diff --git a/package.json b/package.json
index 7a9a64ed..13c62870 100644
--- a/package.json
+++ b/package.json
@@ -39,7 +39,7 @@
     "koa": "^1.0.0",
     "koa-compress": "^1.0.6",
     "koa-mag": "^1.0.4",
-    "koa-passport": "^1.2.0",
+    "koa-passport": "^1.3.0",
     "koa-route": "^2.4.2",
     "koa-static": "^1.4.5",
     "lodash": "^3.5.0",
diff --git a/src/app.js b/src/app.js
index abbd17f5..5a02202f 100644
--- a/src/app.js
+++ b/src/app.js
@@ -1,39 +1,102 @@
 'use strict'
 
+const _ = require('lodash')
+const co = require('co')
 const metadata = require('./controllers/metadata')
 const health = require('./controllers/health')
 const pairs = require('./controllers/pairs')
 const quote = require('./controllers/quote')
 const notifications = require('./controllers/notifications')
+const subscriptions = require('./models/subscriptions')
 const compress = require('koa-compress')
 const serve = require('koa-static')
 const route = require('koa-route')
 const errorHandler = require('five-bells-shared/middlewares/error-handler')
 const koa = require('koa')
 const path = require('path')
-const log = require('./services/log')
 const logger = require('koa-mag')
-const passport = require('koa-passport')
-const app = module.exports = koa()
+const Passport = require('koa-passport').KoaPassport
+const log = require('./services/log')
+
+function listen (koaApp, config, backend, ledgers) {
+  if (config.getIn(['server', 'secure'])) {
+    const spdy = require('spdy')
+    const tls = config.get('tls')
+
+    const options = {
+      port: config.getIn(['server', 'port']),
+      host: config.getIn(['server', 'bind_ip']),
+      key: tls.key,
+      cert: tls.cert,
+      ca: tls.ca,
+      crl: tls.crl,
+      requestCert: config.getIn(['auth', 'client_certificates_enabled']),
+
+      // Certificates are checked in the passport-client-cert middleware
+      // Authorization check is disabled here to allow clients to connect
+      // to some endpoints without presenting client certificates, or using a
+      // different authentication method (e.g., Basic Auth)
+      rejectUnauthorized: false
+    }
+
+    spdy.createServer(
+      options, koaApp.callback()).listen(config.getIn(['server', 'port']))
+  } else {
+    koaApp.listen(config.getIn(['server', 'port']))
+  }
+
+  log('app').info('connector listening on ' + config.getIn(['server', 'bind_ip']) + ':' +
+    config.getIn(['server', 'port']))
+  log('app').info('public at ' + config.getIn(['server', 'base_uri']))
+  for (let pair of config.get('tradingPairs')) {
+    log('app').info('pair', pair)
+  }
+
+  // Start a coroutine that connects to the backend and
+  // subscribes to all the ledgers in the background
+  co(function * () {
+    yield backend.connect()
+
+    yield subscriptions.subscribePairs(config.get('tradingPairs'), ledgers, config)
+  }).catch(function (err) {
+    log('app').error(typeof err === 'object' && err.stack || err)
+  })
+}
+
+function createApp (config, backend, ledgers) {
+  const koaApp = koa()
+
+  koaApp.context.config = config
+  koaApp.context.backend = backend
+  koaApp.context.ledgers = ledgers
+
+  // Configure passport
+  const passport = new Passport()
+  require('./services/auth')(passport, config)
+
+  // Logger
+  koaApp.use(logger())
+  koaApp.use(errorHandler({log: log('error-handler')}))
+  koaApp.use(passport.initialize())
 
-// Configure passport
-require('./services/auth')
+  koaApp.use(route.get('/', metadata.getResource))
+  koaApp.use(route.get('/health', health.getResource))
+  koaApp.use(route.get('/pairs', pairs.getCollection))
 
-// Logger
-app.use(logger())
-app.use(errorHandler({log: log('error-handler')}))
-app.use(passport.initialize())
+  koaApp.use(route.get('/quote', quote.get))
 
-app.use(route.get('/', metadata.getResource))
-app.use(route.get('/health', health.getResource))
-app.use(route.get('/pairs', pairs.getCollection))
+  koaApp.use(route.post('/notifications', notifications.post))
 
-app.use(route.get('/quote', quote.get))
+  // Serve static files
+  koaApp.use(serve(path.join(__dirname, 'public')))
 
-app.use(route.post('/notifications', notifications.post))
+  // Compress
+  koaApp.use(compress())
 
-// Serve static files
-app.use(serve(path.join(__dirname, 'public')))
+  return {
+    koaApp: koaApp,
+    listen: _.partial(listen, koaApp, config, backend, ledgers)
+  }
+}
 
-// Compress
-app.use(compress())
+module.exports = createApp
diff --git a/src/controllers/notifications.js b/src/controllers/notifications.js
index cc5ca4f5..8cf955a6 100644
--- a/src/controllers/notifications.js
+++ b/src/controllers/notifications.js
@@ -72,7 +72,7 @@ exports.post = function * postNotification () {
   const notification = yield requestUtil.validateBody(this, 'Notification')
   log.debug('Got notification: ' + JSON.stringify(notification))
   try {
-    yield model.processNotification(notification)
+    yield model.processNotification(notification, this.config, this.backend, this.ledgers)
   } catch (e) {
     if (!(e instanceof UnacceptableExpiryError)) {
       log.error('Notification handling received critical error: ' + e)
diff --git a/src/controllers/pairs.js b/src/controllers/pairs.js
index e8404729..2343191b 100644
--- a/src/controllers/pairs.js
+++ b/src/controllers/pairs.js
@@ -36,5 +36,5 @@ const model = require('../models/pairs')
  */
 /* eslint-enable */
 exports.getCollection = function * getCollection () {
-  this.body = model.getPairs()
+  this.body = model.getPairs(this.config)
 }
diff --git a/src/controllers/quote.js b/src/controllers/quote.js
index 79449e18..886b41c9 100644
--- a/src/controllers/quote.js
+++ b/src/controllers/quote.js
@@ -109,6 +109,7 @@ const model = require('../models/quote')
 /* eslint-enable */
 
 exports.get = function * () {
-  this.body = yield model.getQuote(this.query)
+  this.body = yield model.getQuote(
+    this.query, this.ledgers, this.backend, this.config)
 }
 
diff --git a/src/index.js b/src/index.js
index e63836ef..e8d491b6 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,65 +1,19 @@
 'use strict'
-const co = require('co')
 const ledgers = require('./services/ledgers')
 const config = require('./services/config')
-const log = require('./services/log')
 const backend = require('./services/backend')
-const subscriptions = require('./models/subscriptions')
-const app = require('./app')
-const ledgersService = require('./services/ledgers')
+const balanceCache = require('./services/balance-cache')
+const createApp = require('./app')
 
-function listen () {
-  if (config.getIn(['server', 'secure'])) {
-    const spdy = require('spdy')
-    const tls = config.get('tls')
-
-    const options = {
-      port: config.getIn(['server', 'port']),
-      host: config.getIn(['server', 'bind_ip']),
-      key: tls.key,
-      cert: tls.cert,
-      ca: tls.ca,
-      crl: tls.crl,
-      requestCert: config.getIn(['auth', 'client_certificates_enabled']),
-
-      // Certificates are checked in the passport-client-cert middleware
-      // Authorization check is disabled here to allow clients to connect
-      // to some endpoints without presenting client certificates, or using a
-      // different authentication method (e.g., Basic Auth)
-      rejectUnauthorized: false
-    }
-
-    spdy.createServer(
-      options, app.callback()).listen(config.getIn(['server', 'port']))
-  } else {
-    app.listen(config.getIn(['server', 'port']))
-  }
-
-  log('app').info('connector listening on ' + config.getIn(['server', 'bind_ip']) + ':' +
-    config.getIn(['server', 'port']))
-  log('app').info('public at ' + config.getIn(['server', 'base_uri']))
-  for (let pair of config.get('tradingPairs')) {
-    log('app').info('pair', pair)
-  }
-
-  // Start a coroutine that connects to the backend and
-  // subscribes to all the ledgers in the background
-  co(function * () {
-    yield backend.connect()
-
-    yield subscriptions.subscribePairs(config.get('tradingPairs'), ledgersService, config)
-  }).catch(function (err) {
-    log('app').error(typeof err === 'object' && err.stack || err)
-  })
-}
+const connector = createApp(config, backend, ledgers)
 
 module.exports = {
-  app: app,
-  listen: listen,
+  app: connector.koaApp,
+  listen: connector.listen,
   addLedger: ledgers.addLedger.bind(ledgers),
   _test: {
     BalanceCache: require('./lib/balance-cache'),
-    balanceCache: require('./services/balance-cache'),
+    balanceCache: balanceCache,
     loadConnectorConfig: require('./lib/config'),
     config: require('./services/config'),
     logger: require('./services/log'),
@@ -68,5 +22,5 @@ module.exports = {
 }
 
 if (!module.parent) {
-  listen()
+  connector.listen()
 }
diff --git a/src/models/notifications.js b/src/models/notifications.js
index e4cda06d..13c3c503 100644
--- a/src/models/notifications.js
+++ b/src/models/notifications.js
@@ -2,9 +2,10 @@
 
 const payments = require('./payments')
 
-function * processNotification (notification) {
+function * processNotification (notification, config, backend, ledgers) {
   if (notification.event === 'transfer.update') {
-    yield payments.updateTransfer(notification.resource, notification.related_resources)
+    yield payments.updateTransfer(
+      notification.resource, notification.related_resources, config, backend, ledgers)
   }
 }
 
diff --git a/src/models/pairs.js b/src/models/pairs.js
index 279d9039..6178836e 100644
--- a/src/models/pairs.js
+++ b/src/models/pairs.js
@@ -1,8 +1,6 @@
 'use strict'
 
-const config = require('../services/config')
-
-function getPairs () {
+function getPairs (config) {
   const tradingPairs = config.get('tradingPairs')
   return tradingPairs.map((pair) => {
     const currencies = pair.map(function (currencyLedgerString) {
diff --git a/src/models/payments.js b/src/models/payments.js
index 92fc6f75..ef3cf646 100644
--- a/src/models/payments.js
+++ b/src/models/payments.js
@@ -16,9 +16,6 @@ const UnrelatedNotificationError =
   require('../errors/unrelated-notification-error')
 const AssetsNotTradedError = require('../errors/assets-not-traded-error')
 const hashJSON = require('five-bells-shared/utils/hashJson')
-const config = require('../services/config')
-const backend = require('../services/backend')
-const ledgers = require('../services/ledgers')
 
 // TODO this should handle the different types of execution_condition's.
 function sourceConditionIsDestinationTransfer (source, destination) {
@@ -89,7 +86,7 @@ function validateExecutionConditions (payment) {
   }
 }
 
-function * validateExecutionConditionPublicKey (payment) {
+function * validateExecutionConditionPublicKey (payment, ledgers) {
   // TODO: use a cache of ledgers' public keys and move this functionality
   // into the synchronous validateExecutionConditions function
   for (const sourceTransfer of payment.source_transfers) {
@@ -118,7 +115,7 @@ function * validateExecutionConditionPublicKey (payment) {
   }
 }
 
-function * validateExpiry (payment) {
+function * validateExpiry (payment, config) {
   // TODO tie the maxHoldTime to the fx rate
   // TODO bring all these loops into one to speed this up
   const tester = yield testPaymentExpiry(config, payment)
@@ -133,7 +130,7 @@ function * validateExpiry (payment) {
   }
 }
 
-function amountFinder (ledger, creditOrDebit) {
+function amountFinder (ledger, creditOrDebit, config) {
   // TODO: we need a more elegant way of handling assets that we don't trade
   if (!config.getIn(['ledgerCredentials', ledger])) {
     throw new AssetsNotTradedError('This connector does not support ' +
@@ -159,7 +156,7 @@ function amountFinder (ledger, creditOrDebit) {
  * @param {String} opts.convertToLedger The ledger representing the asset we will convert all of the amounts into (for easier comparisons)
  * @yield {Float} The total amount converted into the asset represented by opts.convertToLedger
  */
-function * calculateAmountEquivalent (opts) {
+function * calculateAmountEquivalent (opts, config, backend) {
   // convertedAmountTotal is going to be the total of either the credits
   // if the transfers are source_transfers or debits if the transfers
   // are destination_transfers (the amount that is either entering
@@ -174,9 +171,9 @@ function * calculateAmountEquivalent (opts) {
 
   for (const transfer of opts.transfers) {
     // Total the number of credits or debits to the connectors account
-    const relevantAmountTotal = _.reduce(transfer[opts.creditsOrDebits], function (result, creditOrDebit) {
-      return result.plus(amountFinder(transfer.ledger, creditOrDebit))
-    }, new BigNumber(0), this)
+    const relevantAmountTotal = _.reduce(transfer[opts.creditsOrDebits], (result, creditOrDebit) => {
+      return result.plus(amountFinder(transfer.ledger, creditOrDebit, config))
+    }, new BigNumber(0))
 
     // Throw an error if we're not included in the transfer
     if (relevantAmountTotal.lte(0) && !opts.noErrors) {
@@ -215,7 +212,7 @@ function * calculateAmountEquivalent (opts) {
   return convertedAmountTotal
 }
 
-function * validateRate (payment) {
+function * validateRate (payment, config, backend) {
   log.debug('validating rate')
 
   // Determine which ledger's asset we will convert all
@@ -235,14 +232,14 @@ function * validateRate (payment) {
     transferSide: 'source',
     creditsOrDebits: 'credits',
     convertToLedger: convertToLedger
-  })
+  }, config, backend)
   const destinationDebitEquivalent =
   yield calculateAmountEquivalent({
     transfers: payment.destination_transfers,
     transferSide: 'destination',
     creditsOrDebits: 'debits',
     convertToLedger: convertToLedger
-  })
+  }, config, backend)
 
   if (sourceCreditEquivalent.lt(destinationDebitEquivalent)) {
     throw new UnacceptableRateError('Payment rate does not match ' +
@@ -251,7 +248,7 @@ function * validateRate (payment) {
 }
 
 // Note this modifies the original object
-function addAuthorizationToTransfers (transfers) {
+function addAuthorizationToTransfers (transfers, config) {
   // TODO: make sure we're not authorizing anything extra
   // that shouldn't be taking money out of our account
   let credentials
@@ -273,7 +270,7 @@ function addAuthorizationToTransfers (transfers) {
 // TODO authorize credits
 }
 
-function * submitTransfer (destinationTransfer, sourceTransfer) {
+function * submitTransfer (destinationTransfer, sourceTransfer, ledgers) {
   for (const debit of destinationTransfer.debits) {
     debit.memo = Object.assign({}, debit.memo, {
       source_transfer_ledger: sourceTransfer.ledger,
@@ -283,24 +280,24 @@ function * submitTransfer (destinationTransfer, sourceTransfer) {
   yield ledgers.putTransfer(destinationTransfer)
 }
 
-function * validate (payment) {
+function * validate (payment, ledgers, config, backend) {
   // TODO: Check expiry settings
   // TODO: Check ledger signature on source payment
   // TODO: Check ledger signature on destination payment
 
-  yield validateExpiry(payment)
-  yield validateRate(payment)
+  yield validateExpiry(payment, config)
+  yield validateRate(payment, config, backend)
   validateExecutionConditions(payment)
-  yield validateExecutionConditionPublicKey(payment)
+  yield validateExecutionConditionPublicKey(payment, ledgers)
 }
 
-function * settle (payment) {
+function * settle (payment, config, ledgers) {
   log.debug('Settle payment: ' + JSON.stringify(payment))
-  addAuthorizationToTransfers(payment.destination_transfers)
+  addAuthorizationToTransfers(payment.destination_transfers, config)
 
   const sourceTransfer = payment.source_transfers[0]
   for (const destinationTransfer of payment.destination_transfers) {
-    yield submitTransfer(destinationTransfer, sourceTransfer)
+    yield submitTransfer(destinationTransfer, sourceTransfer, ledgers)
   }
 
   const anyTransfersAreExecuted = _.some(payment.destination_transfers, (transfer) => {
@@ -316,13 +313,13 @@ function * settle (payment) {
   }
 }
 
-function isTraderFunds (funds) {
+function isTraderFunds (config, funds) {
   return _.some(config.ledgerCredentials, (credentials) => {
     return credentials.account_uri === funds.account
   })
 }
 
-function * updateSourceTransfer (updatedTransfer, traderCredit) {
+function * updateSourceTransfer (updatedTransfer, traderCredit, ledgers, config, backend) {
   const destinationTransfer = traderCredit.memo && traderCredit.memo.destination_transfer
   if (!destinationTransfer) return
   ledgers.validateTransfer(destinationTransfer)
@@ -334,8 +331,9 @@ function * updateSourceTransfer (updatedTransfer, traderCredit) {
     source_transfers: [updatedTransfer],
     destination_transfers: [destinationTransfer]
   }
-  yield validate(payment)
-  yield settle(payment)
+
+  yield validate(payment, ledgers, config, backend)
+  yield settle(payment, config, ledgers)
 }
 
 function * updateDestinationTransfer (updatedTransfer, traderDebit, relatedResources) {
@@ -348,18 +346,17 @@ function * updateDestinationTransfer (updatedTransfer, traderDebit, relatedResou
   yield executeSourceTransfers([updatedTransfer], relatedResources)
 }
 
-function * updateTransfer (updatedTransfer, relatedResources) {
-  // TODO: make sure the transfer is signed by the ledger
+function * updateTransfer (updatedTransfer, relatedResources, config, backend, ledgers) {
   // Maybe it's a source transfer:
   // When the payment's source transfer is "prepared", authorized/submit the payment.
-  const traderCredit = updatedTransfer.credits.find(isTraderFunds)
+  const traderCredit = updatedTransfer.credits.find(_.partial(isTraderFunds, config))
   if (traderCredit) {
-    yield updateSourceTransfer(updatedTransfer, traderCredit)
+    yield updateSourceTransfer(updatedTransfer, traderCredit, ledgers, config, backend)
     return
   }
 
   // Or a destination transfer:
-  const traderDebit = updatedTransfer.debits.find(isTraderFunds)
+  const traderDebit = updatedTransfer.debits.find(_.partial(isTraderFunds, config))
   if (traderDebit) {
     yield updateDestinationTransfer(updatedTransfer, traderDebit, relatedResources)
     return
diff --git a/src/models/quote.js b/src/models/quote.js
index 9cdfee9f..7721cdaa 100644
--- a/src/models/quote.js
+++ b/src/models/quote.js
@@ -2,17 +2,14 @@
 
 const request = require('co-request')
 const BigNumber = require('bignumber.js')
-const config = require('../services/config')
 const log = require('../services/log')('quote')
-const backend = require('../services/backend')
-const ledgers = require('../services/ledgers')
-const balanceCache = require('../services/balance-cache')
 const UnacceptableExpiryError = require('../errors/unacceptable-expiry-error')
 const UnacceptableAmountError = require('../errors/unacceptable-amount-error')
 const InvalidURIParameterError = require('five-bells-shared').InvalidUriParameterError
 const ExternalError = require('../errors/external-error')
+const balanceCache = require('../services/balance-cache.js')
 
-function * makeQuoteQuery (params) {
+function * makeQuoteQuery (params, config) {
   // TODO: include the expiry duration in the quote logic
   let destinationExpiryDuration = parseFloat(params.destination_expiry_duration)
   let sourceExpiryDuration = parseFloat(params.source_expiry_duration)
@@ -77,7 +74,7 @@ function makeQuoteArgs (query) {
   }
 }
 
-function makePaymentTemplate (query, quote) {
+function makePaymentTemplate (query, quote, ledgers) {
   const source_amount = quote.source_amount
   const destination_amount = quote.destination_amount
   const payment = {
@@ -122,8 +119,8 @@ function * getAccountLedger (account) {
   return ledger
 }
 
-function * getQuote (params) {
-  const query = yield makeQuoteQuery(params)
+function * getQuote (params, ledgers, backend, config) {
+  const query = yield makeQuoteQuery(params, config)
   const quote = yield backend.getQuote(makeQuoteArgs(query))
 
   const sourceBalance = yield balanceCache.get(query.source_ledger)
@@ -138,7 +135,7 @@ function * getQuote (params) {
     quote.destination_amount + ' ' +
     query.destination_ledger)
 
-  return makePaymentTemplate(query, quote)
+  return makePaymentTemplate(query, quote, ledgers)
 }
 
 module.exports = {
diff --git a/src/services/auth.js b/src/services/auth.js
index 38d870da..82877f85 100644
--- a/src/services/auth.js
+++ b/src/services/auth.js
@@ -1,13 +1,13 @@
 'use strict'
 
-const passport = require('koa-passport')
 const ClientCertStrategy = require('passport-client-certificate').Strategy
 const UnauthorizedError = require('five-bells-shared/errors/unauthorized-error')
-const config = require('./config')
 
-passport.use(new ClientCertStrategy((certificate, done) => {
-  if (!config.getIn(['auth', 'client_certificates_enabled'])) {
-    return done(new UnauthorizedError('Unsupported authentication method'))
-  }
-}))
+module.exports = function (passport, config) {
+  passport.use(new ClientCertStrategy((certificate, done) => {
+    if (!config.getIn(['auth', 'client_certificates_enabled'])) {
+      return done(new UnauthorizedError('Unsupported authentication method'))
+    }
+  }))
+}