feat: serve workspace MCP over the web app HTTP endpoint

src/features/mcp/http.server.ts

@@ -0,0 +1,57 @@
+import { randomUUID } from "node:crypto";
+import { createMcpHandler, Server, type ToolAnnotations } from "@modelcontextprotocol/server";
+import { createWorkspaceTools } from "./workspace-tools.server";
+
+type Tools = {
+  definitions: {
+    name: string;
+    description: string;
+    inputSchema: Record<string, unknown>;
+    annotations?: ToolAnnotations;
+  }[];
+  execute: (name: string, input: unknown) => Promise<unknown>;
+};
+
+// The provider and request handler must see the same registrations across Vite HMR.
+const state = globalThis as typeof globalThis & {
+  workspaceMcpResearch?: Map<string, Tools>;
+};
+const research = (state.workspaceMcpResearch ??= new Map<string, Tools>());
+
+export function registerResearchTools(tools: Tools) {
+  const id = randomUUID();
+  research.set(id, tools);
+  return { id, dispose: () => research.delete(id) };
+}
+
+function serverFor(tools: Tools) {
+  const server = new Server(
+    { name: "personal-workspace", version: "1.0.0" },
+    { capabilities: { tools: {} } },
+  );
+  server.setRequestHandler("tools/list", () => ({
+    tools: tools.definitions.map((tool) => ({
+      ...tool,
+      inputSchema: { ...tool.inputSchema, type: "object" as const },
+    })),
+  }));
+  server.setRequestHandler("tools/call", async ({ params }) => {
+    const result = await tools.execute(params.name, params.arguments ?? {});
+    return {
+      content: [{ type: "text" as const, text: JSON.stringify(result) }],
+      isError: !(result && typeof result === "object" && "ok" in result && result.ok === true),
+    };
+  });
+  return server;
+}
+
+export async function handleMcpRequest(request: Request): Promise<Response> {
+  const url = new URL(request.url);
+  const id = url.searchParams.get("research");
+  const tools = id === null ? createWorkspaceTools() : research.get(id);
+  if (!tools) return new Response("Research turn is no longer available.", { status: 404 });
+  const handler = createMcpHandler(() => serverFor(tools));
+  const response = await handler.fetch(request);
+  response.headers.set("Cache-Control", "no-store");
+  return response;
+}