reaper/v1 package

Package reaper is a noticeboard whose garbage is a standing bounty.

Anyone can post a note with an expiry. Posting locks a storage deposit, paid by the poster. Once a note expires, anyone at all can delete it, and the chain refunds that deposit to whoever signed the deleting transaction. So the poster pays to occupy space and a stranger is paid to reclaim it.

Nothing here is a token, a reward pool or an emission schedule. The incentive is the chain's own storage accounting, which already works this way for every realm on gno.land; this realm only makes it legible. Reap and Compact are permissionless because the expiry predicate is checked on chain, so the worst a malicious reaper can do is waste their own gas.

Two collaborators own the parts this realm does not:

• gno.land/p/moul/ulist/v1 stores the notes and owns compaction. Its Delete is a soft delete that leaves a dead tree node behind, and its Compact frees those nodes without moving any live index.
• gno.land/p/moul/x/storagecost/v0 owns the arithmetic: what a byte refunds, and how many bytes a transaction must free to pay for itself.
• gno.land/p/moul/kit/ui/v0 owns display: the escaping, the length cap and the address format. A note body is arbitrary bytes chosen by whoever paid to post it and is rendered back to every reader, so it is attacker-controlled input in a markdown slot. Render never emits a body unescaped; ui.Excerpt is what makes that true, and it delegates to p/nt/markdown/sanitize.

The realm deliberately cannot see its own byte count. No stdlib call exposes a realm's locked storage, so every figure Render shows is an estimate from payload length. The authoritative numbers are the chain's, in the StorageDepositEvent and StorageUnlockEvent each transaction emits.