diff --git a/ext/README b/ext/README
index 2b1f6f01..43894e02 100644
--- a/ext/README
+++ b/ext/README
@@ -9,3 +9,7 @@ debug.py
 on-modify.timewarrior
   This is a Taskwarrior hook script that will integrate Timewarrior.
 
+csv.py
+  This extension exports the data in CSV format, with a variable number of tag
+  fields.
+
diff --git a/ext/csv.py b/ext/csv.py
new file mode 100755
index 00000000..de8ee77a
--- /dev/null
+++ b/ext/csv.py
@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+
+import sys
+import json
+
+# Skip the configuration settings.
+for line in sys.stdin:
+  if line == '\n':
+    break;
+
+# Extract the JSON.
+doc = ''
+for line in sys.stdin:
+  doc += line
+
+total_active_time = 0
+
+j = json.loads(doc)
+for object in j:
+  line = '"%s",' % object['start']
+  line +='"%s"' % (object['end'] if 'end' in object else '')
+
+  if 'tags' in object:
+    for tag in object['tags']:
+      line += ',"%s"' % tag
+
+  print line