aaronbassett/compact-core:typescript-integration

TypeScript Integration

Complete guide to integrating Midnight Compact contracts with TypeScript applications.

Type Mapping Quick Reference

| Compact Type | TypeScript Type | Notes | |--------------|-----------------|-------| | Field | bigint | ZK field element | | Uint<N> | bigint | Any bit width maps to bigint | | Boolean | boolean | Direct mapping | | Bytes<N> | Uint8Array | Fixed-length byte array | | Opaque<'string'> | string | UTF-8 string data | | Opaque<'Uint8Array'> | Uint8Array | Binary data | | struct | { field: Type, ... } | Object with typed fields | | enum | Discriminated union | { tag: 'Variant', value: T } | | Vector<T, N> | T[] | Array of mapped type |

Witness Implementation Pattern

import { WitnessContext } from '@midnight-ntwrk/midnight-js-types';

// Compact declaration: witness get_secret(): Field;
const witnesses = {
  get_secret: ({ privateState }: WitnessContext<PrivateState>): bigint => {
    return privateState.secret;
  }
};

Contract Interaction Flow

1. Compile Compact → Generated TypeScript types
2. Deploy contract → Get contract address
3. Create provider → Connect to Midnight node
4. Build witnesses → Implement private data access
5. Call circuits → Execute transactions
6. Read state → Query ledger values

Quick Examples

Calling a Circuit

import { Contract } from './contract';

const result = await contract.callTx.transfer({
  to: recipientAddress,
  amount: 1000n
}, witnesses);

Reading Ledger State

const balance = await contract.state.balances.get(userAddress);
// balance: bigint | undefined

Deploying a Contract

import { deployContract } from '@midnight-ntwrk/midnight-js-contracts';

const { contract, address } = await deployContract(provider, {
  privateStateKey: 'my-contract',
  initialPrivateState: { secret: 42n },
  witnesses
});

References

For detailed documentation on each topic:

• Type Mapping - Complete Compact ↔ TypeScript type correspondence
• Witness Bridge - Implementing witnesses in TypeScript
• Contract API - Generated contract interface usage
• Deployment - Contract deployment from TypeScript

Examples

Working TypeScript examples:

• Witness Implementation - Complete witness patterns
• Deploy Contract - Contract deployment flow
• Read State - Reading ledger state