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

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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