.NET: Add AIAgent implementation for GitHub Copilot SDK (#3395)

* Initial plan * Add GitHub Copilot SDK AIAgent implementation with tests Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Add projects to solution and fix sample imports Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Improve pragma comment clarity in GithubCopilotAgentThread Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Address PR feedback: internal constructor/setter, remove CopilotClientOptions ctor, streaming improvements, better sample, container warning Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Add ownsClient parameter to allow caller control over client disposal Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Fix unit tests by removing await using to avoid StreamJsonRpc disposal issues Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Fix file encoding: add UTF-8 BOM to Program.cs Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Fix dotnet-format errors: UTF-8 BOM, remove unused logger, add this qualifier, remove unnecessary usings Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Fix test file encoding and remove redundant cast Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Add AsAIAgent extension methods for CopilotClient with tests Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> * Remove IL suppressions, use TryComplete for channel writer, remove TCS from streaming Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Keep session alive across calls, add tools overload, add tests Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Revert session persistence changes - sessions dispose after each call Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Add CreatedAt property mapping using DateTimeOffset.UtcNow Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Add DataContent handling via temp files and attachments Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Fix formatting: remove extra indentation, simplify Path references, remove unused using Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Refactor: extract helper methods to reduce duplication in DataContent handling Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Updated sample and session config mapping * Added instructions parameter * Updated README * Address PR feedback: reorder params, optimize dictionary, update prefix, remove InternalsVisibleTo, update sample prompts, add defaults Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Remove StreamJsonRpc reference from sample project Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Fix parameter ordering: tools now after description, rename to s_mediaTypeExtensions, simplify extension logic, update prompts, fix test expectations Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Fix streaming prompt: change Python to C# for Fibonacci example Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Handle all SDK events, add UsageContent support, fix model name, remove AutoStart, add using for Channels Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com> * Resolved build errors * Addressed comments * Small fix * Addressed comment * Small fix * Addressed comments * Added integration tests * Small update --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: westey-m <164392973+westey-m@users.noreply.github.com> Co-authored-by: Dmytro Struk <13853051+dmytrostruk@users.noreply.github.com> Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
2026-06-16 21:04:09 +08:00 · 2026-01-27 18:51:56 +00:00
parent 968621e817
commit e82d9f5e45
16 changed files with 1300 additions and 0 deletions
@@ -0,0 +1,73 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Collections.Generic;
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.GithubCopilot;
+using Microsoft.Extensions.AI;
+using Microsoft.Shared.Diagnostics;
+
+namespace GitHub.Copilot.SDK;
+
+/// <summary>
+/// Provides extension methods for <see cref="CopilotClient"/>
+/// to simplify the creation of GitHub Copilot agents.
+/// </summary>
+/// <remarks>
+/// These extensions bridge the gap between GitHub Copilot SDK client objects
+/// and the Microsoft Agent Framework.
+/// <para>
+/// They allow developers to easily create AI agents that can interact
+/// with GitHub Copilot by handling the conversion from Copilot clients to
+/// <see cref="GithubCopilotAgent"/> instances that implement the <see cref="AIAgent"/> interface.
+/// </para>
+/// </remarks>
+public static class CopilotClientExtensions
+{
+    /// <summary>
+    /// Retrieves an instance of <see cref="AIAgent"/> for a GitHub Copilot client.
+    /// </summary>
+    /// <param name="client">The <see cref="CopilotClient"/> to use for the agent.</param>
+    /// <param name="sessionConfig">Optional session configuration for the agent.</param>
+    /// <param name="ownsClient">Whether the agent owns the client and should dispose it. Default is false.</param>
+    /// <param name="id">The unique identifier for the agent.</param>
+    /// <param name="name">The name of the agent.</param>
+    /// <param name="description">The description of the agent.</param>
+    /// <returns>An <see cref="AIAgent"/> instance backed by the GitHub Copilot client.</returns>
+    public static AIAgent AsAIAgent(
+        this CopilotClient client,
+        SessionConfig? sessionConfig = null,
+        bool ownsClient = false,
+        string? id = null,
+        string? name = null,
+        string? description = null)
+    {
+        Throw.IfNull(client);
+
+        return new GithubCopilotAgent(client, sessionConfig, ownsClient, id, name, description);
+    }
+
+    /// <summary>
+    /// Retrieves an instance of <see cref="AIAgent"/> for a GitHub Copilot client.
+    /// </summary>
+    /// <param name="client">The <see cref="CopilotClient"/> to use for the agent.</param>
+    /// <param name="ownsClient">Whether the agent owns the client and should dispose it. Default is false.</param>
+    /// <param name="id">The unique identifier for the agent.</param>
+    /// <param name="name">The name of the agent.</param>
+    /// <param name="description">The description of the agent.</param>
+    /// <param name="tools">The tools to make available to the agent.</param>
+    /// <param name="instructions">Optional instructions to append as a system message.</param>
+    /// <returns>An <see cref="AIAgent"/> instance backed by the GitHub Copilot client.</returns>
+    public static AIAgent AsAIAgent(
+        this CopilotClient client,
+        bool ownsClient = false,
+        string? id = null,
+        string? name = null,
+        string? description = null,
+        IList<AITool>? tools = null,
+        string? instructions = null)
+    {
+        Throw.IfNull(client);
+
+        return new GithubCopilotAgent(client, ownsClient, id, name, description, tools, instructions);
+    }
+}
@@ -0,0 +1,470 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Channels;
+using System.Threading.Tasks;
+using GitHub.Copilot.SDK;
+using Microsoft.Extensions.AI;
+using Microsoft.Shared.Diagnostics;
+
+namespace Microsoft.Agents.AI.GithubCopilot;
+
+/// <summary>
+/// Represents an <see cref="AIAgent"/> that uses the GitHub Copilot SDK to provide agentic capabilities.
+/// </summary>
+public sealed class GithubCopilotAgent : AIAgent, IAsyncDisposable
+{
+    private const string DefaultName = "GitHub Copilot Agent";
+    private const string DefaultDescription = "An AI agent powered by GitHub Copilot";
+
+    private readonly CopilotClient _copilotClient;
+    private readonly string? _id;
+    private readonly string _name;
+    private readonly string _description;
+    private readonly SessionConfig? _sessionConfig;
+    private readonly bool _ownsClient;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="GithubCopilotAgent"/> class.
+    /// </summary>
+    /// <param name="copilotClient">The Copilot client to use for interacting with GitHub Copilot.</param>
+    /// <param name="sessionConfig">Optional session configuration for the agent.</param>
+    /// <param name="ownsClient">Whether the agent owns the client and should dispose it. Default is false.</param>
+    /// <param name="id">The unique identifier for the agent.</param>
+    /// <param name="name">The name of the agent.</param>
+    /// <param name="description">The description of the agent.</param>
+    public GithubCopilotAgent(
+        CopilotClient copilotClient,
+        SessionConfig? sessionConfig = null,
+        bool ownsClient = false,
+        string? id = null,
+        string? name = null,
+        string? description = null)
+    {
+        _ = Throw.IfNull(copilotClient);
+
+        this._copilotClient = copilotClient;
+        this._sessionConfig = sessionConfig;
+        this._ownsClient = ownsClient;
+        this._id = id;
+        this._name = name ?? DefaultName;
+        this._description = description ?? DefaultDescription;
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="GithubCopilotAgent"/> class.
+    /// </summary>
+    /// <param name="copilotClient">The Copilot client to use for interacting with GitHub Copilot.</param>
+    /// <param name="ownsClient">Whether the agent owns the client and should dispose it. Default is false.</param>
+    /// <param name="id">The unique identifier for the agent.</param>
+    /// <param name="name">The name of the agent.</param>
+    /// <param name="description">The description of the agent.</param>
+    /// <param name="tools">The tools to make available to the agent.</param>
+    /// <param name="instructions">Optional instructions to append as a system message.</param>
+    public GithubCopilotAgent(
+        CopilotClient copilotClient,
+        bool ownsClient = false,
+        string? id = null,
+        string? name = null,
+        string? description = null,
+        IList<AITool>? tools = null,
+        string? instructions = null)
+        : this(
+            copilotClient,
+            GetSessionConfig(tools, instructions),
+            ownsClient,
+            id,
+            name,
+            description)
+    {
+    }
+
+    /// <inheritdoc/>
+    public sealed override ValueTask<AgentSession> GetNewSessionAsync(CancellationToken cancellationToken = default)
+        => new(new GithubCopilotAgentSession());
+
+    /// <summary>
+    /// Get a new <see cref="AgentSession"/> instance using an existing session id, to continue that conversation.
+    /// </summary>
+    /// <param name="sessionId">The session id to continue.</param>
+    /// <returns>A new <see cref="AgentSession"/> instance.</returns>
+    public ValueTask<AgentSession> GetNewSessionAsync(string sessionId)
+        => new(new GithubCopilotAgentSession() { SessionId = sessionId });
+
+    /// <inheritdoc/>
+    public override ValueTask<AgentSession> DeserializeSessionAsync(
+        JsonElement serializedSession,
+        JsonSerializerOptions? jsonSerializerOptions = null,
+        CancellationToken cancellationToken = default)
+        => new(new GithubCopilotAgentSession(serializedSession, jsonSerializerOptions));
+
+    /// <inheritdoc/>
+    protected override Task<AgentResponse> RunCoreAsync(
+        IEnumerable<ChatMessage> messages,
+        AgentSession? session = null,
+        AgentRunOptions? options = null,
+        CancellationToken cancellationToken = default)
+        => this.RunCoreStreamingAsync(messages, session, options, cancellationToken).ToAgentResponseAsync(cancellationToken);
+
+    /// <inheritdoc/>
+    protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingAsync(
+        IEnumerable<ChatMessage> messages,
+        AgentSession? session = null,
+        AgentRunOptions? options = null,
+        [EnumeratorCancellation] CancellationToken cancellationToken = default)
+    {
+        _ = Throw.IfNull(messages);
+
+        // Ensure we have a valid session
+        session ??= await this.GetNewSessionAsync(cancellationToken).ConfigureAwait(false);
+        if (session is not GithubCopilotAgentSession typedSession)
+        {
+            throw new InvalidOperationException(
+                $"The provided session type {session.GetType()} is not compatible with the agent. Only GitHub Copilot agent created sessions are supported.");
+        }
+
+        // Ensure the client is started
+        await this.EnsureClientStartedAsync(cancellationToken).ConfigureAwait(false);
+
+        // Create or resume a session with streaming enabled
+        SessionConfig sessionConfig = this._sessionConfig != null
+            ? new SessionConfig
+            {
+                Model = this._sessionConfig.Model,
+                Tools = this._sessionConfig.Tools,
+                SystemMessage = this._sessionConfig.SystemMessage,
+                AvailableTools = this._sessionConfig.AvailableTools,
+                ExcludedTools = this._sessionConfig.ExcludedTools,
+                Provider = this._sessionConfig.Provider,
+                OnPermissionRequest = this._sessionConfig.OnPermissionRequest,
+                McpServers = this._sessionConfig.McpServers,
+                CustomAgents = this._sessionConfig.CustomAgents,
+                SkillDirectories = this._sessionConfig.SkillDirectories,
+                DisabledSkills = this._sessionConfig.DisabledSkills,
+                Streaming = true
+            }
+            : new SessionConfig { Streaming = true };
+
+        CopilotSession copilotSession;
+        if (typedSession.SessionId is not null)
+        {
+            copilotSession = await this._copilotClient.ResumeSessionAsync(
+                typedSession.SessionId,
+                this.CreateResumeConfig(),
+                cancellationToken).ConfigureAwait(false);
+        }
+        else
+        {
+            copilotSession = await this._copilotClient.CreateSessionAsync(sessionConfig, cancellationToken).ConfigureAwait(false);
+            typedSession.SessionId = copilotSession.SessionId;
+        }
+
+        try
+        {
+            Channel<AgentResponseUpdate> channel = Channel.CreateUnbounded<AgentResponseUpdate>();
+
+            // Subscribe to session events
+            using IDisposable subscription = copilotSession.On(evt =>
+            {
+                switch (evt)
+                {
+                    case AssistantMessageDeltaEvent deltaEvent:
+                        channel.Writer.TryWrite(this.ConvertToAgentResponseUpdate(deltaEvent));
+                        break;
+
+                    case AssistantMessageEvent assistantMessage:
+                        channel.Writer.TryWrite(this.ConvertToAgentResponseUpdate(assistantMessage));
+                        break;
+
+                    case AssistantUsageEvent usageEvent:
+                        channel.Writer.TryWrite(this.ConvertToAgentResponseUpdate(usageEvent));
+                        break;
+
+                    case SessionIdleEvent idleEvent:
+                        channel.Writer.TryWrite(this.ConvertToAgentResponseUpdate(idleEvent));
+                        channel.Writer.TryComplete();
+                        break;
+
+                    case SessionErrorEvent errorEvent:
+                        channel.Writer.TryWrite(this.ConvertToAgentResponseUpdate(errorEvent));
+                        channel.Writer.TryComplete(new InvalidOperationException(
+                            $"Session error: {errorEvent.Data?.Message ?? "Unknown error"}"));
+                        break;
+
+                    default:
+                        // Handle all other event types by storing as RawRepresentation
+                        channel.Writer.TryWrite(this.ConvertToAgentResponseUpdate(evt));
+                        break;
+                }
+            });
+
+            List<string> tempFiles = [];
+            try
+            {
+                // Build prompt from text content
+                string prompt = string.Join("\n", messages.Select(m => m.Text));
+
+                // Handle DataContent as attachments
+                List<UserMessageDataAttachmentsItem>? attachments = await ProcessDataContentAttachmentsAsync(
+                    messages,
+                    tempFiles,
+                    cancellationToken).ConfigureAwait(false);
+
+                // Send the message with attachments
+                MessageOptions messageOptions = new() { Prompt = prompt };
+                if (attachments is not null)
+                {
+                    messageOptions.Attachments = [.. attachments];
+                }
+
+                await copilotSession.SendAsync(messageOptions, cancellationToken).ConfigureAwait(false);
+                // Yield updates as they arrive
+                await foreach (AgentResponseUpdate update in channel.Reader.ReadAllAsync(cancellationToken).ConfigureAwait(false))
+                {
+                    yield return update;
+                }
+            }
+            finally
+            {
+                CleanupTempFiles(tempFiles);
+            }
+        }
+        finally
+        {
+            await copilotSession.DisposeAsync().ConfigureAwait(false);
+        }
+    }
+
+    /// <inheritdoc/>
+    protected override string? IdCore => this._id;
+
+    /// <inheritdoc/>
+    public override string Name => this._name;
+
+    /// <inheritdoc/>
+    public override string Description => this._description;
+
+    /// <summary>
+    /// Disposes the agent and releases resources.
+    /// </summary>
+    /// <returns>A value task representing the asynchronous dispose operation.</returns>
+    public async ValueTask DisposeAsync()
+    {
+        if (this._ownsClient)
+        {
+            await this._copilotClient.DisposeAsync().ConfigureAwait(false);
+        }
+    }
+
+    private async Task EnsureClientStartedAsync(CancellationToken cancellationToken)
+    {
+        if (this._copilotClient.State != ConnectionState.Connected)
+        {
+            await this._copilotClient.StartAsync(cancellationToken).ConfigureAwait(false);
+        }
+    }
+
+    private ResumeSessionConfig CreateResumeConfig()
+    {
+        return new ResumeSessionConfig
+        {
+            Tools = this._sessionConfig?.Tools,
+            Provider = this._sessionConfig?.Provider,
+            OnPermissionRequest = this._sessionConfig?.OnPermissionRequest,
+            McpServers = this._sessionConfig?.McpServers,
+            CustomAgents = this._sessionConfig?.CustomAgents,
+            SkillDirectories = this._sessionConfig?.SkillDirectories,
+            DisabledSkills = this._sessionConfig?.DisabledSkills,
+            Streaming = true
+        };
+    }
+
+    private AgentResponseUpdate ConvertToAgentResponseUpdate(AssistantMessageDeltaEvent deltaEvent)
+    {
+        TextContent textContent = new(deltaEvent.Data?.DeltaContent ?? string.Empty)
+        {
+            RawRepresentation = deltaEvent
+        };
+
+        return new AgentResponseUpdate(ChatRole.Assistant, [textContent])
+        {
+            AgentId = this.Id,
+            MessageId = deltaEvent.Data?.MessageId,
+            CreatedAt = deltaEvent.Timestamp
+        };
+    }
+
+    private AgentResponseUpdate ConvertToAgentResponseUpdate(AssistantMessageEvent assistantMessage)
+    {
+        TextContent textContent = new(assistantMessage.Data?.Content ?? string.Empty)
+        {
+            RawRepresentation = assistantMessage
+        };
+
+        return new AgentResponseUpdate(ChatRole.Assistant, [textContent])
+        {
+            AgentId = this.Id,
+            ResponseId = assistantMessage.Data?.MessageId,
+            MessageId = assistantMessage.Data?.MessageId,
+            CreatedAt = assistantMessage.Timestamp
+        };
+    }
+
+    private AgentResponseUpdate ConvertToAgentResponseUpdate(AssistantUsageEvent usageEvent)
+    {
+        UsageDetails usageDetails = new()
+        {
+            InputTokenCount = (int?)(usageEvent.Data?.InputTokens),
+            OutputTokenCount = (int?)(usageEvent.Data?.OutputTokens),
+            TotalTokenCount = (int?)((usageEvent.Data?.InputTokens ?? 0) + (usageEvent.Data?.OutputTokens ?? 0)),
+            CachedInputTokenCount = (int?)(usageEvent.Data?.CacheReadTokens),
+            AdditionalCounts = GetAdditionalCounts(usageEvent),
+        };
+
+        UsageContent usageContent = new(usageDetails)
+        {
+            RawRepresentation = usageEvent
+        };
+
+        return new AgentResponseUpdate(ChatRole.Assistant, [usageContent])
+        {
+            AgentId = this.Id,
+            CreatedAt = usageEvent.Timestamp
+        };
+    }
+
+    private static AdditionalPropertiesDictionary<long>? GetAdditionalCounts(AssistantUsageEvent usageEvent)
+    {
+        if (usageEvent.Data is null)
+        {
+            return null;
+        }
+
+        AdditionalPropertiesDictionary<long>? additionalCounts = null;
+
+        if (usageEvent.Data.CacheWriteTokens is double cacheWriteTokens)
+        {
+            additionalCounts ??= [];
+            additionalCounts[nameof(AssistantUsageData.CacheWriteTokens)] = (long)cacheWriteTokens;
+        }
+
+        if (usageEvent.Data.Cost is double cost)
+        {
+            additionalCounts ??= [];
+            additionalCounts[nameof(AssistantUsageData.Cost)] = (long)cost;
+        }
+
+        if (usageEvent.Data.Duration is double duration)
+        {
+            additionalCounts ??= [];
+            additionalCounts[nameof(AssistantUsageData.Duration)] = (long)duration;
+        }
+
+        return additionalCounts;
+    }
+
+    private AgentResponseUpdate ConvertToAgentResponseUpdate(SessionEvent sessionEvent)
+    {
+        // Handle arbitrary events by storing as RawRepresentation
+        AIContent content = new()
+        {
+            RawRepresentation = sessionEvent
+        };
+
+        return new AgentResponseUpdate(ChatRole.Assistant, [content])
+        {
+            AgentId = this.Id,
+            CreatedAt = sessionEvent.Timestamp
+        };
+    }
+
+    private static SessionConfig? GetSessionConfig(IList<AITool>? tools, string? instructions)
+    {
+        List<AIFunction>? mappedTools = tools is { Count: > 0 } ? tools.OfType<AIFunction>().ToList() : null;
+        SystemMessageConfig? systemMessage = instructions is not null ? new SystemMessageConfig { Mode = SystemMessageMode.Append, Content = instructions } : null;
+
+        if (mappedTools is null && systemMessage is null)
+        {
+            return null;
+        }
+
+        return new SessionConfig { Tools = mappedTools, SystemMessage = systemMessage };
+    }
+
+    private static readonly Dictionary<string, string> s_mediaTypeExtensions = new(StringComparer.OrdinalIgnoreCase)
+    {
+        ["image/png"] = ".png",
+        ["image/jpeg"] = ".jpg",
+        ["image/jpg"] = ".jpg",
+        ["image/gif"] = ".gif",
+        ["image/webp"] = ".webp",
+        ["image/svg+xml"] = ".svg",
+        ["text/plain"] = ".txt",
+        ["text/html"] = ".html",
+        ["text/markdown"] = ".md",
+        ["application/json"] = ".json",
+        ["application/xml"] = ".xml",
+        ["application/pdf"] = ".pdf"
+    };
+
+    private static string GetExtensionForMediaType(string? mediaType)
+    {
+        return mediaType is not null && s_mediaTypeExtensions.TryGetValue(mediaType, out string? extension) ? extension : ".dat";
+    }
+
+    private static async Task<List<UserMessageDataAttachmentsItem>?> ProcessDataContentAttachmentsAsync(
+        IEnumerable<ChatMessage> messages,
+        List<string> tempFiles,
+        CancellationToken cancellationToken)
+    {
+        List<UserMessageDataAttachmentsItem>? attachments = null;
+        foreach (ChatMessage message in messages)
+        {
+            foreach (AIContent content in message.Contents)
+            {
+                if (content is DataContent dataContent)
+                {
+                    // Write DataContent to a temp file
+                    string tempFilePath = Path.Combine(Path.GetTempPath(), $"agentframework_copilot_data_{Guid.NewGuid()}{GetExtensionForMediaType(dataContent.MediaType)}");
+                    await File.WriteAllBytesAsync(tempFilePath, dataContent.Data.ToArray(), cancellationToken).ConfigureAwait(false);
+                    tempFiles.Add(tempFilePath);
+
+                    // Create attachment
+                    attachments ??= [];
+                    attachments.Add(new UserMessageDataAttachmentsItem
+                    {
+                        Type = UserMessageDataAttachmentsItemType.File,
+                        Path = tempFilePath,
+                        DisplayName = Path.GetFileName(tempFilePath)
+                    });
+                }
+            }
+        }
+
+        return attachments;
+    }
+
+    private static void CleanupTempFiles(List<string> tempFiles)
+    {
+        foreach (string tempFile in tempFiles)
+        {
+            try
+            {
+                if (File.Exists(tempFile))
+                {
+                    File.Delete(tempFile);
+                }
+            }
+            catch
+            {
+                // Best effort cleanup
+            }
+        }
+    }
+}
@@ -0,0 +1,55 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Text.Json;
+
+namespace Microsoft.Agents.AI.GithubCopilot;
+
+/// <summary>
+/// Represents a session for a GitHub Copilot agent conversation.
+/// </summary>
+public sealed class GithubCopilotAgentSession : AgentSession
+{
+    /// <summary>
+    /// Gets or sets the session ID for the GitHub Copilot conversation.
+    /// </summary>
+    public string? SessionId { get; internal set; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="GithubCopilotAgentSession"/> class.
+    /// </summary>
+    internal GithubCopilotAgentSession()
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="GithubCopilotAgentSession"/> class from serialized data.
+    /// </summary>
+    /// <param name="serializedThread">The serialized thread data.</param>
+    /// <param name="jsonSerializerOptions">Optional JSON serialization options.</param>
+    internal GithubCopilotAgentSession(JsonElement serializedThread, JsonSerializerOptions? jsonSerializerOptions = null)
+    {
+        // The JSON serialization uses camelCase
+        if (serializedThread.TryGetProperty("sessionId", out JsonElement sessionIdElement))
+        {
+            this.SessionId = sessionIdElement.GetString();
+        }
+    }
+
+    /// <inheritdoc/>
+    public override JsonElement Serialize(JsonSerializerOptions? jsonSerializerOptions = null)
+    {
+        State state = new()
+        {
+            SessionId = this.SessionId
+        };
+
+        return JsonSerializer.SerializeToElement(
+            state,
+            GithubCopilotJsonUtilities.DefaultOptions.GetTypeInfo(typeof(State)));
+    }
+
+    internal sealed class State
+    {
+        public string? SessionId { get; set; }
+    }
+}
@@ -0,0 +1,48 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Diagnostics.CodeAnalysis;
+using System.Text.Encodings.Web;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace Microsoft.Agents.AI.GithubCopilot;
+
+/// <summary>
+/// Provides utility methods and configurations for JSON serialization operations within the GitHub Copilot agent implementation.
+/// </summary>
+internal static partial class GithubCopilotJsonUtilities
+{
+    /// <summary>
+    /// Gets the default <see cref="JsonSerializerOptions"/> instance used for JSON serialization operations.
+    /// </summary>
+    public static JsonSerializerOptions DefaultOptions { get; } = CreateDefaultOptions();
+
+    /// <summary>
+    /// Creates and configures the default JSON serialization options.
+    /// </summary>
+    /// <returns>The configured options.</returns>
+    private static JsonSerializerOptions CreateDefaultOptions()
+    {
+        // Copy the configuration from the source generated context.
+        JsonSerializerOptions options = new(JsonContext.Default.Options)
+        {
+            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+        };
+
+        // Chain in the resolvers from both AgentAbstractionsJsonUtilities and our source generated context.
+        options.TypeInfoResolverChain.Clear();
+        options.TypeInfoResolverChain.Add(AgentAbstractionsJsonUtilities.DefaultOptions.TypeInfoResolver!);
+        options.TypeInfoResolverChain.Add(JsonContext.Default.Options.TypeInfoResolver!);
+
+        options.MakeReadOnly();
+        return options;
+    }
+
+    [JsonSourceGenerationOptions(JsonSerializerDefaults.Web,
+        UseStringEnumConverter = true,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        NumberHandling = JsonNumberHandling.AllowReadingFromString)]
+    [JsonSerializable(typeof(GithubCopilotAgentSession.State))]
+    [ExcludeFromCodeCoverage]
+    private sealed partial class JsonContext : JsonSerializerContext;
+}
@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <VersionSuffix>preview</VersionSuffix>
+    <!-- GitHub.Copilot.SDK only supports .NET 8.0+ -->
+    <TargetFrameworks>$(TargetFrameworksCore)</TargetFrameworks>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <InjectSharedThrow>true</InjectSharedThrow>
+    <InjectDiagnosticClassesOnLegacy>true</InjectDiagnosticClassesOnLegacy>
+  </PropertyGroup>
+
+  <Import Project="$(RepoRoot)/dotnet/nuget/nuget-package.props" />
+
+  <ItemGroup>
+    <ProjectReference Include="..\Microsoft.Agents.AI.Abstractions\Microsoft.Agents.AI.Abstractions.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="GitHub.Copilot.SDK" />
+  </ItemGroup>
+
+  <PropertyGroup>
+    <!-- NuGet Package Settings -->
+    <Title>Microsoft Agent Framework GitHub Copilot</Title>
+    <Description>Provides Microsoft Agent Framework support for GitHub Copilot SDK.</Description>
+  </PropertyGroup>
+
+</Project>