Do both servers need Dungeon Keeper?

For a bot-to-bot collaboration, yes. One-sided partnerships can be tracked without the other server running the bot.

Does the auction system process payments?

No. Auction listings are for staff to manage. No payment is processed.

Track collaborations and shared servers in one place, and keep partner promotions running without manual reposting.

Partnerships and collaborations
Record partnerships, or link two servers running Dungeon Keeper in a bot-to-bot collaboration.
Scheduled promotions
Create promotion messages for any active partnership and have them posted on schedule.
Cross-server verification
Share verification results with partner servers you trust.
Counting game
Run a counting channel with milestones for your community.
Auctions and staff availability
Run listings for staff-managed auctions, and post an availability schedule for your team.

Do both servers need Dungeon Keeper?: For a bot-to-bot collaboration, yes. One-sided partnerships can be tracked without the other server running the bot.
Does the auction system process payments?: No. Auction listings are for staff to manage. No payment is processed.