Ask HN: Swagger and RAML model APIs. Is there anything similar to model events?

My company needs to model a lot of events, similarly to how apis are modelled - that is to say, we'll need a standardised system for the "contracts" and a toolset built around them (parsers, linters, UI...).

Is there something on the market we can use either as an out-of-the-box solution or as a starting point?