JKToolKit.CodexSDK.AgentFramework 0.0.167

Microsoft Agent Framework Adapter

JKToolKit.CodexSDK.AgentFramework makes Codex usable from Microsoft Agent Framework and adapts Agent Framework function tools to Codex app-server dynamic tools.

Use it when you want a Codex-backed AIAgent, or when you already have Agent Framework tools represented as Microsoft.Extensions.AI.AIFunction instances and want Codex app-server to call them through its item/tool/call flow.

NuGet package: JKToolKit.CodexSDK.AgentFramework

Microsoft docs: Agent Framework and function tools.

Install

Install the adapter package into the project that owns your Agent Framework tools:

dotnet add package JKToolKit.CodexSDK.AgentFramework

The adapter package depends on JKToolKit.CodexSDK, Microsoft.Agents.AI, and Microsoft.Extensions.AI.Abstractions.

Usage

Create a Codex-backed Agent Framework agent:

using System.Text.Json;
using JKToolKit.CodexSDK.AgentFramework.Agents;
using JKToolKit.CodexSDK.Models;
using Microsoft.Agents.AI;
using Microsoft.Extensions.AI;

AIFunction getWeather = AIFunctionFactory.Create(
    (Func<string, string>)(location => $"Weather in {location}: cloudy."),
    name: "get_weather",
    description: "Gets the weather for a location.");

AIAgent agent = new CodexAgentClient()
    .AsAIAgent(
        model: "gpt-5.5",
        instructions: "You are a helpful assistant.",
        tools: [getWeather]);

Console.WriteLine(await agent.RunAsync("What is the weather like in Amsterdam?"));

Use sessions for multi-turn conversations:

AgentSession session = await agent.CreateSessionAsync();

Console.WriteLine(await agent.RunAsync("My name is Alice.", session));
Console.WriteLine(await agent.RunAsync("What is my name?", session));

JsonElement serialized = await agent.SerializeSessionAsync(session);
AgentSession resumed = await agent.DeserializeSessionAsync(serialized);

Stream responses:

await foreach (AgentResponseUpdate update in agent.RunStreamingAsync("Order a pizza."))
{
    Console.Write(update.Text);
}

Configure Codex-specific run options:

var runOptions = new CodexAgentRunOptions
{
    Cwd = Environment.CurrentDirectory,
    ApprovalPolicy = CodexApprovalPolicy.Never,
    Sandbox = CodexSandboxMode.ReadOnly
};

Console.WriteLine(await agent.RunAsync("Inspect the current project.", options: runOptions));

The lower-level adapter remains available when you want to manually wire Codex app-server:

using JKToolKit.CodexSDK;
using JKToolKit.CodexSDK.AgentFramework.Tools;
using JKToolKit.CodexSDK.AppServer;
using JKToolKit.CodexSDK.Models;
using Microsoft.Extensions.AI;

AIFunction getWeather = AIFunctionFactory.Create(
    (Func<string, string>)(location => $"Weather in {location}: cloudy."),
    name: "get_weather",
    description: "Gets the weather for a location.");

var agentFrameworkTools = AgentFrameworkCodexToolAdapter.Create([getWeather]);

await using var sdk = CodexSdk.Create(builder =>
{
    builder.ConfigureAppServer(o =>
    {
        o.ExperimentalApi = true;
        o.ApprovalHandler = agentFrameworkTools.ApprovalHandler;
    });
});

await using var codex = await sdk.AppServer.StartAsync();
var thread = await codex.StartThreadAsync(new ThreadStartOptions
{
    Cwd = Environment.CurrentDirectory,
    Sandbox = CodexSandboxMode.ReadOnly,
    ApprovalPolicy = CodexApprovalPolicy.Never,
    DynamicTools = agentFrameworkTools.DynamicTools
});

await using var turn = await codex.StartTurnAsync(thread.Id, new TurnStartOptions
{
    Input = [TurnInputItem.Text("Use the weather tool for Vienna.")]
});

Run the end-to-end pizza demo:

dotnet run --project src/JKToolKit.CodexSDK.Demo -- agent-framework-function-calling --repo "<repo-path>"

The demo inherits the default model from your Codex configuration. To force a model, pass --model <MODEL>, for example:

dotnet run --project src/JKToolKit.CodexSDK.Demo -- agent-framework-function-calling --model gpt-5.5

Notes

• CodexAgentClient().AsAIAgent(...) returns a normal Agent Framework AIAgent, so Agent Framework middleware, workflows, RunAsync<T>, RunStreamingAsync, and AIAgent.AsAIFunction(...) can be used on top of it.
• CodexAgentSession stores the backing Codex thread id. Serialize and deserialize the session through the Agent Framework APIs to resume the same Codex thread later.
• Codex dynamic tools are currently behind the app-server experimental API capability. The native AIAgent surface enables it automatically when tools are present.
• Tool names are the AIFunction.Name values supplied by Agent Framework.
• Agent Framework tools must currently be AIFunction instances. Hosted Agent Framework tools such as provider-native code interpreter, file search, or web search are not translated to Codex dynamic tools.
• Per-run tools can be used when creating a new Codex thread. Once a CodexAgentSession has a thread id, create a new session to use a different tool set.
• Agent Framework ApprovalRequiredAIFunction is callable because it is an AIFunction, but Codex does not yet surface Agent Framework ToolApprovalRequestContent / ToolApprovalResponseContent in the same HITL shape.