hedera_flutter_sdk

CI License: Apache 2.0 Dart Flutter Status

The first native Flutter/Dart SDK for the Hedera network.
Pure Dart · No platform channels · Apache 2.0

Status

This SDK is currently in active development by Nemorix Group.

Phase Description Status
1 Architecture + Protobuf ✅ Completed
2 Crypto + Accounts 🔄 In Progress
3 HTS Tokens + NFTs ⏳ Pending
4 Mirror Node + HCS ⏳ Pending
5 Docs + pub.dev v1.0 ⏳ Pending
6 Launch + HIP ⏳ Pending

Why this SDK?

Hedera has official SDKs for Java, JavaScript, Go, Swift, C++ and Rust but no native Flutter/Dart SDK exists on pub.dev.

This project closes that gap.

Installation

# pubspec.yaml
dependencies:
  hedera_flutter_sdk: ^0.1.0-dev

Quick Guide

Connect to Hedera (Phase 1)

final client = HederaClient.forTestnet()
    .setOperator(
      AccountId.fromString('0.0.12345'),
      PrivateKey.fromString('your-private-key'),
    );

print(client.networkEndpoint); // 0.testnet.hedera.com:50211

Wallet and Keys (Phase 2)

Generate a mnemonic

import 'package:hedera_flutter_sdk/hedera_flutter_sdk.dart';

// English (default)
final mnemonic = await Mnemonic.generate24();
print(mnemonic.phrase);      // 24 words
print(mnemonic.wordCount);   // 24
print(mnemonic.validate());  // true

// 12-word mnemonic
final mnemonic12 = await Mnemonic.generate12();

// Spanish - built for LATAM users
final mnemonicEs = await Mnemonic.generate24(
  language: MnemonicLanguage.spanish,
);
print(mnemonicEs.phrase);    // 24 palabras

Recover a wallet

// From word list
final recovered = await Mnemonic.fromWords([
  'word1', 'word2', 'word3', ...
]);

// From phrase string
final recovered = await Mnemonic.fromString(
  'word1 word2 word3 ...',
);

Derive seed bytes

// Without passphrase
final seed = mnemonic.toSeed();
print(seed.length); // 64 bytes

// With passphrase (optional extra security)
final seed = mnemonic.toSeed(passphrase: 'my-passphrase');

Generate a private key

// ED25519 - recommended for Hedera accounts
final privateKey = await PrivateKey.generateED25519();
print(privateKey.type.name);       // ed25519
print(privateKey.toHex().length);  // 64
print(privateKey.toDerString());   // 302e...
print(privateKey.toString());      // [PrivateKey: ed25519]

// ECDSA - for EVM wallet compatibility
final ecdsaKey = await PrivateKey.generateECDSA();

Import a private key

// From DER hex string (HashPack / Blade Wallet format)
final key = PrivateKey.fromString('302e020100300506032b657004220420...');

// From raw hex string
final key = PrivateKey.fromString('4a3b2c1d...');

// From bytes
final key = PrivateKey.fromBytes(keyBytes);

Sign a message

final message = [1, 2, 3, 4, 5];
final signature = await privateKey.sign(message);
print(signature.length); // 64 bytes

Derive and use a public key

// Derive public key from private key
final publicKey = await privateKey.derivePublicKey();
print(publicKey.toHex());        // 32 bytes as hex
print(publicKey.toDerString());  // 302a...
print(publicKey.toString());     // 302a... (safe to expose)

// Import public key
final pubKey = PublicKey.fromString('302a300506032b6570032100...');
final pubKey = PublicKey.fromBytes(pubKeyBytes);

// Verify a signature
final isValid = await publicKey.verify(
  message: message,
  signature: signature,
);
print(isValid); // true

Current Features (v0.1.0-dev)

  • HederaClient with forTestnet(), forMainnet(), forPreviewnet()
  • Mnemonic with BIP-39 generation, validation, and recovery in English and Spanish (generate24, generate12, fromWords, fromString, toSeed, validate)
  • MnemonicLanguage enum with english and spanish options
  • Official BIP-39 wordlists (2048 words each; English and Spanish)
  • Mnemonic.toPrivateKey() and toLegacyPrivateKey() for HD key derivation (12 and 24-word mnemonics; 22-word raises UnsupportedError)
  • PrivateKey with ED25519 and ECDSA generation, import, and signing
  • PublicKey with derivation, import, and ED25519 signature verification
  • Base models: AccountId, TokenId, TransactionId, Hbar
  • HederaStatusException and HederaStatusCode for typed error handling
  • HederaConstants with protocol-level values (ports, fees, endpoints)
  • 335 Dart classes generated from Hedera HAPI Protobuf definitions
  • Transaction<T>: generic base class with fluent API, signing, and Protobuf serialization (Generic Self-Type pattern)
  • Query<R,T>: generic base class with fluent API and Protobuf serialization
  • Account management transactions: AccountCreateTransaction, AccountUpdateTransaction, AccountDeleteTransaction
  • CryptoTransferTransaction: HBAR transfers with sum-zero validation
  • Account queries: AccountBalanceQuery, AccountInfoQuery with AccountInfo model
  • EVM address alias support
  • gRPC execution: execute() via HederaClient for transactions and queries
  • TransactionResponse: getReceipt() and getRecord() via gRPC polling

Planned Features

  • Multi-signature: KeyList with M-of-N threshold
  • Hedera Token Service (HTS): fungible tokens, NFTs, native KYC
  • Mirror Node REST client with real-time WebSocket subscriptions
  • Hedera Consensus Service (HCS)

Real-World Use Case

This SDK is being developed in parallel with NemorixPay; a mobile remittance platform for US-to-LATAM payments; which will use it in production from day one.

Contributing

The SDK is not ready for external contributions yet. Follow this repository for updates; contributions will be welcome starting with v1.0.0.

See CONTRIBUTING.md for future guidelines.

License

Licensed under Apache 2.0. Will be contributed to Hiero under the Linux Foundation Decentralized Trust.

Para desarrolladores en LATAM

Este SDK esta siendo desarrollado con soporte nativo para la region:

  • Mnemonics BIP-39 en espanol
  • Caso de uso principal: remesas Estados Unidos hacia Latinoamerica
  • Desarrollado por Nemorix Group; Ohio, USA

Siguenos para actualizaciones: sdks@nemorixpay.com

Support This Project

If this SDK is useful to you or your team, consider supporting its development. Every contribution helps cover infrastructure, documentation, and the time invested in building and maintaining this open source tool for the Hedera and Flutter community. Thank you!

Buy Me a Coffee Sponsor Ko-fi

Built by Nemorix Group · Apache 2.0 · Contributed to Hiero / Linux Foundation

Libraries

hedera_flutter_sdk
The first native Flutter/Dart SDK for the Hedera network.