The Copilot Agent SDK enables the development of custom AI agents for GitHub Copilot. This allows you to extend Copilot with your business logic.

What is the Copilot Agent SDK?

The SDK is a framework for creating:

• Custom Agents – Specialized AI assistants
• Tool Integrations – Connect external systems
• Workflow Automation – Automate complex processes
• Domain Experts – Incorporate industry-specific knowledge

Architecture Overview

Components

[GitHub Copilot] ←→ [Agent Runtime]
                          ↓
                    [Your Agent]
                          ↓
              [Tools] [Memory] [Context]

Agent Lifecycle

1. 1Initialization – Agent is loaded
2. 2Context Building – Relevant context is provided
3. 3Reasoning – Agent processes the request
4. 4Tool Execution – Agent utilizes tools
5. 5Response – Result is returned

Getting Started

Installation

npm install @github/copilot-agent-sdk

Create a Basic Agent

import { Agent, AgentContext } from '@github/copilot-agent-sdk';

export class MyCustomAgent extends Agent {
  name = 'my-custom-agent';
  description = 'An agent for specific tasks';
  
  async execute(context: AgentContext): Promise<string> {
    const { query, files, history } = context;
    
    // Your logic here
    const result = await this.processQuery(query);
    
    return result;
  }
}

Register the Agent

import { registerAgent } from '@github/copilot-agent-sdk';
import { MyCustomAgent } from './my-agent';

registerAgent(new MyCustomAgent());

Agent Configuration

Manifest

name: my-custom-agent
version: 1.0.0
description: Description of the agent
capabilities:
  - code-generation
  - file-operations
  - external-api
triggers:
  - pattern: "@myagent"
    description: Activates the custom agent

Permissions

permissions:
  files:
    read: true
    write: true
  network:
    allowed_hosts:
      - api.cnext.ch
  secrets:
    - MY_API_KEY

Context and Memory

Accessing Context

async execute(context: AgentContext) {
  // Current file
  const currentFile = context.activeFile;
  
  // Workspace files
  const files = await context.workspace.getFiles('**/*.ts');
  
  // Conversation history
  const previousMessages = context.history;
  
  // User preferences
  const preferences = context.user.preferences;
}

Long-Term Memory

// Save
await context.memory.set('lastAnalysis', analysisResult);

// Retrieve
const cached = await context.memory.get('lastAnalysis');

// With TTL
await context.memory.set('session', data, { ttl: 3600 });

Defining Tools

Tool Structure

import { Tool, ToolResult } from '@github/copilot-agent-sdk';

const searchTool: Tool = {
  name: 'search-docs',
  description: 'Searches the documentation',
  parameters: {
    query: { type: 'string', required: true },
    limit: { type: 'number', default: 10 }
  },
  execute: async (params): Promise<ToolResult> => {
    const results = await searchDocumentation(params.query);
    return { success: true, data: results };
  }
};

Registering Tools

class MyAgent extends Agent {
  tools = [searchTool, analyzeTool, generateTool];
}

Testing

Unit Tests

import { TestContext } from '@github/copilot-agent-sdk/testing';

describe('MyCustomAgent', () => {
  it('should process query correctly', async () => {
    const agent = new MyCustomAgent();
    const context = TestContext.create({
      query: 'Analyze the code',
      files: ['src/main.ts']
    });
    
    const result = await agent.execute(context);
    expect(result).toContain('Analysis');
  });
});

Integration Tests

npx copilot-agent test --interactive

Deployment

Local Development

npx copilot-agent dev

Publishing

npx copilot-agent publish

Best Practices

Clear Responsibilities

• One agent = One task
• Focused functionality
• Good descriptions

Error Handling

try {
  const result = await externalApi.call();
  return formatSuccess(result);
} catch (error) {
  logger.error('API call failed', error);
  return formatError('Please try again later');
}

Performance

• Use caching
• Parallel tool execution
• Streaming for long responses

CNEXT Support

We assist with:

1. 1Agent Design – Define use cases
2. 2Development – Build custom agents
3. 3Integration – Connect enterprise systems
4. 4Deployment – Secure rollout

Conclusion

The Copilot Agent SDK turns Copilot into your platform. Develop agents that understand your business.