Ask HN: Language Server Protocol for backend frameworks and API languages?

Language Server Protocol solves the problem where M integrated development environments need to work with N programming languages. There's a similar problem where M web backend frameworks like Spring or ASP.Net or Express.js need to interact with N API description languages like OpenAPI or OData or GraphQL. In a perfect world there would be a single source of truth and no duplication between the API schema and the backend implementation. This is somewhat hard because currently every framework needs its own integration with every API description language. Perhaps there's space for a protocol that would standardize this interaction: integrate every backend framework once, then integrate every API description language once, then use any backend framework with any API description language with no duplication.