Design, build, and launch smart contracts with practical security controls, comprehensive test discipline, and operating readiness for production systems. We deliver audit-ready Solidity and Rust contracts that are engineered for security — not just functionality.
Most smart contract exploits are not the result of obscure vulnerabilities. They are the result of predictable failure modes that were never addressed during the development phase: reentrancy in external call paths, oracle manipulation in undercollateralized lending markets, admin key exposure in governance contracts, and upgrade patterns that create centralization risk.
These failures share a common root cause — security was treated as a pre-launch checklist rather than a continuous architectural commitment. Xenqube builds contracts where security decisions are made at the design stage and enforced through the implementation, test, and deployment lifecycle.
External function calls and callback patterns are the most common exploit vector in EVM contracts. We apply checks-effects-interactions discipline and explicit reentrancy guards on every external call path, not just the obvious ones.
Admin key exposure, flat ownership models, and missing role-based access design create governance vulnerabilities that persist long after launch. We implement OpenZeppelin AccessControl hierarchies or custom role structures with timelock requirements on privileged functions.
Contracts that depend on a single price oracle with no circuit breaker or staleness check are vulnerable to price manipulation attacks. We implement redundant oracle design, TWAP calculations, staleness validation, and anomalous-price circuit breakers as standard in every lending or derivatives product.
Proxy upgrade patterns that allow immediate state-changing upgrades with no timelock create a significant attack surface. We design upgrade paths with mandatory timelock delays, governance voting requirements for parameter changes above defined thresholds, and emergency pause mechanisms with defined recovery procedures.
We run full-cycle smart contract delivery from architecture design through implementation, test suite, audit package preparation, and production deployment. The engagement is structured around the specific contract type and protocol requirements.
Translate product requirements into an implementable contract specification. Includes function-level design, state variable modelling, event emission strategy, access control hierarchy, and risk register before implementation starts.
Production-grade Solidity for EVM chains with reentrancy protection, access control architecture, upgrade patterns, and event logging for monitoring. Follows NatSpec documentation standard throughout. Code is written to pass automated analysis tools without modifications.
Anchor-framework Solana programs with account validation, privilege escalation protection, instruction-level access checks, and comprehensive error handling. Programs are structured for composability and auditability.
Unit tests for every function with coverage above 95%, integration tests for multi-contract interaction scenarios, fork tests for mainnet-state edge cases, and fuzz testing for high-risk value paths. Foundry or Hardhat tooling matched to the project requirements.
Complete audit readiness package: full natspec documentation, threat model, function specification, test coverage report, and deployment scripts. We coordinate with your chosen audit partner and own the finding remediation cycle to resolution before mainnet.
Deployment scripts for testnet and mainnet with verification, monitoring setup for key on-chain events, operational runbooks for emergency pause and upgrade procedures, and a 30-day post-deployment support window.
We build across the full range of smart contract categories. Each type has specific security requirements and architecture patterns that we address directly rather than applying a generic template.
Lending markets, AMM pools, yield vaults, staking and rewards, governance systems, and treasury management contracts. Core DeFi primitives with layered security architecture and full test coverage.
ERC-20, ERC-721, ERC-1155, and custom token standards. Vesting schedules, transfer restrictions, compliance controls (ERC-1400, ERC-3643), and multi-chain token deployment with bridge integration.
NFT minting with configurable royalty mechanics, marketplace listing and purchase logic, auction contracts, and fractionalization vaults. Optimised for gas efficiency on high-throughput chains.
Multi-sig vault designs, time-locked treasury contracts, escrow logic with defined release conditions, and compliance-aware transfer controls for institutional custody requirements.
On-chain proposal and voting contracts, timelock controller integration, role-based access, Snapshot-compatible off-chain signalling, and DAO treasury management. Architecture aligned to your decentralization roadmap.
Message-passing integration with LayerZero or Wormhole, cross-chain token bridges with canonical token architecture, and multi-chain deployment coordination for protocols operating across multiple networks.
We structure smart contract engagements in defined phases so the team has working, testable contracts at each stage rather than a large delivery at the end.
We start with a 51-hour sprint to validate contract architecture assumptions, prove the core mechanism, and establish the testnet deployment. Output: working MVP contracts on testnet, architecture decision record, and scoped production build roadmap.
Product requirements review, function-level contract specification, state variable design, access control architecture, event emission strategy, oracle and price feed design, and upgrade pattern selection. Output: approved technical specification and risk register.
Smart contract implementation for all protocol logic, unit tests with coverage above 95%, integration tests for multi-contract scenarios, deployment scripts, and testnet deployment. Output: deployed testnet contracts with full test suite passing.
Internal security review, Slither and Mythril automated analysis, natspec documentation completion, audit package preparation, and remediation of any issues identified. Output: audit-ready codebase with supporting documentation package.
Mainnet deployment with contract verification, monitoring configuration, operational runbook delivery, and post-deployment support window. Output: verified mainnet contracts with full operational documentation.
Ethereum, Arbitrum One and Nova, Base, Optimism, Polygon PoS and zkEVM, BNB Chain, Avalanche C-Chain, and Linea. Multi-chain deployments with shared state via cross-chain message passing are supported.
Solana (Anchor framework, Rust programs), Aptos and Sui (Move language). We select the appropriate language and framework for each chain and use case.
Foundry for EVM contract development and advanced testing (fuzz, fork, invariant). Hardhat for deployment scripting and plugin integration. Slither and Mythril for static analysis. Tenderly for simulation and monitoring.
OpenZeppelin Contracts for security-reviewed base implementations (AccessControl, ReentrancyGuard, Ownable, Proxy patterns). We extend these with project-specific controls rather than building from scratch.
We embed into your engineering process rather than operating as a distant vendor. Your dedicated Xenqube team works in your repository, communication channels, and sprint cycles with full transparency throughout.
Structured sessions with your product and engineering team to translate protocol requirements into implementable specifications. We challenge assumptions, identify risk gaps, and produce a risk-registered technical design before implementation starts.
Code reviews, architecture discussions, and progress updates are transparent to your team throughout. We maintain shared documentation and decision records so your team understands every architectural choice.
We prepare the complete audit package, coordinate with your chosen audit partner, and own the remediation cycle. Findings are resolved and verified before mainnet deployment, not handed back as a list of open issues.
We remain engaged through mainnet deployment and the initial live period. Monitoring configuration, incident response procedures, and team knowledge transfer are delivered as part of the engagement.
No. We deliver architecture documentation, natspec-documented contracts, threat models, operational runbooks, and audit packages alongside the code. The full deliverable is a production-ready package — not just source files.
We apply threat modelling at the architecture stage, restricted privilege design, reentrancy protection on all external call paths, oracle redundancy, and comprehensive coverage of high-risk scenarios. Contracts pass Slither and Mythril automated analysis and are structured for manual audit review.
Yes. We can align development and remediation plans to existing audit findings and release windows. We take ownership of the remediation cycle to ensure all issues are resolved and verified before mainnet deployment.
Solidity for EVM chains with Foundry and Hardhat tooling. Rust with Anchor framework for Solana. Move language for Aptos and Sui. We use OpenZeppelin libraries for security-reviewed base implementations.
We start with a 51-hour MVP sprint for mechanism validation and architecture lock. Full production contract development timeline is scoped based on protocol complexity, required test coverage, and audit preparation requirements — typically agreed after the sprint output is reviewed.
Yes. We prepare natspec documentation for every function, threat model, function specification, test coverage report, and deployment scripts. We coordinate with your chosen audit firm and own the remediation cycle to resolution before mainnet.
Share your protocol goals, contract scope, and risk concerns. We will help you define a secure build and launch plan — starting with architecture, through audit, to mainnet.
Schedule a discovery call Start with a 51-hour MVP sprint Explore use cases