feat: lazy load mcp server

app/__test__/app/AppServer.spec.ts

@@ -16,6 +16,7 @@ describe("AppServer", () => {
             mcp: {
                enabled: false,
                path: "/api/system/mcp",
+               logLevel: "warning",
             },
          });
       }
@@ -38,6 +39,7 @@ describe("AppServer", () => {
             mcp: {
                enabled: false,
                path: "/api/system/mcp",
+               logLevel: "warning",
             },
          });
       }

app/__test__/app/mcp/mcp.auth.test.ts

@@ -44,6 +44,7 @@ describe("mcp auth", async () => {
          },
       });
       await app.build();
+      await app.getMcpClient().ping();
       server = app.mcp!;
       server.setLogLevel("error");
       server.onNotification((message) => {

app/__test__/app/mcp/mcp.base.test.ts

@@ -34,6 +34,11 @@ describe("mcp", () => {
       });
       await app.build();
 
+      // expect mcp to not be loaded yet
+      expect(app.mcp).toBeNull();
+
+      // after first request, mcp should be loaded
+      await app.getMcpClient().listTools();
       expect(app.mcp?.tools.length).toBeGreaterThan(0);
    });
 });

app/__test__/app/mcp/mcp.data.test.ts

@@ -50,6 +50,7 @@ describe("mcp data", async () => {
          },
       });
       await app.build();
+      await app.getMcpClient().ping();
       server = app.mcp!;
       server.setLogLevel("error");
       server.onNotification((message) => {

app/__test__/app/mcp/mcp.media.test.ts

@@ -39,6 +39,7 @@ describe("mcp media", async () => {
          },
       });
       await app.build();
+      await app.getMcpClient().ping();
       server = app.mcp!;
       server.setLogLevel("error");
       server.onNotification((message) => {

app/__test__/app/mcp/mcp.server.test.ts

@@ -24,6 +24,7 @@ describe("mcp system", async () => {
          },
       });
       await app.build();
+      await app.getMcpClient().ping();
       server = app.mcp!;
    });
 

app/__test__/app/mcp/mcp.system.test.ts

@@ -23,6 +23,7 @@ describe("mcp system", async () => {
          },
       });
       await app.build();
+      await app.getMcpClient().ping();
       server = app.mcp!;
    });
 

app/package.json

@@ -65,7 +65,7 @@
     "hono": "4.8.3",
     "json-schema-library": "10.0.0-rc7",
     "json-schema-to-ts": "^3.1.1",
-    "jsonv-ts": "0.8.2",
+    "jsonv-ts": "0.8.4",
     "kysely": "0.27.6",
     "lodash-es": "^4.17.21",
     "oauth4webapi": "^2.11.1",

app/src/App.ts

@@ -302,13 +302,13 @@ export class App<
    }
 
    getMcpClient() {
-      if (!this.mcp) {
+      const config = this.modules.get("server").config.mcp;
+      if (!config.enabled) {
          throw new Error("MCP is not enabled");
       }
-      const mcpPath = this.modules.get("server").config.mcp.path;
 
       return new McpClient({
-         url: "http://localhost" + mcpPath,
+         url: "http://localhost" + config.path,
          fetch: this.server.request,
       });
    }

app/src/modules/mcp/system-mcp.ts

@@ -6,7 +6,7 @@ import { getVersion } from "core/env";
 export function getSystemMcp(app: App) {
    const middlewareServer = getMcpServer(app.server);
 
-   const appConfig = app.modules.configs();
+   //const appConfig = app.modules.configs();
    const { version, ...appSchema } = app.getSchema();
    const schema = s.strictObject(appSchema);
    const result = [...schema.walk({ maxDepth: 3 })];

app/src/modules/server/AppServer.ts

@@ -1,6 +1,6 @@
 import { Exception } from "core/errors";
 import { isDebug } from "core/env";
-import { $console, s } from "bknd/utils";
+import { $console, mcpLogLevels, s } from "bknd/utils";
 import { $object } from "modules/mcp";
 import { cors } from "hono/cors";
 import { Module } from "modules/Module";
@@ -25,6 +25,10 @@ export const serverConfigSchema = $object(
       mcp: s.strictObject({
          enabled: s.boolean({ default: false }),
          path: s.string({ default: "/api/system/mcp" }),
+         logLevel: s.string({
+            enum: mcpLogLevels,
+            default: "warning",
+         }),
       }),
    },
    {

app/src/modules/server/SystemController.ts

@@ -70,33 +70,41 @@ export class SystemController extends Controller {
 
       this.registerMcp();
 
-      this._mcpServer = getSystemMcp(app);
-      this._mcpServer.onNotification((message) => {
-         if (message.method === "notification/message") {
-            const consoleMap = {
-               emergency: "error",
-               alert: "error",
-               critical: "error",
-               error: "error",
-               warning: "warn",
-               notice: "log",
-               info: "info",
-               debug: "debug",
-            };
-
-            const level = consoleMap[message.params.level];
-            if (!level) return;
-
-            $console[level]("MCP notification", message.params.message ?? message.params);
-         }
-      });
-
       app.server.use(
          mcpMiddleware({
-            server: this._mcpServer,
+            setup: async () => {
+               if (!this._mcpServer) {
+                  this._mcpServer = getSystemMcp(app);
+                  this._mcpServer.onNotification((message) => {
+                     if (message.method === "notification/message") {
+                        const consoleMap = {
+                           emergency: "error",
+                           alert: "error",
+                           critical: "error",
+                           error: "error",
+                           warning: "warn",
+                           notice: "log",
+                           info: "info",
+                           debug: "debug",
+                        };
+
+                        const level = consoleMap[message.params.level];
+                        if (!level) return;
+
+                        $console[level](
+                           "MCP notification",
+                           message.params.message ?? message.params,
+                        );
+                     }
+                  });
+               }
+               return {
+                  server: this._mcpServer,
+               };
+            },
             sessionsEnabled: true,
             debug: {
-               logLevel: "debug",
+               logLevel: config.mcp.logLevel as any,
                explainEndpoint: true,
             },
             endpoint: {