Copilot Sdk Nodejs

GitHub Copilot SDK — Node.js / TypeScript

Core Principles

• The SDK is in technical preview and may have breaking changes
• Requires Node.js 18.0 or later
• Requires GitHub Copilot CLI installed and in PATH
• Built with TypeScript for type safety
• Uses async/await patterns throughout
• Provides full TypeScript type definitions

Installation

npm install @github/copilot-sdk
# or
pnpm add @github/copilot-sdk
# or
yarn add @github/copilot-sdk

Client Initialization

Basic Client Setup

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

const client = new CopilotClient();
await client.start();
// Use client...
await client.stop();

Client Configuration Options

CopilotClientOptions:

• cliPath - Path to CLI executable (default: "copilot" from PATH)
• cliArgs - Extra arguments prepended before SDK-managed flags (string[])
• cliUrl - URL of existing CLI server (e.g., "localhost:8080"). When provided, client won't spawn a process
• port - Server port (default: 0 for random)
• useStdio - Use stdio transport instead of TCP (default: true)
• logLevel - Log level (default: "debug")
• autoStart - Auto-start server (default: true)
• autoRestart - Auto-restart on crash (default: true)
• cwd - Working directory for the CLI process (default: process.cwd())
• env - Environment variables for the CLI process (default: process.env)

Manual Server Control

const client = new CopilotClient({ autoStart: false });
await client.start();
// Use client...
await client.stop();

Use forceStop() when stop() takes too long.

Session Management

Creating Sessions

const session = await client.createSession({
    onPermissionRequest: approveAll,
    model: "gpt-5",
    streaming: true,
    tools: [...],
    systemMessage: { ... },
    availableTools: ["tool1", "tool2"],
    excludedTools: ["tool3"],
    provider: { ... }
});

Session Config Options

• sessionId - Custom session ID (string)
• model - Model name ("gpt-5", "claude-sonnet-4.5", etc.)
• tools - Custom tools exposed to the CLI (Tool[])
• systemMessage - System message customization (SystemMessageConfig)
• availableTools - Allowlist of tool names (string[])
• excludedTools - Blocklist of tool names (string[])
• provider - Custom API provider configuration (BYOK) (ProviderConfig)
• streaming - Enable streaming response chunks (boolean)
• mcpServers - MCP server configurations (MCPServerConfig[])
• customAgents - Custom agent configurations (CustomAgentConfig[])
• configDir - Config directory override (string)
• skillDirectories - Skill directories (string[])
• disabledSkills - Disabled skills (string[])
• onPermissionRequest - Permission request handler (PermissionHandler)

Resuming Sessions

const session = await client.resumeSession("session-id", {
  tools: [myNewTool],
  onPermissionRequest: approveAll,
});

Session Operations

• session.sessionId - Get session identifier (string)
• await session.send({ prompt: "...", attachments: [...] }) - Send message, returns Promise\
• await session.sendAndWait({ prompt: "..." }, timeout) - Send and wait for idle, returns Promise\
• await session.abort() - Abort current processing
• await session.getMessages() - Get all events/messages, returns Promise\
• await session.destroy() - Clean up session

Event Handling

Event Subscription Pattern

ALWAYS use async/await or Promises for waiting on session events:

await new Promise((resolve) => {
  session.on((event) => {
    if (event.type === "assistant.message") {
      console.log(event.data.content);
    } else if (event.type === "session.idle") {
      resolve();
    }
  });
  session.send({ prompt: "..." });
});

Unsubscribing from Events

The on() method returns an unsubscribe function:

const unsubscribe = session.on((event) => { /* handler */ });
unsubscribe();

Event Types

Use discriminated unions with type guards:

session.on((event) => {
  switch (event.type) {
    case "user.message": break;
    case "assistant.message": console.log(event.data.content); break;
    case "tool.executionStart": break;
    case "tool.executionComplete": break;
    case "session.start": break;
    case "session.idle": break;
    case "session.error": console.error(event.data.message); break;
  }
});

Streaming Responses

Enable with streaming: true in SessionConfig. Handle both delta and final events:

session.on((event) => {
  switch (event.type) {
    case "assistant.message_delta":
      process.stdout.write(event.data.deltaContent); break;
    case "assistant.reasoning_delta":
      process.stdout.write(event.data.deltaContent); break;
    case "assistant.message":
      console.log(event.data.content); break;
    case "assistant.reasoning":
      console.log(event.data.content); break;
    case "session.idle": break;
  }
});

Final events (assistant.message, assistant.reasoning) are ALWAYS sent regardless of streaming setting.

Custom Tools

defineTool (JSON Schema)

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

defineTool({
  name: "lookup_issue",
  description: "Fetch issue details from tracker",
  parameters: {
    type: "object",
    properties: { id: { type: "string", description: "Issue ID" } },
    required: ["id"],
  },
  handler: async (args) => {
    return await fetchIssue(args.id);
  },
})

defineTool (Zod)

import { z } from "zod";
import { defineTool } from "@github/copilot-sdk";

defineTool({
  name: "get_weather",
  description: "Get weather for a location",
  parameters: z.object({
    location: z.string().describe("City name"),
    units: z.enum(["celsius", "fahrenheit"]).optional(),
  }),
  handler: async (args) => {
    return { temperature: 72, units: args.units || "fahrenheit" };
  },
})

Tool Return Types

• Return any JSON-serializable value (automatically wrapped)
• Or return ToolResultObject for full control:

{ textResultForLlm: string; resultType: "success" | "failure"; error?: string; toolTelemetry?: Record; }

System Message Customization

Append Mode (default — preserves guardrails)

systemMessage: { mode: "append", content: "Additional instructions..." }

Replace Mode (full control — removes guardrails)

systemMessage: { mode: "replace", content: "You are a helpful assistant." }

File Attachments

await session.send({
  prompt: "Analyze this file",
  attachments: [{ type: "file", path: "/path/to/file.ts", displayName: "My File" }],
});

Message Delivery Modes

• "enqueue" - Queue message for processing
• "immediate" - Process message immediately

Multiple Sessions

Sessions are independent and can run concurrently. See [multiple-sessions recipe](references/multiple-sessions.md).

Bring Your Own Key (BYOK)

const session = await client.createSession({
  onPermissionRequest: approveAll,
  provider: { type: "openai", baseUrl: "https://api.openai.com/v1", apiKey: "your-api-key" },
});

Session Lifecycle Management

const sessions = await client.listSessions();           // List all sessions
await client.deleteSession(sessionId);                   // Delete a session
const lastId = await client.getLastSessionId();          // Get last session ID
const state = client.getState();                         // "disconnected" | "connecting" | "connected" | "error"

Resource Cleanup

ALWAYS use try-finally:

const client = new CopilotClient();
try {
  await client.start();
  const session = await client.createSession({ onPermissionRequest: approveAll });
  try {
    // Use session...
  } finally {
    await session.destroy();
  }
} finally {
  await client.stop();
}

Cleanup Helper Pattern

async function withClient(fn: (client: CopilotClient) => Promise): Promise {
  const client = new CopilotClient();
  try { await client.start(); return await fn(client); }
  finally { await client.stop(); }
}

async function withSession(client: CopilotClient, fn: (session: CopilotSession) => Promise): Promise {
  const session = await client.createSession({ onPermissionRequest: approveAll });
  try { return await fn(session); }
  finally { await session.destroy(); }
}

Connectivity Testing

const response = await client.ping("health check");

TypeScript Features

Type Inference

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

session.on((event: SessionEvent) => {
  if (event.type === "assistant.message") {
    const content: string = event.data.content; // narrowed
  }
});

Generic Event Helper

async function waitForEvent(
  session: CopilotSession, eventType: T,
): Promise> {
  return new Promise((resolve) => {
    const unsubscribe = session.on((event) => {
      if (event.type === eventType) { unsubscribe(); resolve(event as any); }
    });
  });
}

Best Practices

1. Always use try-finally for resource cleanup
2. Use Promises to wait for session.idle event
3. Handle session.error events for robust error handling
4. Use type guards or switch statements for event handling
5. Enable streaming for better UX in interactive scenarios
6. Use defineTool for type-safe tool definitions
7. Use Zod schemas for runtime parameter validation
8. Dispose event subscriptions when no longer needed
9. Use systemMessage with mode: "append" to preserve safety guardrails
10. Handle both delta and final events when streaming is enabled
11. Leverage TypeScript types for compile-time safety

Cookbook Recipes

For practical, copy-pasteable examples, see the references:

• [Error Handling](references/error-handling.md): Connection failures, timeouts, abort, graceful shutdown
• [Multiple Sessions](references/multiple-sessions.md): Parallel conversations, custom IDs, listing/deleting
• [Managing Local Files](references/managing-local-files.md): AI-powered file organization by metadata
• [PR Visualization](references/pr-visualization.md): Interactive PR age charts using GitHub MCP Server
• [Persisting Sessions](references/persisting-sessions.md): Save and resume sessions across restarts

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: sinedied
• Source: sinedied/agent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.