I had the same problem and used a JSONSchema as a single source of truth. Then from that schema you can generate: - the typescript interfaces: https://www.npmj

I had the same problem and used a JSONSchema as a single source of truth. Then from that schema you can generate: - the typescript interfaces: https://www.npmjs.com/package/json-schema-to-typescript https://www.npmjs.com/package/json-schema-to-typescript - the runtime checks with AJV So you have no duplication and you're type safe.