| @@ -1,222 +0,0 @@ |
| 1 | import { randomUUID } from "node:crypto"; | | |
| 2 | | | |
| 3 | import { createMcpExpressApp } from "@modelcontextprotocol/sdk/server/express.js"; | | |
| 4 | import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; | | |
| 5 | import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js"; | | |
| 6 | import { z } from "zod/v4"; | | |
| 7 | | | |
| 8 | export type McpElicitationDemoServer = { | | |
| 9 | readonly endpoint: string; | | |
| 10 | readonly close: () => Promise<void>; | | |
| 11 | }; | | |
| 12 | | | |
| 13 | const registerDemoTools = (server: McpServer) => { | | |
| 14 | server.registerTool( | | |
| 15 | "gated_echo", | | |
| 16 | { | | |
| 17 | description: "Ask for approval before echoing the provided value.", | | |
| 18 | inputSchema: { | | |
| 19 | value: z.string(), | | |
| 20 | }, | | |
| 21 | }, | | |
| 22 | async ({ value }: { value: string }) => { | | |
| 23 | const response = await server.server.elicitInput({ | | |
| 24 | mode: "form", | | |
| 25 | message: `Approve gated echo for ${value}?`, | | |
| 26 | requestedSchema: { | | |
| 27 | type: "object", | | |
| 28 | properties: { | | |
| 29 | approve: { | | |
| 30 | type: "boolean", | | |
| 31 | title: "Approve", | | |
| 32 | }, | | |
| 33 | }, | | |
| 34 | required: ["approve"], | | |
| 35 | }, | | |
| 36 | }); | | |
| 37 | | | |
| 38 | if ( | | |
| 39 | response.action !== "accept" | | |
| 40 | || !response.content | | |
| 41 | || response.content.approve !== true | | |
| 42 | ) { | | |
| 43 | return { | | |
| 44 | content: [{ type: "text", text: "denied" }], | | |
| 45 | }; | | |
| 46 | } | | |
| 47 | | | |
| 48 | return { | | |
| 49 | content: [{ type: "text", text: `approved:${value}` }], | | |
| 50 | }; | | |
| 51 | }, | | |
| 52 | ); | | |
| 53 | }; | | |
| 54 | | | |
| 55 | export const startMcpElicitationDemoServer = async (input: { | | |
| 56 | readonly host?: string; | | |
| 57 | readonly port?: number; | | |
| 58 | } = {}): Promise<McpElicitationDemoServer> => { | | |
| 59 | const host = input.host ?? "127.0.0.1"; | | |
| 60 | const app = createMcpExpressApp({ host }); | | |
| 61 | const transports: Record<string, StreamableHTTPServerTransport> = {}; | | |
| 62 | const servers: Record<string, McpServer> = {}; | | |
| 63 | | | |
| 64 | const createServer = () => { | | |
| 65 | const server = new McpServer( | | |
| 66 | { | | |
| 67 | name: "executor-mcp-elicitation-demo", | | |
| 68 | version: "1.0.0", | | |
| 69 | }, | | |
| 70 | { | | |
| 71 | capabilities: { | | |
| 72 | tools: {}, | | |
| 73 | }, | | |
| 74 | }, | | |
| 75 | ); | | |
| 76 | | | |
| 77 | registerDemoTools(server); | | |
| 78 | return server; | | |
| 79 | }; | | |
| 80 | | | |
| 81 | app.post("/mcp", async (req: any, res: any) => { | | |
| 82 | const sessionIdHeader = req.headers["mcp-session-id"]; | | |
| 83 | const sessionId = | | |
| 84 | typeof sessionIdHeader === "string" | | |
| 85 | ? sessionIdHeader | | |
| 86 | : Array.isArray(sessionIdHeader) | | |
| 87 | ? sessionIdHeader[0] | | |
| 88 | : undefined; | | |
| 89 | | | |
| 90 | try { | | |
| 91 | let transport: StreamableHTTPServerTransport; | | |
| 92 | | | |
| 93 | if (sessionId && transports[sessionId]) { | | |
| 94 | transport = transports[sessionId]; | | |
| 95 | } else { | | |
| 96 | transport = new StreamableHTTPServerTransport({ | | |
| 97 | sessionIdGenerator: () => randomUUID(), | | |
| 98 | onsessioninitialized: (newSessionId) => { | | |
| 99 | transports[newSessionId] = transport; | | |
| 100 | }, | | |
| 101 | }); | | |
| 102 | | | |
| 103 | transport.onclose = () => { | | |
| 104 | const closedSessionId = transport.sessionId; | | |
| 105 | if (closedSessionId && transports[closedSessionId]) { | | |
| 106 | delete transports[closedSessionId]; | | |
| 107 | } | | |
| 108 | if (closedSessionId && servers[closedSessionId]) { | | |
| 109 | void servers[closedSessionId].close().catch(() => undefined); | | |
| 110 | delete servers[closedSessionId]; | | |
| 111 | } | | |
| 112 | }; | | |
| 113 | | | |
| 114 | const server = createServer(); | | |
| 115 | await server.connect(transport); | | |
| 116 | const newSessionId = transport.sessionId; | | |
| 117 | if (newSessionId) { | | |
| 118 | servers[newSessionId] = server; | | |
| 119 | } | | |
| 120 | } | | |
| 121 | | | |
| 122 | await transport.handleRequest(req, res, req.body); | | |
| 123 | } catch (error) { | | |
| 124 | if (!res.headersSent) { | | |
| 125 | res.status(500).json({ | | |
| 126 | jsonrpc: "2.0", | | |
| 127 | error: { | | |
| 128 | code: -32603, | | |
| 129 | message: error instanceof Error ? error.message : "Internal server error", | | |
| 130 | }, | | |
| 131 | id: null, | | |
| 132 | }); | | |
| 133 | } | | |
| 134 | } | | |
| 135 | }); | | |
| 136 | | | |
| 137 | app.get("/mcp", async (req: any, res: any) => { | | |
| 138 | const sessionIdHeader = req.headers["mcp-session-id"]; | | |
| 139 | const sessionId = | | |
| 140 | typeof sessionIdHeader === "string" | | |
| 141 | ? sessionIdHeader | | |
| 142 | : Array.isArray(sessionIdHeader) | | |
| 143 | ? sessionIdHeader[0] | | |
| 144 | : undefined; | | |
| 145 | | | |
| 146 | if (!sessionId || !transports[sessionId]) { | | |
| 147 | res.status(400).send("Invalid or missing session ID"); | | |
| 148 | return; | | |
| 149 | } | | |
| 150 | | | |
| 151 | await transports[sessionId].handleRequest(req, res); | | |
| 152 | }); | | |
| 153 | | | |
| 154 | app.delete("/mcp", async (req: any, res: any) => { | | |
| 155 | const sessionIdHeader = req.headers["mcp-session-id"]; | | |
| 156 | const sessionId = | | |
| 157 | typeof sessionIdHeader === "string" | | |
| 158 | ? sessionIdHeader | | |
| 159 | : Array.isArray(sessionIdHeader) | | |
| 160 | ? sessionIdHeader[0] | | |
| 161 | : undefined; | | |
| 162 | | | |
| 163 | if (!sessionId || !transports[sessionId]) { | | |
| 164 | res.status(400).send("Invalid or missing session ID"); | | |
| 165 | return; | | |
| 166 | } | | |
| 167 | | | |
| 168 | const transport = transports[sessionId]; | | |
| 169 | await transport.handleRequest(req, res, req.body); | | |
| 170 | await transport.close(); | | |
| 171 | delete transports[sessionId]; | | |
| 172 | | | |
| 173 | if (servers[sessionId]) { | | |
| 174 | await servers[sessionId].close().catch(() => undefined); | | |
| 175 | delete servers[sessionId]; | | |
| 176 | } | | |
| 177 | }); | | |
| 178 | | | |
| 179 | const listener = await new Promise<import("node:http").Server>((resolve, reject) => { | | |
| 180 | const server = app.listen(input.port ?? 0, host); | | |
| 181 | | | |
| 182 | const onListening = () => { | | |
| 183 | server.off("error", onError); | | |
| 184 | resolve(server); | | |
| 185 | }; | | |
| 186 | | | |
| 187 | const onError = (error: Error) => { | | |
| 188 | server.off("listening", onListening); | | |
| 189 | reject(error); | | |
| 190 | }; | | |
| 191 | | | |
| 192 | server.once("listening", onListening); | | |
| 193 | server.once("error", onError); | | |
| 194 | }); | | |
| 195 | | | |
| 196 | const address = listener.address(); | | |
| 197 | if (!address || typeof address === "string") { | | |
| 198 | if (listener.listening) { | | |
| 199 | await new Promise<void>((resolve, reject) => { | | |
| 200 | listener.close((error) => (error ? reject(error) : resolve())); | | |
| 201 | }); | | |
| 202 | } | | |
| 203 | throw new Error("Failed to resolve MCP elicitation demo server address"); | | |
| 204 | } | | |
| 205 | | | |
| 206 | return { | | |
| 207 | endpoint: `http://${host}:${address.port}/mcp`, | | |
| 208 | close: async () => { | | |
| 209 | for (const transport of Object.values(transports)) { | | |
| 210 | await transport.close().catch(() => undefined); | | |
| 211 | } | | |
| 212 | | | |
| 213 | for (const server of Object.values(servers)) { | | |
| 214 | await server.close().catch(() => undefined); | | |
| 215 | } | | |
| 216 | | | |
| 217 | await new Promise<void>((resolve, reject) => { | | |
| 218 | listener.close((error) => (error ? reject(error) : resolve())); | | |
| 219 | }); | | |
| 220 | }, | | |
| 221 | }; | | |
| 222 | }; | | |