Prongs
A prong is a capped, conditional claim on N tokens in a vault. It is placed by a protocol, with the holder's consent.
Fields#
| Field | Description |
|---|---|
| Claim | Number of tokens the prong can take. Fixed at placement. |
| Class | collateral or sale. Determines compatibility. |
| Trigger | The on-chain condition that must be proven for the prong to execute. |
| Expiry | Time after which the prong lapses. |
| Seniority | Rank in the vault's settlement order. |
Claims#
A claim is a number of tokens, not a value. The contract rejects any prong whose claim would make the sum of claims exceed the tokens held. This is the over-pledge check.
Triggers#
A trigger identifies a verifier and its parameters. Examples:
- Lender: loan default proven, health factor below 1.0 at a Chainlink round.
- Options desk: call exercised, Chainlink price at expiry above strike.
- Club: club sale vote executed on-chain.
See Execution & proofs.
Seniority#
Prongs are settled by seniority. Rank 1 settles first.
- Rank is assigned at placement. A new prong ranks below all existing prongs on that asset.
- Ranks are relative. When a senior prong executes, is released or expires, every junior prong moves up one rank.
- When several triggers are proven in the same block, they settle in rank order.
Expiry#
Every prong has an expiry. At expiry the prong lapses and its claim returns to the free balance. Expiry is not extended by a freeze.
Compatibility#
Prongs have a class. Collateral prongs (lenders) take tokens on default. Sale prongs (options desks, clubs) deliver tokens on exercise or on a vote.
Collateral prongs stack freely under the cap. A sale prong can coexist with collateral prongs. Two sale prongs on the same asset in one vault are rejected. A share can be lent and covered by a call, never sold twice.
| Existing ↓ / New → | Lendercollateral | Options desksale | Clubsale |
|---|---|---|---|
| Lendercollateral | Allowed | Allowed | Allowed |
| Options desksale | Allowed | Rejected: A second Options desk prong would put two sale prongs on one asset. A share can be lent and covered by a call, never sold twice. | Rejected: Options desk with Club would put two sale prongs on one asset. A share can be lent and covered by a call, never sold twice. |
| Clubsale | Allowed | Rejected: Club with Options desk would put two sale prongs on one asset. A share can be lent and covered by a call, never sold twice. | Rejected: A second Club prong would put two sale prongs on one asset. A share can be lent and covered by a call, never sold twice. |
The same function drives this table and the simulator.
Rejections#
placeProng reverts when:
- the claim would exceed the free balance (over-pledge);
- the combination is incompatible;
- the asset is frozen;
- the placing protocol has insufficient $BZL staked;
- the holder's consent signature is missing, expired or invalid.