diff --git a/app/__test__/app/mcp/mcp.server.test.ts b/app/__test__/app/mcp/mcp.server.test.ts
new file mode 100644
index 0000000..29113fd
--- /dev/null
+++ b/app/__test__/app/mcp/mcp.server.test.ts
@@ -0,0 +1,62 @@
+import { describe, test, expect, beforeAll, mock } from "bun:test";
+import { type App, createApp, createMcpToolCaller } from "core/test/utils";
+import { getSystemMcp } from "modules/mcp/system-mcp";
+
+/**
+ * - [x] config_server_get
+ * - [x] config_server_update
+ */
+describe("mcp system", async () => {
+   let app: App;
+   let server: ReturnType<typeof getSystemMcp>;
+   beforeAll(async () => {
+      app = createApp({
+         initialConfig: {
+            server: {
+               mcp: {
+                  enabled: true,
+               },
+            },
+         },
+      });
+      await app.build();
+      server = getSystemMcp(app);
+   });
+
+   const tool = createMcpToolCaller();
+
+   test("config_server_get", async () => {
+      const result = await tool(server, "config_server_get", {});
+      expect(result).toEqual({
+         path: "",
+         secrets: false,
+         partial: false,
+         value: app.toJSON().server,
+      });
+   });
+
+   test("config_server_update", async () => {
+      const original = app.toJSON().server;
+      const result = await tool(server, "config_server_update", {
+         value: {
+            cors: {
+               origin: "http://localhost",
+            },
+         },
+         return_config: true,
+      });
+
+      expect(result).toEqual({
+         success: true,
+         module: "server",
+         config: {
+            ...original,
+            cors: {
+               ...original.cors,
+               origin: "http://localhost",
+            },
+         },
+      });
+      expect(app.toJSON().server.cors.origin).toBe("http://localhost");
+   });
+});
diff --git a/app/__test__/app/mcp/mcp.system.test.ts b/app/__test__/app/mcp/mcp.system.test.ts
index 9808a51..60be89b 100644
--- a/app/__test__/app/mcp/mcp.system.test.ts
+++ b/app/__test__/app/mcp/mcp.system.test.ts
@@ -1,16 +1,15 @@
-import { describe, test, expect, beforeAll } from "bun:test";
+import { AppEvents } from "App";
+import { describe, test, expect, beforeAll, mock } from "bun:test";
 import { type App, createApp, createMcpToolCaller } from "core/test/utils";
 import { getSystemMcp } from "modules/mcp/system-mcp";
 import { inspect } from "node:util";
 inspect.defaultOptions.depth = 10;
 
 /**
- * - [ ] system_config
- * - [ ] system_build
- * - [ ] system_ping
- * - [ ] system_info
- * - [ ] config_server_get
- * - [ ] config_server_update
+ * - [x] system_config
+ * - [x] system_build
+ * - [x] system_ping
+ * - [x] system_info
  */
 describe("mcp system", async () => {
    let app: App;
@@ -35,4 +34,25 @@ describe("mcp system", async () => {
       const result = await tool(server, "system_ping", {});
       expect(result).toEqual({ pong: true });
    });
+
+   test("system_info", async () => {
+      const result = await tool(server, "system_info", {});
+      expect(Object.keys(result).length).toBeGreaterThan(0);
+      expect(Object.keys(result)).toContainValues(["version", "runtime", "connection"]);
+   });
+
+   test("system_build", async () => {
+      const called = mock(() => null);
+
+      app.emgr.onEvent(AppEvents.AppBuiltEvent, () => void called(), { once: true });
+
+      const result = await tool(server, "system_build", {});
+      expect(called).toHaveBeenCalledTimes(1);
+      expect(result.success).toBe(true);
+   });
+
+   test("system_config", async () => {
+      const result = await tool(server, "system_config", {});
+      expect(result).toEqual(app.toJSON());
+   });
 });
diff --git a/app/src/core/test/utils.ts b/app/src/core/test/utils.ts
index 30e0642..5702724 100644
--- a/app/src/core/test/utils.ts
+++ b/app/src/core/test/utils.ts
@@ -22,6 +22,11 @@ export function createMcpToolCaller() {
             arguments: args,
          },
       });
+
+      if ((res.result as any)?.isError) {
+         throw new Error((res.result as any)?.content?.[0]?.text ?? "Unknown error");
+      }
+
       return JSON.parse((res.result as any)?.content?.[0]?.text ?? "null");
    };
 }