1 files changed, 26 insertions, 0 deletions
diff --git a/README.md b/README.md
new file mode 100644
index 00000000..3ae3775b
--- /dev/null
+++ b/README.md
@@ -0,0 +1,26 @@
+# OpenXC Message Format Specification
+
+There are two valid message types - single valued and evented.
+
+There may not be a 1:1 relationship between input and output signals - i.e. raw
+engine timing CAN signals may be summarized in an "engine performance" metric on
+the abstract side of the interface.
+
+## Single Valued
+
+The expected format of a single valued message is:
+
+{% highlight javascript %}
+{"name": "steering_wheel_angle", "value": 45}
+{% endhighlight %}
+
+## Evented
+
+The expected format of an event message is:
+
+{% highlight javascript %}
+{"name": "button_event", "value": "up", "event": "pressed"}
+{% endhighlight %}
+
+This format is good for something like a button event, where there are two
+discrete pieces of information in the measurement.