Snowfort Circuit MCP

import { Server } from "@modelcontextprotocol/sdk/server/index.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { CallToolRequestSchema, ListToolsRequestSchema, } from "@modelcontextprotocol/sdk/types.js"; import { Driver, ServerOpts, Session, ToolResult } from "./types.js"; export class MCPServer { protected server: Server; private driver: Driver; private sessions = new Map<string, Session>(); constructor(private opts: ServerOpts) { this.driver = opts.driver; this.server = new Server( { name: opts.name, version: opts.version || "0.1.0", }, { capabilities: { tools: {}, }, } ); this.setupHandlers(); } private setupHandlers() { this.server.setRequestHandler(ListToolsRequestSchema, async () => { return { tools: [ { name: "click", description: "Click on an element identified by a CSS selector", inputSchema: { type: "object", properties: { sessionId: { type: "string", description: "Session ID returned from launch", }, selector: { type: "string", description: "CSS selector for the element to click", }, }, required: ["sessionId", "selector"], }, }, { name: "type", description: "Type text into an element identified by a CSS selector", inputSchema: { type: "object", properties: { sessionId: { type: "string", description: "Session ID returned from launch", }, selector: { type: "string", description: "CSS selector for the element to type into", }, text: { type: "string", description: "Text to type", }, }, required: ["sessionId", "selector", "text"], }, }, { name: "screenshot", description: "Take a screenshot of the current page or window", inputSchema: { type: "object", properties: { sessionId: { type: "string", description: "Session ID returned from launch", }, path: { type: "string", description: "Optional path to save the screenshot", }, }, required: ["sessionId"], }, }, { name: "evaluate", description: "Execute JavaScript in the page or application context", inputSchema: { type: "object", properties: { sessionId: { type: "string", description: "Session ID returned from launch", }, script: { type: "string", description: "JavaScript code to execute", }, }, required: ["sessionId", "script"], }, }, { name: "wait_for_selector", description: "Wait for an element to appear on the page", inputSchema: { type: "object", properties: { sessionId: { type: "string", description: "Session ID returned from launch", }, selector: { type: "string", description: "CSS selector to wait for", }, timeout: { type: "number", description: "Timeout in milliseconds (default: 30000)", }, }, required: ["sessionId", "selector"], }, }, { name: "close", description: "Close a session", inputSchema: { type: "object", properties: { sessionId: { type: "string", description: "Session ID to close", }, }, required: ["sessionId"], }, }, ], }; }); this.server.setRequestHandler(CallToolRequestSchema, async (request): Promise<any> => { const { name, arguments: args } = request.params; try { const toolArgs = args || {}; switch (name) { case "click": await this.handleClick(toolArgs.sessionId as string, toolArgs.selector as string); return { content: [{ type: "text", text: "Element clicked successfully" }] }; case "type": await this.handleType(toolArgs.sessionId as string, toolArgs.selector as string, toolArgs.text as string); return { content: [{ type: "text", text: "Text typed successfully" }] }; case "screenshot": const screenshotPath = await this.handleScreenshot(toolArgs.sessionId as string, toolArgs.path as string); return { content: [{ type: "text", text: `Screenshot saved to: ${screenshotPath}` }] }; case "evaluate": const evalResult = await this.handleEvaluate(toolArgs.sessionId as string, toolArgs.script as string); return { content: [{ type: "text", text: `Result: ${JSON.stringify(evalResult)}` }] }; case "wait_for_selector": await this.handleWaitForSelector(toolArgs.sessionId as string, toolArgs.selector as string, toolArgs.timeout as number); return { content: [{ type: "text", text: "Element found" }] }; case "close": await this.handleClose(toolArgs.sessionId as string); return { content: [{ type: "text", text: "Session closed successfully" }] }; default: throw new Error(`Unknown tool: ${name}`); } } catch (error) { return { content: [{ type: "text", text: `Error: ${error instanceof Error ? error.message : String(error)}` }], isError: true, }; } }); } protected async getSession(sessionId: string): Promise<Session> { const session = this.sessions.get(sessionId); if (!session) { throw new Error(`Session not found: ${sessionId}`); } return session; } protected async handleClick(sessionId: string, selector: string): Promise<void> { const session = await this.getSession(sessionId); await this.driver.click(session, selector); } protected async handleType(sessionId: string, selector: string, text: string): Promise<void> { const session = await this.getSession(sessionId); if (!this.driver.type) { throw new Error("Type operation not supported by this driver"); } await this.driver.type(session, selector, text); } protected async handleScreenshot(sessionId: string, path?: string): Promise<string> { const session = await this.getSession(sessionId); if (!this.driver.screenshot) { throw new Error("Screenshot operation not supported by this driver"); } return await this.driver.screenshot(session, path); } protected async handleEvaluate(sessionId: string, script: string): Promise<any> { const session = await this.getSession(sessionId); if (!this.driver.evaluate) { throw new Error("Evaluate operation not supported by this driver"); } return await this.driver.evaluate(session, script); } protected async handleWaitForSelector(sessionId: string, selector: string, timeout?: number): Promise<void> { const session = await this.getSession(sessionId); if (!this.driver.waitForSelector) { throw new Error("WaitForSelector operation not supported by this driver"); } await this.driver.waitForSelector(session, selector, timeout); } protected async handleClose(sessionId: string): Promise<void> { const session = await this.getSession(sessionId); if (this.driver.close) { await this.driver.close(session); } this.sessions.delete(sessionId); } protected addSession(session: Session): void { this.sessions.set(session.id, session); } async run(): Promise<void> { const transport = new StdioServerTransport(); await this.server.connect(transport); } } export async function runServer(opts: ServerOpts): Promise<void> { const server = new MCPServer(opts); await server.run(); }