Kaspa is expanding beyond simple transactions by introducing ways to run “smart” programs on its network. What makes Kaspa unique is that it’s pursuing two different paths for programmability: Layer-2 smart contracts (like the Kasplex L2 rollup) and vProgs (verifiable programs) that live directly on the main layer.
If you’re new to these terms, don’t worry — this guide explains what each does, how they work, and how they differ, using clear examples that anyone can follow.
What Are Layer-2 Smart Contracts on Kaspa?
Layer-2 (L2) smart contracts are programs that run on a secondary network built on top of Kaspa’s main blockchain (Layer-1). Independent teams like Kasplex and Igra Labs have already launched these L2 solutions to bring smart contracts to Kaspa.
You can think of a Layer-2 as an overlay network — it relies on Kaspa’s base layer for security and ordering, but the actual smart-contract code runs off the main chain.
Kasplex, for example, is an EVM-compatible rollup. This means it can run Ethereum-style smart contracts while using Kaspa for data storage and transaction ordering.
Here’s how it works in simple terms:
- Anchoring on L1: When you interact with an L2 smart contract, you send a special transaction to the Kaspa main chain. That transaction includes some encoded instructions or contract data. Kaspa processes and timestamps it like any normal transaction.
- Execution on L2: The L2 network monitors the Kaspa chain, picks up those special transactions, and runs the logic off-chain in its own EVM environment. The L2 keeps the contract’s internal state and updates it according to the rules.
- Verification: Because every transaction was recorded on the Kaspa chain, anyone can re-execute the L2 code independently to verify the results. Kaspa doesn’t run the code itself — it simply provides the secure timeline of inputs.
Think of Kaspa’s L1 as the court clerk that logs every instruction, while the L2 is the assistant who carries them out.
Users who want to interact with L2 contracts typically use a bridge. For example, they might lock KAS coins on the main chain and receive equivalent tokens on the L2. When they’re done, they can bridge them back.
That’s how you can trade, stake, or mint NFTs on Kasplex without the base chain doing any heavy computation.
Advantages of Kaspa’s L2:
- High scalability and fast execution.
- Ethereum-compatible code (developers can use Solidity).
- Uses Kaspa’s security and data layer for settlement.
The trade-off is that you temporarily move funds through a bridge and rely on a secondary network to execute contracts.
What Are vProgs (Verifiable Programs)?
vProgs, or verifiable programs, are Kaspa’s innovative approach to running smart contracts natively on the main chain — but in a completely different way.
Unlike L2s, vProgs don’t live on another network. They’re designed to be a built-in Kaspa feature, using cryptographic proofs to guarantee correctness.
A vProg runs its computation off-chain, then produces a zero-knowledge proof showing that the result follows the program’s rules. Kaspa’s nodes verify the proof on-chain. If the proof is valid, Kaspa accepts the update.
So instead of every node repeating the same contract code (as Ethereum does), Kaspa only verifies the proof that it was done correctly.
Imagine solving a huge math problem and handing in a sealed certificate saying, “I solved it right.” Kaspa checks the certificate instantly — no need to redo the math.
That’s what makes vProgs powerful: they let complex applications exist without burdening the network.
Each vProg is a self-contained system. It has its own rules and internal state. Kaspa accepts updates from a vProg only if the zero-knowledge proof confirms that the new state is valid.
They’re also sovereign yet composable — each program operates independently but can still read data from others. For instance, one vProg could reference prices or user balances from another, without being able to change them directly.
An advanced feature called proof stitching allows combining proofs from several vProgs into one, so different applications can interact atomically. Imagine a transaction that includes a lending operation and a token swap in one go — both succeed or both fail together, verified by a single proof.
And since vProgs operate on Kaspa’s main chain, there are no bridges, no side networks, and no extra tokens. Everything happens under the same security model as normal KAS transactions.
Example: How Each Works in Practice
Let’s compare the two using an easy-to-grasp example.
Example 1: Decentralized Exchange on L2
Alice wants to trade tokens on a DEX that runs on Kasplex. She first bridges her KAS to the L2. Then she uses a web interface connected to the L2 network to make a trade. The contract matches her order, updates balances, and records the result.
Kaspa’s main chain doesn’t run any code — it just logs the transaction and ensures the sequence is immutable. Later, Alice can bridge her tokens back.
Everything works fast and cheaply, but it depends on the L2 and the bridge.
Example 2: A Lending + Swap Combo with vProgs
Now imagine a future where Kaspa supports vProgs. Alice uses one vProg to borrow stablecoins and another to swap them for a different token — all in one transaction.
Her wallet computes both operations off-chain, generates one combined proof (using proof stitching), and submits it to Kaspa. The network verifies it instantly.
If every rule checks out, both actions finalize atomically. No bridging, no waiting, and no risk of one leg failing halfway through.
That’s the promise of vProgs: true cross-application atomicity, verified cryptographically at the base layer.
How They Differ
Both L2 smart contracts and vProgs make Kaspa programmable, but their approach and purpose are very different.
Layer-2 smart contracts extend Kaspa outward. They’re separate networks (like Kasplex) that rely on Kaspa for ordering and data but execute everything off-chain. They use established technologies like the EVM, so developers can build quickly and users can interact using familiar wallets. They’re available now, ideal for DeFi apps, NFT marketplaces, and other quick-to-deploy projects.
vProgs extend Kaspa inward. They’re part of the main layer itself — verifiable programs that use zero-knowledge proofs to ensure correctness without requiring every node to re-execute the code. They promise a future where users interact directly with smart logic on L1, with no bridges or side networks.
In short:
- L2 smart contracts are fast, live, and familiar, but rely on an external network.
- vProgs are native, trustless, and future-proof, but still under development.
L2s bring Kaspa full smart-contract capability right now; vProgs aim to make that functionality intrinsic to Kaspa’s DNA later on.
Which Will Be Used for What?
Both will likely coexist and even complement each other.
Developers who want to launch dApps quickly or port Ethereum projects will use L2 platforms like Kasplex — ideal for DeFi, NFTs, and high-volume applications.
vProgs, on the other hand, will attract builders focused on long-term security and deep on-chain composability — projects like DAOs, financial primitives, or any system that benefits from atomic cross-app logic verified at the base layer.
Over time, Kaspa may host a mixed ecosystem: some applications on L2s for speed and flexibility, others on vProgs for direct on-chain trust and precision.
Conclusion
Kaspa is taking a two-track path to programmability.
Layer-2 smart contracts make Kaspa powerful right now by adding familiar, Ethereum-like tools on a fast, secure foundation.
vProgs represent Kaspa’s long-term vision — native, verifiable, and bridge-free smart contracts that operate directly on Layer-1.
Together, they show Kaspa’s ambition: to scale both outward (through L2 networks) and inward (through cryptographic innovation), without compromising its speed or decentralization.
The result will be a blockchain that not only confirms transactions faster than almost any other, but also runs logic and applications with the same efficiency — whether on today’s L2s or tomorrow’s verifiable programs.
