Building on vProgs

Developing on Kaspa’s Layer 1 requires robust, efficient tooling. The ecosystem is rapidly maturing to support a seamless developer experience for writing, testing, and deploying Verifiable Programs (vProgs).

Silverscript

Kaspa introduces Silverscript, a high-level smart contract language that compiles directly into native Kaspa Script. Designed for flexibility, it empowers developers to write complex UTXO spending conditions without managing low-level assembly.

Recent upgrades have introduced compiler optimizations and opcode hardening, improving both the security and performance of the smart contract language as it moves closer to a production-ready state.

Community-driven testing recently identified and resolved a critical bug causing mismatches between compile-time and runtime integer math. This fix prevents silent, hard-to-debug errors and significantly improves the overall reliability of vProg execution.

Recently, a major refactoring of the SilverScript codebase was completed (PR #91). This significant overhaul simplifies the architecture, paving the way for more stable and rapid future development of the language.

Currently, an ecosystem consensus is forming to steer early development efforts toward Covenants. Because Silverscript offers a familiar, Solidity-like syntax, this strategy effectively lowers the barrier to entry, accelerating the deployment of smart contracts by providing a more accessible path than building low-level ZK-based vProgs directly.

Ongoing development continues to advance Silverscript’s core capabilities. Recent pull requests (such as PRs #95 and #96) iteratively build out the scripting functionality required for Kaspa’s next-generation smart contract layer.

Opcode Refinement and Standardization

The underlying native Kaspa Script is being continuously enhanced to support advanced applications. Recent developments include:

• Arbitrary Data Signatures: New opcodes (such as the proposed checkdatasig / CheckSignedMsgFromStack under review in PR #926) allow covenants to verify signatures on arbitrary data directly from the stack.

• Standardized Documentation: Comprehensive, standardized documentation for opcode stack usage is being rolled out to clarify developer expectations and reduce bugs.

• Flexible Number Encoding: The requirement for minimally encoded numbers in scripts has been removed from rusty-kaspa. This protocol simplification liberalizes integer encoding rules, offering greater flexibility for vProg developers and tooling.

• Advanced Authentication: The integration of new signature-checking opcodes (checkDataSig / checkSigFromStack) into both rusty-kaspa and the SilverScript compiler provides a fundamental building block for enabling complex authentication logic.

• Cross-Chain Opcode Research: Developers are actively analyzing use cases for BCH’s OP_CHECKDATASIG (typically used for oracle price verification) to evaluate proven patterns for on-chain data validation. Concurrently, discussions around OpCheckSigFromStack highlight its potential to enable concurrent payments and state validation without requiring consensus changes, effectively decoupling actions from specific UTXOs.

Enhanced Debugger Capabilities & WebAssembly

Building decentralized applications on a parallelized BlockDAG requires deep visibility into execution paths. The Kaspa developer tooling suite is expanding to include enhanced vProg debugger capabilities, allowing developers to step through complex multi-contract flows, inspect stack states, and simulate transactions locally before deploying to the TN12 testnet. Additionally, WebAssembly support continues to bridge the gap for browser-based toolchains and client-side proof generation.

To further streamline integration, recent architecture refinements (such as PR #935 in Rusty-Kaspa) separate core logic from WASM-specific types. This separation paves the way for easier usage across native Rust and Python SDKs. Meanwhile, rigorous R&D on the testnet continues to fortify the smart contract layer; active testing has identified and addressed vital edge cases, including potential integer overflow and clamping issues with large numbers.

SilverScript now officially supports source-level debugging and complex state-transition test scenarios. This represents a major leap in developer experience, drastically simplifying the process of building and testing sophisticated smart contracts.

Note: To accelerate the recent major codebase refactoring, the debugger recording feature was temporarily removed from the SilverScript compilation path. The development team plans to re-integrate this key developer tool soon as part of their iterative progress.

The Three-Layer Programmability Model

To help developers navigate Kaspa’s ecosystem, the community is framing programmability as a three-layer system:

• Covenants: Simple, L1-native local-state contracts (via Silverscript) for isolated actions and peer-to-peer flows.
• ZK-Inline: For verifying lightweight off-chain computations directly within a single transaction.
• ZK-Based (vProgs): Full off-chain execution with shared state for complex applications like rollups and heavy DeFi protocols.

This mental model clarifies the developer’s choice between on-chain versus off-chain logic based on specific application requirements.

Developer Experience (DevX)

The Kaspa R&D community is placing a heavy emphasis on Developer Experience (DevX) for the upcoming programmability features. Dedicated contributors are actively focusing on post-covenants DevX, ensuring that the powerful tools being built—from Silverscript compilers to ZK proving pipelines—are accessible, well-documented, and ready for builders.

Core Test Suite Hardening

Maintaining a robust testing environment is critical for developer velocity and the stability of future protocol upgrades. Recent infrastructure work (such as PR #944 in Rusty-Kaspa) focuses on fixing non-deterministic tests and race conditions, ensuring that the core codebase remains reliable as complex vProgs capabilities are integrated.

Continuous iterative refinement of the core Rust implementation is ongoing, with recent codebase merges (such as PR #945 in Rusty Kaspa) reflecting a steady commitment to stabilizing the foundation before deploying complex programmability features.