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+Testing a schema
+----------------
+There are [many](http://json-schema.org/implementations.html) JSON Schema
+validators you can use to validate incoming events. Not all of them support
+JSON Schema v4, and some of them have bugs which prevent ``$ref`` from being
+resolved correctly. For basic CLI testing, we recommend and have verified they
+work with the Node.js package [z-schema](https://github.com/zaggino/z-schema):
+```
+ $ npm install -g z-schema
+ $ z-schema m.room.message /path/to/json/file.json
+ schema validation passed
+ json #1 validation passed
+```