copilot-sdk

name	copilot-sdk
description	Build agentic applications with GitHub Copilot SDK. Use when embedding AI agents in apps, creating custom tools, implementing streaming responses, managing sessions, connecting to MCP servers, or creating custom agents. Triggers on Copilot SDK, GitHub SDK, agentic app, embed Copilot, programmable agent, MCP server, custom agent.
tags	["copilot-sdk","sdk","csharp","go","nodejs","typescript","python","ai","github-copilot"]

GitHub Copilot SDK

Embed Copilot's agentic workflows in any application using Python, TypeScript, Go, or .NET.

Overview

The GitHub Copilot SDK exposes the same engine behind Copilot CLI: a production-tested agent runtime you can invoke programmatically. No need to build your own orchestration - you define agent behavior, Copilot handles planning, tool invocation, file edits, and more.

Prerequisites

1. GitHub Copilot CLI installed and authenticated (Installation guide)
2. Language runtime: Node.js 18+, Python 3.8+, Go 1.21+, or .NET 8.0+

Verify CLI: copilot --version

Installation

Node.js/TypeScript

mkdir copilot-demo && cd copilot-demo
npm init -y --init-type module
npm install @github/copilot-sdk tsx

Python

pip install github-copilot-sdk

Go

mkdir copilot-demo && cd copilot-demo
go mod init copilot-demo
go get github.com/github/copilot-sdk/go

.NET

dotnet new console -n CopilotDemo && cd CopilotDemo
dotnet add package GitHub.Copilot.SDK

Quick Start

TypeScript

import { CopilotClient } from "@github/copilot-sdk";

const client = new CopilotClient();
const session = await client.createSession({ model: "gpt-4.1" });

const response = await session.sendAndWait({ prompt: "What is 2 + 2?" });
console.log(response?.data.content);

await client.stop();
process.exit(0);

Run: npx tsx index.ts

Python

import asyncio
from copilot import CopilotClient

async def main():
    client = CopilotClient()
    await client.start()

    session = await client.create_session({"model": "gpt-4.1"})
    response = await session.send_and_wait({"prompt": "What is 2 + 2?"})

    print(response.data.content)
    await client.stop()

asyncio.run(main())

Go

package main

import (
    "fmt"
    "log"
    "os"
    copilot "github.com/github/copilot-sdk/go"
)

func main() {
    client := copilot.NewClient(nil)
    if err := client.Start(); err != nil {
        log.Fatal(err)
    }
    defer client.Stop()

    session, err := client.CreateSession(&copilot.SessionConfig{Model: "gpt-4.1"})
    if err != nil {
        log.Fatal(err)
    }

    response, err := session.SendAndWait(copilot.MessageOptions{Prompt: "What is 2 + 2?"}, 0)
    if err != nil {
        log.Fatal(err)
    }

    fmt.Println(*response.Data.Content)
    os.Exit(0)
}

.NET (C#)

using GitHub.Copilot.SDK;

await using var client = new CopilotClient();
await using var session = await client.CreateSessionAsync(new SessionConfig { Model = "gpt-4.1" });

var response = await session.SendAndWaitAsync(new MessageOptions { Prompt = "What is 2 + 2?" });
Console.WriteLine(response?.Data.Content);

Run: dotnet run

Streaming Responses

Enable real-time output for better UX:

TypeScript

import { CopilotClient, SessionEvent } from "@github/copilot-sdk";

const client = new CopilotClient();
const session = await client.createSession({
    model: "gpt-4.1",
    streaming: true,
});

session.on((event: SessionEvent) => {
    if (event.type === "assistant.message_delta") {
        process.stdout.write(event.data.deltaContent);
    }
    if (event.type === "session.idle") {
        console.log(); // New line when done
    }
});

await session.sendAndWait({ prompt: "Tell me a short joke" });

await client.stop();
process.exit(0);

Python

import asyncio
import sys
from copilot import CopilotClient
from copilot.generated.session_events import SessionEventType

async def main():
    client = CopilotClient()
    await client.start()

    session = await client.create_session({
        "model": "gpt-4.1",
        "streaming": True,
    })

    def handle_event(event):
        if event.type == SessionEventType.ASSISTANT_MESSAGE_DELTA:
            sys.stdout.write(event.data.delta_content)
            sys.stdout.flush()
        if event.type == SessionEventType.SESSION_IDLE:
            print()

    session.on(handle_event)
    await session.send_and_wait({"prompt": "Tell me a short joke"})
    await client.stop()

asyncio.run(main())

Go

session, err := client.CreateSession(&copilot.SessionConfig{
    Model:     "gpt-4.1",
    Streaming: true,
})

session.On(func(event copilot.SessionEvent) {
    if event.Type == "assistant.message_delta" {
        fmt.Print(*event.Data.DeltaContent)
    }
    if event.Type == "session.idle" {
        fmt.Println()
    }
})

_, err = session.SendAndWait(copilot.MessageOptions{Prompt: "Tell me a short joke"}, 0)

.NET

await using var session = await client.CreateSessionAsync(new SessionConfig
{
    Model = "gpt-4.1",
    Streaming = true,
});

session.On(ev =>
{
    if (ev is AssistantMessageDeltaEvent deltaEvent)
        Console.Write(deltaEvent.Data.DeltaContent);
    if (ev is SessionIdleEvent)
        Console.WriteLine();
});

await session.SendAndWaitAsync(new MessageOptions { Prompt = "Tell me a short joke" });

Custom Tools

Define tools that Copilot can invoke during reasoning. When you define a tool, you tell Copilot:

1. What the tool does (description)
2. What parameters it needs (schema)
3. What code to run (handler)

TypeScript (JSON Schema)

import { CopilotClient, defineTool, SessionEvent } from "@github/copilot-sdk";

const getWeather = defineTool("get_weather", {
    description: "Get the current weather for a city",
    parameters: {
        type: "object",
        properties: {
            city: { type: "string", description: "The city name" },
        },
        required: ["city"],
    },
    handler: async (args: { city: string }) => {
        const { city } = args;
        // In a real app, call a weather API here
        const conditions = ["sunny", "cloudy", "rainy", "partly cloudy"];
        const temp = Math.floor(Math.random() * 30) + 50;
        const condition = conditions[Math.floor(Math.random() * conditions.length)];
        return { city, temperature: `${temp}°F`, condition };
    },
});

 client =  ();
 session =  client.({
    : ,
    : ,
    : [getWeather],
});

session.( {
     (event. === ) {
        process..(event..);
    }
});

 session.({
    : ,
});

 client.();
process.();

Python (Pydantic)

import asyncio
import random
import sys
from copilot import CopilotClient
from copilot.tools import define_tool
from copilot.generated.session_events import SessionEventType
from pydantic import BaseModel, Field

class GetWeatherParams(BaseModel):
    city: str = Field(description="The name of the city to get weather for")

@define_tool(description="Get the current weather for a city")
async def get_weather(params: GetWeatherParams) -> dict:
    city = params.city
    conditions = ["sunny", "cloudy", "rainy", "partly cloudy"]
    temp = random.randint(50, 80)
    condition = random.choice(conditions)
    return {"city": city, "temperature": f"{temp}°F", "condition": condition}

async def main():
    client = CopilotClient()
    await client.start()

    session = await client.create_session({
        "model": "gpt-4.1",
        "streaming": True,
        "tools": [get_weather],
    })

    def ():
         event. == SessionEventType.ASSISTANT_MESSAGE_DELTA:
            sys.stdout.write(event.data.delta_content)
            sys.stdout.flush()

    session.on(handle_event)

     session.send_and_wait({
        : 
    })

     client.stop()

asyncio.run(main())

Go

type WeatherParams struct {
    City string `json:"city" jsonschema:"The city name"`
}

type WeatherResult struct {
    City        string `json:"city"`
    Temperature string `json:"temperature"`
    Condition   string `json:"condition"`
}

getWeather := copilot.DefineTool(
    "get_weather",
    "Get the current weather for a city",
    func(params WeatherParams, inv copilot.ToolInvocation) (WeatherResult, error) {
        conditions := []string{"sunny", "cloudy", "rainy", "partly cloudy"}
        temp := rand.Intn(30) + 50
        condition := conditions[rand.Intn(len(conditions))]
        return WeatherResult{
            City:        params.City,
            Temperature: fmt.Sprintf("%d°F", temp),
            Condition:   condition,
        }, nil
    },
)

session, _ := client.CreateSession(&copilot.SessionConfig{
    Model:     "gpt-4.1",
    Streaming: true,
    Tools:     []copilot.Tool{getWeather},
})

.NET (Microsoft.Extensions.AI)

using GitHub.Copilot.SDK;
using Microsoft.Extensions.AI;
using System.ComponentModel;

var getWeather = AIFunctionFactory.Create(
    ([Description("The city name")] string city) =>
    {
        var conditions = new[] { "sunny", "cloudy", "rainy", "partly cloudy" };
        var temp = Random.Shared.Next(50, 80);
        var condition = conditions[Random.Shared.Next(conditions.Length)];
        return new { city, temperature = $"{temp}°F", condition };
    },
    "get_weather",
    "Get the current weather for a city"
);

await using var session = await client.CreateSessionAsync(new SessionConfig
{
    Model = "gpt-4.1",
    Streaming = true,
    Tools = [getWeather],
});

How Tools Work

When Copilot decides to call your tool:

1. Copilot sends a tool call request with the parameters
2. The SDK runs your handler function
3. The result is sent back to Copilot
4. Copilot incorporates the result into its response

Copilot decides when to call your tool based on the user's question and your tool's description.

Interactive CLI Assistant

Build a complete interactive assistant:

TypeScript

import { CopilotClient, defineTool, SessionEvent } from "@github/copilot-sdk";
import * as readline from "readline";

const getWeather = defineTool("get_weather", {
    description: "Get the current weather for a city",
    parameters: {
        type: "object",
        properties: {
            city: { type: "string", description: "The city name" },
        },
        required: ["city"],
    },
    handler: async ({ city }) => {
        const conditions = ["sunny", "cloudy", "rainy", "partly cloudy"];
        const temp = Math.floor(Math.random() * 30) + 50;
        const condition = conditions[Math.floor(Math.random() * conditions.length)];
        return { city, temperature: `${temp}°F`, condition };
    },
});

const client =  ();
 session =  client.({
    : ,
    : ,
    : [getWeather],
});

session.( {
     (event. === ) {
        process..(event..);
    }
});

 rl = readline.({
    : process.,
    : process.,
});

.();
.();

  = () => {
    rl.(,  (input) => {
         (input.() === ) {
             client.();
            rl.();
            ;
        }

        process..();
         session.({ : input });
        .();
        ();
    });
};

();

Python

import asyncio
import random
import sys
from copilot import CopilotClient
from copilot.tools import define_tool
from copilot.generated.session_events import SessionEventType
from pydantic import BaseModel, Field

class GetWeatherParams(BaseModel):
    city: str = Field(description="The name of the city to get weather for")

@define_tool(description="Get the current weather for a city")
async def get_weather(params: GetWeatherParams) -> dict:
    conditions = ["sunny", "cloudy", "rainy", "partly cloudy"]
    temp = random.randint(50, 80)
    condition = random.choice(conditions)
    return {"city": params.city, "temperature": f"{temp}°F", "condition": condition}

async def main():
    client = CopilotClient()
    await client.start()

    session = await client.create_session({
        "model": "gpt-4.1",
        "streaming": True,
        "tools": [get_weather],
    })

    def ():
         event. == SessionEventType.ASSISTANT_MESSAGE_DELTA:
            sys.stdout.write(event.data.delta_content)
            sys.stdout.flush()

    session.on(handle_event)

    ()
    ()

     :
        :
            user_input = ()
         EOFError:
            

         user_input.lower() == :
            

        sys.stdout.write()
         session.send_and_wait({: user_input})
        ()

     client.stop()

asyncio.run(main())

MCP Server Integration

Connect to MCP (Model Context Protocol) servers for pre-built tools. Connect to GitHub's MCP server for repository, issue, and PR access:

TypeScript

const session = await client.createSession({
    model: "gpt-4.1",
    mcpServers: {
        github: {
            type: "http",
            url: "https://api.githubcopilot.com/mcp/",
        },
    },
});

Python

session = await client.create_session({
    "model": "gpt-4.1",
    "mcp_servers": {
        "github": {
            "type": "http",
            "url": "https://api.githubcopilot.com/mcp/",
        },
    },
})

Go

session, _ := client.CreateSession(&copilot.SessionConfig{
    Model: "gpt-4.1",
    MCPServers: map[string]copilot.MCPServerConfig{
        "github": {
            Type: "http",
            URL:  "https://api.githubcopilot.com/mcp/",
        },
    },
})

.NET

await using var session = await client.CreateSessionAsync(new SessionConfig
{
    Model = "gpt-4.1",
    McpServers = new Dictionary<string, McpServerConfig>
    {
        ["github"] = new McpServerConfig
        {
            Type = "http",
            Url = "https://api.githubcopilot.com/mcp/",
        },
    },
});

Custom Agents

Define specialized AI personas for specific tasks:

TypeScript

const session = await client.createSession({
    model: "gpt-4.1",
    customAgents: [{
        name: "pr-reviewer",
        displayName: "PR Reviewer",
        description: "Reviews pull requests for best practices",
        prompt: "You are an expert code reviewer. Focus on security, performance, and maintainability.",
    }],
});

Python

session = await client.create_session({
    "model": "gpt-4.1",
    "custom_agents": [{
        "name": "pr-reviewer",
        "display_name": "PR Reviewer",
        "description": "Reviews pull requests for best practices",
        "prompt": "You are an expert code reviewer. Focus on security, performance, and maintainability.",
    }],
})

System Message

Customize the AI's behavior and personality:

TypeScript

const session = await client.createSession({
    model: "gpt-4.1",
    systemMessage: {
        content: "You are a helpful assistant for our engineering team. Always be concise.",
    },
});

Python

session = await client.create_session({
    "model": "gpt-4.1",
    "system_message": {
        "content": "You are a helpful assistant for our engineering team. Always be concise.",
    },
})

External CLI Server

Run the CLI in server mode separately and connect the SDK to it. Useful for debugging, resource sharing, or custom environments.

Start CLI in Server Mode

copilot --server --port 4321

Connect SDK to External Server

TypeScript

const client = new CopilotClient({
    cliUrl: "localhost:4321"
});

const session = await client.createSession({ model: "gpt-4.1" });

Python

client = CopilotClient({
    "cli_url": "localhost:4321"
})
await client.start()

session = await client.create_session({"model": "gpt-4.1"})

Go

client := copilot.NewClient(&copilot.ClientOptions{
    CLIUrl: "localhost:4321",
})

if err := client.Start(); err != nil {
    log.Fatal(err)
}

session, _ := client.CreateSession(&copilot.SessionConfig{Model: "gpt-4.1"})

.NET

using var client = new CopilotClient(new CopilotClientOptions
{
    CliUrl = "localhost:4321"
});

await using var session = await client.CreateSessionAsync(new SessionConfig { Model = "gpt-4.1" });

Note: When cliUrl is provided, the SDK will not spawn or manage a CLI process - it only connects to the existing server.

Event Types

Event	Description
user.message	User input added
assistant.message	Complete model response
assistant.message_delta	Streaming response chunk
assistant.reasoning	Model reasoning (model-dependent)
assistant.reasoning_delta	Streaming reasoning chunk
tool.execution_start	Tool invocation started
tool.execution_complete	Tool execution finished
session.idle	No active processing
session.error	Error occurred

Client Configuration

Option	Description	Default
cliPath	Path to Copilot CLI executable	System PATH
cliUrl	Connect to existing server (e.g., "localhost:4321")	None
port	Server communication port	Random
useStdio	Use stdio transport instead of TCP	true
logLevel	Logging verbosity	"info"
autoStart	Launch server automatically	true
autoRestart	Restart on crashes	true
cwd	Working directory for CLI process	Inherited

Session Configuration

Option	Description
model	LLM to use ("gpt-4.1", "claude-sonnet-4.5", etc.)
sessionId	Custom session identifier
tools	Custom tool definitions
mcpServers	MCP server connections
customAgents	Custom agent personas
systemMessage	Override default system prompt
streaming	Enable incremental response chunks
availableTools	Whitelist of permitted tools
excludedTools	Blacklist of disabled tools

Session Persistence

Save and resume conversations across restarts:

Create with Custom ID

const session = await client.createSession({
    sessionId: "user-123-conversation",
    model: "gpt-4.1"
});

Resume Session

const session = await client.resumeSession("user-123-conversation");
await session.send({ prompt: "What did we discuss earlier?" });

List and Delete Sessions

const sessions = await client.listSessions();
await client.deleteSession("old-session-id");

Error Handling

try {
    const client = new CopilotClient();
    const session = await client.createSession({ model: "gpt-4.1" });
    const response = await session.sendAndWait(
        { prompt: "Hello!" },
        30000 // timeout in ms
    );
} catch (error) {
    if (error.code === "ENOENT") {
        console.error("Copilot CLI not installed");
    } else if (error.code === "ECONNREFUSED") {
        console.error("Cannot connect to Copilot server");
    } else {
        console.error("Error:", error.message);
    }
} finally {
    await client.stop();
}

Graceful Shutdown

process.on("SIGINT", async () => {
    console.log("Shutting down...");
    await client.stop();
    process.exit(0);
});

Common Patterns

Multi-turn Conversation

const session = await client.createSession({ model: "gpt-4.1" });

await session.sendAndWait({ prompt: "My name is Alice" });
await session.sendAndWait({ prompt: "What's my name?" });
// Response: "Your name is Alice"

File Attachments

await session.send({
    prompt: "Analyze this file",
    attachments: [{
        type: "file",
        path: "./data.csv",
        displayName: "Sales Data"
    }]
});

Abort Long Operations

const timeoutId = setTimeout(() => {
    session.abort();
}, 60000);

session.on((event) => {
    if (event.type === "session.idle") {
        clearTimeout(timeoutId);
    }
});

Available Models

Query available models at runtime:

const models = await client.getModels();
// Returns: ["gpt-4.1", "gpt-4o", "claude-sonnet-4.5", ...]

Best Practices

1. Always cleanup: Use try-finally or defer to ensure client.stop() is called
2. Set timeouts: Use sendAndWait with timeout for long operations
3. Handle events: Subscribe to error events for robust error handling
4. Use streaming: Enable streaming for better UX on long responses
5. Persist sessions: Use custom session IDs for multi-turn conversations
6. Define clear tools: Write descriptive tool names and descriptions

Architecture

Your Application
       |
  SDK Client
       | JSON-RPC
  Copilot CLI (server mode)
       |
  GitHub (models, auth)

The SDK manages the CLI process lifecycle automatically. All communication happens via JSON-RPC over stdio or TCP.

Resources

• GitHub Repository: https://github.com/github/copilot-sdk
• Getting Started Tutorial: https://github.com/github/copilot-sdk/blob/main/docs/tutorials/first-app.md
• GitHub MCP Server: https://github.com/github/github-mcp-server
• MCP Servers Directory: https://github.com/modelcontextprotocol/servers
• Cookbook: https://github.com/github/copilot-sdk/tree/main/cookbook
• Samples: https://github.com/github/copilot-sdk/tree/main/samples

Status

This SDK is in Technical Preview and may have breaking changes. Not recommended for production use yet.