At a Slay the Spire 2 rest site you normally pick one option: Rest heals 30% of your max HP, Smith upgrades a card. Both relics below change that choice.

What each relic does

RelicRarityEffect
Miniature TentShop (Merchant only)You may choose any number of options at rest sites
Eternal FeatherUncommonWhen you enter a rest site, heal 3 HP for every 5 cards in your deck

With Miniature Tent you can Rest and Smith at the same rest site, and also use any extra options your relics add, such as Cook or Clone.

Eternal Feather heals as soon as you enter, so you keep your one option for Smith or anything else.

Eternal Feather healing by deck size

Cards beyond a multiple of 5 do not count.

Deck sizeHeal on entering
10-146
15-199
20-2412
25-2915
30-3418

Compared with Rest

Max HPRest heals (30%)
6018
7021
8024
9027

A 20-card deck with Eternal Feather heals 12 on every visit and still Smiths. Miniature Tent gives the full Rest heal and a Smith on the same visit.

Every path in an act passes a rest site right before the boss, in addition to the rest sites placed on the map. See map generation.