diff --git a/.vscode/launch.json b/.vscode/launch.json
index 65f5196..9e124d0 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -1,13 +1,11 @@
 {
-    // Use IntelliSense to learn about possible attributes.
-    // Hover to view descriptions of existing attributes.
-    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
     "version": "0.2.0",
     "configurations": [
         {
             "type": "pwa-node",
+            "runtimeVersion": "16",
             "request": "launch",
-            "name": "Launch Program",
+            "name": "remex",
             "skipFiles": [
                 "<node_internals>/**"
             ],
diff --git a/config.json b/config.json
index 896adf9..c8e9838 100644
--- a/config.json
+++ b/config.json
@@ -8,14 +8,21 @@
     "timestamp": "DD.MM.YYYY HH:mm:ss:SS"
   },
   "api": [
+    {
+      "url": "/tail",
+      "type": "get",
+      "command": "tail",
+      "args": [
+        "-f", "/tmp/test"
+      ],
+      "detach": true
+    },
     {
       "url": "/uptime",
       "type": "get",
-      "command": "uptime1",
+      "command": "uptime",
       "args": [
-      ],
-      "passargs": true,
-      "detach": false
+      ]
     }
   ]
 }
\ No newline at end of file
diff --git a/libs/commands.js b/libs/commands.js
index 7889214..7fe85e2 100644
--- a/libs/commands.js
+++ b/libs/commands.js
@@ -7,6 +7,10 @@ async function execute(endpoint) {
     if (endpoint === undefined) {
         return;
     }
+    if (isCommandActive(endpoint)) {
+        logger.info('not executing command \'' + endpoint.command + '\' (args: \'' + endpoint.args + '\') because it is already active');
+        throw new Error('command is already active');
+    }
     return new Promise((resolve, reject) => {
         logger.info('executing command \'' + endpoint.command + '\' (args: \'' + endpoint.args + '\')...');
         var cmd = spawn(endpoint.command, endpoint.args);
@@ -22,14 +26,14 @@ async function execute(endpoint) {
         cmd.on('spawn', () => {
             logger.info('spawned command \'' + endpoint.command + '\' (args: \'' + endpoint.args + '\')');
             addCommand(cmd, endpoint);
-            if (endpoint.detach !== false) {
+            if (endpoint.detach === true) {
                 resolve();
             }
         });
         cmd.on('error', (err) => {
             error += err;
             removeCommand(endpoint);
-            if (endpoint.detach !== false) {
+            if (endpoint.detach === true) {
                 reject();
             }
         });
@@ -38,12 +42,14 @@ async function execute(endpoint) {
             let fn = logger.info;
             let msg = 'command \'' + endpoint.command + '\' (args: \'' + endpoint.args + '\') finished with exit code ' + code + ' after ' + (new Date().getTime() - cmd.timestamp) + 'ms';
             if (error !== undefined && error.length > 0) {
-                msg += ' >>> ' + error;
+                error = error.trim();
+                msg += ' > error: ' + error;
                 fn = logger.error;
                 reject(error);
             }
             if (result !== undefined && result.length > 0) {
-                msg += ' > ' + result;
+                result = result.trim();
+                msg += ' > data: ' + result;
             }
             fn(msg);
             resolve(result);
diff --git a/libs/logger.js b/libs/logger.js
index bfb436b..55bdc7d 100644
--- a/libs/logger.js
+++ b/libs/logger.js
@@ -113,11 +113,7 @@ function error(message) {
         }
         return;
     }
-    if (message.message) {
-        trace(message.message, 'error');
-        return;
-    }
-    trace(message, 'error');
+    trace(message.toString(), 'error');
 }
 
 // default logging function
diff --git a/libs/server.js b/libs/server.js
index 9365466..8e9565a 100644
--- a/libs/server.js
+++ b/libs/server.js
@@ -1,7 +1,6 @@
-const logger = require('../libs/logger.js');
-const commands = require('../libs/commands.js');
+const logger = require('./logger.js');
+const commands = require('./commands.js');
 const http = require('http');
-const { time } = require('console');
 
 let server;
 let api;
@@ -9,7 +8,7 @@ let api;
 async function start() {
     const listen = global.config?.server?.listen || '0.0.0.0';
     const port = global.config?.server?.port;
-    buildAPI();
+    setupAPI();
     if (server === undefined) {
         server = http.createServer();
     }
@@ -35,8 +34,13 @@ async function respond(request, response, endpoint) {
         return;
     }
     let data = {
-        status: 'ok'
+        status: 'ok',
+        command: endpoint.command,
+        args: endpoint.args
     };
+    if (endpoint.detached === true) {
+        data.detached = true;
+    }
     let code = 200;
     if (endpoint === undefined) {
         code = 501;
@@ -48,20 +52,24 @@ async function respond(request, response, endpoint) {
         data.msg = 'endpoint does not support ' + request.method + ' requests';
     } else {
         try {
-            data.result = await commands.execute(endpoint);
+            const result = await commands.execute(endpoint);
+            if (result !== undefined) {
+                data.result = result;
+            }
         } catch (err) {
             code = 501;
             data.status = 'error';
-            data.msg = err;
+            data.msg = err.toString();
         }
     }
+    data.time = new Date().getTime() - request.timestamp + 'ms';
     const json = JSON.stringify(data);
     response.writeHead(code);
     response.end(json);
-    logger.http({ request: request, code: code, data: data });
+    logger.http({ request: request, code: code, data: json });
 }
 
-function buildAPI() {
+function setupAPI() {
     const apiConfig = global.config?.api;
     if (apiConfig === undefined || apiConfig.length === 0) {
         throw new Error('no api endpoints configured - aborting');
diff --git a/package.json b/package.json
index 19f692f..8128570 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,6 @@
   "description": "execute local commands remotely via http requests",
   "main": "remex.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
   },
   "keywords": [
     "scripts",