Quick Start

Installation

TypeScript
Go
Kotlin

npm install @d4mr/t2z-wasm
# or
pnpm add @d4mr/t2z-wasm
# or
yarn add @d4mr/t2z-wasm

go get github.com/d4mr/t2z-go

Go SDK coming soon

// build.gradle.kts
dependencies {
    implementation("com.d4mr:t2z:0.1.0")
}

Kotlin SDK coming soon

Basic Example

Build a transaction that sends from a transparent input to a shielded Orchard address:

TypeScript
Go
Kotlin

import * as t2z from '@d4mr/t2z-wasm';

// 1. Create the transaction
const pczt = t2z.propose_transaction(
  // Transparent inputs
  [new t2z.WasmTransparentInput(
    pubkeyHex,        // 33-byte compressed pubkey
    prevoutTxid,      // Previous tx ID (little-endian)
    0,                // Output index
    1000000n,         // Value: 0.01 ZEC in zatoshis
    scriptPubkey,     // P2PKH script
    null              // Sequence (default: 0xffffffff)
  )],
  // Payments
  [new t2z.WasmPayment(
    'u1...',          // Unified address with Orchard
    900000n,          // Amount in zatoshis
    null,             // Optional memo (hex)
    null              // Optional label
  )],
  'u1...',            // Change address
  'testnet',          // 'mainnet' or 'testnet'
  3720100             // Expiry height
);

// 2. Sign transparent inputs
const sighash = t2z.get_sighash(pczt, 0);
// Sign with your key (external signer, hardware wallet, etc.)
const signature = sign(sighash, privateKey);
pczt = t2z.append_signature(pczt, 0, pubkeyHex, signature);

// 3. Generate Orchard proofs
pczt = t2z.prove_transaction(pczt);

// 4. Finalize and get raw transaction
const txHex = t2z.finalize_and_extract_hex(pczt);

// 5. Broadcast to network
await broadcastTransaction(txHex);

package main

import (
    "github.com/d4mr/t2z-go"
)

func main() {
    // 1. Create the transaction
    pczt, err := t2z.ProposeTransaction(
        []t2z.TransparentInput{{
            Pubkey:       pubkey,
            PrevoutTxid:  txid,
            PrevoutIndex: 0,
            Value:        1000000,
            ScriptPubkey: script,
        }},
        []t2z.Payment{{
            Address: "u1...",
            Amount:  900000,
        }},
        "u1...",     // Change address
        "testnet",   // Network
        3720100,     // Expiry height
    )
    
    // 2. Sign transparent inputs
    sighash, _ := t2z.GetSighash(pczt, 0)
    signature := sign(sighash, privateKey)
    pczt, _ = t2z.AppendSignature(pczt, 0, pubkey, signature)
    
    // 3. Generate Orchard proofs
    pczt, _ = t2z.ProveTransaction(pczt)
    
    // 4. Finalize
    txBytes, _ := t2z.FinalizeAndExtract(pczt)
    
    // 5. Broadcast
    broadcastTransaction(txBytes)
}

Go SDK coming soon

import com.d4mr.t2z.*

fun main() {
    // 1. Create the transaction
    val pczt = proposeTransaction(
        inputs = listOf(
            TransparentInput(
                pubkey = pubkey,
                prevoutTxid = txid,
                prevoutIndex = 0u,
                value = 1_000_000uL,
                scriptPubkey = script
            )
        ),
        payments = listOf(
            Payment(
                address = "u1...",
                amount = 900_000uL
            )
        ),
        changeAddress = "u1...",
        network = "testnet",
        expiryHeight = 3720100u
    )
    
    // 2. Sign transparent inputs
    val sighash = getSighash(pczt, 0u)
    val signature = sign(sighash, privateKey)
    pczt = appendSignature(pczt, 0u, pubkey, signature)
    
    // 3. Generate Orchard proofs
    pczt = proveTransaction(pczt)
    
    // 4. Finalize
    val txHex = finalizeAndExtractHex(pczt)
    
    // 5. Broadcast
    broadcastTransaction(txHex)
}

Kotlin SDK coming soon

Key Concepts

What is a PCZT?

A Partially Constructed Zcash Transaction (PCZT) is a standardized format for building Zcash transactions incrementally. It allows different parties to add inputs, signatures, and proofs without needing access to all private keys.Learn more about PCZT →

Why little-endian for txids?

Block explorers display transaction IDs in big-endian (human-readable) format, but Zcash internally uses little-endian. When using a txid from an explorer, you need to reverse the bytes.

// Explorer shows: abcd1234...
// Internal format: ...3412cdab
const internalTxid = explorerTxid.match(/../g).reverse().join('');

What's the expiry height?

Every Zcash transaction has an expiry height - the block height after which the transaction is no longer valid. You should set this to currentBlockHeight + 40 or more to avoid “tx-expiring-soon” errors.

const currentHeight = await fetchCurrentBlockHeight();
const expiryHeight = currentHeight + 100; // ~2.5 hour buffer

Next Steps

Understand the Flow

Learn each step of the transaction process in detail.

Core Concepts

Deep dive into PCZT, Orchard, and Zcash fundamentals.

Try the Demo

Build a transaction interactively in your browser.

API Reference

Complete function documentation.

Getting Started

Transaction Flow

Platform Guides

Advanced

Quick Start

Installation

Basic Example

Key Concepts

Next Steps

Understand the Flow

Core Concepts

Try the Demo

API Reference

​Installation

​Basic Example

​Key Concepts

​Next Steps

Understand the Flow

Core Concepts

Try the Demo

API Reference

Installation

Basic Example

Key Concepts

Next Steps