diff --git a/common/actions/notifications.js b/common/actions/notifications.js
index 8b6bb993..5c0cee61 100644
--- a/common/actions/notifications.js
+++ b/common/actions/notifications.js
@@ -20,7 +20,7 @@ export type ShowNotificationAction = {
 export function showNotification(
   level: NOTIFICATION_LEVEL = 'info',
   msg: Element<*> | string,
-  duration?: number
+  duration?: number | INFINITY
 ): ShowNotificationAction {
   return {
     type: 'SHOW_NOTIFICATION',
diff --git a/common/reducers/index.js b/common/reducers/index.js
index e7705f6d..70402039 100644
--- a/common/reducers/index.js
+++ b/common/reducers/index.js
@@ -28,6 +28,8 @@ import type { State as ContractsState } from './contracts';
 import * as deterministicWallets from './deterministicWallets';
 import type { State as DeterministicWalletsState } from './deterministicWallets';
 
+import type { State as SwapState } from './swap';
+
 import { reducer as formReducer } from 'redux-form';
 import { combineReducers } from 'redux';
 import { routerReducer } from 'react-router-redux';
@@ -45,7 +47,8 @@ export type State = {
   deterministicWallets: DeterministicWalletsState,
   // Third party reducers (TODO: Fill these out)
   form: Object,
-  routing: Object
+  routing: Object,
+  swap: SwapState
 };
 
 export default combineReducers({
diff --git a/common/reducers/swap/index.js b/common/reducers/swap/index.js
index b17ed8e0..12d33f42 100644
--- a/common/reducers/swap/index.js
+++ b/common/reducers/swap/index.js
@@ -10,7 +10,7 @@ export const ALL_CRYPTO_KIND_OPTIONS = ['BTC', 'ETH', 'REP'];
 const DEFAULT_ORIGIN_KIND = 'BTC';
 const DEFAULT_DESTINATION_KIND = 'ETH';
 
-type State = {
+export type State = {
   originAmount: ?number,
   destinationAmount: ?number,
   originKind: string,
diff --git a/common/sagas/config.js b/common/sagas/config.js
index 0db7c06a..2fd51fa9 100644
--- a/common/sagas/config.js
+++ b/common/sagas/config.js
@@ -1,11 +1,13 @@
 import { takeEvery } from 'redux-saga/effects';
 
+import type { Yield, Return, Next } from 'sagas/types';
+
 // @HACK For now we reload the app when doing a language swap to force non-connected
 // data to reload. Also the use of timeout to avoid using additional actions for now.
-function* handleLanguageChange() {
+function* handleLanguageChange(): Generator<Yield, Return, Next> {
   yield setTimeout(() => location.reload(), 250);
 }
 
-export default function* handleConfigChanges() {
+export default function* handleConfigChanges(): Generator<Yield, Return, Next> {
   yield takeEvery('CONFIG_LANGUAGE_CHANGE', handleLanguageChange);
 }
diff --git a/common/sagas/contracts.js b/common/sagas/contracts.js
index cc8f7d6b..f20a3ab8 100644
--- a/common/sagas/contracts.js
+++ b/common/sagas/contracts.js
@@ -1,15 +1,19 @@
 import { takeEvery, put } from 'redux-saga/effects';
-import type { Effect } from 'redux-saga/effects';
+
+import type { Yield, Return, Next } from 'sagas/types';
+
 import translate from 'translations';
+import { isValidETHAddress } from 'libs/validators';
 
 import {
   AccessContractAction,
   setInteractiveContract
 } from 'actions/contracts';
 import { showNotification } from 'actions/notifications';
-import { isValidETHAddress } from 'libs/validators';
 
-function* handleAccessContract(action: AccessContractAction) {
+function* handleAccessContract(
+  action: AccessContractAction
+): Generator<Yield, Return, Next> {
   const contractFunctions = [];
 
   if (!action.address || !isValidETHAddress(action.address)) {
@@ -36,6 +40,6 @@ function* handleAccessContract(action: AccessContractAction) {
   }
 }
 
-export default function* contractsSaga(): Generator<Effect, void, any> {
+export default function* contractsSaga(): Generator<Yield, Return, Next> {
   yield takeEvery('ACCESS_CONTRACT', handleAccessContract);
 }
diff --git a/common/sagas/deterministicWallets.js b/common/sagas/deterministicWallets.js
index 96a15963..da300ba6 100644
--- a/common/sagas/deterministicWallets.js
+++ b/common/sagas/deterministicWallets.js
@@ -11,26 +11,29 @@ import {
 } from 'redux-saga/effects';
 import HDKey from 'hdkey';
 import { publicToAddress, toChecksumAddress } from 'ethereumjs-util';
+
 import {
   setDeterministicWallets,
   updateDeterministicWallet
 } from 'actions/deterministicWallets';
-import { getWallets, getDesiredToken } from 'selectors/deterministicWallets';
-import { getNodeLib } from 'selectors/config';
-import { getTokens } from 'selectors/wallet';
-
 import type {
   DeterministicWalletData,
   GetDeterministicWalletsAction
 } from 'actions/deterministicWallets';
-import type { Effect } from 'redux-saga/effects';
+
+import type { Yield, Return, Next } from 'sagas/types';
+
+import { getWallets, getDesiredToken } from 'selectors/deterministicWallets';
+import { getNodeLib } from 'selectors/config';
+import { getTokens } from 'selectors/wallet';
+
 import type { BaseNode } from 'libs/nodes';
 import type { Token } from 'config/data';
 
 // TODO: BIP39 for mnemonic wallets?
 function* getDeterministicWallets(
   action?: GetDeterministicWalletsAction
-): Generator<Effect, void, any> {
+): Generator<Yield, Return, Next> {
   if (!action) return;
 
   const { publicKey, chainCode, limit, offset } = action.payload;
@@ -56,7 +59,7 @@ function* getDeterministicWallets(
 }
 
 // Grab each wallet's main network token, and update it with it
-function* updateWalletValues() {
+function* updateWalletValues(): Generator<Yield, Return, Next> {
   const node: BaseNode = yield select(getNodeLib);
   const wallets: DeterministicWalletData[] = yield select(getWallets);
   const calls = wallets.map(w => apply(node, node.getBalance, [w.address]));
@@ -73,7 +76,7 @@ function* updateWalletValues() {
 }
 
 // Grab the current desired token, and update the wallet with it
-function* updateWalletTokenValues() {
+function* updateWalletTokenValues(): Generator<Yield, Return, Next> {
   const desiredToken: string = yield select(getDesiredToken);
   if (!desiredToken) return;
 
@@ -102,9 +105,9 @@ function* updateWalletTokenValues() {
 }
 
 export default function* deterministicWalletsSaga(): Generator<
-  Effect,
-  void,
-  any
+  Yield,
+  Return,
+  Next
 > {
   yield takeLatest('DW_GET_WALLETS', getDeterministicWallets);
   yield takeEvery('DW_SET_DESIRED_TOKEN', updateWalletTokenValues);
diff --git a/common/sagas/ens.js b/common/sagas/ens.js
index 50582121..afecc2de 100644
--- a/common/sagas/ens.js
+++ b/common/sagas/ens.js
@@ -1,13 +1,18 @@
 // @flow
 import { takeEvery, call, put, select } from 'redux-saga/effects';
 import { delay } from 'redux-saga';
-import type { Effect } from 'redux-saga/effects';
+
 import { cacheEnsAddress } from 'actions/ens';
 import type { ResolveEnsNameAction } from 'actions/ens';
+
 import { getEnsAddress } from 'selectors/ens';
 import { donationAddressMap } from 'config/data';
 
-function* resolveEns(action?: ResolveEnsNameAction) {
+import type { Yield, Return, Next } from 'sagas/types';
+
+function* resolveEns(
+  action?: ResolveEnsNameAction
+): Generator<Yield, Return, Next> {
   if (!action) return;
   const ensName = action.payload;
   // FIXME Add resolve logic
@@ -31,6 +36,6 @@ function* resolveEns(action?: ResolveEnsNameAction) {
   yield put(cacheEnsAddress(ensName, donationAddressMap.ETH));
 }
 
-export default function* notificationsSaga(): Generator<Effect, void, any> {
+export default function* notificationsSaga(): Generator<Yield, Return, Next> {
   yield takeEvery('ENS_RESOLVE', resolveEns);
 }
diff --git a/common/sagas/notifications.js b/common/sagas/notifications.js
index 71140a65..73ba4479 100644
--- a/common/sagas/notifications.js
+++ b/common/sagas/notifications.js
@@ -1,11 +1,15 @@
 // @flow
 import { takeEvery, put, call } from 'redux-saga/effects';
 import { delay } from 'redux-saga';
-import type { Effect } from 'redux-saga/effects';
+
+import type { Yield, Return, Next } from 'sagas/types';
+
 import { closeNotification } from 'actions/notifications';
 import type { ShowNotificationAction } from 'actions/notifications';
 
-function* handleNotification(action?: ShowNotificationAction) {
+function* handleNotification(
+  action?: ShowNotificationAction
+): Generator<Yield, Return, Next> {
   if (!action) return;
   const { duration } = action.payload;
   // show forever
@@ -18,6 +22,6 @@ function* handleNotification(action?: ShowNotificationAction) {
   yield put(closeNotification(action.payload));
 }
 
-export default function* notificationsSaga(): Generator<Effect, void, any> {
+export default function* notificationsSaga(): Generator<Yield, Return, Next> {
   yield takeEvery('SHOW_NOTIFICATION', handleNotification);
 }
diff --git a/common/sagas/swap/orders.js b/common/sagas/swap/orders.js
index 8a00bda5..b74b845f 100644
--- a/common/sagas/swap/orders.js
+++ b/common/sagas/swap/orders.js
@@ -1,6 +1,5 @@
-import { showNotification } from 'actions/notifications';
+// @flow
 import { delay } from 'redux-saga';
-import { postOrder, getOrderStatus } from 'api/bity';
 import {
   call,
   put,
@@ -9,9 +8,11 @@ import {
   cancel,
   select,
   cancelled,
-  takeEvery,
-  Effect
+  takeEvery
 } from 'redux-saga/effects';
+import moment from 'moment';
+
+import { showNotification } from 'actions/notifications';
 import {
   orderTimeSwap,
   bityOrderCreateSucceededSwap,
@@ -23,19 +24,25 @@ import {
   startPollBityOrderStatus,
   stopPollBityOrderStatus
 } from 'actions/swap';
-import moment from 'moment';
 
-export const getSwap = state => state.swap;
+import { postOrder, getOrderStatus } from 'api/bity';
+
+import type { Yield, Return, Next } from 'sagas/types';
+import type { State as SwapState } from 'reducers/swap';
+import type { State } from 'reducers';
+import type { BityOrderCreateRequestedSwapAction } from 'actions/swapTypes';
+
+export const getSwap = (state: State): SwapState => state.swap;
 const ONE_SECOND = 1000;
 const TEN_SECONDS = ONE_SECOND * 10;
 const BITY_TIMEOUT_MESSAGE = `
-    Time has run out. 
-    If you have already sent, please wait 1 hour. 
-    If your order has not be processed after 1 hour, 
+    Time has run out.
+    If you have already sent, please wait 1 hour.
+    If your order has not be processed after 1 hour,
     please press the orange 'Issue with your Swap?' button.
 `;
 
-export function* pollBityOrderStatus(): Generator<Effect, void, any> {
+export function* pollBityOrderStatus(): Generator<Yield, Return, Next> {
   try {
     let swap = yield select(getSwap);
     while (true) {
@@ -66,7 +73,7 @@ export function* pollBityOrderStatus(): Generator<Effect, void, any> {
   }
 }
 
-export function* pollBityOrderStatusSaga(): Generator<Effect, void, any> {
+export function* pollBityOrderStatusSaga(): Generator<Yield, Return, Next> {
   while (yield take('SWAP_START_POLL_BITY_ORDER_STATUS')) {
     // starts the task in the background
     const pollBityOrderStatusTask = yield fork(pollBityOrderStatus);
@@ -78,7 +85,9 @@ export function* pollBityOrderStatusSaga(): Generator<Effect, void, any> {
   }
 }
 
-function* postBityOrderCreate(action) {
+function* postBityOrderCreate(
+  action: BityOrderCreateRequestedSwapAction
+): Generator<Yield, Return, Next> {
   const payload = action.payload;
   try {
     yield put(stopLoadBityRatesSwap());
@@ -111,11 +120,11 @@ function* postBityOrderCreate(action) {
   }
 }
 
-export function* postBityOrderSaga(): Generator<Effect, void, any> {
+export function* postBityOrderSaga(): Generator<Yield, Return, Next> {
   yield takeEvery('SWAP_ORDER_CREATE_REQUESTED', postBityOrderCreate);
 }
 
-export function* bityTimeRemaining() {
+export function* bityTimeRemaining(): Generator<Yield, Return, Next> {
   while (yield take('SWAP_ORDER_START_TIMER')) {
     let hasShownNotification = false;
     while (true) {
diff --git a/common/sagas/wallet.js b/common/sagas/wallet.js
index cbb50850..ccf6ae53 100644
--- a/common/sagas/wallet.js
+++ b/common/sagas/wallet.js
@@ -1,13 +1,17 @@
 // @flow
 import React from 'react';
 import { takeEvery, call, apply, put, select, fork } from 'redux-saga/effects';
-import type { Effect } from 'redux-saga/effects';
+
 import { setWallet, setBalance, setTokenBalances } from 'actions/wallet';
 import type {
   UnlockPrivateKeyAction,
   UnlockKeystoreAction
 } from 'actions/wallet';
 import { showNotification } from 'actions/notifications';
+import type { BroadcastTxRequestedAction } from 'actions/wallet';
+
+import type { Yield, Return, Next } from 'sagas/types';
+
 import translate from 'translations';
 import {
   PresaleWallet,
@@ -18,13 +22,14 @@ import {
   BaseWallet
 } from 'libs/wallet';
 import { BaseNode } from 'libs/nodes';
+import { determineKeystoreType } from 'libs/keystore';
+
 import { getNodeLib } from 'selectors/config';
 import { getWalletInst, getTokens } from 'selectors/wallet';
-import { determineKeystoreType } from 'libs/keystore';
-import TransactionSucceeded from 'components/ExtendedNotifications/TransactionSucceeded';
-import type { BroadcastTxRequestedAction } from 'actions/wallet';
 
-function* updateAccountBalance() {
+import TransactionSucceeded from 'components/ExtendedNotifications/TransactionSucceeded';
+
+function* updateAccountBalance(): Generator<Yield, Return, Next> {
   try {
     const wallet: ?BaseWallet = yield select(getWalletInst);
     if (!wallet) {
@@ -40,7 +45,7 @@ function* updateAccountBalance() {
   }
 }
 
-function* updateTokenBalances() {
+function* updateTokenBalances(): Generator<Yield, Return, Next> {
   try {
     const node: BaseNode = yield select(getNodeLib);
     const wallet: ?BaseWallet = yield select(getWalletInst);
@@ -68,14 +73,14 @@ function* updateTokenBalances() {
   }
 }
 
-function* updateBalances() {
+function* updateBalances(): Generator<Yield, Return, Next> {
   yield fork(updateAccountBalance);
   yield fork(updateTokenBalances);
 }
 
 export function* unlockPrivateKey(
   action?: UnlockPrivateKeyAction
-): Generator<Effect, void, any> {
+): Generator<Yield, Return, Next> {
   if (!action) return;
   let wallet = null;
 
@@ -97,7 +102,7 @@ export function* unlockPrivateKey(
 
 export function* unlockKeystore(
   action?: UnlockKeystoreAction
-): Generator<Effect, void, any> {
+): Generator<Yield, Return, Next> {
   if (!action) return;
 
   const file = action.payload.file;
@@ -138,7 +143,7 @@ export function* unlockKeystore(
 
 function* broadcastTx(
   action: BroadcastTxRequestedAction
-): Generator<Effect, void, any> {
+): Generator<Yield, Return, Next> {
   const signedTx = action.payload.signedTx;
   try {
     const node: BaseNode = yield select(getNodeLib);
@@ -165,7 +170,7 @@ function* broadcastTx(
   }
 }
 
-export default function* walletSaga(): Generator<Effect | Effect[], void, any> {
+export default function* walletSaga(): Generator<Yield, Return, Next> {
   // useful for development
   yield call(updateBalances);
   yield [