midnight-sdk-guide

Midnight TypeScript SDK Quick Reference

Guide for integrating Midnight contracts with TypeScript applications.

When to Use

Reference this guide when:

• Building a frontend for a Midnight dApp
• Connecting the Lace wallet
• Deploying or calling contracts from TypeScript
• Handling errors from the SDK
• Building transaction flows

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Installation

npm install @midnight-ntwrk/midnight-js-contracts

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Core Types

Contract Deployment

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

const deployment: ContractDeployment = await deployContract({
  contract: compiledContract,
  privateState: initialPrivateState,
  args: constructorArgs,
});

const { contractAddress, initialState } = deployment;

Contract Interaction

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

// Call a circuit
const result = await callContract({
  contractAddress,
  circuitName: 'increment',
  args: [amount],
  privateState: currentPrivateState,
});

// Result contains new state and return value
const { newPrivateState, returnValue, proof } = result;

Providers

import {
  MidnightProvider,
  createMidnightProvider
} from '@midnight-ntwrk/midnight-js-contracts';

const provider = await createMidnightProvider({
  indexer: 'https://indexer.testnet.midnight.network',
  node: 'https://node.testnet.midnight.network',
  proofServer: 'https://prover.testnet.midnight.network',
});

---

State Management

interface ContractState<T> {
  publicState: PublicState;
  privateState: T;
}

// Subscribe to state changes
provider.subscribeToContract(contractAddress, (state) => {
  console.log('New state:', state);
});

---

Transaction Building

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

const tx = await buildTransaction({
  contractAddress,
  circuitName: 'transfer',
  args: [recipient, amount],
  privateState,
});

// Sign and submit
const signedTx = await wallet.signTransaction(tx);
const txHash = await provider.submitTransaction(signedTx);