Building on Avalanche: Why HyperSDK

VEIL runs on a custom VM built with Avalanche's HyperSDK — not a Subnet-EVM fork. This post covers the technical rationale and tradeoffs.

Why Not Subnet-EVM

Subnet-EVM is great for EVM compatibility but locks you into EVM semantics. VEIL needs custom mempool behavior (threshold-encrypted sealed order flow), native proof verification in the execution path, and custom economic routing — none of which fit cleanly into the EVM model.

HyperSDK Advantages

• Custom action types (42 defined for VeilVM)
• Native proof verification in action execution
• Custom mempool semantics (sealed order flow, admission control)
• Deterministic batch clearing with configurable window timing
• Inherits Avalanche consensus finality and security

Companion EVM

A companion EVM layer provides interoperability for standard tooling, wallets, and DeFi integrations. The companion EVM is an interoperability rail — not the private execution engine. Privacy claims apply only to VeilVM-native paths.