diff --git a/common/actions/config.js b/common/actions/config.js
index ee0d607f..8cbd61b2 100644
--- a/common/actions/config.js
+++ b/common/actions/config.js
@@ -1,18 +1,30 @@
 // @flow
 import { setLanguage } from 'translations';
-export const CONFIG_LANGUAGE_CHANGE = 'CONFIG_LANGUAGE_CHANGE';
-export const CONFIG_NODE_CHANGE = 'CONFIG_NODE_CHANGE';
 
-export const CHANGE_LANGUAGE = (value: any) => {
-    setLanguage(value.sign);
-    return {
-        type: CONFIG_LANGUAGE_CHANGE,
-        value
-    };
+export type ChangeNodeAction = {
+    type: 'CONFIG_NODE_CHANGE',
+    // FIXME $keyof?
+    value: string
 };
 
-export const CHANGE_NODE = (value: any) =>
-    Object({
-        type: CONFIG_NODE_CHANGE,
+export type ChangeLanguageAction = {
+    type: 'CONFIG_LANGUAGE_CHANGE',
+    value: string
+};
+
+export type ConfigAction = ChangeNodeAction | ChangeLanguageAction;
+
+export function changeLanguage(sign: string) {
+    setLanguage(sign);
+    return {
+        type: 'CONFIG_LANGUAGE_CHANGE',
+        value: sign
+    };
+}
+
+export function changeNode(value: string): ChangeNodeAction {
+    return {
+        type: 'CONFIG_NODE_CHANGE',
         value
-    });
+    };
+}
diff --git a/common/components/Header/index.jsx b/common/components/Header/index.jsx
index 727d4cac..a721008f 100644
--- a/common/components/Header/index.jsx
+++ b/common/components/Header/index.jsx
@@ -1,26 +1,23 @@
 // @flow
 import React, { Component } from 'react';
-import PropTypes from 'prop-types';
 import TabsOptions from './components/TabsOptions';
 import { Link } from 'react-router';
 import { Dropdown } from 'components/ui';
-import { languages, nodeList } from '../../config/data';
+import { languages, NODES } from '../../config/data';
 
 export default class Header extends Component {
-    static propTypes = {
-        location: PropTypes.object,
+    props: {
+        languageSelection: string,
+        nodeSelection: string,
 
-        // Language DropDown
-        changeLanguage: PropTypes.func,
-        languageSelection: PropTypes.object,
-
-        // Node Dropdown
-        changeNode: PropTypes.func,
-        nodeSelection: PropTypes.object
+        changeLanguage: (sign: string) => any,
+        changeNode: (key: string) => any
     };
 
     render() {
-        const { languageSelection, changeLanguage, changeNode, nodeSelection } = this.props;
+        const { languageSelection, changeNode, nodeSelection } = this.props;
+        const selectedLanguage = languages.find(l => l.sign === languageSelection) || languages[0];
+        const selectedNode = NODES[nodeSelection];
 
         return (
             <div>
@@ -41,10 +38,10 @@ export default class Header extends Component {
                             </span>
                             &nbsp;&nbsp;&nbsp;
                             <Dropdown
-                                ariaLabel={`change language. current language ${languageSelection.name}`}
+                                ariaLabel={`change language. current language ${selectedLanguage.name}`}
                                 options={languages}
                                 formatTitle={o => o.name}
-                                value={languageSelection}
+                                value={selectedLanguage}
                                 extra={[
                                     <li key={'separator'} role="separator" className="divider" />,
                                     <li key={'disclaimer'}>
@@ -53,23 +50,23 @@ export default class Header extends Component {
                                         </a>
                                     </li>
                                 ]}
-                                onChange={changeLanguage}
+                                onChange={this.changeLanguage}
                             />
                             &nbsp;&nbsp;&nbsp;
                             <Dropdown
-                                ariaLabel={`change node. current node ${nodeSelection.name} node by ${nodeSelection.service}`}
-                                options={nodeList}
+                                ariaLabel={`change node. current node ${selectedNode.network} node by ${selectedNode.service}`}
+                                options={Object.keys(NODES)}
                                 formatTitle={o => [
-                                    o.name,
+                                    NODES[o].network,
                                     ' ',
-                                    <small key="service">({o.service})</small>
+                                    <small key="service">
+                                        ({NODES[o].service})
+                                    </small>
                                 ]}
                                 value={nodeSelection}
                                 extra={
                                     <li>
-                                        <a onClick={() => {}}>
-                                            Add Custom Node
-                                        </a>
+                                        <a onClick={() => {}}>Add Custom Node</a>
                                     </li>
                                 }
                                 onChange={changeNode}
@@ -79,8 +76,11 @@ export default class Header extends Component {
                 </section>
 
                 <TabsOptions {...this.props} />
-
             </div>
         );
     }
+
+    changeLanguage = (value: { sign: string }) => {
+        this.props.changeLanguage(value.sign);
+    };
 }
diff --git a/common/components/index.js b/common/components/index.js
index 9372d321..e4fe4b8f 100644
--- a/common/components/index.js
+++ b/common/components/index.js
@@ -1,3 +1,5 @@
-export Header from './Header';
-export Footer from './Footer';
-export Root from './Root';
+// @flow
+
+export { default as Header } from './Header';
+export { default as Footer } from './Footer';
+export { default as Root } from './Root';
diff --git a/common/components/ui/Dropdown.jsx b/common/components/ui/Dropdown.jsx
index 0ccc6c43..f576ffef 100644
--- a/common/components/ui/Dropdown.jsx
+++ b/common/components/ui/Dropdown.jsx
@@ -1,26 +1,21 @@
 // @flow
 import React, { Component } from 'react';
-import PropTypes from 'prop-types';
 
-export default class DropdownComponent extends Component {
-    static propTypes = {
-        value: PropTypes.object.isRequired,
-        options: PropTypes.arrayOf(PropTypes.object).isRequired,
-        ariaLabel: PropTypes.string.isRequired,
-        formatTitle: PropTypes.func.isRequired,
-        extra: PropTypes.node,
-        onChange: PropTypes.func.isRequired
-    };
+type Props<T> = {
+    value: T,
+    options: T[],
+    ariaLabel: string,
+    formatTitle: (option: T) => any,
+    extra?: any,
+    onChange: (value: T) => void
+}
 
-    // FIXME
-    props: {
-        value: any,
-        options: any[],
-        ariaLabel: string,
-        formatTitle: (option: any) => any,
-        extra?: any,
-        onChange: (value: any) => void
-    };
+type State = {
+    expanded: boolean
+}
+
+export default class DropdownComponent<T: *> extends Component<void, Props<T>, State> {
+    props: Props<T>
 
     state = {
         expanded: false
diff --git a/common/config/data.js b/common/config/data.js
index dac459b5..09dd1a6d 100644
--- a/common/config/data.js
+++ b/common/config/data.js
@@ -1,168 +1,124 @@
+// @flow
+import { RPCNode } from 'libs/nodes';
+
 export const DONATION_ADDRESSES_MAP = {
-  BTC: '1MEWT2SGbqtz6mPCgFcnea8XmWV5Z4Wc6',
-  ETH: '0x7cB57B5A97eAbe94205C07890BE4c1aD31E486A8',
-  REP: '0x7cB57B5A97eAbe94205C07890BE4c1aD31E486A8'
+    BTC: '1MEWT2SGbqtz6mPCgFcnea8XmWV5Z4Wc6',
+    ETH: '0x7cB57B5A97eAbe94205C07890BE4c1aD31E486A8',
+    REP: '0x7cB57B5A97eAbe94205C07890BE4c1aD31E486A8'
 };
 
 export const languages = [
-  {
-    sign: 'en',
-    name: 'English'
-  },
-  {
-    sign: 'de',
-    name: 'Deutsch'
-  },
-  {
-    sign: 'el',
-    name: 'Ελληνικά'
-  },
-  {
-    sign: 'es',
-    name: 'Español'
-  },
-  {
-    sign: 'fi',
-    name: 'Suomi'
-  },
-  {
-    sign: 'fr',
-    name: 'Français'
-  },
-  {
-    sign: 'hu',
-    name: 'Magyar'
-  },
-  {
-    sign: 'id',
-    name: 'Indonesian'
-  },
-  {
-    sign: 'it',
-    name: 'Italiano'
-  },
-  {
-    sign: 'ja',
-    name: '日本語'
-  },
-  {
-    sign: 'nl',
-    name: 'Nederlands'
-  },
-  {
-    sign: 'no',
-    name: 'Norsk Bokmål'
-  },
-  {
-    sign: 'pl',
-    name: 'Polski'
-  },
-  {
-    sign: 'pt',
-    name: 'Português'
-  },
-  {
-    sign: 'ru',
-    name: 'Русский'
-  },
-  {
-    sign: 'ko',
-    name: 'Korean'
-  },
-  // {
-  //     'sign': 'sk',
-  //     'name': 'Slovenčina'
-  // },
-  // {
-  //     'sign': 'sl',
-  //     'name': 'Slovenščina'
-  // },
-  // {
-  //     'sign': 'sv',
-  //     'name': 'Svenska'
-  // },
-  {
-    sign: 'tr',
-    name: 'Türkçe'
-  },
-  {
-    sign: 'vi',
-    name: 'Tiếng Việt'
-  },
-  {
-    sign: 'zhcn',
-    name: '简体中文'
-  },
-  {
-    sign: 'zhtw',
-    name: '繁體中文'
-  }
+    {
+        sign: 'en',
+        name: 'English'
+    },
+    {
+        sign: 'de',
+        name: 'Deutsch'
+    },
+    {
+        sign: 'el',
+        name: 'Ελληνικά'
+    },
+    {
+        sign: 'es',
+        name: 'Español'
+    },
+    {
+        sign: 'fi',
+        name: 'Suomi'
+    },
+    {
+        sign: 'fr',
+        name: 'Français'
+    },
+    {
+        sign: 'hu',
+        name: 'Magyar'
+    },
+    {
+        sign: 'id',
+        name: 'Indonesian'
+    },
+    {
+        sign: 'it',
+        name: 'Italiano'
+    },
+    {
+        sign: 'ja',
+        name: '日本語'
+    },
+    {
+        sign: 'nl',
+        name: 'Nederlands'
+    },
+    {
+        sign: 'no',
+        name: 'Norsk Bokmål'
+    },
+    {
+        sign: 'pl',
+        name: 'Polski'
+    },
+    {
+        sign: 'pt',
+        name: 'Português'
+    },
+    {
+        sign: 'ru',
+        name: 'Русский'
+    },
+    {
+        sign: 'ko',
+        name: 'Korean'
+    },
+    // {
+    //     'sign': 'sk',
+    //     'name': 'Slovenčina'
+    // },
+    // {
+    //     'sign': 'sl',
+    //     'name': 'Slovenščina'
+    // },
+    // {
+    //     'sign': 'sv',
+    //     'name': 'Svenska'
+    // },
+    {
+        sign: 'tr',
+        name: 'Türkçe'
+    },
+    {
+        sign: 'vi',
+        name: 'Tiếng Việt'
+    },
+    {
+        sign: 'zhcn',
+        name: '简体中文'
+    },
+    {
+        sign: 'zhtw',
+        name: '繁體中文'
+    }
 ];
 
-export const nodeList = [
-  {
-    name: 'ETH',
-    blockExplorerTX: 'https://etherscan.io/tx/[[txHash]]',
-    blockExplorerAddr: 'https://etherscan.io/address/[[address]]',
-    // 'type': nodes.nodeTypes.ETH,
-    eip155: true,
-    chainId: 1,
-    // 'tokenList': require('./tokens/ethTokens.json'),
-    // 'abiList': require('./abiDefinitions/ethAbi.json'),
-    estimateGas: true,
-    service: 'MyEtherWallet'
-    // 'lib': new nodes.customNode('https://api.myetherapi.com/eth', '')
-  },
-  {
-    name: 'ETH',
-    blockExplorerTX: 'https://etherscan.io/tx/[[txHash]]',
-    blockExplorerAddr: 'https://etherscan.io/address/[[address]]',
-    // 'type': nodes.nodeTypes.ETH,
-    eip155: true,
-    chainId: 1,
-    // 'tokenList': require('./tokens/ethTokens.json'),
-    // 'abiList': require('./abiDefinitions/ethAbi.json'),
-    estimateGas: false,
-    service: 'Etherscan.io'
-    // 'lib': require('./nodeHelpers/etherscan')
-  },
-  {
-    name: 'Ropsten',
-    // 'type': nodes.nodeTypes.Ropsten,
-    blockExplorerTX: 'https://ropsten.etherscan.io/tx/[[txHash]]',
-    blockExplorerAddr: 'https://ropsten.etherscan.io/address/[[address]]',
-    eip155: true,
-    chainId: 3,
-    // 'tokenList': require('./tokens/ropstenTokens.json'),
-    // 'abiList': require('./abiDefinitions/ropstenAbi.json'),
-    estimateGas: false,
-    service: 'MyEtherWallet'
-    // 'lib': new nodes.customNode('https://api.myetherapi.com/rop', '')
-  },
-  {
-    name: 'Kovan',
-    // 'type': nodes.nodeTypes.Kovan,
-    blockExplorerTX: 'https://kovan.etherscan.io/tx/[[txHash]]',
-    blockExplorerAddr: 'https://kovan.etherscan.io/address/[[address]]',
-    eip155: true,
-    chainId: 42,
-    // 'tokenList': require('./tokens/kovanTokens.json'),
-    // 'abiList': require('./abiDefinitions/kovanAbi.json'),
-    estimateGas: false,
-    service: 'Etherscan.io'
-    // 'lib': require('./nodeHelpers/etherscanKov')
-  },
-  {
-    name: 'ETC',
-    blockExplorerTX: 'https://gastracker.io/tx/[[txHash]]',
-    blockExplorerAddr: 'https://gastracker.io/addr/[[address]]',
-    // 'type': nodes.nodeTypes.ETC,
-    eip155: true,
-    chainId: 61,
-    // 'tokenList': require('./tokens/etcTokens.json'),
-    // 'abiList': require('./abiDefinitions/etcAbi.json'),
-    estimateGas: false,
-    service: 'Epool.io'
-    // 'lib': new nodes.customNode('https://mewapi.epool.io', '')
-  }
-];
+export const NETWORKS = {
+    ETH: {
+        name: 'ETH',
+        blockExplorerTX: 'https://etherscan.io/tx/[[txHash]]',
+        blockExplorerAddr: 'https://etherscan.io/address/[[address]]',
+        chainId: 1
+    }
+};
+
+export const NODES = {
+    eth_mew: {
+        network: 'ETH',
+        lib: new RPCNode('https://api.myetherapi.com/eth'),
+        service: 'MyEtherWallet',
+        estimateGas: true,
+        eip155: true
+        // 'tokenList': require('./tokens/ethTokens.json'),
+        // 'abiList': require('./abiDefinitions/ethAbi.json'),
+    }
+};
diff --git a/common/containers/App/index.jsx b/common/containers/App/index.jsx
index 1d6d3127..47c300e3 100644
--- a/common/containers/App/index.jsx
+++ b/common/containers/App/index.jsx
@@ -2,32 +2,23 @@
 import React, { Component } from 'react';
 import { connect } from 'react-redux';
 import { Footer, Header } from 'components';
-import PropTypes from 'prop-types';
 import Notifications from './Notifications';
-
-import { CHANGE_LANGUAGE, CHANGE_NODE } from 'actions/config';
+import * as actions from 'actions/config';
 
 class App extends Component {
-    constructor(props) {
-        super(props);
-    }
+    props: {
+        // FIXME
+        children: any,
+        location: any,
+        router: any,
+        isMobile: boolean,
 
-    static propTypes = {
-        children: PropTypes.node.isRequired,
-        location: PropTypes.object,
-        handleWindowResize: PropTypes.func,
+        languageSelection: string,
+        nodeSelection: string,
 
-        router: PropTypes.object,
-        isMobile: PropTypes.bool,
-
-        // BEGIN ACTUAL
-        languageSelection: PropTypes.object,
-        changeLanguage: PropTypes.func,
-
-        changeNode: PropTypes.func,
-        nodeSelection: PropTypes.object,
-
-        showNotification: PropTypes.func
+        changeLanguage: typeof actions.changeLanguage,
+        changeNode: typeof actions.changeNode,
+        handleWindowResize: () => void
     };
 
     render() {
@@ -72,16 +63,4 @@ function mapStateToProps(state) {
     };
 }
 
-function mapDispatchToProps(dispatch) {
-    return {
-        // FIXME replace with actual types
-        changeNode: (i: any) => {
-            dispatch(CHANGE_NODE(i));
-        },
-        changeLanguage: (i: any) => {
-            dispatch(CHANGE_LANGUAGE(i));
-        }
-    };
-}
-
-export default connect(mapStateToProps, mapDispatchToProps)(App);
+export default connect(mapStateToProps, actions)(App);
diff --git a/common/libs/nodes/base.js b/common/libs/nodes/base.js
new file mode 100644
index 00000000..2cf5a517
--- /dev/null
+++ b/common/libs/nodes/base.js
@@ -0,0 +1,8 @@
+// @flow
+
+export default class BaseNode {
+    // FIXME bignumber?
+    queryBalance(address: string): Promise<number> {
+        throw 'Implement me';
+    }
+}
diff --git a/common/libs/nodes/index.js b/common/libs/nodes/index.js
new file mode 100644
index 00000000..4ac70297
--- /dev/null
+++ b/common/libs/nodes/index.js
@@ -0,0 +1,3 @@
+// @flow
+export { default as BaseNode } from './base';
+export { default as RPCNode } from './rpc';
diff --git a/common/libs/nodes/rpc.js b/common/libs/nodes/rpc.js
new file mode 100644
index 00000000..1c4e3059
--- /dev/null
+++ b/common/libs/nodes/rpc.js
@@ -0,0 +1,10 @@
+// @flow
+import BaseNode from './base';
+
+export default class RPCNode extends BaseNode {
+    endpoint: string;
+    constructor(endpoint: string) {
+        super();
+        this.endpoint = endpoint;
+    }
+}
diff --git a/common/reducers/config.js b/common/reducers/config.js
index 984a08a5..16bc939f 100644
--- a/common/reducers/config.js
+++ b/common/reducers/config.js
@@ -1,36 +1,39 @@
 // @flow
-import {
-    CONFIG_LANGUAGE_CHANGE,
-    CONFIG_NODE_CHANGE
-} from 'actions/config';
-import {languages, nodeList} from '../config/data';
+import type { ConfigAction, ChangeNodeAction, ChangeLanguageAction } from 'actions/config';
+import { languages, NODES } from '../config/data';
 
 export type State = {
     // FIXME
     languageSelection: string,
     nodeSelection: string
+};
+
+const initialState: State = {
+    languageSelection: languages[0].sign,
+    nodeSelection: Object.keys(NODES)[0]
+};
+
+function changeLanguage(state: State, action: ChangeLanguageAction): State {
+    return {
+        ...state,
+        languageSelection: action.value
+    };
 }
 
-const initialState = {
-    languageSelection: languages[0],
-    nodeSelection: nodeList[0]
+function changeNode(state: State, action: ChangeNodeAction): State {
+    return {
+        ...state,
+        nodeSelection: action.value
+    };
 }
 
-export function config(state: State = initialState, action): State {
+export function config(state: State = initialState, action: ConfigAction): State {
     switch (action.type) {
-        case CONFIG_LANGUAGE_CHANGE: {
-            return {
-                ...state,
-                languageSelection: action.value
-            }
-        }
-        case CONFIG_NODE_CHANGE: {
-            return {
-                ...state,
-                nodeSelection: action.value
-            }
-        }
+        case 'CONFIG_LANGUAGE_CHANGE':
+            return changeLanguage(state, action);
+        case 'CONFIG_NODE_CHANGE':
+            return changeNode(state, action);
         default:
-            return state
+            return state;
     }
 }
diff --git a/common/reducers/index.js b/common/reducers/index.js
index a56d3b27..1813c015 100644
--- a/common/reducers/index.js
+++ b/common/reducers/index.js
@@ -22,7 +22,7 @@ import { routerReducer } from 'react-router-redux';
 
 export type State = {
     generateWallet: GenerateWalletState,
-    conig: ConfigState,
+    config: ConfigState,
     notifications: NotificationsState,
     ens: EnsState,
     wallet: WalletState
diff --git a/common/sagas/wallet.js b/common/sagas/wallet.js
index 0a356630..b09bd42b 100644
--- a/common/sagas/wallet.js
+++ b/common/sagas/wallet.js
@@ -8,7 +8,7 @@ import PrivKeyWallet from 'libs/wallet/privkey';
 
 function* init() {
     yield put(initWallet());
-    // const node = select(node);
+    // const node = select(getNode);
     // yield call();
     // fetch balance,
     // fetch tokens
diff --git a/common/selectors/config.js b/common/selectors/config.js
new file mode 100644
index 00000000..00389dfd
--- /dev/null
+++ b/common/selectors/config.js
@@ -0,0 +1,8 @@
+// @flow
+import type { State } from 'reducers';
+import { BaseNode } from 'libs/nodes';
+import { NODES } from 'config/data';
+
+export function getNodeLib(state: State): BaseNode {
+    return NODES[state.config.nodeSelection].lib;
+}
diff --git a/common/translations/index.js b/common/translations/index.js
index df491f12..668599a3 100644
--- a/common/translations/index.js
+++ b/common/translations/index.js
@@ -37,7 +37,9 @@ export function setLanguage(code: string) {
 
 export default function translate(key: string) {
     return markupToReact(
-        repository[activeLanguage][key] || repository[fallbackLanguage][key] || key
+        (repository[activeLanguage] && repository[activeLanguage][key]) ||
+            repository[fallbackLanguage][key] ||
+            key
     );
 }