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DocumentationCatalyst1100198 - Multiplatform support

Multiplatform Plutus Script Cost & Evaluation Library (JS/JVM/LLVM)

IdeaScale Link: https://cardano.ideascale.com/c/cardano/idea/111227 

Project Number: 1100198

Project Manager: Alexander Nemish

Date Project Started: 2024-03-11

Date Project Completed: 2025-06-23

Project Description

At the moment of project initiation, there was no library to evaluate Plutus scripts and its execution budget except Haskell implementation.

The goal of this project was to create a multiplatform library for evaluating Plutus scripts and calculating their execution budget on JVM, JavaScript, and Native platforms. The library is written in Scala 3 and compiles to all three platforms, providing a unified codebase that significantly reduces code duplication and enhances developer productivity.

List of Challenge/Project KPIs and How the Project Addressed Them

The key performance indicators (KPIs) for this project were:

  1. Plutus Script Evaluation: The library must accurately evaluate Plutus V1 and V2 scripts, including built-in functions and data models.
  2. Execution Budget Calculation: The library must calculate the execution budget for Plutus scripts, ensuring compatibility with Cardano’s cost model.
  3. Testing and Validation: The library must pass all Plutus V1 and V2 conformance tests and be tested against a substantial number of Mainnet scripts to ensure reliability and accuracy.
  4. Cross-platform Compatibility: The library must compile and run on JVM, JavaScript, and Native platforms
  5. Publish Platform Artifacts: The library must be published as platform artifacts for JVM and JavaScript platforms, ensuring easy integration into existing projects.

We successfully addressed these KPIs through the following achievements:

  1. Robust Scala 3 implementation of Plutus V1/V2 CEK virtual machine.
  2. Complete implementation of Plutus V1/V2 built-in functions and data model.
  3. Comprehensive Plutus V1/V2 cost models and execution budget calculation logic.
  4. UPLC parser and pretty-printer implementation.
  5. Successful compilation to JavaScript using Scala.js .
  6. Successful compilation to native binaries via Scala Native  and LLVM .
  7. Full compatibility and availability for JVM languages, including Java and Kotlin.
  8. Extensive testing using property-based testing with ScalaCheck  and ScalaTest , and comparing results with the Haskell uplc CLI tool to ensure we are getting the same results as the reference implementation.
  9. Passing all Plutus V1 and V2 conformance tests 
  10. Extensive testing on ~100k mainnet Plutus scripts, ensuring high accuracy and reliability.
  11. Publishing platform artifacts on Maven Central  for JVM, and NPM  for JavaScript platforms, making the library easily accessible for developers.
  12. Integration into the BloxBean Cardano Client Library (CCL)  - a JVM transaction building library as a TransactionEvaluator implementation. This integration allows developers to calculate the exact execution budget and fees during Transaction construction, eliminating the need for querying an external service and speed up transaction building.

Key Achievements

Cross-platform Plutus Execution

Provided robust implementations of Plutus V1/V2 Virtual Machine across JVM, JavaScript, and Native platforms from the same codebase.

Developer Efficiency

Enabled significant code reuse through multiplatform Scala 3 compilation, enhancing developer productivity.

Accuracy and Reliability

Passed all Plutus V1 and V2 Plutus Conformance , demonstrating compatibility with the reference Haskell implementation.

Implemented thorough testing against ~100k Cardano mainnet scripts to ensure correctness and reliability.

Adoption

Scalus ability to calculate Plutus script budgets and evaluate scripts has been integrated into BloxBean Cardano Client Library (CCL)  and is used in production by Cardano Foundation.

Current applications and protocols using Scalus include:

  • Hydrozoa Protocol  A simplified and modern Hydra implementation.
  • Binocular  A decentralized optimistic Bitcoin oracle on Cardano.
  • Cosmex  A specialized L2 off-chain order book exchange protocol.

Key Learnings

Compiling Scala 3 to JVM, JavaScript, and Native from a unified codebase is achievable and highly beneficial, significantly improving maintainability and reducing code duplication. Ensuring platform agnosticism requires deliberate planning but is feasible with careful architectural considerations.

Overall, Scala 3’s multiplatform capabilities have proven to be a powerful tool for building cross-platform libraries, enabling us to deliver a robust and efficient solution for Plutus script evaluation and budget calculation across multiple platforms.

Next Steps for the Product/Service Developed

Ongoing development of Scalus includes the recent implementation of Plutus V3 CEK machine and Conway era built-in functions on JVM and JavaScript platforms.

Future integration plans involve Scalus JS library integration into Lucid Evolution  and Mesh.JS  for enhanced script budget evaluation capabilities.

Final Thoughts/Comments

Catalyst funding significantly accelerated our project’s development, providing essential resources that led to substantial adoption and validation.

Completion of this project makes Scalus the only end-to-end multiplatform and well tested Plutus execution library available today.

We remain committed to enhancing Scalus further as the leading platform for full-stack Cardano DApp development.

Here is the link to the full Scalus multiplatform capabilities video presentation: https://youtu.be/A8MQsGn5XFo 

There I demonstrate the Plutus V2 script evaluation and execution cost calculation on 3 platforms: JVM, JavaScript, and Native.

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