Ask HN: YC hackathon Apr 13th, need idea? a team?

If we'd like to apply, are we expected to have an idea or a team assembled beforehand?

Can anyone who is familiar with YC hackathons before can share some details on the format of the event? and what we can expect compared to a traditional hackathon?

If so, I'm an entrepreneur with full stack skills looking to attend the event with a team.

email patrick.y.xie at gmail