HL Price Guard: read Hyperliquid prices safely from HyperEVM
A Solidity library for any HyperEVM app that leans on HyperCore prices. It returns the oracle price and refuses it when other views of the market disagree beyond bounds you set.
What it does
Price read
Reads the oracle, mark and best bid/ask through the precompiles, with the two index encodings they use (checked on mainnet).
Deviation checks
Rejects the oracle when the book or the mark is too far from it.
Independent reference
Compares against a price from outside Hyperliquid (Pyth on HyperEVM).
Jump latch
Trips on a jump between reads and stays tripped until the app re-arms it, which it should do only after checking the price independently.
Exposure cap
Caps the notional settled per time window, including a rolling window no stretch of time can exceed.
Request an Operator Readiness Review
For teams opening a HIP-3 market, or already running one.
Where it stops
It reads and checks prices and caps exposure. Pools, liquidation and UI belong to the apps that use it.
Versions are tagged. Apps should pin a tag and move to a new one deliberately.
Evidence
Two incidents rebuilt from public data: one wallet that moved ETH's mid on Hyperliquid and settled 500x positions against it (2026-10-10), and a deployer oracle that fell 15.6% in one update (xyz:SKHX, 2026-07-27). In the first, the oracle also moved with the push, so a bounds check would not have caught it; in our replay, an exposure cap of $3.3M per minute would have cut the take to an estimated $55K, below the $130,873 the push cost (assuming the incident's average edge and pushes that cost what Papertrade's did; an estimate, not a bound).
The SK Hynix replay in HIP-3 RecordWhere it stands
- Tested with forge, with the precompiles mocked at their real addresses using mainnet values.
- It has not been audited.
- The source is public under Apache-2.0: github.com/fabrknt/hl-price-guard. Pin a tagged version.
Used in
Our own projects pin it by tag, the way an outside app would.
- Day One · a launch pool for new HIP-3 listings: price checks, the jump latch and the rolling cap.
- hyperevm-lend · a lending market: borrowing and withdrawals go through the guarded read.
- hyperevm-perp · a perp pool that settles through the guarded read.
Operator Readiness Review
For teams opening a HIP-3 market, or already running one. We check your setup against what has gone wrong for HIP-3 operators in the public record, and say what we could not check.