ndk 0.2.0-dev004

Nostr Development Kit - the most performant lib for all your nostr usecases

example/README.md

NDK

Basic example

This example uses a generic low level nostr request

import 'package:ndk/ndk.dart';

// Create an instance of Ndk
// It's recommended to keep this instance global as it holds critical application state
final ndk = Ndk(
  // Configure the Ndk instance using NdkConfig
  NdkConfig(
    // Use Bip340EventVerifier for event verification
    // in production RustEventVerifier() is recommended
    eventVerifier: Bip340EventVerifier(),
    // Use in-memory cache for storing Nostr data
    cache: MemCacheManager(),
  ),
);

// Create a query request using the Ndk instance
final response = ndk.requests.query(
  filters: [
    // Define a filter for the query
    Filter(
      // Query for fiatjaf npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6
      authors: [
        '3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d'
      ],
      // Query for text note events (kind 1)
      kinds: [Nip01Event.TEXT_NODE_KIND],
      // Limit the results to 10 events
      limit: 10,
    ),
  ],
);
// Process the events as they arrive
await for (final event in response.stream) {
  print(event);
}

breakdown

initialize

1️⃣ Initialize a global ndk object

setup your preferred config/dependencies.

final ndk = Ndk(
  NdkConfig(
    eventVerifier: RustEventVerifier(),
    cache: MemCacheManager(),
  ),
);

Available configs:

eventVerifier: Bip340EventVerifier() RustEventVerifier()
cache: MemCacheManager()
bootstrapRelays: ['wss://myrelay.example']
engine: NdkEngine.RELAY_SETS NdkEngine.JIT
eventSigner: Bip340EventSigner('nsec1...', 'npub1...')
ignoreRelays: ['wss://bad.reputation']

$~~~~~~~~~~~$

2️⃣ Usecase

Use a prebuilt ndk usecase (contact list in this case)

final ContactList? response = await ndk.follows.getContactList('3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d');

3️⃣ read response

depending on the usecase entity or a NdkResponse is returned

// read entity
print(response)
// read NdkResponse
final response_stream = ndkResponse.stream;
final response_future = ndkResponse.future;

imports

import 'package:ndk/ndk.dart';
contains everything exposed by ndk.
If you want to reuse ndk entities you can use them like this:

import 'package:ndk/entities.dart' as ndk_entities;

final ndk_entities.Nip01Event myEvent = ndk_entities.Nip01Event(...);

other imports:

import 'package:ndk_rust_verifier/ndk_rust_verifier.dart';
import 'package:ndk_amber/ndk_amber.dart';

tip: how to keep the ndk obj global

If you have a relatively simple app you can initialize ndk in your main method and pass down ndk on the widget tree.
For more more complex applications we recommend using riverpod or simmilar packages/methods (get_it, singletons etc).

riverpod example:

import 'package:ndk/ndk.dart';
import 'package:riverpod/riverpod.dart';

final ndkProvider = Provider<Ndk>((ref) {
  final EventSigner eventSigner = Bip340EventSigner("privateKey", "publicKey");
  final EventVerifier eventVerifier = RustEventVerifier();
  final CacheManager cache = MemCacheManager();

  final NdkConfig ndkConfig = NdkConfig(
    engine: NdkEngine.JIT,
    cache: cache,
    eventSigner: eventSigner,
    eventVerifier: eventVerifier,
  );

  final ndk = Ndk(ndkConfig);
  return ndk;
});

more examples

• example folder github
• example app
• yana
• camelus