GitHub Copilot SDK Skill

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

Language-Specific SDK Docs

CLI and Configuration Docs

Prerequisites

GitHub Copilot Subscription - Pro, Pro+, Business, or Enterprise
GitHub Copilot CLI - Installed and authenticated (copilot --version)
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.

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.

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.

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.

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.

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.

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.

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

Agent Skills: GitHub Copilot SDK

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