Compilation Tooling

Complete guide to the Compact compiler (compactc), project organization, build workflows, and understanding compilation output.

Quick Reference

Basic Compilation

bash

# Compile a contract
compactc contract.compact -o output/

# Compile with debug mode (faster, no ZK proofs)
compactc contract.compact -o output/ --skip-zk

# Generate VS Code language server support
compactc contract.compact -o output/ --vscode

Compiler Flags

Flag	Description	Example
`-o, --output`	Output directory	`-o build/`
`--skip-zk`	Skip ZK proof generation (dev mode)	`--skip-zk`
`--vscode`	Generate VS Code language server files	`--vscode`
`-I, --include`	Add include path	`-I ./lib`
`--verbose`	Verbose output	`--verbose`
`--json`	JSON output format	`--json`
`--no-typescript`	Skip TypeScript generation	`--no-typescript`

Environment Variables

Variable	Purpose	Example
`COMPACT_PATH`	Include path resolution	`export COMPACT_PATH="/libs:/project/src"`
`MIDNIGHT_NETWORK`	Target network	`export MIDNIGHT_NETWORK="testnet"`

Output Artifacts

Compilation produces several output files:

code

output/
├── zkir/                    # Zero-knowledge intermediate representation
│   ├── circuit_name.zkir    # Circuit IR for each exported circuit
│   └── ...
├── keys/
│   ├── prover/              # Prover keys (for proof generation)
│   │   └── circuit_name.pk
│   └── verifier/            # Verifier keys (for on-chain verification)
│       └── circuit_name.vk
├── contract.ts              # TypeScript types and contract interface
├── witnesses.ts             # Witness type definitions
└── index.ts                 # Main export file

Development Workflow

code

1. Write Compact contract
2. Compile with --skip-zk for fast iteration
3. Run TypeScript tests
4. When ready: Full compile (generates ZK keys)
5. Deploy to testnet

Fast Development Loop

bash

# Fast iteration (no proof generation)
compactc contract.compact -o build/ --skip-zk

# Full build for deployment
compactc contract.compact -o build/

Project Structure

Recommended project layout for Midnight DApps:

code

my-midnight-project/
├── contracts/
│   ├── main.compact           # Main contract entry point
│   ├── types.compact          # Shared type definitions
│   └── lib/                   # Helper modules
│       └── utils.compact
├── src/                       # TypeScript application code
│   ├── index.ts
│   ├── witnesses.ts           # Witness implementations
│   └── deploy.ts
├── build/                     # Compiled output (gitignored)
│   ├── zkir/
│   ├── keys/
│   └── *.ts
├── tests/
│   └── contract.test.ts
├── package.json
├── tsconfig.json
└── .env                       # Environment configuration

VS Code Integration

Generate language server support for VS Code:

bash

compactc contract.compact -o build/ --vscode

This creates .vscode/ configuration for:

•Syntax highlighting
•Error diagnostics
•Type checking
•Go to definition

References

For detailed documentation:

•Compiler Usage - All compactc flags and options
•Project Structure - Recommended project layouts
•Output Artifacts - Understanding compiled output

Examples

Working project templates and scripts:

•Project Template - Complete starter project
•Build Scripts - Build, watch, and validation scripts