diff --git a/.circleci/config.yml b/.circleci/config.yml
index 04bea2dccc..188cde6d17 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -26,10 +26,10 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - dep-bundle-15-{{ checksum "package.json" }}
+            - dep-bundle-16-{{ checksum "package.json" }}
       - run: npm install
       - save_cache:
-          key: dep-bundle-15-{{ checksum "package.json" }}
+          key: dep-bundle-16-{{ checksum "package.json" }}
           paths:
             - ~/repo/node_modules
       - run: npm run lint && npm run test && npm run downloadsolc && npm run make-mock-compiler && npm run build
@@ -46,10 +46,10 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - dep-bundle-10-{{ checksum "package.json" }}
+            - dep-bundle-11-{{ checksum "package.json" }}
       - run: npm install
       - save_cache:
-          key: dep-bundle-10-{{ checksum "package.json" }}
+          key: dep-bundle-11-{{ checksum "package.json" }}
           paths:
             - ~/repo/node_modules
       - run: npm run build_debugger
diff --git a/src/app/files/compiler-metadata.js b/src/app/files/compiler-metadata.js
new file mode 100644
index 0000000000..8a29287e84
--- /dev/null
+++ b/src/app/files/compiler-metadata.js
@@ -0,0 +1,69 @@
+'use strict'
+
+class CompilerMetadata {
+  constructor (events, opts) {
+    var self = this
+    self._events = events
+    self._opts = opts
+  }
+
+  syncContractMetadata () {
+    var self = this
+    self._events.compiler.register('compilationFinished', (success, data, source) => {
+      if (success) {
+        var provider = self._opts.fileManager.currentFileProvider()
+        var path = self._opts.fileManager.currentPath()
+        if (provider && path) {
+          self._opts.compiler.visitContracts((contract) => {
+            var fileName = path + '/' + contract.name + '.json'
+            provider.get(fileName, (error, content) => {
+              if (!error) {
+                content = content || '{}'
+                var metadata
+                try {
+                  metadata = JSON.parse(content)
+                } catch (e) {
+                  console.log(e)
+                }
+                var linkReferences = metadata['linkReferences']
+                var autoDeployLib = metadata['autoDeployLib']
+                if (!linkReferences) linkReferences = {}
+                if (autoDeployLib === undefined) autoDeployLib = true
+                for (var libFile in contract.object.evm.bytecode.linkReferences) {
+                  if (!linkReferences[libFile]) linkReferences[libFile] = {}
+                  for (var lib in contract.object.evm.bytecode.linkReferences[libFile]) {
+                    if (!linkReferences[libFile][lib]) {
+                      linkReferences[libFile][lib] = '<address>'
+                    }
+                  }
+                }
+                metadata['linkReferences'] = linkReferences
+                metadata['autoDeployLib'] = autoDeployLib
+                provider.set(fileName, JSON.stringify(metadata, null, '\t'))
+              }
+            })
+          })
+        }
+      }
+    })
+  }
+
+  metadataOf (contractName, callback) {
+    var self = this
+    var provider = self._opts.fileManager.currentFileProvider()
+    var path = self._opts.fileManager.currentPath()
+    if (provider && path) {
+      var fileName = path + '/' + contractName + '.json'
+      provider.get(fileName, (error, content) => {
+        if (error) return callback(error)
+        try {
+          callback(null, JSON.parse(content))
+        } catch (e) {
+          callback(e.message)
+        }
+      })
+    }
+  }
+}
+
+module.exports = CompilerMetadata
diff --git a/src/app/files/fileManager.js b/src/app/files/fileManager.js
index fbaf2dc0d7..17e13486f4 100644
--- a/src/app/files/fileManager.js
+++ b/src/app/files/fileManager.js
@@ -71,6 +71,14 @@ class FileManager {
     this.refreshTabs()
   }
 
+  currentFileProvider () {
+    var path = this.currentPath()
+    if (path) {
+      return this.fileProviderOf(path)
+    }
+    return null
+  }
+
   currentPath () {
     var self = this
     var currentFile = self._deps.config.get('currentFile')
diff --git a/src/app/panels/file-panel.js b/src/app/panels/file-panel.js
index b30bfb86eb..e990d4a9db 100644
--- a/src/app/panels/file-panel.js
+++ b/src/app/panels/file-panel.js
@@ -2,6 +2,7 @@
 var async = require('async')
 var $ = require('jquery')
 var yo = require('yo-yo')
+var CompilerMetadata = require('../files/compiler-metadata')
 var remixLib = require('remix-lib')
 var Gists = require('gists')
 var EventManager = remixLib.EventManager
@@ -48,7 +49,8 @@ function filepanel (localRegistry) {
   self._deps = {
     fileProviders: self._components.registry.get('fileproviders').api,
     fileManager: self._components.registry.get('filemanager').api,
-    config: self._components.registry.get('config').api
+    config: self._components.registry.get('config').api,
+    compiler: self._components.registry.get('compiler').api
   }
   var fileExplorer = new FileExplorer(self._components.registry, self._deps.fileProviders['browser'])
   var fileSystemExplorer = new FileExplorer(self._components.registry, self._deps.fileProviders['localhost'])
@@ -57,6 +59,19 @@ function filepanel (localRegistry) {
   var gistExplorer = new FileExplorer(self._components.registry, self._deps.fileProviders['gist'])
   var configExplorer = new FileExplorer(self._components.registry, self._deps.fileProviders['config'])
 
+  // ----------------- editor panel ----------------------
+  self._compilerMetadata = new CompilerMetadata(
+    {
+      compiler: self._deps.compiler.event
+    },
+    {
+      fileManager: self._deps.fileManager,
+      compiler: self._deps.compiler
+    }
+  )
+  self._compilerMetadata.syncContractMetadata()
+
+  self.compilerMetadata = () => { return self._compilerMetadata }
   var dragbar = yo`<div onmousedown=${mousedown} class=${css.dragbar}></div>`
 
   function remixdDialog () {
diff --git a/src/app/tabs/compile-tab.js b/src/app/tabs/compile-tab.js
index 4de77bfd16..d128c99cc3 100644
--- a/src/app/tabs/compile-tab.js
+++ b/src/app/tabs/compile-tab.js
@@ -61,9 +61,9 @@ module.exports = class CompileTab {
       if (speed > self.data.maxTime) {
         const msg = `Last compilation took ${speed}ms. We suggest to turn off autocompilation.`
         self._view.warnCompilationSlow.setAttribute('title', msg)
-        self._view.warnCompilationSlow.style.display = 'inline-block'
+        self._view.warnCompilationSlow.style.visibility = 'visible'
       } else {
-        self._view.warnCompilationSlow.style.display = 'none'
+        self._view.warnCompilationSlow.style.visibility = 'hidden'
       }
     })
     self._deps.editor.event.register('contentChanged', function changedFile () {
@@ -75,7 +75,7 @@ module.exports = class CompileTab {
     self._deps.compiler.event.register('loadingCompiler', function start () {
       if (!self._view.compileIcon) return
       self._view.compileIcon.classList.add(`${css.spinningIcon}`)
-      self._view.warnCompilationSlow.style.display = 'none'
+      self._view.warnCompilationSlow.style.visibility = 'hidden'
       self._view.compileIcon.setAttribute('title', 'compiler is loading, please wait a few moments.')
     })
     self._deps.compiler.event.register('compilationStarted', function start () {
@@ -149,7 +149,7 @@ module.exports = class CompileTab {
   render () {
     const self = this
     if (self._view.el) return self._view.el
-    self._view.warnCompilationSlow = yo`<i title="Copy Address" style="display:none" class="${css.warnCompilationSlow} fa fa-exclamation-triangle" aria-hidden="true"></i>`
+    self._view.warnCompilationSlow = yo`<i title="Compilation Slow" style="visibility:hidden" class="${css.warnCompilationSlow} fa fa-exclamation-triangle" aria-hidden="true"></i>`
     self._view.compileIcon = yo`<i class="fa fa-refresh ${css.icon}" aria-hidden="true"></i>`
     self._view.compileButton = yo`<div class="${css.compileButton}" onclick=${compile} id="compile" title="Compile source code">${self._view.compileIcon} Start to compile</div>`
     self._view.autoCompile = yo`<input class="${css.autocompile}" onchange=${updateAutoCompile} id="autoCompile" type="checkbox" title="Auto compile">`
@@ -339,7 +339,10 @@ const css = csjs`
     margin-bottom: 2%;
   }
   .autocompileContainer {
-    width: 90px;
+    display: flex;
+    align-items: center;
+  }
+  .hideWarningsContainer {
     display: flex;
     align-items: center;
   }
diff --git a/src/app/tabs/run-tab.js b/src/app/tabs/run-tab.js
index 75589c0ff0..f14f144d33 100644
--- a/src/app/tabs/run-tab.js
+++ b/src/app/tabs/run-tab.js
@@ -72,7 +72,8 @@ function runTab (opts, localRegistry) {
     config: self._components.registry.get('config').api,
     fileManager: self._components.registry.get('filemanager').api,
     editor: self._components.registry.get('editor').api,
-    logCallback: self._components.registry.get('logCallback').api
+    logCallback: self._components.registry.get('logCallback').api,
+    filePanel: self._components.registry.get('filepanel').api
   }
   self._deps.udapp.resetAPI(self._components.transactionContextAPI)
   self._view.recorderCount = yo`<span>0</span>`
@@ -128,9 +129,9 @@ function runTab (opts, localRegistry) {
       status.appendChild(self._view.collapsedView)
     }
   })
-    /* -------------------------
-         MAIN HTML ELEMENT
-    --------------------------- */
+  /* -------------------------
+       MAIN HTML ELEMENT
+  --------------------------- */
   var el = yo`
   <div>
     ${settings(container, self)}
@@ -386,6 +387,31 @@ function contractDropdown (events, self) {
 
   selectContractNames.addEventListener('change', setInputParamsPlaceHolder)
 
+  function createInstanceCallback (error, selectedContract, data) {
+    if (error) return self._deps.logCallback(`creation of ${selectedContract.name} errored: ` + error)
+    self._deps.logCallback(`creation of ${selectedContract.name} pending...`)
+    self._deps.udapp.createContract(data, (error, txResult) => {
+      if (!error) {
+        var isVM = executionContext.isVM()
+        if (isVM) {
+          var vmError = txExecution.checkVMError(txResult)
+          if (vmError.error) {
+            self._deps.logCallback(vmError.message)
+            return
+          }
+        }
+        if (txResult.result.status && txResult.result.status === '0x0') {
+          self._deps.logCallback(`creation of ${selectedContract.name} errored: transaction execution failed`)
+          return
+        }
+        var noInstancesText = self._view.noInstancesText
+        if (noInstancesText.parentNode) { noInstancesText.parentNode.removeChild(noInstancesText) }
+        var address = isVM ? txResult.result.createdAddress : txResult.result.contractAddress
+        instanceContainer.appendChild(self._deps.udappUI.renderInstance(selectedContract.contract.object, address, selectContractNames.value))
+      }
+    })
+  }
+
   // DEPLOY INSTANCE
   function createInstance (args) {
     var selectedContract = getSelectedContract()
@@ -396,39 +422,22 @@ function contractDropdown (events, self) {
     }
 
     var constructor = txHelper.getConstructorInterface(selectedContract.contract.object.abi)
-    txFormat.buildData(selectedContract.name, selectedContract.contract.object, self._deps.compiler.getContracts(), true, constructor, args, (error, data) => {
-      if (!error) {
-        self._deps.logCallback(`creation of ${selectedContract.name} pending...`)
-        self._deps.udapp.createContract(data, (error, txResult) => {
-          if (error) {
-            self._deps.logCallback(`creation of ${selectedContract.name} errored: ` + error)
-          } else {
-            var isVM = executionContext.isVM()
-            if (isVM) {
-              var vmError = txExecution.checkVMError(txResult)
-              if (vmError.error) {
-                self._deps.logCallback(vmError.message)
-                return
-              }
-            }
-            if (txResult.result.status && txResult.result.status === '0x0') {
-              self._deps.logCallback(`creation of ${selectedContract.name} errored: transaction execution failed`)
-              return
-            }
-            var noInstancesText = self._view.noInstancesText
-            if (noInstancesText.parentNode) { noInstancesText.parentNode.removeChild(noInstancesText) }
-            var address = isVM ? txResult.result.createdAddress : txResult.result.contractAddress
-            instanceContainer.appendChild(self._deps.udappUI.renderInstance(selectedContract.contract.object, address, selectContractNames.value))
-          }
+    self._deps.filePanel.compilerMetadata().metadataOf(selectedContract.name, (error, contractMetadata) => {
+      if (error) return self._deps.logCallback(`creation of ${selectedContract.name} errored: ` + error)
+      if (contractMetadata.autoDeployLib) {
+        txFormat.buildData(selectedContract.name, selectedContract.contract.object, self._deps.compiler.getContracts(), true, constructor, args, (error, data) => {
+          createInstanceCallback(error, selectedContract, data)
+        }, (msg) => {
+          self._deps.logCallback(msg)
+        }, (data, runTxCallback) => {
+          // called for libraries deployment
+          self._deps.udapp.runTx(data, runTxCallback)
         })
       } else {
-        self._deps.logCallback(`creation of ${selectedContract.name} errored: ` + error)
+        txFormat.encodeConstructorCallAndLinkLibraries(selectedContract.contract.object, args, constructor, contractMetadata.linkReferences, selectedContract.contract.object.evm.bytecode.linkReferences, (error, data) => {
+          createInstanceCallback(error, selectedContract, data)
+        })
       }
-    }, (msg) => {
-      self._deps.logCallback(msg)
-    }, (data, runTxCallback) => {
-      // called for libraries deployment
-      self._deps.udapp.runTx(data, runTxCallback)
     })
   }