USC Testnet v2: The Next Generation of Universal Smart Contracts
We're excited to introduce USC Testnet v2, the next generation of Universal Smart Contracts that delivers faster execution, simpler integration, and significantly improved developer experience. This represents a natural evolution - taking the existing model and optimizing it for real-world deployment.
Why USC Testnet v2?
USC Testnet v1 was our initial implementation using STARK proofs and a more complex architecture. V1 successfully demonstrated the viability of Universal Smart Contracts, providing strong cryptographic security guarantees through its STARK proof system and establishing a solid foundation for cross-chain state verification. It served as an important proof of concept that validated the core concepts and enabled real-world testing. However, through extensive use and feedback, we identified opportunities to create a much more efficient and developer-friendly system.
USC Testnet v2 is the result of that optimization: a streamlined architecture that maintains the same security guarantees while dramatically improving performance, simplicity, and cost efficiency.
We will be maintaining both testnets during a transition period to give existing developers time to migrate their projects. However, we strongly recommend building new projects on v2 and migrating existing v1 projects as soon as possible.
What's New in USC Testnet v2?
Performance: Orders of Magnitude Faster
USC Testnet v1: Proof verification took 6-20 minutes using STARK proofs
USC Testnet v2: Verification completes in a single Creditcoin block, i.e., under 15 seconds, using native Merkle proof
End-to-end time is reduced drastically - from minues to seconds - providing instant feedback and orders of magnitude higher throughput compared to v1's processing.
Simplicity: Cleaner Architecture with Fewer Dependencies
USC Testnet v1: Required multiple external dependencies (Cairo, STARK proof systems, Python toolchains, specialized verifiers)
USC Testnet v2: Streamlined architecture using standard Solidity and Rust with Merkle proofs, eliminating the need for specialized proof generation infrastructure
The architecture eliminates specialized toolchains (Cairo compiler, Stone Prover, Python environments) and reduces dependencies to familiar, well-maintained libraries. Developers now work with a single synchronous function call instead of managing multi-step async processes with prover contracts and parsing complex ResultSegments.
Cost Efficiency: Streamlined Operations
USC Testnet v1: Required high-compute infrastructure and complex dependency management for STARK proof generation
USC Testnet v2: Runs efficiently on standard servers with minimal external dependencies
The system now runs on standard servers instead of specialized compute clusters, with fewer external dependencies reducing maintenance overhead and security updates. Fewer transactions per query result in significant gas savings, with even greater reductions for batch operations.
Developer Experience: Greatly Improved
USC Testnet v1: Developers had to handle async flows with multiple steps - submitting queries to prover contracts, waiting for processing, retrieving ResultSegments, and parsing complex data structures
USC Testnet v2: Simple, synchronous API with standard tools and minimal dependencies - no prover contracts, no async waiting, no complex data parsing
The API now uses a single function call with direct precompile calls instead of multi-step async processes, parsing data directly from transaction bytes instead of retrieving and parsing ResultSegments from prover contract storage. Clear error messages and faster iteration cycles enable developers to get started without understanding prover contract flows or async query management.
Security: Same Guarantees, Simpler Implementation
USC Testnet v1: STARK proofs provided strong security guarantees
USC Testnet v2: Native Merkle proofs with enhanced security features
Native Merkle proofs maintain the same cryptographic guarantees while adding atomic operations that eliminate race conditions and reducing the attack surface through fewer components.
Offline Attestation Aggregation: Scalable Consensus
USC Testnet v1: Individual signature verification scaled linearly with attestor count
USC Testnet v2: Offline BLS signature aggregation via gossip protocol before on-chain submission
The gossip protocol coordinates attestation votes off-chain, resulting in fixed-cost signature verification instead of per-attestor costs. This provides significant gas savings per additional attestor, especially for larger attestor sets (20+ attestors), while reducing on-chain transaction and communication overhead.
Should You Migrate?
If you're already building on USC Testnet v1
We strongly recommend migrating to USC Testnet v2 to take advantage of:
- Significantly faster performance (seconds vs. minutes)
- Simpler development workflow
- Lower gas costs
- Better long-term support and active development
The migration path is straightforward, and the improved developer experience will make your development process significantly smoother.
If you're new to USC
Start with USC Testnet v2. It's the future of the platform, offers a much better developer experience, and will receive updates and improvements.
Frequently Asked Questions
I am already currently building on USC Testnet v1, should I migrate to USC Testnet v2?
It is strongly recommended that you migrate to USC Testnet v2. While USC Testnet v1 will continue to be supported until the end of March, v2 offers significant advantages:
- Performance: Queries complete in seconds instead of minutes
- Developer Experience: Simpler API with synchronous calls instead of complex async flows
- Cost Efficiency: Lower gas costs and reduced operational overhead
- Easier Maintenance: Fewer dependencies and simpler architecture
- Future-Proof: Future support and improvements will focus on v2
The migration process is straightforward with provided documentation, guides and other support resources to help you transition smoothly.
Until when will USC Testnet v1 be supported?
USC Testnet v1 will be supported until the end of March. After this date, we will focus all resources on USC Testnet v2. We recommend planning your migration well before this deadline to ensure a smooth transition.
I am interested in building with USC and haven't started yet, which one should I build with?
We strongly recommend starting with USC Testnet v2. It offers a simpler developer experience, faster performance, lower costs, and is where future development and support will be focused. Starting with v2 will save you time and effort in the long run.
Will my v1 code work on v2?
The APIs are different, so you'll need to update your integration code. However, the migration is straightforward, and the v2 API is simpler to work with. We provide documentation, guides and other support resources to help with the transition.
Can I use both testnets simultaneously?
Yes, both testnets are currently running. However, we recommend focusing on v2 for new development and planning your v1 migration as soon as possible.
Where can I find documentation and resources for USC Testnet v2?
You can find comprehensive documentation, guides, migration resources, and examples in the USC Product Overview section of the Creditcoin dev docs. This includes:
- Architecture overview and technical documentation
- Developer guides and integration examples
- API references and smart contract interfaces
- Migration guide for moving from v1 to v2
- Tutorials and code examples
Let's see what you can BUIDL!