diff --git a/examples/http/client.js b/examples/http/client.js
index c1473a5..44974b3 100644
--- a/examples/http/client.js
+++ b/examples/http/client.js
@@ -2,7 +2,26 @@ const choo = require('../../')
 
 const mainView = require('./views/main')
 
-const app = choo()
+const app = choo({
+  onError: function (err, state, createSend) {
+    console.groupCollapsed(`Error: ${err.message}`)
+    console.error(err)
+    console.groupEnd()
+    const send = createSend('onError: ')
+    send('app:error', err)
+  },
+  onAction: function (action, state, name, caller, createSend) {
+    console.groupCollapsed(`Action: ${caller} -> ${name}`)
+    console.log(action)
+    console.groupEnd()
+  },
+  onState: function (action, state, prev, createSend) {
+    console.groupCollapsed('State')
+    console.log(prev)
+    console.log(state)
+    console.groupEnd()
+  }
+})
 
 app.model(require('./models/error'))
 app.model(require('./models/api'))
diff --git a/examples/http/models/api.js b/examples/http/models/api.js
index 65be0db..e7bd2c0 100644
--- a/examples/http/models/api.js
+++ b/examples/http/models/api.js
@@ -6,26 +6,26 @@ module.exports = {
     title: 'Button pushing machine 3000'
   },
   reducers: {
-    set: (action, state) => ({ 'title': action.payload })
+    set: (action, state) => ({ 'title': action.data })
   },
   effects: {
-    good: (action, state, send) => request('/good', send),
-    bad: (action, state, send) => request('/bad', send)
+    good: function (action, state, send, done) {
+      request('/good', send, done)
+    },
+    bad: (action, state, send, done) => request('/bad', send, done)
   }
 }
 
-function request (uri, send, state) {
+function request (uri, send, done) {
   http(uri, { json: true }, function (err, res, body) {
-    if (err) return send('app:error', { payload: 'HTTP error' })
+    if (err) return done(new Error('HTTP error'))
     if (res.statusCode !== 200) {
       const message = (body && body.message)
         ? body.message
         : 'unknown server error'
-      return send('app:error', { payload: message })
+      return done(new Error(message))
     }
-    if (!body) {
-      return send('app:error', { payload: 'fatal: no body received' })
-    }
-    send('api:set', { payload: body.message || body.title })
+    if (!body) return done(new Error('fatal: no body received'))
+    send('api:set', { data: body.message || body.title }, done)
   })
 }
diff --git a/examples/http/models/error.js b/examples/http/models/error.js
index 632d0e5..b3e0cea 100644
--- a/examples/http/models/error.js
+++ b/examples/http/models/error.js
@@ -10,34 +10,43 @@ const ERROR_TIMEOUT = 1000
 module.exports = {
   namespace: 'app',
   state: {
-    error: [],
-    errorTimeDone: null,
+    errors: [],
+    errorTimeDone: 0,
     triggerTime: null
   },
   reducers: {
-    error: function (action, state) {
-      const now = Date.now()
-      const timeDone = state.errorTimeDone
-      const newTimestamp = (timeDone && timeDone >= now)
-        ? timeDone + ERROR_TIMEOUT
-        : now + ERROR_TIMEOUT
-
+    setError: function (action, state) {
       return {
-        error: state.error.concat(action.payload),
-        errorTimeDone: newTimestamp
+        errors: state.errors.concat(action.message),
+        errorTimeDone: action.errorTimeDone
       }
     },
-    'error:delete': function (action, state) {
-      state.error.shift()
-      return { error: state.error }
+    'delError': function (action, state) {
+      state.errors.shift()
+      return { errors: state.errors }
     }
   },
   effects: {
-    error: function (action, state, send) {
-      const timeout = state.errorTimeDone - Date.now()
-      setTimeout(function () {
-        send('app:error:delete')
-      }, timeout)
+    error: function (err, state, send, done) {
+      const timeDone = state.errorTimeDone
+      const now = Date.now()
+
+      const timeStamp = (timeDone && timeDone >= now)
+        ? timeDone + ERROR_TIMEOUT
+        : now + ERROR_TIMEOUT
+
+      const timeout = timeStamp - now
+
+      const errAction = {
+        message: err.message,
+        errorTimeDone: timeStamp
+      }
+      send('app:setError', errAction, function (err) {
+        if (err) return done(err)
+        setTimeout(function () {
+          send('app:delError', done)
+        }, timeout)
+      })
     }
   }
 }
diff --git a/examples/http/views/main.js b/examples/http/views/main.js
index 683d3aa..0811c69 100644
--- a/examples/http/views/main.js
+++ b/examples/http/views/main.js
@@ -1,7 +1,7 @@
 const html = require('../../../html')
 
 module.exports = function (params, state, send) {
-  const error = state.app.error[0]
+  const error = state.app.errors[0]
   const title = state.api.title
   return html`
     <section>
diff --git a/examples/mailbox/client.js b/examples/mailbox/client.js
index e71b15c..a5f118f 100644
--- a/examples/mailbox/client.js
+++ b/examples/mailbox/client.js
@@ -2,7 +2,6 @@ const choo = require('../../')
 const sf = require('sheetify')
 
 sf('css-wipe/dest/bundle')
-sf('tachyons')
 
 const app = choo()
 
diff --git a/examples/mailbox/package.json b/examples/mailbox/package.json
index f29ef4d..9a1e58b 100644
--- a/examples/mailbox/package.json
+++ b/examples/mailbox/package.json
@@ -6,16 +6,18 @@
   "scripts": {
     "start": "NODE_ENV=development node server.js"
   },
-  "browserify": {
-    "transform": [
-      "sheetify/transform"
-    ]
-  },
   "author": "Yoshua Wuyts <i@yoshuawuyts.com>",
   "license": "ISC",
   "dependencies": {
     "css-wipe": "^4.2.1",
     "dateformat": "^1.0.12",
     "tachyons": "^4.0.0-beta.33"
+  },
+  "devDependencies": {
+    "bankai": "^2.0.5",
+    "browserify": "^13.0.1",
+    "insert-css": "^0.2.0",
+    "server-router": "^2.1.0",
+    "sheetify": "^5.0.3"
   }
 }
diff --git a/examples/title/package.json b/examples/title/package.json
new file mode 100644
index 0000000..731e7c1
--- /dev/null
+++ b/examples/title/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "title",
+  "version": "1.0.0",
+  "description": "",
+  "main": "client.js",
+  "scripts": {
+    "start": "budo client.js -p 8080"
+  },
+  "keywords": [],
+  "author": "Yoshua Wuyts <i@yoshuawuyts.com>",
+  "license": "ISC",
+  "dependencies": {
+    "budo": "^8.3.0"
+  }
+}
diff --git a/index.js b/index.js
index 92c4cd3..1e3848f 100644
--- a/index.js
+++ b/index.js
@@ -4,8 +4,7 @@ const document = require('global/document')
 const href = require('sheet-router/href')
 const hash = require('sheet-router/hash')
 const hashMatch = require('hash-match')
-const sendAction = require('send-action')
-const mutate = require('xtend/mutable')
+const barracks = require('barracks')
 const assert = require('assert')
 const xtend = require('xtend')
 const yo = require('yo-yo')
@@ -14,8 +13,11 @@ module.exports = choo
 
 // framework for creating sturdy web applications
 // null -> fn
-function choo () {
-  const _models = []
+function choo (opts) {
+  opts = opts || {}
+
+  const _store = barracks(xtend(opts, { onState: render }))
+  var _rootNode = null
   var _router = null
 
   start.toString = toString
@@ -28,153 +30,55 @@ function choo () {
   // render the application to a string
   // (str, obj) -> str
   function toString (route, serverState) {
-    const initialState = {}
-    const nsState = {}
-
-    _models.forEach(function (model) {
-      const ns = model.namespace
-      if (ns) {
-        if (!nsState[ns]) nsState[ns] = {}
-        apply(ns, model.state, nsState)
-        nsState[ns] = xtend(nsState[ns], serverState[ns])
-      } else {
-        apply(model.namespace, model.state, initialState)
-      }
-    })
-
-    const state = xtend(initialState, xtend(serverState, nsState))
+    serverState = serverState || {}
+    assert.equal(typeof route, 'string', 'choo.app.toString: route must be a string')
+    assert.equal(typeof serverState, 'object', 'choo.app.toString: serverState must be an object')
+    _store.start({ noSubscriptions: true, noReducers: true, noEffects: true })
+    const state = _store.state({ state: serverState })
     const tree = _router(route, state, function () {
-      throw new Error('send() cannot be called on the server')
+      assert.fail('choo: send() cannot be called from Node')
     })
-
     return tree.toString()
   }
 
   // start the application
   // (str?, obj?) -> DOMNode
-  function start (rootId, opts) {
-    if (!opts && typeof rootId !== 'string') {
-      opts = rootId
-      rootId = null
+  function start (selector, startOpts) {
+    if (!startOpts && typeof selector !== 'string') {
+      startOpts = selector
+      selector = null
     }
-    opts = opts || {}
-    const name = opts.name || 'choo'
-    const initialState = {}
-    const reducers = {}
-    const effects = {}
+    startOpts = startOpts || {}
 
-    _models.push(appInit(opts))
-    _models.forEach(function (model) {
-      if (model.state) apply(model.namespace, model.state, initialState)
-      if (model.reducers) apply(model.namespace, model.reducers, reducers)
-      if (model.effects) apply(model.namespace, model.effects, effects)
-    })
+    _store.model(appInit(startOpts))
+    const createSend = _store.start(startOpts)
+    const send = createSend('view', true)
+    const state = _store.state()
 
-    // send() is used to trigger actions inside
-    // views, effects and subscriptions
-    const send = sendAction({
-      onaction: handleAction,
-      onchange: onchange,
-      state: initialState
-    })
-
-    // subscriptions are loaded after sendAction() is called
-    // because they both need access to send() and can't
-    // react to actions (read-only) - also wait on DOM to
-    // be loaded
-    document.addEventListener('DOMContentLoaded', function () {
-      _models.forEach(function (model) {
-        if (model.subscriptions) {
-          assert.ok(Array.isArray(model.subscriptions), 'subs must be an arr')
-          model.subscriptions.forEach(function (sub) {
-            sub(send)
-          })
-        }
-      })
-    })
-
-    // If an id is provided, the application will rehydrate
-    // on the node. If no id is provided it will return
-    // a tree that's ready to be appended to the DOM.
-    //
-    // The rootId is determined to find the application root
-    // on update. Since the DOM nodes change between updates,
-    // we must call document.querySelector() to find the root.
-    // Use different names when loading multiple choo applications
-    // on the same page
-    if (rootId) {
-      document.addEventListener('DOMContentLoaded', function (event) {
-        rootId = rootId.replace(/^#/, '')
-
-        const oldTree = document.querySelector('#' + rootId)
-        assert.ok(oldTree, 'could not find node #' + rootId)
-
-        const newTree = _router(send.state().app.location, send.state(), send)
-
-        yo.update(oldTree, newTree)
-      })
-    } else {
-      rootId = name + '-root'
-      const tree = _router(send.state().app.location, send.state(), send)
-      tree.setAttribute('id', rootId)
+    if (!selector) {
+      const tree = _router(state.app.location, state, send)
+      _rootNode = tree
       return tree
+    } else {
+      document.addEventListener('DOMContentLoaded', function (event) {
+        const oldTree = document.querySelector(selector)
+        assert.ok(oldTree, 'could not query selector: ' + selector)
+        const newTree = _router(state.app.location, state, send)
+        _rootNode = yo.update(oldTree, newTree)
+      })
     }
+  }
 
-    // handle an action by either reducers, effects
-    // or both - return the new state when done
-    // (obj, obj, fn) -> obj
-    function handleAction (action, state, send) {
-      var reducersCalled = false
-      var effectsCalled = false
-      const newState = xtend(state)
+  // update the DOM after every state mutation
+  // (obj, obj, obj, str, fn) -> null
+  function render (action, state, prev, name, createSend) {
+    if (opts.onState) opts.onState(action, state, prev, name, createSend)
+    if (state === prev) return
 
-      // validate if a namespace exists. Namespaces
-      // are delimited by the first ':'. Perhaps
-      // we'll allow recursive namespaces in the
-      // future - who knows
-      if (/:/.test(action.type)) {
-        const arr = action.type.split(':')
-        var ns = arr.shift()
-        action.type = arr.join(':')
-      }
-
-      const _reducers = ns ? reducers[ns] : reducers
-      if (_reducers && _reducers[action.type]) {
-        if (ns) {
-          const reducedState = _reducers[action.type](action, state[ns])
-          if (!newState[ns]) newState[ns] = {}
-          mutate(newState[ns], xtend(state[ns], reducedState))
-        } else {
-          mutate(newState, reducers[action.type](action, state))
-        }
-        reducersCalled = true
-      }
-
-      const _effects = ns ? effects[ns] : effects
-      if (_effects && _effects[action.type]) {
-        if (ns) _effects[action.type](action, state[ns], send)
-        else _effects[action.type](action, state, send)
-        effectsCalled = true
-      }
-
-      if (!reducersCalled && !effectsCalled) {
-        throw new Error('Could not find action ' + action.type)
-      }
-
-      // allows (newState === oldState) checks
-      return (reducersCalled) ? newState : state
-    }
-
-    // update the DOM after every state mutation
-    // (obj, obj) -> null
-    function onchange (action, newState, oldState) {
-      if (newState === oldState) return
-      const oldTree = document.querySelector('#' + rootId)
-      assert.ok(oldTree, "Could not find DOM node '#" + rootId + "' to update")
-      const newTree = _router(newState.app.location, newState, send, oldState)
-      newTree.setAttribute('id', rootId)
-      yo.update(oldTree, newTree)
-    }
+    // note(yw): only here till sheet-router supports custom constructors
+    const send = createSend('view', true)
+    const newTree = _router(state.app.location, state, send, prev)
+    _rootNode = yo.update(_rootNode, newTree)
   }
 
   // register all routes on the router
@@ -187,68 +91,48 @@ function choo () {
   // create a new model
   // (str?, obj) -> null
   function model (model) {
-    _models.push(model)
+    _store.model(model)
   }
 }
 
 // initial application state model
 // obj -> obj
 function appInit (opts) {
-  const initialLocation = (opts.hash === true)
-    ? hashMatch(document.location.hash)
-    : document.location.href
-
-  const model = {
-    namespace: 'app',
-    state: { location: initialLocation },
-    subscriptions: [],
-    reducers: {
-      // handle href links
-      location: function setLocation (action, state) {
-        return {
-          location: action.location.replace(/#.*/, '')
-        }
-      }
+  const loc = document.location
+  const state = { location: (opts.hash) ? hashMatch(loc.hash) : loc.href }
+  const reducers = {
+    location: function setLocation (action, state) {
+      return { location: action.location.replace(/#.*/, '') }
     }
   }
-
   // if hash routing explicitly enabled, subscribe to it
+  const subs = {}
   if (opts.hash === true) {
     pushLocationSub(function (navigate) {
       hash(function (fragment) {
         navigate(hashMatch(fragment))
       })
-    })
-  // otherwise, subscribe to HTML5 history API
+    }, 'handleHash', subs)
   } else {
-    if (opts.history !== false) pushLocationSub(history)
-    // enable catching <a href=""></a> links
-    if (opts.href !== false) pushLocationSub(href)
+    if (opts.history !== false) pushLocationSub(history, 'setLocation', subs)
+    if (opts.href !== false) pushLocationSub(href, 'handleHref', subs)
   }
 
-  return model
+  return {
+    namespace: 'app',
+    subscriptions: subs,
+    reducers: reducers,
+    state: state
+  }
 
   // create a new subscription that modifies
   // 'app:location' and push it to be loaded
-  // fn -> null
-  function pushLocationSub (cb) {
-    model.subscriptions.push(function (send) {
-      cb(function (href) {
-        send('app:location', { location: href })
+  // (fn, obj) -> null
+  function pushLocationSub (cb, key, model) {
+    model[key] = function (send, done) {
+      cb(function navigate (href) {
+        send('app:location', { location: href }, done)
       })
-    })
+    }
   }
 }
-
-// compose an object conditionally
-// optionally contains a namespace
-// which is used to nest properties.
-// (str, obj, obj) -> null
-function apply (ns, source, target) {
-  Object.keys(source).forEach(function (key) {
-    if (ns) {
-      if (!target[ns]) target[ns] = {}
-      target[ns][key] = source[key]
-    } else target[key] = source[key]
-  })
-}
diff --git a/package.json b/package.json
index 98b920b..dbea8fa 100644
--- a/package.json
+++ b/package.json
@@ -24,9 +24,9 @@
   ],
   "license": "MIT",
   "dependencies": {
+    "barracks": "^7.0.3",
     "global": "^4.3.0",
     "hash-match": "^1.0.2",
-    "send-action": "^2.0.2",
     "sheet-router": "^3.1.0",
     "xhr": "^2.2.0",
     "xtend": "^4.0.1",
diff --git a/tests/server/index.js b/tests/server/index.js
index 29d8f7f..ac5417b 100644
--- a/tests/server/index.js
+++ b/tests/server/index.js
@@ -98,7 +98,7 @@ tape('should render on the server', function (t) {
       })
     ])
 
-    const msg = /send\(\) cannot be called on the server/
+    const msg = /send\(\) cannot be called/
     t.throws(app.toString.bind(null, '/', { message: 'nyan!' }), msg)
   })
 })