import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
import express from "express";
import { createFuelMCPServer } from "../server.js";
import { log } from "../query.js";
export interface HttpServerOptions {
port?: number;
}
export async function startHttpServer(
options: HttpServerOptions = {}
): Promise<never> {
const port = options.port || 3500;
try {
log("Creating Fuel MCP server instance...");
const server = createFuelMCPServer();
const app = express();
function validateAcceptHeader(
req: express.Request,
requiredTypes: string[]
): boolean {
const acceptHeader = req.headers.accept;
if (!acceptHeader) return false;
return requiredTypes.every((type) => acceptHeader.includes(type));
}
app.use((req, res, next) => {
res.setHeader("Access-Control-Allow-Origin", "*");
res.setHeader(
"Access-Control-Allow-Methods",
"POST, GET, DELETE, OPTIONS"
);
res.setHeader(
"Access-Control-Allow-Headers",
"Content-Type, Accept, Last-Event-ID"
);
if (req.method === "OPTIONS") {
return res.status(204).end();
}
next();
});
app.post("/mcp", async (req, res) => {
try {
if (
!validateAcceptHeader(req, ["application/json", "text/event-stream"])
) {
return res.status(400).json({
jsonrpc: "2.0",
error: {
code: -32000,
message:
"Bad Request: Accept header must include application/json and text/event-stream",
},
id: null,
});
}
const transport = new StreamableHTTPServerTransport({
sessionIdGenerator: undefined,
});
await server.connect(transport);
await transport.handleRequest(req, res);
} catch (error) {
console.error("Error handling MCP request:", 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, res) => {
try {
if (!req.headers.accept?.includes("text/event-stream")) {
return res.status(400).json({
jsonrpc: "2.0",
error: {
code: -32000,
message:
"Bad Request: Accept header must include text/event-stream",
},
id: null,
});
}
return res.status(404).json({
jsonrpc: "2.0",
error: {
code: -32000,
message: "Not Found: SSE endpoint disabled for stateless mode",
},
id: null,
});
} catch (error) {
console.error("Error handling SSE request:", error);
if (!res.headersSent) {
res.status(500).json({
jsonrpc: "2.0",
error: { code: -32603, message: "Internal server error" },
id: null,
});
}
}
});
app.delete("/mcp", async (_, res) => {
return res.status(404).json({
jsonrpc: "2.0",
error: {
code: -32000,
message: "Not Found: Session termination disabled for stateless mode",
},
id: null,
});
});
const jsonParser = express.json();
app.get("/health", jsonParser, (_, res) => {
const indexPath = "./vectra_index";
const fs = require("fs");
let indexStatus = "unknown";
let indexReady = false;
try {
if (fs.existsSync(indexPath) && fs.existsSync(`${indexPath}/index.json`)) {
const indexFile = fs.readFileSync(`${indexPath}/index.json`, 'utf8');
if (indexFile.length > 0) {
indexStatus = "ready";
indexReady = true;
} else {
indexStatus = "empty";
}
} else {
indexStatus = "missing";
}
} catch (error) {
indexStatus = "error";
}
res.json({
status: indexReady ? "ok" : "degraded",
timestamp: new Date().toISOString(),
index: {
status: indexStatus,
ready: indexReady,
path: indexPath
}
});
});
app.use("/mcp", (_, res) => {
res.status(405).json({
jsonrpc: "2.0",
error: { code: -32000, message: "Method Not Allowed" },
id: null,
});
});
const httpServer = app.listen(port, "0.0.0.0", () => {
console.log(`Fuel MCP Server running at http://0.0.0.0:${port}/mcp`);
console.log(`Health check: http://0.0.0.0:${port}/health`);
});
process.on("SIGINT", async () => {
console.log("\nShutting down HTTP server...");
httpServer.close(() => console.log("HTTP server shutdown complete"));
await server.close();
process.exit(0);
});
return new Promise(() => {});
} catch (error) {
console.error("Failed to start HTTP server:", error);
process.exit(1);
}
}
