Affinidi Meeting Place - Chat SDK for Dart #

Affinidi Meeting Place - Chat SDK for Dart provides the libraries to send a secure and private messages utilising Decentralised Identifiers (DIDs) and DIDComm v2.1 protocol for a safe digital interactions. The messages are protected with end-to-end encryption and only the intended recipient can read the content.

The Chat SDK is part of the Meeting Place SDK toolkit and enables a safe and secure method of discovering, connecting, and communicating between individuals, businesses, and AI agents.

DISCLAIMER: Affinidi provides this SDK as a developer tool to facilitate decentralized messaging. Any personal data exchanged or stored via this tool is entirely initiated and controlled by end-users. Affinidi does not collect, access, or process such data. Implementing parties are responsible for ensuring that their applications comply with applicable privacy laws and user transparency obligations.

Core Concepts #

• Decentralised Identifier (DID) - A globally unique identifier that enables secure interactions. The DID is the cornerstone of Self-Sovereign Identity (SSI), a concept that aims to put individuals or entities in control of their digital identities.

• DIDComm Message - is a JSON Web Message (JWM), a lightweight, secure, and standardised format for structured communication using JSON. It represents headers, message types, routing metadata, and payloads designed to enable secure and interoperable communication across different systems.

• Mediator - A service that handles and routes messages sent between participants (e.g., users, organisations, another mediator, or even AI agents).

• Out-Of-Band - The protocol defined in DIDComm enables sharing a DIDComm message or invitation through a transport method other than a direct, established DIDComm channel, such as via a QR code or a URL.

• Connection Offer (Invitation) - An invite to connect containing description and ContactCard info of the publisher. Each connection offer is assigned with a unique passphrase that others can use to discover and accept the offer to connect.

Key Features #

• End-to-end encryption of messages for more secure and private communication.
• Support for individual or group chats, delivery receipt and chat presence.
• Notifies connections for contact details update (e.g., name change).
• Support ContactCard in publishing a connection offer (invitation) and establishing connections with others to chat.
• Implements the DIDComm Message v2.1 protocol for sending and receiving messages.

Requirements #

• Dart SDK >=3.6.0 <4.0.0

Installation #

Run:

dart pub add chat_sdk

or manually, add the package into your pubspec.yaml file:

dependencies:
  chat_sdk: ^<version_number>

and then run the command below to install the package:

dart pub get

Visit the pub.dev install page of the Dart package for more information.

Usage #

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'lib/chat_sdk.dart';
import 'package:meeting_place_core/meeting_place_core.dart';
import 'package:ssi/ssi.dart';
import 'package:uuid/uuid.dart';

void main() async {
   final storage = InMemoryStorage();

   final aliceSDK = MeetingPlaceCoreSDK.create(
      wallet: PersistentWallet(InMemoryKeyStore()),
      repositoryConfig: RepositoryConfig(
         connectionOfferRepository: ConnectionOfferRepositoryImpl(storage: storage),
         groupRepository: GroupRepositoryImpl(storage: storage),
         channelRepository: ChannelRepositoryImpl(storage: storage),
         keyRepository: KeyRepositoryImpl(storage: storage),
      ),
      mediatorDid: 'did:web:samplemediator.affinidi.io:.well-known',
      controlPlaneDid: 'did:web:samplecontrolplane.affinidi.io',
   );

   await aliceSDK.registerForPushNotifications(const Uuid().v4());

  final publishOfferResult = await aliceSDK.publishOffer(
    offerName: 'Example offer',
    offerDescription: 'Example offer to test.',
    contactCard: ContactCard(
      did: 'did:test:alice',
      type: 'human',
      contactInfo: {
        'n': {'given': 'Alice'},
      },
    ),
    publishAsGroup: false,
    validUntil: DateTime.now().toUtc().add(const Duration(minutes: 5)),
  );

  final waitForInvitationAccept = Completer<ControlPlaneStreamEvent>();
  final waitForChannelActivity = Completer<ControlPlaneStreamEvent>();

  aliceSDK.discoveryEventsStream.listen((event) {
    if (event.type == DiscoveryEventType.InvitationAccept) {
      waitForInvitationAccept.complete(event);
    }
  });

  final receivedEvent = await waitForInvitationAccept.future;

  final channel = await aliceSDK.approveConnectionRequest(
    connectionOffer: publishOfferResult.connectionOffer,
    channel: receivedEvent.channel,
  );

  final aliceChatSDK = await ChatSDK.initialiseFromChannel(
      channel,
      coreSDK: aliceSDK,
      chatRepository: ChatRepositoryImpl(storage: InMemoryStorage()),
  );
}

For more sample usage, go to example folder.

Support & feedback #

If you face any issues or have suggestions, please don't hesitate to contact us using this link.

Reporting technical issues #

If you have a technical issue with the project's codebase, you can also create an issue directly in GitHub.

1. Ensure the bug was not already reported by searching on GitHub under Issues.

2. If you're unable to find an open issue addressing the problem, open a new one. Be sure to include a title and clear description, as much relevant information as possible, and a code sample or an executable test case demonstrating the expected behaviour that is not occurring.

Contributing #

Want to contribute?

Head over to our CONTRIBUTING guidelines.