Dart SDK

A Dart SDK for sending and receiving emails over the Nostr protocol using NIP-59 gift-wrapped messages.

There is also a JavaScript SDK for Node and the browser.

Installation

dart pub add nostr_mail

Or add to your pubspec.yaml:

dependencies:
  nostr_mail: ^3.2.1

Features

Send to Nostr users, to legacy addresses through a bridge, or both at once
NIP-59 gift wrapping, with signed rumors and public emails when you want them
Attachments of any size, stored encrypted on Blossom
Local store on drift (SQLite) with full-text search
Folders, read state and stars as NIP-32 labels
Settings synced across devices with NIP-78
Scheduled sending through a Scheduler DVM
Offline-first: queued sends and uploads survive a restart

What you provide

The client does not own its infrastructure. You build it and hand it over, so it can share what your app already runs.

Dependency	Role
`ndk`	Relays, signing, the event cache. One account logged in.
`NostrMailDatabase`	The mail store, drift over SQLite. `NativeDatabase` on native, `WasmDatabase` on web.
`sembast` database	Shared by the broadcast queue, the Blossom upload queue and the scheduler.
`SyncEngine`	Keeps the ndk cache filled from the relays. Yours to own: the client starts it, never stops it.
`BlossomCache`	Local blob store for large emails and attachments.

Quick Start

import 'dart:io';

import 'package:drift/native.dart';
import 'package:ndk/ndk.dart';
import 'package:nostr_mail/nostr_mail.dart';
import 'package:sembast/sembast_io.dart' hide Filter;
import 'package:sync_engine_shim_for_ndk/sync_engine_shim_for_ndk.dart';

void main() async {
  final ndk = Ndk(NdkConfig(
    cache: MemCacheManager(),
    eventVerifier: Bip340EventVerifier(),
  ));
  final keyPair = Bip340.generatePrivateKey();
  ndk.accounts.loginPrivateKey(
    pubkey: keyPair.publicKey,
    privkey: keyPair.privateKey!,
  );

  final database = NostrMailDatabase(NativeDatabase(File('nostr_mail.sqlite')));
  final db = await databaseFactoryIo.openDatabase('emails.db');
  final blossomCache = await IdbBlossomCache.open(factory: idbFactorySembastIo);
  final syncEngine = SyncEngine(ndk, db: db);

  final client = await NostrMailClient.create(
    ndk: ndk,
    database: database,
    db: db,
    blossomCache: blossomCache,
    syncEngine: syncEngine,
  );

  await client.send(
    to: [await resolveRecipient(to: 'bob@example.com', ndk: ndk)],
    subject: 'Hello from Nostr!',
    body: 'This email was sent over the Nostr protocol.',
  );

  client.onEmail.listen((email) {
    print('New email: ${email.mime.decodeSubject()}');
  });
}

Remote signers

With a remote signer, give ndk a cache manager that persists (SembastCacheManager). ndk keeps the plaintext it decrypted there, so approvals already granted are not asked for again.

Sending Emails

Receiving Emails

Local Storage

API Reference

JavaScript SDK

Recipients, transports, scheduling, public emails

Sync, mailbox listing, labels and folders

The drift store, Blossom cache, clearing an account

The client surface, models and exceptions

The same protocol from Node and the browser