MCP Development

# MCP Development in XSky

This skill provides knowledge for Model Context Protocol integrations.

## MCP Client Types

| Type | Package | Use Case |
|------|---------|----------|
| SSE | ai-agent-core | Web-based MCP servers |
| HTTP | ai-agent-core | REST API MCP servers |
| STDIO | ai-agent-nodejs | Local subprocess servers |

## Basic Usage

```typescript
import { SimpleSseMcpClient } from "@xsky/ai-agent-core";

const mcpClient = new SimpleSseMcpClient("http://localhost:3000/mcp");
await mcpClient.connect();

const xsky = new XSky({
  llms: { /* ... */ },
  defaultMcpClient: mcpClient
});

// MCP tools now available to all agents
```

## IMcpClient Interface

```typescript
interface IMcpClient {
  connect(): Promise<void>;
  disconnect(): Promise<void>;
  listTools(): Promise<McpTool[]>;
  callTool(name: string, args: Record<string, unknown>): Promise<McpToolResult>;
  isConnected(): boolean;
}
```

## Tool Result Format

```typescript
interface McpToolResult {
  content: Array<{
    type: "text" | "image" | "resource";
    text?: string;
    data?: string;
    mimeType?: string;
  }>;
  isError?: boolean;
}
```

## STDIO Client (Node.js)

```typescript
import { SimpleStdioMcpClient } from "@xsky/ai-agent-nodejs";

const mcpClient = new SimpleStdioMcpClient("node", ["server.js"]);
await mcpClient.connect();

// Uses JSON-RPC over stdin/stdout
```

## Error Handling

```typescript
try {
  await mcpClient.connect();
} catch (error) {
  if (error.message.includes('timeout')) {
    // Handle connection timeout
  }
  // Handle other errors
}
```

## Tool Discovery

```typescript
const tools = await mcpClient.listTools();
// Returns: { name, description, inputSchema }[]

// Tools automatically converted to XSky format
// and registered with agents
```

## Key Source Files

| File | Purpose |
|------|---------|
| `packages/ai-agent-core/src/mcp/sse.ts` | SSE client |
| `packages/ai-agent-core/src/mcp/http.ts` | HTTP client |
| `packages/ai-agent-nodejs/src/mcp/stdio.ts` | STDIO client |
| `packages/ai-agent-core/src/types/mcp.types.ts` | MCP types |