​
Custom Networks addition and selection

AppKit Flutter supports EVM and Solana networks by default since version 1.2.0, meaning that you can connect to these networks with no extra configuration and it already comes with a predefined list of chains within the ReownAppKitModalNetworks class. This means that if you intend to support just EVM and Solana networks then no further adjustments are necessary. However, with extra configuration to ReownAppKitModalNetworks and optionalNamespaces you can connect to whatever other network you’d like.
If you are starting from scratch, you can avoid this by using our CLI tool and passing the chains you want to support as arguments.
For instance, if you want to support also Polkadot blockchain then first add Polkadot to the supported networks list: 
// Add more non-EVM nor Solana networks, such as Polkadot
ReownAppKitModalNetworks.addSupportedNetworks('polkadot', [
  ReownAppKitModalNetworkInfo(
    name: 'Polkadot',
    chainId: '91b171bb158e2d3848fa23a9f1c25182',
    chainIcon: 'https://cryptologos.cc/logos/polkadot-new-dot-logo.png',
    currency: 'DOT',
    rpcUrl: 'https://rpc.polkadot.io',
    explorerUrl: 'https://polkadot.subscan.io',
  ),
  ReownAppKitModalNetworkInfo(
    name: 'Westend',
    chainId: 'e143f23803ac50e8f6f8e62695d1ce9e',
    currency: 'DOT',
    rpcUrl: 'https://westend-rpc.polkadot.io',
    explorerUrl: 'https://westend.subscan.io',
    isTestNetwork: true,
  ),
]);
Remember to do this before ReownAppKitModal instance configuration and to set isTestNetwork: true if you are adding a testnet Then modify/add optionalNamespaces: property in ReownAppKitModal instance as follows: 
optionalNamespaces: {
  'eip155': RequiredNamespace.fromJson({
    'chains': ReownAppKitModalNetworks.getAllSupportedNetworks(
      namespace: 'eip155',
    ).map((chain) => '${chain.chainId}').toList(),
    'methods': NetworkUtils.defaultNetworkMethods['eip155']!.toList(),
    'events': NetworkUtils.defaultNetworkEvents['eip155']!.toList(),
  }),
  'solana': RequiredNamespace.fromJson({
    'chains': ReownAppKitModalNetworks.getAllSupportedNetworks(
      namespace: 'solana',
    ).map((chain) => '${chain.chainId}').toList(),
    'methods': NetworkUtils.defaultNetworkMethods['solana']!.toList(),
    'events': [],
  }),
  'polkadot': RequiredNamespace.fromJson({
    'chains': ReownAppKitModalNetworks.getAllSupportedNetworks(
      namespace: 'polkadot',
    ).map((chain) => '${chain.chainId}').toList(),
    'methods': [
      'polkadot_signMessage',
      'polkadot_signTransaction',
    ],
    'events': []
  }),
},
When you set optionalNamespaces property you are overwriting the internal definition of it so it is important that you also include eip155 and solana in this case. If you plan to support only EVM + Solana then this extra step is not needed as mentioned before ReownAppKitModalNetworks class also comes with handy methods to change the configuration of the supported networks list:
  • You can add more EVM networks
List<ReownAppKitModalNetworkInfo> extraChains = [...];
ReownAppKitModalNetworks.addSupportedNetworks('eip155', extraChains);
// The same applies for other namespaces
  • You can remove Solana networks if you don’t want to support it
ReownAppKitModalNetworks.removeSupportedNetworks('solana');
// The same applies for other namespaces
  • You can remove test networks altogether
// Remove every test network
ReownAppKitModalNetworks.removeTestNetworks();

​
Configuration examples

A list of different ways of configure ReownAppKitModal() instance to support different blockchains.

​
1. Default support (EVM + Solana blockchains)

// Nothing more is required to support EVM + Solana networks besides adding more EVM or Solana networks
// ReownAppKitModalNetworks.addSupportedNetworks('eip155', extraChains);
// ReownAppKitModalNetworks.addSupportedNetworks('solana', extraChains);

final _appKitModal = ReownAppKitModal(
  context: context,
  projectId: '{YOUR_PROJECT_ID}',
  metadata: const PairingMetadata(
    name: 'Example App',
    description: 'Example app description',
    url: 'https://example.com/',
    icons: ['https://example.com/logo.png'],
    redirect: Redirect( // OPTIONAL
      native: 'exampleapp://',
      universal: 'https://reown.com/exampleapp',
      linkMode: false,
    ),
  ),
  // With default configuration you can enable Email + Social Login
  featuresConfig: FeaturesConfig(
    email: true,
    socials: [...],
    showMainWallets: true|false,
  ),
);

​
2. Only EVM blockchains support

// first remove support for Solana networks
ReownAppKitModalNetworks.removeSupportedNetworks('solana');

final _appKitModal = ReownAppKitModal(
  context: context,
  projectId: '{YOUR_PROJECT_ID}',
  metadata: const PairingMetadata(
    name: 'Example App',
    description: 'Example app description',
    url: 'https://example.com/',
    icons: ['https://example.com/logo.png'],
    redirect: Redirect( // OPTIONAL
      native: 'exampleapp://',
      universal: 'https://reown.com/exampleapp',
      linkMode: false,
    ),
  ),
  // With only EVM support configuration you can enable Link Mode + SIWE feature
  siweConfig: SIWEConfig(...),
  // With only EVM support configuration you can enable Email + Social Login
  featuresConfig: FeaturesConfig(
    email: true,
    socials: [...],
    showMainWallets: true|false,
  ),
);

​
3. Only Solana blockchain support

// first remove support for EVM networks
ReownAppKitModalNetworks.removeSupportedNetworks('eip155');

final _appKitModal = ReownAppKitModal(
  context: context,
  projectId: '{YOUR_PROJECT_ID}',
  metadata: const PairingMetadata(
    name: 'Example App',
    description: 'Example app description',
    url: 'https://example.com/',
    icons: ['https://example.com/logo.png'],
    redirect: Redirect( // OPTIONAL
      native: 'exampleapp://',
      universal: 'https://reown.com/exampleapp',
      linkMode: false,
    ),
  ),
  // With only Solana support configuration you can enable Email + Social Login
  featuresConfig: FeaturesConfig(
    email: true,
    socials: [...],
    showMainWallets: true|false,
  ),
);

​
4. Default support (EVM + Solana blockchains) + Polkadot + Tron

// Add Polkadot and Tron before instantiating ReownAppKitModal()
ReownAppKitModalNetworks.addSupportedNetworks('polkadot', [
  ReownAppKitModalNetworkInfo(
    name: 'Polkadot',
    chainId: '91b171bb158e2d3848fa23a9f1c25182',
    chainIcon: 'https://cryptologos.cc/logos/polkadot-new-dot-logo.png',
    currency: 'DOT',
    rpcUrl: 'https://rpc.polkadot.io',
    explorerUrl: 'https://polkadot.subscan.io',
  ),
  ReownAppKitModalNetworkInfo(
    name: 'Westend',
    chainId: 'e143f23803ac50e8f6f8e62695d1ce9e',
    currency: 'DOT',
    rpcUrl: 'https://westend-rpc.polkadot.io',
    explorerUrl: 'https://westend.subscan.io',
    isTestNetwork: true,
  ),
]);

ReownAppKitModalNetworks.addSupportedNetworks('tron', [
  ReownAppKitModalNetworkInfo(
    name: 'Tron',
    chainId: '0x2b6653dc',
    chainIcon: 'https://cryptologos.cc/logos/tron-trx-logo.png',
    currency: 'TRX',
    rpcUrl: 'https://api.trongrid.io',
    explorerUrl: 'https://tronscan.org',
  ),
  ReownAppKitModalNetworkInfo(
    name: 'Tron testnet',
    chainId: '0xcd8690dc',
    chainIcon: 'https://cryptologos.cc/logos/tron-trx-logo.png',
    currency: 'TRX',
    rpcUrl: 'https://nile.trongrid.io',
    explorerUrl: 'https://test.tronscan.org',
    isTestNetwork: true,
  ),
]);

final _appKitModal = ReownAppKitModal(
  context: context,
  projectId: '{YOUR_PROJECT_ID}',
  metadata: const PairingMetadata(
    name: 'Example App',
    description: 'Example app description',
    url: 'https://example.com/',
    icons: ['https://example.com/logo.png'],
    redirect: Redirect( // OPTIONAL
      native: 'exampleapp://',
      universal: 'https://reown.com/exampleapp',
      linkMode: false,
    ),
  ),
  // With this configuration you can enable Email + Social Login but it will only work with EVM and Solana blockchains
  featuresConfig: FeaturesConfig(
    email: true,
    socials: [...],
    showMainWallets: true|false,
  ),
  // optionalNamespaces are mandatory with this kind of configuration 
  optionalNamespaces: {
    'eip155': RequiredNamespace.fromJson({
      'chains': ReownAppKitModalNetworks.getAllSupportedNetworks(
        namespace: 'eip155',
      ).map((chain) => '${chain.chainId}').toList(),
      'methods':
          NetworkUtils.defaultNetworkMethods['eip155']!.toList(),
      'events':
          NetworkUtils.defaultNetworkEvents['eip155']!.toList(),
    }),
    'solana': RequiredNamespace.fromJson({
      'chains': ReownAppKitModalNetworks.getAllSupportedNetworks(
        namespace: 'solana',
      ).map((chain) => '${chain.chainId}').toList(),
      'methods':
          NetworkUtils.defaultNetworkMethods['solana']!.toList(),
      'events': [],
    }),
    'polkadot': RequiredNamespace.fromJson({
      'chains': ReownAppKitModalNetworks.getAllSupportedNetworks(
        namespace: 'polkadot',
      ).map((chain) => '${chain.chainId}').toList(),
      'methods': [
        'polkadot_signMessage',
        'polkadot_signTransaction',
      ],
      'events': []
    }),
    'tron': RequiredNamespace.fromJson({
      'chains': ReownAppKitModalNetworks.getAllSupportedNetworks(
        namespace: 'tron',
      ).map((chain) => '${chain.chainId}').toList(),
      'methods': [
        'tron_signMessage',
        'tron_signTransaction',
      ],
      'events': []
    }),
  },
);