Merge pull request #4042 from MetaMask/tx-controller-rewrite-v3

docs and file organization for txController

8 files changed, 1402 insertions, 144 deletions

diff --git a/app/scripts/controllers/transactions/README.md b/app/scripts/controllers/transactions/README.md
new file mode 100644
index 000000000..b414762dc
--- /dev/null
+++ b/app/scripts/controllers/transactions/README.md
@@ -0,0 +1,92 @@
+# Transaction Controller
+
+Transaction Controller is an aggregate of sub-controllers and trackers
+exposed to the MetaMask controller.
+
+- txStateManager
+    responsible for the state of a transaction and
+    storing the transaction
+- pendingTxTracker
+    watching blocks for transactions to be include
+    and emitting confirmed events
+- txGasUtil
+    gas calculations and safety buffering
+- nonceTracker
+    calculating nonces
+
+## Flow diagram of processing a transaction
+
+![transaction-flow](../../../../docs/transaction-flow.png)
+
+## txMeta's & txParams
+
+A txMeta is the "meta" object it has all the random bits of info we need about a transaction on it. txParams are sacred every thing on txParams gets signed so it must
+be a valid key and be hex prefixed except for the network number. Extra stuff must go on the txMeta!
+
+Here is a txMeta too look at:
+
+```js
+txMeta = {
+  "id": 2828415030114568, // unique id for this txMeta used for look ups
+  "time": 1524094064821, // time of creation
+  "status": "confirmed",
+  "metamaskNetworkId": "1524091532133", //the network id for the transaction
+  "loadingDefaults": false, // used to tell the ui when we are done calculatyig gass defaults
+  "txParams": { // the txParams object
+    "from": "0x8acce2391c0d510a6c5e5d8f819a678f79b7e675",
+    "to": "0x8acce2391c0d510a6c5e5d8f819a678f79b7e675",
+    "value": "0x0",
+    "gasPrice": "0x3b9aca00",
+    "gas": "0x7b0c",
+    "nonce": "0x0"
+  },
+  "history": [{ //debug
+            "id": 2828415030114568,
+            "time": 1524094064821,
+            "status": "unapproved",
+            "metamaskNetworkId": "1524091532133",
+            "loadingDefaults": true,
+            "txParams": {
+              "from": "0x8acce2391c0d510a6c5e5d8f819a678f79b7e675",
+              "to": "0x8acce2391c0d510a6c5e5d8f819a678f79b7e675",
+              "value": "0x0"
+            }
+          },
+          [
+            {
+              "op": "add",
+              "path": "/txParams/gasPrice",
+              "value": "0x3b9aca00"
+            },
+            ...], // I've removed most of history for this
+  "gasPriceSpecified": false, //whether or not the user/dapp has specified gasPrice
+  "gasLimitSpecified": false, //whether or not the user/dapp has specified gas
+  "estimatedGas": "5208",
+  "origin": "MetaMask", //debug
+  "nonceDetails": {
+    "params": {
+      "highestLocallyConfirmed": 0,
+      "highestSuggested": 0,
+      "nextNetworkNonce": 0
+    },
+    "local": {
+      "name": "local",
+      "nonce": 0,
+      "details": {
+        "startPoint": 0,
+        "highest": 0
+      }
+    },
+    "network": {
+      "name": "network",
+      "nonce": 0,
+      "details": {
+        "baseCount": 0
+      }
+    }
+  },
+  "rawTx": "0xf86980843b9aca00827b0c948acce2391c0d510a6c5e5d8f819a678f79b7e67580808602c5b5de66eea05c01a320b96ac730cb210ca56d2cb71fa360e1fc2c21fa5cf333687d18eb323fa02ed05987a6e5fd0f2459fcff80710b76b83b296454ad9a37594a0ccb4643ea90", // used for rebroadcast
+  "hash": "0xa45ba834b97c15e6ff4ed09badd04ecd5ce884b455eb60192cdc73bcc583972a",
+  "submittedTime": 1524094077902 // time of the attempt to submit the raw tx to the network, used in the ui to show the retry button
+}
+```
diff --git a/app/scripts/controllers/transactions.js b/app/scripts/controllers/transactions/index.js
index c8211ebd7..541f1db73 100644
--- a/app/scripts/controllers/transactions.js
+++ b/app/scripts/controllers/transactions/index.js
@@ -3,28 +3,42 @@ const ObservableStore = require('obs-store')
 const ethUtil = require('ethereumjs-util')
 const Transaction = require('ethereumjs-tx')
 const EthQuery = require('ethjs-query')
-const TransactionStateManager = require('../lib/tx-state-manager')
-const TxGasUtil = require('../lib/tx-gas-utils')
-const PendingTransactionTracker = require('../lib/pending-tx-tracker')
-const NonceTracker = require('../lib/nonce-tracker')
+const TransactionStateManager = require('./tx-state-manager')
+const TxGasUtil = require('./tx-gas-utils')
+const PendingTransactionTracker = require('./pending-tx-tracker')
+const NonceTracker = require('./nonce-tracker')
+const txUtils = require('./lib/util')
 const log = require('loglevel')
 
-/*
+/**
   Transaction Controller is an aggregate of sub-controllers and trackers
   composing them in a way to be exposed to the metamask controller
-    - txStateManager
+    <br>- txStateManager
       responsible for the state of a transaction and
       storing the transaction
-    - pendingTxTracker
+    <br>- pendingTxTracker
       watching blocks for transactions to be include
       and emitting confirmed events
-    - txGasUtil
+    <br>- txGasUtil
       gas calculations and safety buffering
-    - nonceTracker
+    <br>- nonceTracker
       calculating nonces
+
+
+  @class
+  @param {object} - opts
+  @param {object}  opts.initState - initial transaction list default is an empty array
+  @param {Object}  opts.networkStore - an observable store for network number
+  @param {Object}  opts.blockTracker - An instance of eth-blocktracker
+  @param {Object}  opts.provider - A network provider.
+  @param {Function}  opts.signTransaction - function the signs an ethereumjs-tx
+  @param {Function}  [opts.getGasPrice] - optional gas price calculator
+  @param {Function}  opts.signTransaction - ethTx signer that returns a rawTx
+  @param {Number}  [opts.txHistoryLimit] - number *optional* for limiting how many transactions are in state
+  @param {Object}  opts.preferencesStore
 */
 
-module.exports = class TransactionController extends EventEmitter {
+class TransactionController extends EventEmitter {
   constructor (opts) {
     super()
     this.networkStore = opts.networkStore || new ObservableStore({})
@@ -38,45 +52,19 @@ module.exports = class TransactionController extends EventEmitter {
     this.query = new EthQuery(this.provider)
     this.txGasUtil = new TxGasUtil(this.provider)
 
+    this._mapMethods()
     this.txStateManager = new TransactionStateManager({
       initState: opts.initState,
       txHistoryLimit: opts.txHistoryLimit,
       getNetwork: this.getNetwork.bind(this),
     })
-
-    this.txStateManager.getFilteredTxList({
-      status: 'unapproved',
-      loadingDefaults: true,
-    }).forEach((tx) => {
-      this.addTxDefaults(tx)
-      .then((txMeta) => {
-        txMeta.loadingDefaults = false
-        this.txStateManager.updateTx(txMeta, 'transactions: gas estimation for tx on boot')
-      }).catch((error) => {
-        this.txStateManager.setTxStatusFailed(tx.id, error)
-      })
-    })
-
-    this.txStateManager.getFilteredTxList({
-      status: 'approved',
-    }).forEach((txMeta) => {
-      const txSignError = new Error('Transaction found as "approved" during boot - possibly stuck during signing')
-      this.txStateManager.setTxStatusFailed(txMeta.id, txSignError)
-    })
-
+    this._onBootCleanUp()
 
     this.store = this.txStateManager.store
-    this.txStateManager.on('tx:status-update', this.emit.bind(this, 'tx:status-update'))
     this.nonceTracker = new NonceTracker({
       provider: this.provider,
       getPendingTransactions: this.txStateManager.getPendingTransactions.bind(this.txStateManager),
-      getConfirmedTransactions: (address) => {
-        return this.txStateManager.getFilteredTxList({
-          from: address,
-          status: 'confirmed',
-          err: undefined,
-        })
-      },
+      getConfirmedTransactions: this.txStateManager.getConfirmedTransactions.bind(this.txStateManager),
     })
 
     this.pendingTxTracker = new PendingTransactionTracker({
@@ -88,60 +76,14 @@ module.exports = class TransactionController extends EventEmitter {
     })
 
     this.txStateManager.store.subscribe(() => this.emit('update:badge'))
-
-    this.pendingTxTracker.on('tx:warning', (txMeta) => {
-      this.txStateManager.updateTx(txMeta, 'transactions/pending-tx-tracker#event: tx:warning')
-    })
-    this.pendingTxTracker.on('tx:confirmed', (txId) => this._markNonceDuplicatesDropped(txId))
-    this.pendingTxTracker.on('tx:failed', this.txStateManager.setTxStatusFailed.bind(this.txStateManager))
-    this.pendingTxTracker.on('tx:block-update', (txMeta, latestBlockNumber) => {
-      if (!txMeta.firstRetryBlockNumber) {
-        txMeta.firstRetryBlockNumber = latestBlockNumber
-        this.txStateManager.updateTx(txMeta, 'transactions/pending-tx-tracker#event: tx:block-update')
-      }
-    })
-    this.pendingTxTracker.on('tx:retry', (txMeta) => {
-      if (!('retryCount' in txMeta)) txMeta.retryCount = 0
-      txMeta.retryCount++
-      this.txStateManager.updateTx(txMeta, 'transactions/pending-tx-tracker#event: tx:retry')
-    })
-
-    this.blockTracker.on('block', this.pendingTxTracker.checkForTxInBlock.bind(this.pendingTxTracker))
-    // this is a little messy but until ethstore has been either
-    // removed or redone this is to guard against the race condition
-    this.blockTracker.on('latest', this.pendingTxTracker.resubmitPendingTxs.bind(this.pendingTxTracker))
-    this.blockTracker.on('sync', this.pendingTxTracker.queryPendingTxs.bind(this.pendingTxTracker))
+    this._setupListners()
     // memstore is computed from a few different stores
     this._updateMemstore()
     this.txStateManager.store.subscribe(() => this._updateMemstore())
     this.networkStore.subscribe(() => this._updateMemstore())
     this.preferencesStore.subscribe(() => this._updateMemstore())
   }
-
-  getState () {
-    return this.memStore.getState()
-  }
-
-  getNetwork () {
-    return this.networkStore.getState()
-  }
-
-  getSelectedAddress () {
-    return this.preferencesStore.getState().selectedAddress
-  }
-
-  getUnapprovedTxCount () {
-    return Object.keys(this.txStateManager.getUnapprovedTxList()).length
-  }
-
-  getPendingTxCount (account) {
-    return this.txStateManager.getPendingTransactions(account).length
-  }
-
-  getFilteredTxList (opts) {
-    return this.txStateManager.getFilteredTxList(opts)
-  }
-
+  /** @returns {number} the chainId*/
   getChainId () {
     const networkState = this.networkStore.getState()
     const getChainId = parseInt(networkState)
@@ -152,16 +94,30 @@ module.exports = class TransactionController extends EventEmitter {
     }
   }
 
-  wipeTransactions (address) {
-    this.txStateManager.wipeTransactions(address)
-  }
-
-  // Adds a tx to the txlist
+/**
+  Adds a tx to the txlist
+  @emits ${txMeta.id}:unapproved
+*/
   addTx (txMeta) {
     this.txStateManager.addTx(txMeta)
     this.emit(`${txMeta.id}:unapproved`, txMeta)
   }
 
+  /**
+  Wipes the transactions for a given account
+  @param {string} address - hex string of the from address for txs being removed
+  */
+  wipeTransactions (address) {
+    this.txStateManager.wipeTransactions(address)
+  }
+
+  /**
+  add a new unapproved transaction to the pipeline
+
+  @returns {Promise<string>} the hash of the transaction after being submitted to the network
+  @param txParams {object} - txParams for the transaction
+  @param opts {object} - with the key origin to put the origin on the txMeta
+  */
   async newUnapprovedTransaction (txParams, opts = {}) {
     log.debug(`MetaMaskController newUnapprovedTransaction ${JSON.stringify(txParams)}`)
     const initialTxMeta = await this.addUnapprovedTransaction(txParams)
@@ -184,17 +140,24 @@ module.exports = class TransactionController extends EventEmitter {
     })
   }
 
+  /**
+  Validates and generates a txMeta with defaults and puts it in txStateManager
+  store
+
+  @returns {txMeta}
+  */
+
   async addUnapprovedTransaction (txParams) {
     // validate
-    const normalizedTxParams = this._normalizeTxParams(txParams)
-    this._validateTxParams(normalizedTxParams)
+    const normalizedTxParams = txUtils.normalizeTxParams(txParams)
+    txUtils.validateTxParams(normalizedTxParams)
     // construct txMeta
     let txMeta = this.txStateManager.generateTxMeta({ txParams: normalizedTxParams })
     this.addTx(txMeta)
     this.emit('newUnapprovedTx', txMeta)
     // add default tx params
     try {
-      txMeta = await this.addTxDefaults(txMeta)
+      txMeta = await this.addTxGasDefaults(txMeta)
     } catch (error) {
       console.log(error)
       this.txStateManager.setTxStatusFailed(txMeta.id, error)
@@ -206,21 +169,33 @@ module.exports = class TransactionController extends EventEmitter {
 
     return txMeta
   }
-
-  async addTxDefaults (txMeta) {
+/**
+  adds the tx gas defaults: gas && gasPrice
+  @param txMeta {Object} - the txMeta object
+  @returns {Promise<object>} resolves with txMeta
+*/
+  async addTxGasDefaults (txMeta) {
     const txParams = txMeta.txParams
     // ensure value
+    txParams.value = txParams.value ? ethUtil.addHexPrefix(txParams.value) : '0x0'
     txMeta.gasPriceSpecified = Boolean(txParams.gasPrice)
     let gasPrice = txParams.gasPrice
     if (!gasPrice) {
       gasPrice = this.getGasPrice ? this.getGasPrice() : await this.query.gasPrice()
     }
     txParams.gasPrice = ethUtil.addHexPrefix(gasPrice.toString(16))
-    txParams.value = txParams.value || '0x0'
     // set gasLimit
     return await this.txGasUtil.analyzeGasUsage(txMeta)
   }
 
+  /**
+    Creates a new txMeta with the same txParams as the original
+    to allow the user to resign the transaction with a higher gas values
+    @param  originalTxId {number} - the id of the txMeta that
+    you want to attempt to retry
+    @return {txMeta}
+  */
+
   async retryTransaction (originalTxId) {
     const originalTxMeta = this.txStateManager.getTx(originalTxId)
     const lastGasPrice = originalTxMeta.txParams.gasPrice
@@ -234,15 +209,31 @@ module.exports = class TransactionController extends EventEmitter {
     return txMeta
   }
 
+  /**
+  updates the txMeta in the txStateManager
+  @param txMeta {Object} - the updated txMeta
+  */
   async updateTransaction (txMeta) {
     this.txStateManager.updateTx(txMeta, 'confTx: user updated transaction')
   }
 
+  /**
+  updates and approves the transaction
+  @param txMeta {Object}
+  */
   async updateAndApproveTransaction (txMeta) {
     this.txStateManager.updateTx(txMeta, 'confTx: user approved transaction')
     await this.approveTransaction(txMeta.id)
   }
 
+  /**
+  sets the tx status to approved
+  auto fills the nonce
+  signs the transaction
+  publishes the transaction
+  if any of these steps fails the tx status will be set to failed
+    @param txId {number} - the tx's Id
+  */
   async approveTransaction (txId) {
     let nonceLock
     try {
@@ -274,7 +265,11 @@ module.exports = class TransactionController extends EventEmitter {
       throw err
     }
   }
-
+  /**
+    adds the chain id and signs the transaction and set the status to signed
+    @param txId {number} - the tx's Id
+    @returns - rawTx {string}
+  */
   async signTransaction (txId) {
     const txMeta = this.txStateManager.getTx(txId)
     // add network/chain id
@@ -290,6 +285,12 @@ module.exports = class TransactionController extends EventEmitter {
     return rawTx
   }
 
+  /**
+    publishes the raw tx and sets the txMeta to submitted
+    @param txId {number} - the tx's Id
+    @param rawTx {string} - the hex string of the serialized signed transaction
+    @returns {Promise<void>}
+  */
   async publishTransaction (txId, rawTx) {
     const txMeta = this.txStateManager.getTx(txId)
     txMeta.rawTx = rawTx
@@ -299,11 +300,20 @@ module.exports = class TransactionController extends EventEmitter {
     this.txStateManager.setTxStatusSubmitted(txId)
   }
 
+  /**
+    Convenience method for the ui thats sets the transaction to rejected
+    @param txId {number} - the tx's Id
+    @returns {Promise<void>}
+  */
   async cancelTransaction (txId) {
     this.txStateManager.setTxStatusRejected(txId)
   }
 
-  // receives a txHash records the tx as signed
+  /**
+    Sets the txHas on the txMeta
+    @param txId {number} - the tx's Id
+    @param txHash {string} - the hash for the txMeta
+  */
   setTxHash (txId, txHash) {
     // Add the tx hash to the persisted meta-tx object
     const txMeta = this.txStateManager.getTx(txId)
@@ -314,63 +324,92 @@ module.exports = class TransactionController extends EventEmitter {
 //
 //           PRIVATE METHODS
 //
+  /** maps methods for convenience*/
+  _mapMethods () {
+    /** @returns the state in transaction controller */
+    this.getState = () => this.memStore.getState()
+    /** @returns the network number stored in networkStore */
+    this.getNetwork = () => this.networkStore.getState()
+    /** @returns the user selected address */
+    this.getSelectedAddress = () => this.preferencesStore.getState().selectedAddress
+    /** Returns an array of transactions whos status is unapproved */
+    this.getUnapprovedTxCount = () => Object.keys(this.txStateManager.getUnapprovedTxList()).length
+    /**
+      @returns a number that represents how many transactions have the status submitted
+      @param account {String} - hex prefixed account
+    */
+    this.getPendingTxCount = (account) => this.txStateManager.getPendingTransactions(account).length
+    /** see txStateManager */
+    this.getFilteredTxList = (opts) => this.txStateManager.getFilteredTxList(opts)
+  }
 
-  _normalizeTxParams (txParams) {
-    // functions that handle normalizing of that key in txParams
-    const whiteList = {
-      from: from => ethUtil.addHexPrefix(from).toLowerCase(),
-      to: to => ethUtil.addHexPrefix(txParams.to).toLowerCase(),
-      nonce: nonce => ethUtil.addHexPrefix(nonce),
-      value: value => ethUtil.addHexPrefix(value),
-      data: data => ethUtil.addHexPrefix(data),
-      gas: gas => ethUtil.addHexPrefix(gas),
-      gasPrice: gasPrice => ethUtil.addHexPrefix(gasPrice),
-    }
+  /**
+    If transaction controller was rebooted with transactions that are uncompleted
+    in steps of the transaction signing or user confirmation process it will either
+    transition txMetas to a failed state or try to redo those tasks.
+  */
 
-    // apply only keys in the whiteList
-    const normalizedTxParams = {}
-    Object.keys(whiteList).forEach((key) => {
-      if (txParams[key]) normalizedTxParams[key] = whiteList[key](txParams[key])
+  _onBootCleanUp () {
+    this.txStateManager.getFilteredTxList({
+      status: 'unapproved',
+      loadingDefaults: true,
+    }).forEach((tx) => {
+      this.addTxGasDefaults(tx)
+      .then((txMeta) => {
+        txMeta.loadingDefaults = false
+        this.txStateManager.updateTx(txMeta, 'transactions: gas estimation for tx on boot')
+      }).catch((error) => {
+        this.txStateManager.setTxStatusFailed(tx.id, error)
+      })
     })
 
-    return normalizedTxParams
+    this.txStateManager.getFilteredTxList({
+      status: 'approved',
+    }).forEach((txMeta) => {
+      const txSignError = new Error('Transaction found as "approved" during boot - possibly stuck during signing')
+      this.txStateManager.setTxStatusFailed(txMeta.id, txSignError)
+    })
   }
 
-  _validateTxParams (txParams) {
-    this._validateFrom(txParams)
-    this._validateRecipient(txParams)
-    if ('value' in txParams) {
-      const value = txParams.value.toString()
-      if (value.includes('-')) {
-        throw new Error(`Invalid transaction value of ${txParams.value} not a positive number.`)
+  /**
+    is called in constructor applies the listeners for pendingTxTracker txStateManager
+    and blockTracker
+  */
+  _setupListners () {
+    this.txStateManager.on('tx:status-update', this.emit.bind(this, 'tx:status-update'))
+    this.pendingTxTracker.on('tx:warning', (txMeta) => {
+      this.txStateManager.updateTx(txMeta, 'transactions/pending-tx-tracker#event: tx:warning')
+    })
+    this.pendingTxTracker.on('tx:confirmed', (txId) => this.txStateManager.setTxStatusConfirmed(txId))
+    this.pendingTxTracker.on('tx:confirmed', (txId) => this._markNonceDuplicatesDropped(txId))
+    this.pendingTxTracker.on('tx:failed', this.txStateManager.setTxStatusFailed.bind(this.txStateManager))
+    this.pendingTxTracker.on('tx:block-update', (txMeta, latestBlockNumber) => {
+      if (!txMeta.firstRetryBlockNumber) {
+        txMeta.firstRetryBlockNumber = latestBlockNumber
+        this.txStateManager.updateTx(txMeta, 'transactions/pending-tx-tracker#event: tx:block-update')
       }
+    })
+    this.pendingTxTracker.on('tx:retry', (txMeta) => {
+      if (!('retryCount' in txMeta)) txMeta.retryCount = 0
+      txMeta.retryCount++
+      this.txStateManager.updateTx(txMeta, 'transactions/pending-tx-tracker#event: tx:retry')
+    })
 
-      if (value.includes('.')) {
-        throw new Error(`Invalid transaction value of ${txParams.value} number must be in wei`)
-      }
-    }
-  }
+    this.blockTracker.on('block', this.pendingTxTracker.checkForTxInBlock.bind(this.pendingTxTracker))
+    // this is a little messy but until ethstore has been either
+    // removed or redone this is to guard against the race condition
+    this.blockTracker.on('latest', this.pendingTxTracker.resubmitPendingTxs.bind(this.pendingTxTracker))
+    this.blockTracker.on('sync', this.pendingTxTracker.queryPendingTxs.bind(this.pendingTxTracker))
 
-  _validateFrom (txParams) {
-    if ( !(typeof txParams.from === 'string') ) throw new Error(`Invalid from address ${txParams.from} not a string`)
-    if (!ethUtil.isValidAddress(txParams.from)) throw new Error('Invalid from address')
   }
 
-  _validateRecipient (txParams) {
-    if (txParams.to === '0x' || txParams.to === null ) {
-      if (txParams.data) {
-        delete txParams.to
-      } else {
-        throw new Error('Invalid recipient address')
-      }
-    } else if ( txParams.to !== undefined && !ethUtil.isValidAddress(txParams.to) ) {
-      throw new Error('Invalid recipient address')
-    }
-    return txParams
-  }
+  /**
+    Sets other txMeta statuses to dropped if the txMeta that has been confirmed has other transactions
+    in the list have the same nonce
 
+    @param txId {Number} - the txId of the transaction that has been confirmed in a block
+  */
   _markNonceDuplicatesDropped (txId) {
-    this.txStateManager.setTxStatusConfirmed(txId)
     // get the confirmed transactions nonce and from address
     const txMeta = this.txStateManager.getTx(txId)
     const { nonce, from } = txMeta.txParams
@@ -385,6 +424,9 @@ module.exports = class TransactionController extends EventEmitter {
     })
   }
 
+  /**
+    Updates the memStore in transaction controller
+  */
   _updateMemstore () {
     const unapprovedTxs = this.txStateManager.getUnapprovedTxList()
     const selectedAddressTxList = this.txStateManager.getFilteredTxList({
@@ -394,3 +436,5 @@ module.exports = class TransactionController extends EventEmitter {
     this.memStore.updateState({ unapprovedTxs, selectedAddressTxList })
   }
 }
+
+module.exports = TransactionController
diff --git a/app/scripts/controllers/transactions/lib/tx-state-history-helper.js b/app/scripts/controllers/transactions/lib/tx-state-history-helper.js
new file mode 100644
index 000000000..59a4b562c
--- /dev/null
+++ b/app/scripts/controllers/transactions/lib/tx-state-history-helper.js
@@ -0,0 +1,64 @@
+const jsonDiffer = require('fast-json-patch')
+const clone = require('clone')
+/** @module*/
+module.exports = {
+  generateHistoryEntry,
+  replayHistory,
+  snapshotFromTxMeta,
+  migrateFromSnapshotsToDiffs,
+}
+
+/**
+  converts non-initial history entries into diffs
+  @param longHistory {array}
+  @returns {array}
+*/
+function migrateFromSnapshotsToDiffs (longHistory) {
+  return (
+    longHistory
+    // convert non-initial history entries into diffs
+    .map((entry, index) => {
+      if (index === 0) return entry
+      return generateHistoryEntry(longHistory[index - 1], entry)
+    })
+  )
+}
+
+/**
+  generates an array of history objects sense the previous state.
+  The object has the keys opp(the operation preformed),
+  path(the key and if a nested object then each key will be seperated with a `/`)
+  value
+  with the first entry having the note
+  @param previousState {object} - the previous state of the object
+  @param newState {object} - the update object
+  @param note {string} - a optional note for the state change
+  @reurns {array}
+*/
+function generateHistoryEntry (previousState, newState, note) {
+  const entry = jsonDiffer.compare(previousState, newState)
+  // Add a note to the first op, since it breaks if we append it to the entry
+  if (note && entry[0]) entry[0].note = note
+  return entry
+}
+
+/**
+  Recovers previous txMeta state obj
+  @return {object}
+*/
+function replayHistory (_shortHistory) {
+  const shortHistory = clone(_shortHistory)
+  return shortHistory.reduce((val, entry) => jsonDiffer.applyPatch(val, entry).newDocument)
+}
+
+/**
+  @param txMeta {Object}
+  @returns {object} a clone object of the txMeta with out history
+*/
+function snapshotFromTxMeta (txMeta) {
+  // create txMeta snapshot for history
+  const snapshot = clone(txMeta)
+  // dont include previous history in this snapshot
+  delete snapshot.history
+  return snapshot
+}
diff --git a/app/scripts/controllers/transactions/lib/util.js b/app/scripts/controllers/transactions/lib/util.js
new file mode 100644
index 000000000..84f7592a0
--- /dev/null
+++ b/app/scripts/controllers/transactions/lib/util.js
@@ -0,0 +1,99 @@
+const {
+  addHexPrefix,
+  isValidAddress,
+} = require('ethereumjs-util')
+
+/**
+@module
+*/
+module.exports = {
+  normalizeTxParams,
+  validateTxParams,
+  validateFrom,
+  validateRecipient,
+  getFinalStates,
+}
+
+
+// functions that handle normalizing of that key in txParams
+const normalizers = {
+  from: from => addHexPrefix(from).toLowerCase(),
+  to: to => addHexPrefix(to).toLowerCase(),
+  nonce: nonce => addHexPrefix(nonce),
+  value: value => addHexPrefix(value),
+  data: data => addHexPrefix(data),
+  gas: gas => addHexPrefix(gas),
+  gasPrice: gasPrice => addHexPrefix(gasPrice),
+}
+
+ /**
+  normalizes txParams
+  @param txParams {object}
+  @returns {object} normalized txParams
+ */
+function normalizeTxParams (txParams) {
+  // apply only keys in the normalizers
+  const normalizedTxParams = {}
+  for (const key in normalizers) {
+    if (txParams[key]) normalizedTxParams[key] = normalizers[key](txParams[key])
+  }
+  return normalizedTxParams
+}
+
+ /**
+  validates txParams
+  @param txParams {object}
+ */
+function validateTxParams (txParams) {
+  validateFrom(txParams)
+  validateRecipient(txParams)
+  if ('value' in txParams) {
+    const value = txParams.value.toString()
+    if (value.includes('-')) {
+      throw new Error(`Invalid transaction value of ${txParams.value} not a positive number.`)
+    }
+
+    if (value.includes('.')) {
+      throw new Error(`Invalid transaction value of ${txParams.value} number must be in wei`)
+    }
+  }
+}
+
+ /**
+  validates the from field in  txParams
+  @param txParams {object}
+ */
+function validateFrom (txParams) {
+  if (!(typeof txParams.from === 'string')) throw new Error(`Invalid from address ${txParams.from} not a string`)
+  if (!isValidAddress(txParams.from)) throw new Error('Invalid from address')
+}
+
+ /**
+  validates the to field in  txParams
+  @param txParams {object}
+ */
+function validateRecipient (txParams) {
+  if (txParams.to === '0x' || txParams.to === null) {
+    if (txParams.data) {
+      delete txParams.to
+    } else {
+      throw new Error('Invalid recipient address')
+    }
+  } else if (txParams.to !== undefined && !isValidAddress(txParams.to)) {
+    throw new Error('Invalid recipient address')
+  }
+  return txParams
+}
+
+  /**
+    @returns an {array} of states that can be considered final
+  */
+function getFinalStates () {
+  return [
+    'rejected', // the user has responded no!
+    'confirmed', // the tx has been included in a block.
+    'failed', // the tx failed for some reason, included on tx data.
+    'dropped', // the tx nonce was already used
+  ]
+}
+
diff --git a/app/scripts/controllers/transactions/nonce-tracker.js b/app/scripts/controllers/transactions/nonce-tracker.js
new file mode 100644
index 000000000..f8cdc5523
--- /dev/null
+++ b/app/scripts/controllers/transactions/nonce-tracker.js
@@ -0,0 +1,186 @@
+const EthQuery = require('ethjs-query')
+const assert = require('assert')
+const Mutex = require('await-semaphore').Mutex
+/**
+  @param opts {Object}
+    @param {Object} opts.provider a ethereum provider
+    @param {Function} opts.getPendingTransactions a function that returns an array of txMeta
+    whosee status is `submitted`
+    @param {Function} opts.getConfirmedTransactions a function that returns an array of txMeta
+    whose status is `confirmed`
+  @class
+*/
+class NonceTracker {
+
+  constructor ({ provider, getPendingTransactions, getConfirmedTransactions }) {
+    this.provider = provider
+    this.ethQuery = new EthQuery(provider)
+    this.getPendingTransactions = getPendingTransactions
+    this.getConfirmedTransactions = getConfirmedTransactions
+    this.lockMap = {}
+  }
+
+  /**
+    @returns {Promise<Object>} with the key releaseLock (the gloabl mutex)
+  */
+  async getGlobalLock () {
+    const globalMutex = this._lookupMutex('global')
+    // await global mutex free
+    const releaseLock = await globalMutex.acquire()
+    return { releaseLock }
+  }
+
+  /**
+   * @typedef NonceDetails
+   * @property {number} highestLocallyConfirmed - A hex string of the highest nonce on a confirmed transaction.
+   * @property {number} nextNetworkNonce - The next nonce suggested by the eth_getTransactionCount method.
+   * @property {number} highetSuggested - The maximum between the other two, the number returned.
+   */
+
+  /**
+  this will return an object with the `nextNonce` `nonceDetails` of type NonceDetails, and the releaseLock
+  Note: releaseLock must be called after adding a signed tx to pending transactions (or discarding).
+
+  @param address {string} the hex string for the address whose nonce we are calculating
+  @returns {Promise<NonceDetails>}
+  */
+  async getNonceLock (address) {
+    // await global mutex free
+    await this._globalMutexFree()
+    // await lock free, then take lock
+    const releaseLock = await this._takeMutex(address)
+    // evaluate multiple nextNonce strategies
+    const nonceDetails = {}
+    const networkNonceResult = await this._getNetworkNextNonce(address)
+    const highestLocallyConfirmed = this._getHighestLocallyConfirmed(address)
+    const nextNetworkNonce = networkNonceResult.nonce
+    const highestSuggested = Math.max(nextNetworkNonce, highestLocallyConfirmed)
+
+    const pendingTxs = this.getPendingTransactions(address)
+    const localNonceResult = this._getHighestContinuousFrom(pendingTxs, highestSuggested) || 0
+
+    nonceDetails.params = {
+      highestLocallyConfirmed,
+      highestSuggested,
+      nextNetworkNonce,
+    }
+    nonceDetails.local = localNonceResult
+    nonceDetails.network = networkNonceResult
+
+    const nextNonce = Math.max(networkNonceResult.nonce, localNonceResult.nonce)
+    assert(Number.isInteger(nextNonce), `nonce-tracker - nextNonce is not an integer - got: (${typeof nextNonce}) "${nextNonce}"`)
+
+    // return nonce and release cb
+    return { nextNonce, nonceDetails, releaseLock }
+  }
+
+  async _getCurrentBlock () {
+    const blockTracker = this._getBlockTracker()
+    const currentBlock = blockTracker.getCurrentBlock()
+    if (currentBlock) return currentBlock
+    return await new Promise((reject, resolve) => {
+      blockTracker.once('latest', resolve)
+    })
+  }
+
+  async _globalMutexFree () {
+    const globalMutex = this._lookupMutex('global')
+    const release = await globalMutex.acquire()
+    release()
+  }
+
+  async _takeMutex (lockId) {
+    const mutex = this._lookupMutex(lockId)
+    const releaseLock = await mutex.acquire()
+    return releaseLock
+  }
+
+  _lookupMutex (lockId) {
+    let mutex = this.lockMap[lockId]
+    if (!mutex) {
+      mutex = new Mutex()
+      this.lockMap[lockId] = mutex
+    }
+    return mutex
+  }
+
+  async _getNetworkNextNonce (address) {
+    // calculate next nonce
+    // we need to make sure our base count
+    // and pending count are from the same block
+    const currentBlock = await this._getCurrentBlock()
+    const blockNumber = currentBlock.blockNumber
+    const baseCountBN = await this.ethQuery.getTransactionCount(address, blockNumber || 'latest')
+    const baseCount = baseCountBN.toNumber()
+    assert(Number.isInteger(baseCount), `nonce-tracker - baseCount is not an integer - got: (${typeof baseCount}) "${baseCount}"`)
+    const nonceDetails = { blockNumber, baseCount }
+    return { name: 'network', nonce: baseCount, details: nonceDetails }
+  }
+
+  _getHighestLocallyConfirmed (address) {
+    const confirmedTransactions = this.getConfirmedTransactions(address)
+    const highest = this._getHighestNonce(confirmedTransactions)
+    return Number.isInteger(highest) ? highest + 1 : 0
+  }
+
+  _reduceTxListToUniqueNonces (txList) {
+    const reducedTxList = txList.reduce((reducedList, txMeta, index) => {
+      if (!index) return [txMeta]
+      const nonceMatches = txList.filter((txData) => {
+        return txMeta.txParams.nonce === txData.txParams.nonce
+      })
+      if (nonceMatches.length > 1) return reducedList
+      reducedList.push(txMeta)
+      return reducedList
+    }, [])
+    return reducedTxList
+  }
+
+  _getHighestNonce (txList) {
+    const nonces = txList.map((txMeta) => {
+      const nonce = txMeta.txParams.nonce
+      assert(typeof nonce, 'string', 'nonces should be hex strings')
+      return parseInt(nonce, 16)
+    })
+    const highestNonce = Math.max.apply(null, nonces)
+    return highestNonce
+  }
+
+  /**
+    @typedef {object} highestContinuousFrom
+    @property {string} - name the name for how the nonce was calculated based on the data used
+    @property {number} - nonce the next suggested nonce
+    @property {object} - details the provided starting nonce that was used (for debugging)
+  */
+  /**
+    @param txList {array} - list of txMeta's
+    @param startPoint {number} - the highest known locally confirmed nonce
+    @returns {highestContinuousFrom}
+  */
+  _getHighestContinuousFrom (txList, startPoint) {
+    const nonces = txList.map((txMeta) => {
+      const nonce = txMeta.txParams.nonce
+      assert(typeof nonce, 'string', 'nonces should be hex strings')
+      return parseInt(nonce, 16)
+    })
+
+    let highest = startPoint
+    while (nonces.includes(highest)) {
+      highest++
+    }
+
+    return { name: 'local', nonce: highest, details: { startPoint, highest } }
+  }
+
+  // this is a hotfix for the fact that the blockTracker will
+  // change when the network changes
+
+  /**
+    @returns {Object} the current blockTracker
+  */
+  _getBlockTracker () {
+    return this.provider._blockTracker
+  }
+}
+
+module.exports = NonceTracker
diff --git a/app/scripts/controllers/transactions/pending-tx-tracker.js b/app/scripts/controllers/transactions/pending-tx-tracker.js
new file mode 100644
index 000000000..6e2fcb40b
--- /dev/null
+++ b/app/scripts/controllers/transactions/pending-tx-tracker.js
@@ -0,0 +1,224 @@
+const EventEmitter = require('events')
+const log = require('loglevel')
+const EthQuery = require('ethjs-query')
+/**
+
+  Event emitter utility class for tracking the transactions as they<br>
+  go from a pending state to a confirmed (mined in a block) state<br>
+<br>
+  As well as continues broadcast while in the pending state
+<br>
+@param config {object} - non optional configuration object consists of:
+    @param {Object} config.provider - A network provider.
+    @param {Object} config.nonceTracker see nonce tracker
+    @param {function} config.getPendingTransactions a function for getting an array of transactions,
+    @param {function} config.publishTransaction a async function for publishing raw transactions,
+
+
+@class
+*/
+
+class PendingTransactionTracker extends EventEmitter {
+  constructor (config) {
+    super()
+    this.query = new EthQuery(config.provider)
+    this.nonceTracker = config.nonceTracker
+    // default is one day
+    this.getPendingTransactions = config.getPendingTransactions
+    this.getCompletedTransactions = config.getCompletedTransactions
+    this.publishTransaction = config.publishTransaction
+    this._checkPendingTxs()
+  }
+
+  /**
+    checks if a signed tx is in a block and
+    if it is included emits tx status as 'confirmed'
+    @param block {object}, a full block
+    @emits tx:confirmed
+    @emits tx:failed
+  */
+  checkForTxInBlock (block) {
+    const signedTxList = this.getPendingTransactions()
+    if (!signedTxList.length) return
+    signedTxList.forEach((txMeta) => {
+      const txHash = txMeta.hash
+      const txId = txMeta.id
+
+      if (!txHash) {
+        const noTxHashErr = new Error('We had an error while submitting this transaction, please try again.')
+        noTxHashErr.name = 'NoTxHashError'
+        this.emit('tx:failed', txId, noTxHashErr)
+        return
+      }
+
+
+      block.transactions.forEach((tx) => {
+        if (tx.hash === txHash) this.emit('tx:confirmed', txId)
+      })
+    })
+  }
+
+  /**
+    asks the network for the transaction to see if a block number is included on it
+    if we have skipped/missed blocks
+    @param object - oldBlock newBlock
+  */
+  queryPendingTxs ({ oldBlock, newBlock }) {
+    // check pending transactions on start
+    if (!oldBlock) {
+      this._checkPendingTxs()
+      return
+    }
+    // if we synced by more than one block, check for missed pending transactions
+    const diff = Number.parseInt(newBlock.number, 16) - Number.parseInt(oldBlock.number, 16)
+    if (diff > 1) this._checkPendingTxs()
+  }
+
+  /**
+    Will resubmit any transactions who have not been confirmed in a block
+    @param block {object} - a block object
+    @emits tx:warning
+  */
+  resubmitPendingTxs (block) {
+    const pending = this.getPendingTransactions()
+    // only try resubmitting if their are transactions to resubmit
+    if (!pending.length) return
+    pending.forEach((txMeta) => this._resubmitTx(txMeta, block.number).catch((err) => {
+      /*
+      Dont marked as failed if the error is a "known" transaction warning
+      "there is already a transaction with the same sender-nonce
+      but higher/same gas price"
+
+      Also don't mark as failed if it has ever been broadcast successfully.
+      A successful broadcast means it may still be mined.
+      */
+      const errorMessage = err.message.toLowerCase()
+      const isKnownTx = (
+        // geth
+        errorMessage.includes('replacement transaction underpriced') ||
+        errorMessage.includes('known transaction') ||
+        // parity
+        errorMessage.includes('gas price too low to replace') ||
+        errorMessage.includes('transaction with the same hash was already imported') ||
+        // other
+        errorMessage.includes('gateway timeout') ||
+        errorMessage.includes('nonce too low')
+      )
+      // ignore resubmit warnings, return early
+      if (isKnownTx) return
+      // encountered real error - transition to error state
+      txMeta.warning = {
+        error: errorMessage,
+        message: 'There was an error when resubmitting this transaction.',
+      }
+      this.emit('tx:warning', txMeta, err)
+    }))
+  }
+
+  /**
+    resubmits the individual txMeta used in resubmitPendingTxs
+    @param txMeta {Object} - txMeta object
+    @param latestBlockNumber {string} - hex string for the latest block number
+    @emits tx:retry
+    @returns txHash {string}
+  */
+  async _resubmitTx (txMeta, latestBlockNumber) {
+    if (!txMeta.firstRetryBlockNumber) {
+      this.emit('tx:block-update', txMeta, latestBlockNumber)
+    }
+
+    const firstRetryBlockNumber = txMeta.firstRetryBlockNumber || latestBlockNumber
+    const txBlockDistance = Number.parseInt(latestBlockNumber, 16) - Number.parseInt(firstRetryBlockNumber, 16)
+
+    const retryCount = txMeta.retryCount || 0
+
+    // Exponential backoff to limit retries at publishing
+    if (txBlockDistance <= Math.pow(2, retryCount) - 1) return
+
+    // Only auto-submit already-signed txs:
+    if (!('rawTx' in txMeta)) return
+
+    const rawTx = txMeta.rawTx
+    const txHash = await this.publishTransaction(rawTx)
+
+    // Increment successful tries:
+    this.emit('tx:retry', txMeta)
+    return txHash
+  }
+  /**
+    Ask the network for the transaction to see if it has been include in a block
+    @param txMeta {Object} - the txMeta object
+    @emits tx:failed
+    @emits tx:confirmed
+    @emits tx:warning
+  */
+  async _checkPendingTx (txMeta) {
+    const txHash = txMeta.hash
+    const txId = txMeta.id
+
+    // extra check in case there was an uncaught error during the
+    // signature and submission process
+    if (!txHash) {
+      const noTxHashErr = new Error('We had an error while submitting this transaction, please try again.')
+      noTxHashErr.name = 'NoTxHashError'
+      this.emit('tx:failed', txId, noTxHashErr)
+      return
+    }
+
+    // If another tx with the same nonce is mined, set as failed.
+    const taken = await this._checkIfNonceIsTaken(txMeta)
+    if (taken) {
+      const nonceTakenErr = new Error('Another transaction with this nonce has been mined.')
+      nonceTakenErr.name = 'NonceTakenErr'
+      return this.emit('tx:failed', txId, nonceTakenErr)
+    }
+
+    // get latest transaction status
+    let txParams
+    try {
+      txParams = await this.query.getTransactionByHash(txHash)
+      if (!txParams) return
+      if (txParams.blockNumber) {
+        this.emit('tx:confirmed', txId)
+      }
+    } catch (err) {
+      txMeta.warning = {
+        error: err.message,
+        message: 'There was a problem loading this transaction.',
+      }
+      this.emit('tx:warning', txMeta, err)
+    }
+  }
+
+  /**
+    checks the network for signed txs and releases the nonce global lock if it is
+  */
+  async _checkPendingTxs () {
+    const signedTxList = this.getPendingTransactions()
+    // in order to keep the nonceTracker accurate we block it while updating pending transactions
+    const nonceGlobalLock = await this.nonceTracker.getGlobalLock()
+    try {
+      await Promise.all(signedTxList.map((txMeta) => this._checkPendingTx(txMeta)))
+    } catch (err) {
+      log.error('PendingTransactionWatcher - Error updating pending transactions')
+      log.error(err)
+    }
+    nonceGlobalLock.releaseLock()
+  }
+
+  /**
+    checks to see if a confirmed txMeta has the same nonce
+    @param txMeta {Object} - txMeta object
+    @returns {boolean}
+  */
+  async _checkIfNonceIsTaken (txMeta) {
+    const address = txMeta.txParams.from
+    const completed = this.getCompletedTransactions(address)
+    const sameNonce = completed.filter((otherMeta) => {
+      return otherMeta.txParams.nonce === txMeta.txParams.nonce
+    })
+    return sameNonce.length > 0
+  }
+}
+
+module.exports = PendingTransactionTracker
diff --git a/app/scripts/controllers/transactions/tx-gas-utils.js b/app/scripts/controllers/transactions/tx-gas-utils.js
new file mode 100644
index 000000000..36b5cdbc9
--- /dev/null
+++ b/app/scripts/controllers/transactions/tx-gas-utils.js
@@ -0,0 +1,129 @@
+const EthQuery = require('ethjs-query')
+const {
+  hexToBn,
+  BnMultiplyByFraction,
+  bnToHex,
+} = require('../../lib/util')
+const { addHexPrefix } = require('ethereumjs-util')
+const SIMPLE_GAS_COST = '0x5208' // Hex for 21000, cost of a simple send.
+
+/**
+tx-gas-utils are gas utility methods for Transaction manager
+its passed ethquery
+and used to do things like calculate gas of a tx.
+@param {Object} provider - A network provider.
+*/
+
+class TxGasUtil {
+
+  constructor (provider) {
+    this.query = new EthQuery(provider)
+  }
+
+  /**
+    @param txMeta {Object} - the txMeta object
+    @returns {object} the txMeta object with the gas written to the txParams
+  */
+  async analyzeGasUsage (txMeta) {
+    const block = await this.query.getBlockByNumber('latest', true)
+    let estimatedGasHex
+    try {
+      estimatedGasHex = await this.estimateTxGas(txMeta, block.gasLimit)
+    } catch (err) {
+      const simulationFailed = (
+        err.message.includes('Transaction execution error.') ||
+        err.message.includes('gas required exceeds allowance or always failing transaction')
+      )
+      if (simulationFailed) {
+        txMeta.simulationFails = true
+        return txMeta
+      }
+    }
+    this.setTxGas(txMeta, block.gasLimit, estimatedGasHex)
+    return txMeta
+  }
+
+  /**
+    Estimates the tx's gas usage
+    @param txMeta {Object} - the txMeta object
+    @param blockGasLimitHex {string} - hex string of the block's gas limit
+    @returns {string} the estimated gas limit as a hex string
+  */
+  async estimateTxGas (txMeta, blockGasLimitHex) {
+    const txParams = txMeta.txParams
+
+    // check if gasLimit is already specified
+    txMeta.gasLimitSpecified = Boolean(txParams.gas)
+
+    // if it is, use that value
+    if (txMeta.gasLimitSpecified) {
+      return txParams.gas
+    }
+
+    // if recipient has no code, gas is 21k max:
+    const recipient = txParams.to
+    const hasRecipient = Boolean(recipient)
+    let code
+    if (recipient) code = await this.query.getCode(recipient)
+
+    if (hasRecipient && (!code || code === '0x')) {
+      txParams.gas = SIMPLE_GAS_COST
+      txMeta.simpleSend = true // Prevents buffer addition
+      return SIMPLE_GAS_COST
+    }
+
+    // if not, fall back to block gasLimit
+    const blockGasLimitBN = hexToBn(blockGasLimitHex)
+    const saferGasLimitBN = BnMultiplyByFraction(blockGasLimitBN, 19, 20)
+    txParams.gas = bnToHex(saferGasLimitBN)
+
+    // run tx
+    return await this.query.estimateGas(txParams)
+  }
+
+  /**
+    Writes the gas on the txParams in the txMeta
+    @param txMeta {Object} - the txMeta object to write to
+    @param blockGasLimitHex {string} - the block gas limit hex
+    @param estimatedGasHex {string} - the estimated gas hex
+  */
+  setTxGas (txMeta, blockGasLimitHex, estimatedGasHex) {
+    txMeta.estimatedGas = addHexPrefix(estimatedGasHex)
+    const txParams = txMeta.txParams
+
+    // if gasLimit was specified and doesnt OOG,
+    // use original specified amount
+    if (txMeta.gasLimitSpecified || txMeta.simpleSend) {
+      txMeta.estimatedGas = txParams.gas
+      return
+    }
+    // if gasLimit not originally specified,
+    // try adding an additional gas buffer to our estimation for safety
+    const recommendedGasHex = this.addGasBuffer(txMeta.estimatedGas, blockGasLimitHex)
+    txParams.gas = recommendedGasHex
+    return
+  }
+
+  /**
+    Adds a gas buffer with out exceeding the block gas limit
+
+    @param initialGasLimitHex {string} - the initial gas limit to add the buffer too
+    @param blockGasLimitHex {string} - the block gas limit
+    @returns {string} the buffered gas limit as a hex string
+  */
+  addGasBuffer (initialGasLimitHex, blockGasLimitHex) {
+    const initialGasLimitBn = hexToBn(initialGasLimitHex)
+    const blockGasLimitBn = hexToBn(blockGasLimitHex)
+    const upperGasLimitBn = blockGasLimitBn.muln(0.9)
+    const bufferedGasLimitBn = initialGasLimitBn.muln(1.5)
+
+    // if initialGasLimit is above blockGasLimit, dont modify it
+    if (initialGasLimitBn.gt(upperGasLimitBn)) return bnToHex(initialGasLimitBn)
+    // if bufferedGasLimit is below blockGasLimit, use bufferedGasLimit
+    if (bufferedGasLimitBn.lt(upperGasLimitBn)) return bnToHex(bufferedGasLimitBn)
+    // otherwise use blockGasLimit
+    return bnToHex(upperGasLimitBn)
+  }
+}
+
+module.exports = TxGasUtil
\ No newline at end of file
diff --git a/app/scripts/controllers/transactions/tx-state-manager.js b/app/scripts/controllers/transactions/tx-state-manager.js
new file mode 100644
index 000000000..53428c333
--- /dev/null
+++ b/app/scripts/controllers/transactions/tx-state-manager.js
@@ -0,0 +1,420 @@
+const extend = require('xtend')
+const EventEmitter = require('events')
+const ObservableStore = require('obs-store')
+const ethUtil = require('ethereumjs-util')
+const txStateHistoryHelper = require('./lib/tx-state-history-helper')
+const createId = require('../../lib/random-id')
+const { getFinalStates } = require('./lib/util')
+/**
+  TransactionStateManager is responsible for the state of a transaction and
+  storing the transaction
+  it also has some convenience methods for finding subsets of transactions
+  *
+  *STATUS METHODS
+  <br>statuses:
+  <br>   - `'unapproved'` the user has not responded
+  <br>   - `'rejected'` the user has responded no!
+  <br>   - `'approved'` the user has approved the tx
+  <br>   - `'signed'` the tx is signed
+  <br>   - `'submitted'` the tx is sent to a server
+  <br>   - `'confirmed'` the tx has been included in a block.
+  <br>   - `'failed'` the tx failed for some reason, included on tx data.
+  <br>   - `'dropped'` the tx nonce was already used
+  @param opts {object}
+  @param {object} [opts.initState={ transactions: [] }] initial transactions list with the key transaction {array}
+  @param {number} [opts.txHistoryLimit] limit for how many finished
+  transactions can hang around in state
+  @param {function} opts.getNetwork return network number
+  @class
+*/
+class TransactionStateManager extends EventEmitter {
+  constructor ({ initState, txHistoryLimit, getNetwork }) {
+    super()
+
+    this.store = new ObservableStore(
+      extend({
+        transactions: [],
+    }, initState))
+    this.txHistoryLimit = txHistoryLimit
+    this.getNetwork = getNetwork
+  }
+
+  /**
+    @param opts {object} - the object to use when overwriting defaults
+    @returns {txMeta} the default txMeta object
+  */
+  generateTxMeta (opts) {
+    return extend({
+      id: createId(),
+      time: (new Date()).getTime(),
+      status: 'unapproved',
+      metamaskNetworkId: this.getNetwork(),
+      loadingDefaults: true,
+    }, opts)
+  }
+
+  /**
+    @returns {array} of txMetas that have been filtered for only the current network
+  */
+  getTxList () {
+    const network = this.getNetwork()
+    const fullTxList = this.getFullTxList()
+    return fullTxList.filter((txMeta) => txMeta.metamaskNetworkId === network)
+  }
+
+  /**
+    @returns {array} of all the txMetas in store
+  */
+  getFullTxList () {
+    return this.store.getState().transactions
+  }
+
+  /**
+    @returns {array} the tx list whos status is unapproved
+  */
+  getUnapprovedTxList () {
+    const txList = this.getTxsByMetaData('status', 'unapproved')
+    return txList.reduce((result, tx) => {
+      result[tx.id] = tx
+      return result
+    }, {})
+  }
+
+  /**
+    @param [address] {string} - hex prefixed address to sort the txMetas for [optional]
+    @returns {array} the tx list whos status is submitted if no address is provide
+    returns all txMetas who's status is submitted for the current network
+  */
+  getPendingTransactions (address) {
+    const opts = { status: 'submitted' }
+    if (address) opts.from = address
+    return this.getFilteredTxList(opts)
+  }
+
+  /**
+    @param [address] {string} - hex prefixed address to sort the txMetas for [optional]
+    @returns {array} the tx list whos status is confirmed if no address is provide
+    returns all txMetas who's status is confirmed for the current network
+  */
+  getConfirmedTransactions (address) {
+    const opts = { status: 'confirmed' }
+    if (address) opts.from = address
+    return this.getFilteredTxList(opts)
+  }
+
+  /**
+    Adds the txMeta to the list of transactions in the store.
+    if the list is over txHistoryLimit it will remove a transaction that
+    is in its final state
+    it will allso add the key `history` to the txMeta with the snap shot of the original
+    object
+    @param txMeta {Object}
+    @returns {object} the txMeta
+  */
+  addTx (txMeta) {
+    this.once(`${txMeta.id}:signed`, function (txId) {
+      this.removeAllListeners(`${txMeta.id}:rejected`)
+    })
+    this.once(`${txMeta.id}:rejected`, function (txId) {
+      this.removeAllListeners(`${txMeta.id}:signed`)
+    })
+    // initialize history
+    txMeta.history = []
+    // capture initial snapshot of txMeta for history
+    const snapshot = txStateHistoryHelper.snapshotFromTxMeta(txMeta)
+    txMeta.history.push(snapshot)
+
+    const transactions = this.getFullTxList()
+    const txCount = transactions.length
+    const txHistoryLimit = this.txHistoryLimit
+
+    // checks if the length of the tx history is
+    // longer then desired persistence limit
+    // and then if it is removes only confirmed
+    // or rejected tx's.
+    // not tx's that are pending or unapproved
+    if (txCount > txHistoryLimit - 1) {
+      const index = transactions.findIndex((metaTx) => {
+        return getFinalStates().includes(metaTx.status)
+      })
+      if (index !== -1) {
+        transactions.splice(index, 1)
+      }
+    }
+    transactions.push(txMeta)
+    this._saveTxList(transactions)
+    return txMeta
+  }
+  /**
+    @param txId {number}
+    @returns {object} the txMeta who matches the given id if none found
+    for the network returns undefined
+  */
+  getTx (txId) {
+    const txMeta = this.getTxsByMetaData('id', txId)[0]
+    return txMeta
+  }
+
+  /**
+    updates the txMeta in the list and adds a history entry
+    @param txMeta {Object} - the txMeta to update
+    @param [note] {string} - a not about the update for history
+  */
+  updateTx (txMeta, note) {
+    // validate txParams
+    if (txMeta.txParams) {
+      if (typeof txMeta.txParams.data === 'undefined') {
+        delete txMeta.txParams.data
+      }
+
+      this.validateTxParams(txMeta.txParams)
+    }
+
+    // create txMeta snapshot for history
+    const currentState = txStateHistoryHelper.snapshotFromTxMeta(txMeta)
+    // recover previous tx state obj
+    const previousState = txStateHistoryHelper.replayHistory(txMeta.history)
+    // generate history entry and add to history
+    const entry = txStateHistoryHelper.generateHistoryEntry(previousState, currentState, note)
+    txMeta.history.push(entry)
+
+    // commit txMeta to state
+    const txId = txMeta.id
+    const txList = this.getFullTxList()
+    const index = txList.findIndex(txData => txData.id === txId)
+    txList[index] = txMeta
+    this._saveTxList(txList)
+  }
+
+
+  /**
+    merges txParams obj onto txMeta.txParams
+    use extend to ensure that all fields are filled
+    @param txId {number} - the id of the txMeta
+    @param txParams {object} - the updated txParams
+  */
+  updateTxParams (txId, txParams) {
+    const txMeta = this.getTx(txId)
+    txMeta.txParams = extend(txMeta.txParams, txParams)
+    this.updateTx(txMeta, `txStateManager#updateTxParams`)
+  }
+
+  /**
+    validates txParams members by type
+    @param txParams {object} - txParams to validate
+  */
+  validateTxParams (txParams) {
+    Object.keys(txParams).forEach((key) => {
+      const value = txParams[key]
+      // validate types
+      switch (key) {
+        case 'chainId':
+          if (typeof value !== 'number' && typeof value !== 'string') throw new Error(`${key} in txParams is not a Number or hex string. got: (${value})`)
+          break
+        default:
+          if (typeof value !== 'string') throw new Error(`${key} in txParams is not a string. got: (${value})`)
+          if (!ethUtil.isHexPrefixed(value)) throw new Error(`${key} in txParams is not hex prefixed. got: (${value})`)
+          break
+      }
+    })
+  }
+
+/**
+  @param opts {object} -  an object of fields to search for eg:<br>
+  let <code>thingsToLookFor = {<br>
+    to: '0x0..',<br>
+    from: '0x0..',<br>
+    status: 'signed',<br>
+    err: undefined,<br>
+  }<br></code>
+  @param [initialList=this.getTxList()]
+  @returns a {array} of txMeta with all
+  options matching
+  */
+  /*
+  ****************HINT****************
+  | `err: undefined` is like looking |
+  | for a tx with no err             |
+  | so you can also search txs that  |
+  | dont have something as well by   |
+  | setting the value as undefined   |
+  ************************************
+
+  this is for things like filtering a the tx list
+  for only tx's from 1 account
+  or for filltering for all txs from one account
+  and that have been 'confirmed'
+  */
+  getFilteredTxList (opts, initialList) {
+    let filteredTxList = initialList
+    Object.keys(opts).forEach((key) => {
+      filteredTxList = this.getTxsByMetaData(key, opts[key], filteredTxList)
+    })
+    return filteredTxList
+  }
+  /**
+
+    @param key {string} - the key to check
+    @param value - the value your looking for
+    @param [txList=this.getTxList()] {array} - the list to search. default is the txList
+    from txStateManager#getTxList
+    @returns {array} a list of txMetas who matches the search params
+  */
+  getTxsByMetaData (key, value, txList = this.getTxList()) {
+    return txList.filter((txMeta) => {
+      if (txMeta.txParams[key]) {
+        return txMeta.txParams[key] === value
+      } else {
+        return txMeta[key] === value
+      }
+    })
+  }
+
+  // get::set status
+
+  /**
+    @param txId {number} - the txMeta Id
+    @return {string} the status of the tx.
+  */
+  getTxStatus (txId) {
+    const txMeta = this.getTx(txId)
+    return txMeta.status
+  }
+
+  /**
+    should update the status of the tx to 'rejected'.
+    @param txId {number} - the txMeta Id
+  */
+  setTxStatusRejected (txId) {
+    this._setTxStatus(txId, 'rejected')
+  }
+
+  /**
+    should update the status of the tx to 'unapproved'.
+    @param txId {number} - the txMeta Id
+  */
+  setTxStatusUnapproved (txId) {
+    this._setTxStatus(txId, 'unapproved')
+  }
+  /**
+    should update the status of the tx to 'approved'.
+    @param txId {number} - the txMeta Id
+  */
+  setTxStatusApproved (txId) {
+    this._setTxStatus(txId, 'approved')
+  }
+
+  /**
+    should update the status of the tx to 'signed'.
+    @param txId {number} - the txMeta Id
+  */
+  setTxStatusSigned (txId) {
+    this._setTxStatus(txId, 'signed')
+  }
+
+  /**
+    should update the status of the tx to 'submitted'.
+    and add a time stamp for when it was called
+    @param txId {number} - the txMeta Id
+  */
+  setTxStatusSubmitted (txId) {
+    const txMeta = this.getTx(txId)
+    txMeta.submittedTime = (new Date()).getTime()
+    this.updateTx(txMeta, 'txStateManager - add submitted time stamp')
+    this._setTxStatus(txId, 'submitted')
+  }
+
+  /**
+    should update the status of the tx to 'confirmed'.
+    @param txId {number} - the txMeta Id
+  */
+  setTxStatusConfirmed (txId) {
+    this._setTxStatus(txId, 'confirmed')
+  }
+
+  /**
+    should update the status of the tx to 'dropped'.
+    @param txId {number} - the txMeta Id
+  */
+  setTxStatusDropped (txId) {
+    this._setTxStatus(txId, 'dropped')
+  }
+
+
+  /**
+    should update the status of the tx to 'failed'.
+    and put the error on the txMeta
+    @param txId {number} - the txMeta Id
+    @param err {erroObject} - error object
+  */
+  setTxStatusFailed (txId, err) {
+    const txMeta = this.getTx(txId)
+    txMeta.err = {
+      message: err.toString(),
+      stack: err.stack,
+    }
+    this.updateTx(txMeta)
+    this._setTxStatus(txId, 'failed')
+  }
+
+  /**
+    Removes transaction from the given address for the current network
+    from the txList
+    @param address {string} - hex string of the from address on the txParams to remove
+  */
+  wipeTransactions (address) {
+    // network only tx
+    const txs = this.getFullTxList()
+    const network = this.getNetwork()
+
+    // Filter out the ones from the current account and network
+    const otherAccountTxs = txs.filter((txMeta) => !(txMeta.txParams.from === address && txMeta.metamaskNetworkId === network))
+
+    // Update state
+    this._saveTxList(otherAccountTxs)
+  }
+//
+//           PRIVATE METHODS
+//
+
+  // STATUS METHODS
+  // statuses:
+  //    - `'unapproved'` the user has not responded
+  //    - `'rejected'` the user has responded no!
+  //    - `'approved'` the user has approved the tx
+  //    - `'signed'` the tx is signed
+  //    - `'submitted'` the tx is sent to a server
+  //    - `'confirmed'` the tx has been included in a block.
+  //    - `'failed'` the tx failed for some reason, included on tx data.
+  //    - `'dropped'` the tx nonce was already used
+
+  /**
+    @param txId {number} - the txMeta Id
+    @param status {string} - the status to set on the txMeta
+    @emits tx:status-update - passes txId and status
+    @emits ${txMeta.id}:finished - if it is a finished state. Passes the txMeta
+    @emits update:badge
+  */
+  _setTxStatus (txId, status) {
+    const txMeta = this.getTx(txId)
+    txMeta.status = status
+    this.emit(`${txMeta.id}:${status}`, txId)
+    this.emit(`tx:status-update`, txId, status)
+    if (['submitted', 'rejected', 'failed'].includes(status)) {
+      this.emit(`${txMeta.id}:finished`, txMeta)
+    }
+    this.updateTx(txMeta, `txStateManager: setting status to ${status}`)
+    this.emit('update:badge')
+  }
+
+  /**
+    Saves the new/updated txList.
+    @param transactions {array} - the list of transactions to save
+  */
+  // Function is intended only for internal use
+  _saveTxList (transactions) {
+    this.store.updateState({ transactions })
+  }
+}
+
+module.exports = TransactionStateManager