Formal specification of serverless.yml

Does anyone here know of there is a formal specification for a serverless.yml file? I’m working on some tooling for vscode that leverages the yaml server extension’s ability to map a file to a json schema. I’ve got the start of one here ( ) but it’s largely incomplete because I wasn’t able to find documentation on what fields are defined across the supported providers. If there’s any documentation ( source code links are fine ) that would help me completed this schema that would be great!