ADR 0002: Hatcher NFA is soulbound
Status: Accepted Sprint: B.4 Date: 2026-04-17
Context
Hatcher is a Non-Fungible Agent representing a verified human participant. The NFA accumulates reputation based on outcomes the owner backed. The engineering spec left open whether Hatcher NFAs should be transferable, licensable, or sellable.
Decision
Soulbound. Hatcher NFAs are non-transferable. Burning is admin-gated (used only for severe-misconduct slashing).
Rationale
- Reputation collapse. If a Hatcher with 8,000 rep sells the NFA to someone who hasn't done the work, the buyer inherits trust they didn't earn. The entire Hatch Score signal depends on Hatcher reputation being causally linked to one human's behavior.
- Sybil surface. Transferable NFAs create a secondary market where attackers buy high-rep identities to manipulate hatching phases or vouching. World ID nullifier protection is defeated if the NFA itself is tradable.
- Incentive alignment. Hatchers who know they can sell will play for short-term rep extraction, not long-term participation. Soulbound enforces skin-in-the-game.
Alternatives Considered
| Option | Why rejected |
|---|---|
| Freely transferable | Collapses reputation causality; breaks Sybil protection |
| Transferable with rep reset on transfer | Destroys value signal — new owner pays for nothing |
| Leasable (revocable transfer) | Adds complexity + still allows rep laundering per session |
| Soulbound with explicit admin-gated burn | Chosen — preserves signal; allows slashing |
Consequences
- Hatchers cannot sell their position; liquidity is not an option.
- Mitigated by rewards (Sprint D.6) + future HATCH-token value share (Sprint K.3).
- If a Hatcher wants to exit, we need a "retire" flow that doesn't require burning — parked for Sprint D.3 refinement.