceProvider _services;
+    private readonly ILogger<ListSkillDirectoryFn> _logger;
+    private readonly BotSharpOptions _options;
+
+    public ListSkillDirectoryFn(
+        IServiceProvider services,
+        ILogger<ListSkillDirectoryFn> logger,
+        BotSharpOptions options)
+    {
+        _services = services;
+        _logger = logger;
+        _options = options;
+    }
+
+    public async Task<bool> Execute(RoleDialogModel message)
+    {
+        var args = JsonSerializer.Deserialize<ListSkillDirectoryArgs>(message.FunctionArgs, _options.JsonSerializerOptions);
+        var skillName = args?.SkillName;
+        var relativePath = args?.RelativePath;
+
+        if (string.IsNullOrWhiteSpace(skillName))
+        {
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = false,
+                error = "Skill name is required."
+            }, _options.JsonSerializerOptions);
+            return false;
+        }
+
+        try
+        {
+            var settings = _services.GetRequiredService<AgentSkillsSettings>();
+            var loader = _services.GetRequiredService<SkillLoader>();
+
+            // Load skills and find the requested one
+            var state = loader.LoadSkills(settings);
+            var skill = state.GetSkill(skillName);
+
+            if (skill is null)
+            {
+                message.Content = JsonSerializer.Serialize(new
+                {
+                    success = false,
+                    error = $"Skill '{skillName}' not found."
+                }, _options.JsonSerializerOptions);
+                return false;
+            }
+
+            var entries = loader.ListSkillDirectory(skill, relativePath).ToList();
+
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = true,
+                skill_name = skill.Name,
+                path = relativePath ?? "/",
+                entries = entries.Select(e => new
+                {
+                    name = e.Name,
+                    type = e.IsDirectory ? "directory" : "file",
+                    size = e.Size
+                })
+            }, _options.JsonSerializerOptions);
+
+            return true;
+        }
+        catch (UnauthorizedAccessException ex)
+        {
+            _logger.LogWarning(ex, "Path traversal attempt for skill: {SkillName}", skillName);
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = false,
+                error = "Access denied: path traversal detected."
+            }, _options.JsonSerializerOptions);
+            return false;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to list skill directory: {SkillName}/{Path}", skillName, relativePath);
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = false,
+                error = $"Failed to list directory: {ex.Message}"
+            }, _options.JsonSerializerOptions);
+            return false;
+        }
+    }
+
+    private class ListSkillDirectoryArgs
+    {
+        [JsonPropertyName("skill_name")]
+        public string? SkillName { get; set; }
+
+        [JsonPropertyName("relative_path")]
+        public string? RelativePath { get; set; }
+    }
+}

src/Plugins/BotSharp.Plugin.AgentSkills/Functions/ReadSkillFileFn.cs

@@ -0,0 +1,132 @@
+namespace BotSharp.Plugin.AgentSkills.Functions;
+
+/// <summary>
+/// Function that reads a file within a skill's directory.
+/// </summary>
+public class ReadSkillFileFn : IFunctionCallback
+{
+    public string Name => "skill-read_skill_file";
+    public string Indication => "Reading skill file...";
+
+    private readonly IServiceProvider _services;
+    private readonly ILogger<ReadSkillFileFn> _logger;
+    private readonly BotSharpOptions _options;
+
+    public ReadSkillFileFn(
+        IServiceProvider services,
+        ILogger<ReadSkillFileFn> logger,
+        BotSharpOptions options)
+    {
+        _services = services;
+        _logger = logger;
+        _options = options;
+    }
+
+    public async Task<bool> Execute(RoleDialogModel message)
+    {
+        var args = JsonSerializer.Deserialize<ReadSkillFileArgs>(message.FunctionArgs, _options.JsonSerializerOptions);
+        var skillName = args?.SkillName;
+        var filePath = args?.FilePath;
+
+        if (string.IsNullOrWhiteSpace(skillName))
+        {
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = false,
+                error = "Skill name is required."
+            }, _options.JsonSerializerOptions);
+            return false;
+        }
+
+        if (string.IsNullOrWhiteSpace(filePath))
+        {
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = false,
+                error = "File path is required."
+            }, _options.JsonSerializerOptions);
+            return false;
+        }
+
+        try
+        {
+            var settings = _services.GetRequiredService<AgentSkillsSettings>();
+            var loader = _services.GetRequiredService<SkillLoader>();
+
+            // Load skills and find the requested one
+            var state = loader.LoadSkills(settings);
+            var skill = state.GetSkill(skillName);
+
+            if (skill is null)
+            {
+                message.Content = JsonSerializer.Serialize(new
+                {
+                    success = false,
+                    error = $"Skill '{skillName}' not found."
+                }, _options.JsonSerializerOptions);
+                return false;
+            }
+
+            var content = loader.ReadSkillFile(skill, filePath);
+
+            // Truncate if necessary
+            var maxSize = settings.MaxOutputSizeBytes;
+            var originalLength = content.Length;
+            var truncated = content.Length > maxSize;
+            if (truncated)
+            {
+                content = content.Substring(0, maxSize);
+            }
+
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = true,
+                skill_name = skill.Name,
+                file_path = filePath,
+                content,
+                truncated,
+                total_length = originalLength
+            }, _options.JsonSerializerOptions);
+
+            return true;
+        }
+        catch (UnauthorizedAccessException ex)
+        {
+            _logger.LogWarning(ex, "Path traversal attempt for skill: {SkillName}", skillName);
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = false,
+                error = "Access denied: path traversal detected."
+            }, _options.JsonSerializerOptions);
+            return false;
+        }
+        catch (FileNotFoundException)
+        {
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = false,
+                error = $"File not found: {filePath}"
+            }, _options.JsonSerializerOptions);
+            return false;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to read skill file: {SkillName}/{FilePath}", skillName, filePath);
+            message.Content = JsonSerializer.Serialize(new
+            {
+                success = false,
+                error = $"Failed to read file: {ex.Message}"
+            }, _options.JsonSerializerOptions);
+            return false;
+        }
+    }
+
+    private class ReadSkillFileArgs
+    {
+        [JsonPropertyName("skill_name")]
+        public string? SkillName { get; set; }
+
+        [JsonPropertyName("file_path")]
+        public string? FilePath { get; set; }
+    }
+}