the-algorithm/unified_user_actions/graphql/TweetHydration.graphql

query TweetHydration($rest_id: NumericString!) {
  tweet_result_by_rest_id(rest_id: $rest_id, safety_level: ForDevelopmentOnly) {
    result {
      ... on Tweet {
        core {
          user {
            legacy {
              id_str
            }
          }
        }
      }
    }
  }
}