Licenses
Our technology is available under a few different sets of terms, some open source, and some source-available.
- Smart Contracts: StarkWare’s smart contracts on Ethereum are all open source under Apache 2.0. This includes the StarkEx and Cairo Verifier smart contracts.
- Cairo Programs: StarkWare’s programs written in Cairo, including business logic included in StarkEx deployments, are open source under Apache 2.0.
- Cairo Compiler Toolchain: The toolchain used for developing Cairo 1.0 programs is open source under Apache 2.0.
- Stone Prover: The Stone prover is open-sourced under the Apache 2.0 license.
- Stwo Prover: The Stwo prover is open-sourced under the Apache 2.0 license.
- StarkEx Cloud Service: The StarkEx Prover cloud service is closed source, and currently operated by StarkWar
ethSTARK
Description
A library implementing ZK-STARK prover and verifier
Off-Chain Components
Prover – Open Source
Verifier – Open Source
On-Chain Components
None
StarkEx
Description
Scalability engine for commercial deployment
Off-Chain Components
Prover Service – Closed Source
Cairo Programs – Source Available
On-Chain Components
Cairo Verifier – Open Source
StarkNet / Cairo
Description
Scalability for L2 dApp developers
Off-Chain Components
Cairo Toolchain: StarkWare Toolchain License
Prover Service – Closed Source
StarkNet Prover (arriving later) – Polaris Source Available
On-Chain Components
StarkNet Polaris Verifier (arriving later) – Open Source
FAQs
What limitations does StarkWare's Source Available License impose on my use of Cairo programs?
You may distribute and run Cairo programs during the lifetime of the license, but you may not make commercial use of it, nor sell it. For more details, check the terms of the license here. The Source Available License applies for a limited time, while Starkware is considering what terms will apply afterwards.
Why did StarkWare adopt the Source Available License for its Cairo programs?
We wish to allow scrutiny of the programs and allow the public to read and audit the code in a transparent manner, during an initial testing period. StarkWare is still considering which licenses to use in the long term when releasing various components of the Cairo toolchain and applications built on it.
Why did StarkWare adopt the Source Available License for its Cairo programs?
Informally, the Polaris license says that anyone may use and modify the Prover code, including for commercial use, as long as proofs generated by it are submitted to one of the white-listed Polaris Verifiers. A white-listed Verifier is a smart contract address appearing on an append-only list, which means that StarkWare may only add Verifiers to that list, but never remove them.
The name Polaris (North Star) captures the essence of the license. The Polaris is a faithful address to which compasses and maps can be pointed, assisting free-roaming travellers on their myriad forays. Like the star, a Polaris Verifier is everlasting and unchanging. More coming soon.
The name Polaris (North Star) captures the essence of the license. The Polaris is a faithful address to which compasses and maps can be pointed, assisting free-roaming travellers on their myriad forays. Like the star, a Polaris Verifier is everlasting and unchanging. More coming soon.
If you have any questions about our products and how to use them, talk to us:
If you have any questions about our products and how to use them, talk to us: