diff --git a/lib/app.js b/lib/app.js
index 709f78d2..d4d5f00c 100644
--- a/lib/app.js
+++ b/lib/app.js
@@ -54,9 +54,9 @@ module.exports = function(options) {
       }
       plugins.configure(config);
       next();
-    });    
+    });
   };
-  
+
   var authMiddleware;
 
   if (options.https) {
diff --git a/lib/plugins.js b/lib/plugins.js
index d8494f80..dbbdbb85 100644
--- a/lib/plugins.js
+++ b/lib/plugins.js
@@ -1,9 +1,9 @@
 'use strict';
 
+var uuid = require('node-uuid')
 var _ = require('lodash');
 var async   = require('async');
 var logger  = require('./logger');
-
 var argv = require('minimist')(process.argv.slice(2));
 
 var SATOSHI_FACTOR = 1e8;
@@ -323,7 +323,18 @@ exports.stateChange = function stateChange(session, rec, cb) {
     fingerprint: session.fingerprint,
     eventType: 'stateChange',
     note: JSON.stringify({state: rec.state, sessionId: session.id}),
-    deviceTime: rec.deviceTime
+    deviceTime: session.deviceTime
+  }
+  db.machineEvent(rec, cb)
+};
+
+exports.recordPing = function recordPing(session, rec, cb) {
+  var rec = {
+    id: uuid.v4(),
+    fingerprint: session.fingerprint,
+    eventType: 'ping',
+    note: JSON.stringify({state: rec.state, sessionId: session.id}),
+    deviceTime: session.deviceTime
   }
   db.machineEvent(rec, cb)
 };
diff --git a/lib/postgresql_interface.js b/lib/postgresql_interface.js
index f1311271..f0e1116b 100644
--- a/lib/postgresql_interface.js
+++ b/lib/postgresql_interface.js
@@ -100,17 +100,6 @@ exports.recordBill = function recordBill(session, rec, cb) {
   });
 };
 
-exports.recordDeviceEvent = function recordDeviceEvent(session, event) {
-  connect(function(cerr, client, done) {
-    if (cerr) return;
-    var sql = 'INSERT INTO device_events (device_fingerprint, event_type, ' +
-      'note, device_time) VALUES ($1, $2, $3, $4)';
-    var values = [session.fingerprint, event.eventType, event.note,
-      event.deviceTime];
-    client.query(sql, values, done);
-  });
-};
-
 function query(client, queryStr, values, cb) {
   if (!cb) {
     cb = values;
@@ -514,11 +503,20 @@ exports.cartridgeCounts = function cartridgeCounts(session, cb) {
 };
 
 exports.machineEvent = function machineEvent(rec, cb) {
+  var TTL = 2 * 60 * 60 * 1000
   connect(function(cerr, client, done) {
     if (cerr) return cb(cerr);
-    var sql = 'insert into machine_events (id, device_fingerprint, event_type, note, device_time) ' +
-      'VALUES (?, ?, ?, ?, ?)';
-    var values = [rec.id, rec.fingerprint, rec.eventType, rec.note, rec.deviceTime]
+    var fields = ['id', 'device_fingerprint', 'event_type', 'note', 'device_time', 'created']
+    var sql = getInsertQuery('machine_events', fields, false)
+    var values = [rec.id, rec.fingerprint, rec.eventType, rec.note, rec.deviceTime, new Date().toISOString()]
+
+    var deleteSql = 'DELETE FROM machine_events WHERE created < $1';
+    var deleteValues = [new Date(Date.now() - TTL).toISOString()];
+
+    query(client, deleteSql, deleteValues, function(err) {
+      if (err) console.error(err)
+    })
+
     query(client, sql, values, function(err, results) {
       done();
       return cb(err, results);
diff --git a/lib/routes.js b/lib/routes.js
index a032a3c7..8ecd8c60 100644
--- a/lib/routes.js
+++ b/lib/routes.js
@@ -78,6 +78,10 @@ function poll(req, res) {
 
     res.json(response);
   });
+
+  plugins.recordPing(session(req), req.query, function(err) {
+    if (err) console.error(err);
+  });
 }
 
 function trade(req, res) {
@@ -89,6 +93,7 @@ function trade(req, res) {
 
 function stateChange(req, res) {
   plugins.stateChange(session(req), req.body, function(err) {
+    if (err) console.error(err)
     res.json(200)
   })
 }
@@ -211,7 +216,11 @@ function init(localConfig) {
 }
 
 function session(req) {
-  return {fingerprint: getFingerprint(req), id: req.get('session-id')};
+  return {
+    fingerprint: getFingerprint(req),
+    id: req.get('session-id'),
+    deviceTime: Date.parse(req.get('date'))
+  };
 }
 
 function getFingerprint(req) {