import express, { type Request, type Response } from "express";
import cors from "cors";
import { parseAndValidateConfig } from "@smithery/sdk";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
import { mcpConfig } from "./config/index.js";
import { solX402Tools, solanaMcpServerTools } from "./tools/index.js";
import z from "zod";
import { DEFAULT_DEVNET_RPC_URL, PAYAI_FACILITATOR_URL } from "./config/constants.js";
import type { SessionConfig } from "./types/config.js";
export const configSchema = z.object({
isMainnet: z.boolean().default(false).describe("Set to true for mainnet, false for devnet"),
facilitatorUrl: z.string().default(PAYAI_FACILITATOR_URL).describe("URL of the x402 facilitator"),
maxPrice: z.number().default(0).describe("Maximum price to pay for services in USDC. e.g 10000 = 0.01 USDC"),
privateKey: z.string().describe("Private key in Bs58 format"),
mainnetRpcUrl: z.string().describe("RPC URL for Solana mainnet"),
devnetRpcUrl: z.string().default(DEFAULT_DEVNET_RPC_URL).describe("RPC URL for Solana devnet"),
useSolanaMcpServer: z.boolean().default(false).describe("Set to true to use Solana MCP Server. Default false")
});
async function createMcpServer(config: SessionConfig) {
const server = new McpServer(
{
name: mcpConfig.server.name,
version: mcpConfig.server.version,
},
{
capabilities: {},
},
);
console.log("\n Creating MCP Server with config:", JSON.stringify({
isMainnet: config.isMainnet,
facilitatorUrl: config.facilitatorUrl,
maxPrice: config.maxPrice,
useSolanaMcpServer: config.useSolanaMcpServer
}, null, 2));
const tools = config.useSolanaMcpServer ? [...solX402Tools, ...solanaMcpServerTools] : solX402Tools;
for (const t of tools) {
server.registerTool(
t.name,
t.config,
async (args) => {
const result = await t.callback(args, config);
return {
content: result.content.map(item => ({
...item,
type: "text" as const,
text: item.text ?? String(item.data ?? "")
}))
};
}
);
}
return server;
}
export async function run() {
console.log("\n", JSON.stringify({
mcpConfig
}, null, 2));
const app = express();
app.use(express.json());
app.use(
cors({
origin: "*",
allowedHeaders: ["Content-Type", "mcp-session-id"],
})
);
app.post("/mcp", async (req: Request, res: Response) => {
console.info('\n Received POST MCP request');
const result = parseAndValidateConfig(req, configSchema);
if (result.error) {
const isDummyConfig = req.query.privateKey === 'string' ||
req.query.mainnetRpcUrl === 'string';
if (isDummyConfig) {
console.info('\n Detected dummy config for deployment scanning');
const sessionConfig: SessionConfig = {
isMainnet: false,
facilitatorUrl: PAYAI_FACILITATOR_URL,
maxPrice: 0,
privateKey: '',
mainnetRpcUrl: '',
devnetRpcUrl: DEFAULT_DEVNET_RPC_URL,
useSolanaMcpServer: false
};
try {
const sessionServer = await createMcpServer(sessionConfig);
const transport: StreamableHTTPServerTransport = new StreamableHTTPServerTransport({
enableDnsRebindingProtection: true,
sessionIdGenerator: undefined,
});
res.on('close', () => {
console.info('POST MCP request closed (dummy config)');
transport.close();
sessionServer.close();
});
await sessionServer.connect(transport);
await transport.handleRequest(req, res, req.body);
return;
} catch (error) {
console.error('\n Error handling POST MCP request with dummy config:', String(error));
if (!res.headersSent) {
res.status(500).json({
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Internal server error',
},
id: null,
});
}
return;
}
} else {
return res.status(400).json({
error: 'Invalid or missing configuration. Please provide required configuration parameters.',
details: result.error
});
}
}
const config = result.value;
const sessionConfig: SessionConfig = {
isMainnet: config.isMainnet ?? false,
facilitatorUrl: config.facilitatorUrl ?? PAYAI_FACILITATOR_URL,
maxPrice: config.maxPrice ?? 0,
privateKey: config.privateKey,
mainnetRpcUrl: config.mainnetRpcUrl,
devnetRpcUrl: config.devnetRpcUrl ?? DEFAULT_DEVNET_RPC_URL,
useSolanaMcpServer: config.useSolanaMcpServer ?? false
};
try {
const sessionServer = await createMcpServer(sessionConfig);
const transport: StreamableHTTPServerTransport = new StreamableHTTPServerTransport({
enableDnsRebindingProtection: true,
sessionIdGenerator: undefined,
});
res.on('close', () => {
console.info('POST MCP request closed');
transport.close();
sessionServer.close();
});
await sessionServer.connect(transport);
await transport.handleRequest(req, res, req.body);
} catch (error) {
console.error('\n Error handling POST MCP request:', String(error));
if (!res.headersSent) {
res.status(500).json({
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Internal server error',
},
id: null,
});
}
}
});
app.get('/mcp', async (req: Request, res: Response) => {
console.info('\n Received GET MCP request');
const result = parseAndValidateConfig(req, configSchema);
if (result.error) {
// Allow dummy config during deployment scanning
const isDummyConfig = req.query.privateKey === 'string' ||
req.query.mainnetRpcUrl === 'string';
if (isDummyConfig) {
console.info('\n Detected dummy config for deployment scanning (GET)');
// Use default/empty config for scanning
const sessionConfig: SessionConfig = {
isMainnet: false,
facilitatorUrl: PAYAI_FACILITATOR_URL,
maxPrice: 0,
privateKey: '',
mainnetRpcUrl: '',
devnetRpcUrl: DEFAULT_DEVNET_RPC_URL,
useSolanaMcpServer: false
};
try {
const sessionServer = await createMcpServer(sessionConfig);
const transport: StreamableHTTPServerTransport = new StreamableHTTPServerTransport({
enableDnsRebindingProtection: true,
sessionIdGenerator: undefined,
});
res.on('close', () => {
console.info('GET MCP request closed (dummy config)');
transport.close();
sessionServer.close();
});
await sessionServer.connect(transport);
await transport.handleRequest(req, res, req.body);
return;
} catch (error) {
console.error('\n Error handling GET MCP request with dummy config:', String(error));
if (!res.headersSent) {
res.status(500).json({
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Internal server error',
},
id: null,
});
}
return;
}
} else {
return res.status(400).json({ error: 'Invalid configuration' });
}
}
const config = result.value;
const sessionConfig: SessionConfig = {
isMainnet: config.isMainnet ?? false,
facilitatorUrl: config.facilitatorUrl ?? PAYAI_FACILITATOR_URL,
maxPrice: config.maxPrice ?? 0,
privateKey: config.privateKey,
mainnetRpcUrl: config.mainnetRpcUrl,
devnetRpcUrl: config.devnetRpcUrl ?? DEFAULT_DEVNET_RPC_URL,
useSolanaMcpServer: config.useSolanaMcpServer ?? false
};
try {
const sessionServer = await createMcpServer(sessionConfig);
const transport: StreamableHTTPServerTransport = new StreamableHTTPServerTransport({
enableDnsRebindingProtection: true,
sessionIdGenerator: undefined,
});
res.on('close', () => {
console.info('GET MCP request closed');
transport.close();
sessionServer.close();
});
await sessionServer.connect(transport);
await transport.handleRequest(req, res, req.body);
} catch (error) {
console.error('\n Error handling GET MCP request:', String(error));
if (!res.headersSent) {
res.status(500).json({
jsonrpc: '2.0',
error: {
code: -32603,
message: 'Internal server error',
},
id: null,
});
}
}
});
app.delete('/mcp', async (req: Request, res: Response) => {
console.info('\n Received DELETE MCP request');
res.writeHead(405).end(JSON.stringify({
jsonrpc: "2.0",
error: {
code: -32000,
message: "Method not allowed."
},
id: null
}));
});
app.get("/.well-known/mcp-config", (_req, res) => {
const schema = {
"$schema": "http://json-schema.org/draft-07/schema#",
"$id": `http://${mcpConfig.environment.host}:${mcpConfig.environment.port}/.well-known/mcp-config`,
"title": "Solx402 MCP Server Configuration",
"description": "Configuration for connecting to the Solx402 MCP server",
"x-query-style": "dot+bracket",
"type": "object",
"properties": {
"isMainnet": {
"type": "boolean",
"title": "Use Mainnet",
"description": "Set to true for mainnet, false for devnet",
"default": false
},
"facilitatorUrl": {
"type": "string",
"format": "uri",
"title": "Facilitator URL",
"description": "URL of the x402 facilitator",
"default": PAYAI_FACILITATOR_URL
},
"maxPrice": {
"type": "number",
"title": "Max Price",
"description": "Maximum price to pay for services in USDC. e.g 10000 = 0.01 USDC",
"default": 0,
"minimum": 0
},
"privateKey": {
"type": "string",
"title": "Private Key",
"description": "Private key in Bs58 format",
"x-secret": true
},
"mainnetRpcUrl": {
"type": "string",
"format": "uri",
"title": "Mainnet RPC URL",
"description": "RPC URL for Solana mainnet"
},
"devnetRpcUrl": {
"type": "string",
"format": "uri",
"title": "Devnet RPC URL",
"description": "RPC URL for Solana devnet",
"default": DEFAULT_DEVNET_RPC_URL
},
"useSolanaMcpServer": {
"type": "boolean",
"title": "Use Solana MCP Server",
"description": "Set to true to use Solana MCP Server. Default false",
"default": false
}
},
"required": ["privateKey", "mainnetRpcUrl"],
"additionalProperties": false
};
res.setHeader('Content-Type', 'application/json');
res.json(schema);
});
app.get("/health", (_req, res) => res.status(200).send("ok"));
app.listen(mcpConfig.environment.port, mcpConfig.environment.host, () => {
console.info(`\n MCP Stateless Streamable HTTP listening on http://${mcpConfig.environment.host}:${mcpConfig.environment.port}`);
});
}
