Why BUSL-1.1
The code is fully readable and usable on-chain. You can integrate with deployed x402r contracts, build on top of them, and inspect every line of source. The license protects against forks that compete with or commoditize the protocol (for example, stripping fees and redeploying), so that protocol fees can keep funding development, audits, and new features for everyone building on x402r.
BUSL-1.1 protects against that while keeping the code open. After the Change Date, everything converts to MIT and is fully permissionless. Uniswap, Aave, and other major DeFi protocols use the same approach.
License Terms
The Business Source License 1.1 covers all Solidity source files in x402r-contracts/src/.
| Parameter | Value |
|---|
| License | BUSL-1.1 |
| SPDX Identifier | BUSL-1.1 |
| Licensor | Ali Abdoli and Vrajang Parikh |
| Licensed Work | x402r-contracts |
| Copyright | 2025-2026 |
| Change Date | December 9, 2029 |
| Change License | MIT License |
What you can do
On-chain
You can interact with deployed x402r contracts:
- Integrate: call x402r contracts from your own contracts or dApps
- Build: create applications, services, and protocols on top of x402r
- Deploy via factories: use x402r’s official factories (for example,
PaymentOperatorFactory and EscrowPeriodFactory) to deploy your own operator instances with your own configuration
Off-chain
You can work with the source code:
- Read and learn from the code
- Fork and adapt for local development and testing
- Redistribute the source code
- Deploy locally: spin up Anvil, Hardhat, or any local or test environment for integration testing
The one restriction
Do not deploy x402r contracts outside of the official factories, whether modified or unmodified.
- Take the source code and deploy your own instances outside of the factories
- Deploy a modified fork (for example, removing fees or changing parameters) to any production chain
- Remove or change the license notice
Deploying to local chains, testnets, and private forks for development and testing is fine.
Change Date
On December 9, 2029 (or 4 years after the first public release of each version, whichever comes first), the license automatically converts to the MIT License, at which point you can deploy, fork, and do anything you want.
Summary
| Now | After Dec 9, 2029 |
|---|
| License | BUSL-1.1 | MIT |
| Integrate on-chain | Free | Free |
| Build on top | Free | Free |
| Deploy via factories | Free | Free |
| Deploy to local/testnet | Free | Free |
| Deploy outside factories | Not allowed | Free |
