I see Compact as one of the standout innovations of Midnight, a smart contract language designed to let developers build privacy-focused dApps without struggling with ZK complexity like in Circom or Halo2.
Compact closely follows TypeScript-like syntax. If you already know TypeScript, you can almost immediately read and write Compact. It’s statically typed, uses a functional style, enforces immutability, and applies eager evaluation, but all within safe bounds tailored for zero-knowledge systems.
The key advantage is that the compiler abstracts away ZK complexity. It automatically handles circuit generation, proof creation, key management, and even produces JavaScript implementations for the public/replicated parts. Developers don’t need to manually wire constraints or deal with custom gates.
A quick comparison:
Circom: A circuit-focused DSL based on R1CS. It’s verbose when defining signals and constraints, lacks high-level features (like complex loops or powerful functions), and has relatively primitive tooling. Developers must think at a low-level arithmetic layer, making it error-prone and harder to learn for application builders.
Halo2: A Rust-based, highly flexible Plonkish system (supporting custom gates and lookups). However, it involves significant boilerplate, long compilation times, and verbose code. It requires deep understanding of proving systems—great for research or extreme optimization, but not ideal for rapid prototyping.
Compact really shines in ergonomics. Its learning curve is minimal (thanks to its TypeScript-like design), it integrates seamlessly with TypeScript for off-chain logic, supports witness functions that can call external code, and provides clear ledger declarations for both public and private state.
As a result, developers can focus on business logic and privacy rules, rather than debugging circuit constraints. This leads to faster development of shielded contracts, fewer bugs, and easier onboarding for Web2 developers transitioning into Web3 privacy.
If you’re aiming to ship real-world privacy applications, like private DeFi, AI on sensitive data, or tokenized equity, without spending months learning ZK DSLs, Compact is arguably one of the most practical choices right now. Midnight is genuinely making zero-knowledge more accessible. 🚀