XML or API for filing accounts?

The Information for Developers document says the XML platform is planned to be replaced by a (REST JSON) API in the long-term future. Webfiling is ending next year. I am a micro business managing everything myself. There does not appear to be much information at present about API accounts filing. My question is, will the API facility be available and properly documented before web-filing ends, or do I have to waste my time implementing a short-term XML solution?