/**
* Vite plugin that exposes a POST /api/tools/call endpoint on the dev server.
*
* The browser-side dev.tsx forwards MCP tool calls to this endpoint via fetch.
* The endpoint delegates to the real MCP server running in-process (see dev-server.ts).
*
* Uses viteServer.ssrLoadModule() to import dev-server.ts through Vite's SSR
* transform pipeline — Node's native import() cannot resolve .ts files directly.
*/
import type { Plugin, ViteDevServer } from "vite";
export default function devPlugin(): Plugin {
let viteServer: ViteDevServer;
return {
name: "garmin-dev-plugin",
configureServer(server) {
viteServer = server;
server.middlewares.use(async (req, res, next) => {
if (req.url !== "/api/tools/call" || req.method !== "POST") return next();
const chunks: Buffer[] = [];
for await (const chunk of req) chunks.push(chunk as Buffer);
const body = JSON.parse(Buffer.concat(chunks).toString());
try {
// Load via ssrLoadModule so Vite handles TS transform and module caching.
const { getDevClient } = (await viteServer.ssrLoadModule(
"./src/dev-server.ts",
)) as typeof import("./dev-server.js");
const client = await getDevClient();
const result = await client.callTool({ name: body.name, arguments: body.arguments });
res.setHeader("Content-Type", "application/json");
res.end(JSON.stringify(result));
} catch (err) {
console.error("[dev-plugin]", err);
res.statusCode = 500;
res.setHeader("Content-Type", "application/json");
res.end(JSON.stringify({ error: String(err) }));
}
});
},
};
}
