compact-corecontract-patterns

name	compact-core:contract-patterns
description	Use when implementing common Compact contract patterns such as voting systems, escrow, token transfers, access control, auctions, registries, or when looking for reusable contract templates and design patterns for Midnight blockchain development.

Contract Patterns

Reusable Compact contract patterns and best practices for Midnight development

Overview

This skill provides a comprehensive catalog of Compact contract patterns for the Midnight blockchain. Patterns range from simple building blocks to comprehensive multi-contract systems.

Pattern Categories

1. Simple Patterns (~10 focused examples)

   • Basic state management
   • Access control primitives
   • Time-based logic
   • Cryptographic commitments

2. Deep-Dive Implementations (3 comprehensive systems)

   • Private Voting System
   • Multi-Party Token Escrow
   • Role-Based Access Registry

Quick Navigation

Simple Patterns

Pattern	File	Use Case
Counter	examples/simple/counter.compact	Basic state increments
Ownership	examples/simple/ownership.compact	Single-owner control
Time Lock	examples/simple/time-lock.compact	Delayed execution
Whitelist	examples/simple/whitelist.compact	Membership verification
Rate Limit	examples/simple/rate-limit.compact	Action throttling
Multi-Sig	examples/simple/multi-sig.compact	N-of-M approvals
Pausable	examples/simple/pausable.compact	Emergency stops
Upgradeable	examples/simple/upgradeable.compact	Logic migration
Fee Collector	examples/simple/fee-collector.compact	Payment handling
Random Selection	examples/simple/random-selection.compact	Commit-reveal randomness

Deep-Dive Systems

System	Directory	Description
Private Voting	examples/deep-dives/private-voting/	Complete anonymous voting with ZK proofs
Token Escrow	examples/deep-dives/token-escrow/	Multi-party custody with conditions
Access Registry	examples/deep-dives/access-registry/	Role-based access with Merkle proofs

References

• Pattern Catalog - Quick reference for all patterns
• Private Voting Deep-Dive - Voting system architecture
• Token Escrow Deep-Dive - Escrow implementation guide
• Access Registry Deep-Dive - Role-based access patterns

Usage Examples

Finding a Pattern

"Show me the counter pattern" → Read examples/simple/counter.compact

Understanding Complex Systems

"How do I implement private voting?" → Read references/private-voting.md then explore examples/deep-dives/private-voting/

Adapting Patterns

"I need time-locked multi-sig" → Combine time-lock.compact + multi-sig.compact patterns

Best Practices

1. Start Simple: Use simple patterns as building blocks
2. Understand Privacy: Know what's public vs private in each pattern
3. Test Thoroughly: Each pattern includes test considerations
4. Combine Carefully: When mixing patterns, verify privacy guarantees
5. Document Intent: Add comments explaining business logic

Dependencies

All patterns use standard library imports:

import CompactStandardLibrary;

Some advanced patterns may require additional imports:

import CompactStandardLibrary.Merkle;
import CompactStandardLibrary.Crypto;