Reference app

Clone and run the Meeting Place Flutter reference app locally to explore all Meeting Place SDK features end-to-end.

By the end of this guide, you will have the Meeting Place Flutter reference app running locally on a simulator or physical device.

The reference app demonstrates peer-to-peer and group messaging over DIDComm v2.1 and Matrix, verifiable credential exchange via R-Cards and VRCs, and an optional Human ZKP liveness demo. It is designed as a working baseline. Explore its architecture and integration patterns before building your own application.

If you only need the SDK API reference, see the Meeting Place SDK docs.

Prerequisites

Flutter 3.44.1.
Dart SDK ^3.12.0, bundled with Flutter.

You also need the following services running before the app starts:

DIDComm Mediator: routes encrypted messages between participants. See Mediator deployment options.
Control Plane API: manages connection offers and establishes DIDComm channels. See Control Plane deployment options.
Firebase project: required for push notifications. Create one at firebase.google.com.

After deploying each service, copy its DID value. You need both DEFAULT_MEDIATOR_DID and CONTROL_PLANE_DID in Step 3.

Matrix E2EE (optional)

Matrix transport uses flutter_vodozemac, a Rust-based Olm/Megolm implementation, and requires Rust to build. Skip this section if you use DIDComm only (ENABLED_INDIVIDUAL_CHAT_TRANSPORTS='["didcomm"]').

Show installation steps

Install Rust:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
. "$HOME/.cargo/env"

Add compilation targets.

For iOS:

rustup target add aarch64-apple-ios aarch64-apple-ios-sim

For Android:

rustup target add aarch64-linux-android armv7-linux-androideabi x86_64-linux-android i686-linux-android

Android builds also require the NDK. Install it in Android Studio under SDK Manager > SDK Tools > NDK.

If builds fail after flutter clean, run:

rm -rf app/build/flutter_vodozemac
flutter run

Transport capabilities

Both transports include

✅ Individual chat ✅ Text messages ✅ Image attachments ✅ Reactions ✅ Typing indicators ✅ Delivery receipts ✅ Visual effects

DIDComm

Lightweight peer-to-peer transport

Exclusive features

✅ Presence indicator

Not supported

❌ Group chat
❌ Voice, file, audio/video attachments
❌ Message edit / delete

Matrix

Full-featured group messaging

Exclusive features

✅ Group chat
✅ Voice messages
✅ File, audio/video attachments
✅ Message edit / delete

Not supported

❌ Presence indicator

Steps

Clone the repository

git clone git@github.com:affinidi/affinidi-meetingplace-reference-app.git
cd affinidi-meetingplace-reference-app

Copy the environment template

mkdir -p configurations && cp templates/.example.env configurations/.env

Run this from the root folder of the repository. The .env file holds all configuration used in the following steps. Most variables have sensible defaults. Only supply values specific to your setup.

Configure environment variables

Edit configurations/.env and set the required variables.

Control Plane API

# Your Control Plane DID (did:web value from your API server)
CONTROL_PLANE_DID=""

DIDComm Mediator

# Your Mediator DID
DEFAULT_MEDIATOR_DID=""

Chat transport

# DIDComm only (default — no transport picker shown)
ENABLED_INDIVIDUAL_CHAT_TRANSPORTS='["didcomm"]'

# Matrix only (requires MATRIX_HOMESERVER)
ENABLED_INDIVIDUAL_CHAT_TRANSPORTS='["matrix"]'

# Both — shows a picker when creating an offer
ENABLED_INDIVIDUAL_CHAT_TRANSPORTS='["didcomm", "matrix"]'

Group chats always use Matrix. Enabling group chat also requires MATRIX_HOMESERVER.

DIDComm vs Matrix: choosing a transport

Use Matrix if you need group chat, voice messages, file or audio/video attachments, or message editing and deletion. Use DIDComm if you need presence indicators or a lighter-weight transport without media support. For a full breakdown, see Transport capabilities above.

When both transports are enabled, the app shows a transport picker at offer creation.

Matrix Homeserver (required for Matrix transport)

Deploy a Matrix Synapse server configured for JWT-based login using the Control Plane’s public key as the JWT secret. See the Control Plane API: Matrix Authentication guide for full setup details.

MATRIX_HOMESERVER=""

Push notifications (Firebase)

# Shared
FIREBASE_MESSAGING_SENDER_ID=""
FIREBASE_PROJECT_ID=""
FIREBASE_STORAGE_BUCKET=""

# iOS
FIREBASE_IOS_APIKEY=""
FIREBASE_IOS_APP_ID=""
FIREBASE_IOS_BUNDLE_ID=""

# Android
FIREBASE_ANDROID_APIKEY=""
FIREBASE_ANDROID_APP_ID=""

Optional variables (all have defaults; override only when needed)

# App
APP_VERSION_NAME=""
BIOMETRICS_ENABLED="true"                       # Default: true
DATABASE_LOGGING_ENABLED="false"                # Default: false
FOREGROUND_NOTIFICATIONS_ENABLED="false"        # Default: false
TAPS_TO_UNLOCK_DEBUG="7"                        # Default: 7

# Chat
CHAT_ACTIVITY_EXPIRES_IN_SECONDS="3"            # Default: 3
CHAT_PRESENCE_SEND_INTERVAL_IN_SECONDS="60"     # Default: 60
CHAT_IMAGE_MAX_SIZE="800"                       # Default: 800 px
CHAT_IMAGE_QUALITY_PERCENT="80"                 # Default: 80 %

# Profile
PROFILE_IMAGE_MAX_SIZE="100"                    # Default: 100 px
PROFILE_IMAGE_QUALITY_PERCENT="80"              # Default: 80 %

# Marketplace
MARKETPLACE_QR_PREFIX=""

# Out-of-Band flow type (distinguishes multiple OOB flows so QR validation does not interfere)
DIRECT_INTERACTIVE_OOB_TYPE=""

# Human ZKP demo — enables ZKP and the Credentials tab
ZKP_ENABLED="false"                             # Default: false

# Matrix media cache
MATRIX_MEDIA_MAX_CACHE_MB=""                    # Default: 30 MB per Matrix account
MATRIX_MEDIA_CACHE_TTL_DAYS=""                  # Default: 30 days

Find all configuration options and their defaults in app/lib/infrastructure/configuration/environment.dart.

Set up Firebase configuration files

Follow the iOS Firebase setup guide to download GoogleService-Info.plist. Copy the file to app/ios/Runner/.
Follow the Android Firebase setup guide to download google-services.json. Copy the file to app/android/app/.

You only need the configuration files. Skip the other SDK setup steps in the Firebase guides.

Activate Melos and install dependencies

Melos manages the monorepo packages. Activate it globally and add it to your PATH:

dart pub global activate melos && export PATH="$PATH":"$HOME/.pub-cache/bin"

Add the export PATH line to your ~/.zshrc or ~/.bashrc so it persists across sessions.

Then install all package dependencies:

melos pubget

Generate models and localised strings

melos gen

melos strings

Run the app

cd app
flutter run

If multiple devices are available, select one from the prompt.

VS Code: Copy the template launch configuration to set up device IDs and environment targets:

mkdir -p .vscode && cp templates/.example.launch.json .vscode/launch.json

Simulators: See the Flutter documentation for Android emulator setup and iOS simulator setup. For Face Liveness testing, use a physical device. The camera challenge does not work on simulators or emulators.

Explore the app

Once the app is running, try these flows to see the SDK capabilities in action:

1 Create an identity

Generate one or more decentralised identities. Switch between identities based on context.

2 Publish an invitation

Create a connection offer with a custom passphrase, usage limit, or expiry date.

3 Start messaging

Open a private DIDComm or Matrix channel and exchange end-to-end encrypted messages.

4 Exchange credentials

Share an R-Card (your signed contact card) or initiate a VRC handshake to establish a verifiable relationship record.

5 Try Human ZKP

Set ZKP_ENABLED=true in your .env file to enable the liveness proof demo without sharing biometric data.

Feature walkthroughs

Each section below shows a feature as a step-by-step flow. Click any screenshot to view it full size.

R-Card exchange

Your R-Card is a signed digital contact card. Automatic flow: the app sends it when a new channel opens. Manual flow: tap + in chat and select Share R-Card.

View walkthrough

Automatic flow

R-Card sent on channel open

→

Received in thread

→

Saved to Credentials tab

Manual flow

Open chat action menu

→

Select R-Card to share

→

Visible to both parties

VRC exchange

A Verifiable Relationship Credential (VRC) encodes the DIDs of both participants and the timestamp of exchange. One party initiates, the other reciprocates, and both receive a signed copy in their Credentials tab.

View walkthrough

Initiate request

→

Request sent

→

Contact prompted

→

Both parties sign

Matrix-based features

Matrix enables group chat and richer message types: voice messages, reactions, edit and delete, and media attachments. Set ENABLED_INDIVIDUAL_CHAT_TRANSPORTS='["matrix"]' to activate it.

View walkthrough

Transport picker

Voice messages

Reactions

Edit message

Delete message

Group chat

Human ZKP demo

Enable with ZKP_ENABLED=true. A Credentials tab appears. Request a liveness proof from a contact. They complete a face challenge and you receive a Zero Knowledge Proof that confirms humanness without sharing biometric data.

View walkthrough

Open chat

→

Send liveness request

→

Proof sent

→

✓

Liveness complete

Verification failure

Troubleshooting

Symptom	Likely cause	Fix
`FirebaseException ([core/duplicate-app] A Firebase App named "[DEFAULT]" already exists)`	The Firebase configuration files do not match the environment variables in `configurations/.env`.	Check that `FIREBASE_PROJECT_ID`, `FIREBASE_MESSAGING_SENDER_ID`, and `FIREBASE_STORAGE_BUCKET` match across `google-services.json`, `GoogleService-Info.plist`, and your `.env` file.
Build fails after `flutter clean` with Matrix enabled	Stale Vodozemac build artefacts.	Run `rm -rf app/build/flutter_vodozemac` then `flutter run`.

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