We need a way to indicate the set of variables that are available to templates in order to (a) validate messages that are being displayed (b) provide something that is readable by the Snippets Service in order to create appropriate admin UI I was thinking JSON schema might be a good option since there is pretty wide support for it in JS/Python, but it could be something else For our 61 experiment, the schema should match the existing one in https://github.com/mozmeao/snippets/blob/master/activity-stream/simple-snippet.html#L4

Commits pushed to master at https://github.com/mozilla/activity-stream https://github.com/mozilla/activity-stream/commit/e653af476c770ab0b797a44efc1eeb521fef6c99 Bug 1456158 - Add schema for AS Router Simple Snippet template https://github.com/mozilla/activity-stream/commit/e2b091726703f3c806222aff26d5a38603c72ddb Merge pull request #4153 from k88hudson/bug1456158 Bug 1456158 - Add schema for AS Router Simple Snippet template