[Home](./index.md) > [@snowplow/node-tracker](./node-tracker.md) > [SelfDescribingJson](./node-tracker.selfdescribingjson.md) ## SelfDescribingJson type Export interface for any Self-Describing JSON such as context or Self Describing events Signature: ```typescript type SelfDescribingJson> = { schema: string; data: T extends any[] ? never : T extends {} ? T : never; }; ```