Cardano Smart Contract Design Patterns

Proven patterns for building efficient and secure Cardano smart contracts, implemented in Scalus.

Optimization Patterns

Reduce execution costs by delegating computation to single-execution endpoints:

• Withdraw Zero — Delegate computation to staking scripts using the “withdraw zero trick”, reducing costs from O(N²) to O(N)
• Transaction Level Minting — Couple spend and mint endpoints so spending validators stay minimal
• Merkelized Validator — Read verified data from stake validator redeemers for efficient batch operations

Validation Patterns

• Parameter Validation — Verify that script instances across a multi-script protocol are parameterized with expected values

Indexing Patterns

• UTxO Indexer — Map inputs to outputs using pre-computed indices for O(1) on-chain verification

Data Structures

• Linked List — Ordered and unordered linked lists using NFTs and datums for on-chain state management

Utilities

• Validity Range — Normalize time ranges to simplify interval validation in your contracts

Related

• Security Guide — Common vulnerabilities these patterns help prevent
• Smart Contract Optimization — Compiler-level optimizations
• Testing — Test your pattern implementations

Resources

• Scalus Design Patterns  — Implementation and tests
• Anastasia Labs Design Patterns  — Original pattern documentation
• Plutonomicon  — Community-driven Plutus knowledge base