The Standard Message Format is an expression of a message, including its content, type, targeting, and timing using JSON. Here is an example:
{
id: "PIN_TABS",
message_type: "feature_callout",
template: "cfr_general",
content: {
title: "Try Pinning a Tab",
body: "Find a better example"
},
targeting: "hasFxAccount && !addonsInfo.addons['activity-stream@mozilla.org']",
trigger: "visitSite(gmail.com)"
frequency: {
lifetime: 20,
custom: [{period: "daily", cap: 5}, {period: 3600000, cap: 1}]
}
}