copilot-sdk

name	copilot-sdk
description	This skill provides guidance for creating agents and applications with the GitHub Copilot SDK. It should be used when the user wants to create, modify, or work on software that uses the GitHub Copilot SDK in TypeScript, Python, Go, or .NET. The skill covers SDK usage patterns, CLI configuration, custom tools, MCP servers, and custom agents.

GitHub Copilot SDK

Overview

The GitHub Copilot SDK is a multi-platform agent runtime that embeds Copilot's agentic workflows into applications. It exposes the same engine behind Copilot CLI, enabling programmatic invocation without requiring custom orchestration development.

Status: Technical Preview (suitable for development and testing)

Supported Languages: TypeScript/Node.js, Python, Go, .NET

Primary Documentation

• GitHub Copilot SDK Repository
• Getting Started Guide
• Cookbook with Recipes

Language-Specific SDK Docs

• Node.js/TypeScript SDK
• Python SDK
• Go SDK
• .NET SDK

CLI and Configuration Docs

• About GitHub Copilot CLI
• Using GitHub Copilot CLI
• Creating Custom Agents
• Custom Agents Configuration Reference
• Enhancing Agent Mode with MCP
• Supported AI Models

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Prerequisites

1. GitHub Copilot Subscription - Pro, Pro+, Business, or Enterprise
2. GitHub Copilot CLI - Installed and authenticated (copilot --version)
3. Runtime: Node.js 18+, Python 3.8+, Go 1.21+, or .NET 8.0+

Installation

Language	Command
TypeScript/Node.js	npm install @github/copilot-sdk
Python	pip install github-copilot-sdk
Go	go get github.com/github/copilot-sdk/go
.NET	dotnet add package GitHub.Copilot.SDK

Architecture

Application → SDK Client → JSON-RPC → Copilot CLI (server mode)

The SDK manages CLI lifecycle automatically. External server connections supported via cliUrl / cli_url.

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Quick Start (TypeScript)

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

const client = new CopilotClient();
await client.start();

const session = await client.createSession({ model: "gpt-5" });

// Register handler BEFORE send()
session.on((event) => {
  if (event.type === "assistant.message") {
    console.log(event.data.content);
  }
});

await session.send({ prompt: "What is 2 + 2?" });

await session.destroy();
await client.stop();

Critical: Register event handlers before calling send() to capture all events.

For complete examples in all languages, see references/working-examples.md.

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Core Concepts

Client

Main entry point. Manages CLI server lifecycle and session creation.

Operations: start(), stop(), createSession(), resumeSession()

Config: cliPath, cliUrl, port, useStdio, autoStart, autoRestart

Session

Individual conversation context with message history.

Operations: send(), sendAndWait(), on(), abort(), getMessages(), destroy()

Config: model, streaming, tools, systemMessage

Events

Key events during processing:

Event	Purpose
assistant.message	Complete response
assistant.message_delta	Streaming chunk
session.idle	Ready for next prompt
tool.execution_start/end	Tool invocations

For full event lifecycle and SessionEvent structure, see references/event-system.md.

Streaming

• streaming: false (default) - Content arrives all at once
• streaming: true - Content arrives incrementally via assistant.message_delta

Final assistant.message always fires regardless of streaming setting.

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Available Models

See Supported AI Models for full list.

Provider	Model ID	Notes
OpenAI	gpt-4.1, gpt-5, gpt-5-mini	Included
OpenAI	gpt-5.1, gpt-5.1-codex, gpt-5.2	Premium
Anthropic	claude-sonnet-4.5	Premium (CLI default)
Anthropic	claude-opus-4.5	Premium (3× multiplier)
Google	gemini-3-pro-preview	Premium

---

Custom Tools

TypeScript (Zod):

const tool = defineTool("lookup_issue", {
  description: "Fetch issue details",
  parameters: z.object({ id: z.string() }),
  handler: async ({ id }) => fetchIssue(id),
});

Python (Pydantic):

@define_tool(description="Fetch issue details")
async def lookup_issue(params: IssueParams) -> dict:
    return fetch_issue(params.id)

For complete tool examples in all languages, see references/working-examples.md.

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Language Conventions

Concept	TypeScript	Python	Go	.NET
Create session	createSession()	create_session()	CreateSession()	CreateSessionAsync()
Delta content	deltaContent	delta_content	DeltaContent	DeltaContent

For full conventions table, see references/event-system.md.

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CLI Configuration

Config stored in ~/.copilot/:

• config.json - General configuration
• mcp-config.json - MCP server definitions

For custom agents and MCP setup, see references/cli-agents-mcp.md.

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Troubleshooting

Problem	Solution
Events fire but content empty	Use event.data.content, not event.content
Handler never fires	Register before send()
Python enum issues	Use event.type.value
Go nil pointer	Check != nil before dereferencing

For debugging techniques, see references/troubleshooting.md.

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Skill References

Detailed documentation in this skill:

• references/working-examples.md - Complete examples for all languages, custom tools
• references/event-system.md - Event lifecycle, SessionEvent structure, language conventions
• references/troubleshooting.md - Common issues, debugging techniques
• references/cli-agents-mcp.md - CLI configuration, custom agents, MCP server setup

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Additional Resources

• SDK Samples
• SDK Releases
• Cookbook
• awesome-copilot