compact-core:typescript-integration
Use when implementing witness functions in TypeScript, mapping Compact types to TypeScript (Field→bigint, Bytes→Uint8Array), deploying contracts, calling circuits from TypeScript, reading ledger state, or building Midnight DApps with the JavaScript SDK.
SKILL.md
Full skill instructions
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