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Verifiable Application Pattern

Verifiable applications (vApps) are a hybrid approach to building web services that integrate with public blockchains (L1s). They operate much like traditional web services on the frontend but may include key enhancements that set them apart:

  • Verified State Snapshots - Regular snapshots of the vApp's state can be taken and cryptographically proven; allowing anyone to independently verify correctness onchain.
  • Onchain Settlement - Onchain smart contracts can programmatically settle the vApp's state; creating a global point of synchronization.
  • Noncustodial By Design - vApp logic can be predefined, verified and enforced onchain; constraining the vApp or its operators from seizing or misusing user funds.
  • Protocol Enforced Withdrawals - vApps can enforce strong, onchain withdraw guarantees for users; constraining the vApp or its operators from discriminating against users via selective censorship.

Advantages Over Conventional Scaling Solutions

When compared to popular web3 scaling solutions such as rollups, vApps can bring distinct benefits to the table:

  • No Data Availability Bottleneck - By limiting the use of dynamically priced onchain resources to essential elements like state roots and proofs, vApps can scale more predictably. This approach is akin to Validium architectures.
  • Deeply Customizable UX - Developers can design bespoke state models and transaction types, enabling tailored functionality, security, and scalability far beyond what generalized blockchains or smart contracts allow for.

Dual Execution Paths: Fast & Verifiable

vApps operate on two parallel tracks:

  1. Realtime Hot Path - Delivers instant, scalable API-like responses using familiar web patterns.
  2. Verifiable Path - In the background, batches of transactions are cryptographically proven and merklized, producing delayed but independently verifiable state snapshots.

The Role of Public Blockchains (L1s)

In this setup, L1s play a few small but critical roles for vApps:

  • Programmatic Settlement - Publicly verified state transitions create a natural synchronization point and finality anchor.
  • Interoperability Hub - Assets, state, and services settling to the same L1 can bridge and interact seamlessly.
  • Censorship Resistance Backstop - By enforcing onchain conditions such as force-included transactions or DA challenges, vApps can inherit credible neutrality from the L1 they settle to.

Based on our current criteria, we view Ethereum as the ideal settlement layer for vApps. A smart contract on Ethereum can act as a light client for vApps and their users, benefitting from its expressive programmability, network effect of L2s, and inclusive accountability.

Liveness

Because the state of the vApp may not be made available onchain, it is important to note the risk of a vApp that goes offline. While access to the L1 can ensure that a user can always force-include a transaction, a vApp that goes offline could prevent a user from accessing their funds. Mechanisms such as rollbacks, DA committees, social deterrents, and other designs can be used to heavily disincentivize such a liveness failure, but this risk should be considered nonetheless for certain vApp types.

References & Inspiration