Decoding Prop AMMs: Humidifi
What Is a Prop AMM?
A Proprietary AMM (Prop AMM) is a new breed of automated market maker that differs fundamentally from traditional AMMs like Uniswap or Raydium:
- Market-making logic is embedded directly inside on-chain programs
- Pricing comes from actively updated strategies, not fixed mathematical formulas
- Leverages Solana's high throughput and low latency for real-time price updates
Humidifi

At its peak, Humidifi accounted for nearly half of Solana's total trading volume — a remarkable feat for a single AMM.
XOR State Obfuscation

Humidifi uses hardcoded 64-bit XOR keys to obfuscate its internal state. Values are never stored in plain form on-chain, making it significantly harder for external observers to read pool state directly.
Q48 Extreme Precision

The protocol uses Q48 fixed-point arithmetic — 48 bits for the fractional part, providing approximately 14 decimal places of precision. This level of precision is critical for accurate pricing in high-frequency trading environments.
No Formula: Table-Driven Market Making

Instead of using a mathematical curve (like x * y = k), Humidifi uses lookup tables for pricing:
- Table A: 18 integers
- Table B: 30 integers
- Table C: 10 integers
Prices are determined by linear interpolation between table points, giving the market maker complete control over the pricing curve.
Built-In MEV Defense

Humidifi scans all instructions within the same transaction for non-whitelisted programs. This is an execution-layer MEV defense that prevents sandwich attacks and other MEV extraction techniques from operating within the same transaction.
Summary

Humidifi represents a new paradigm in AMM design:
- XOR-locked state prevents easy state reading
- Q48 precision ensures accurate pricing
- Lookup tables replace mathematical formulas
- Execution-layer MEV defenses protect against extraction
Despite these defenses, SolanaMevBot supports Humidifi through careful reverse engineering of the protocol's state and pricing mechanisms.