Ask HN: What do you use to document API Contracts?

[ternaryJimbo]

For example, I work in a big company with many teams responsible for small components. My team has an API contract with our mobile app team and sometimes the mobile app team decides to change something in the API request format without telling us. We use Jira tickets to communicate these requirements. Wondering if anyone else has had this experience, of this other team is just being lazy.

[DaOne256]

OpenAPI spec as a YAML file in a git (Gitlab) repo.