diff --git a/src/components/App.jsx b/src/components/App.jsx
index 29d5305..e3ddf0d 100644
--- a/src/components/App.jsx
+++ b/src/components/App.jsx
@@ -10,6 +10,7 @@ import Toolbar from './Toolbar'
 import AppLayout from './AppLayout'
 import MessagePanel from './MessagePanel'
 
+import { downloadGlyphsMetadata, downloadSpriteMetadata } from '../libs/metadata'
 import GlSpec from 'mapbox-gl-style-spec/reference/latest.js'
 import validateStyleMin from 'mapbox-gl-style-spec/lib/validate_style.min'
 import formatStyle from 'mapbox-gl-style-spec/lib/format'
@@ -21,6 +22,18 @@ import { ApiStyleStore } from '../libs/apistore'
 import { RevisionStore } from '../libs/revisions'
 import LayerWatcher from '../libs/layerwatcher'
 
+function updateRootSpec(spec, fieldName, newValues) {
+  return {
+    ...spec,
+    $root: {
+      ...spec.$root,
+      [fieldName]: {
+        ...spec.$root[fieldName],
+        values: newValues
+      }
+    }
+  }
+}
 
 export default class App extends React.Component {
   constructor(props) {
@@ -52,6 +65,7 @@ export default class App extends React.Component {
       sources: {},
       vectorLayers: {},
       inspectModeEnabled: false,
+      spec: GlSpec,
     }
 
     this.layerWatcher = new LayerWatcher({
@@ -85,7 +99,26 @@ export default class App extends React.Component {
     this.styleStore.save(snapshotStyle)
   }
 
+  updateFonts(urlTemplate) {
+    downloadGlyphsMetadata(urlTemplate, fonts => {
+      this.setState({ spec: updateRootSpec(this.state.spec, 'glyphs', fonts)})
+    })
+  }
+
+  updateIcons(baseUrl) {
+    downloadSpriteMetadata(baseUrl, icons => {
+      this.setState({ spec: updateRootSpec(this.state.spec, 'sprite', icons)})
+    })
+  }
+
   onStyleChanged(newStyle, save=true) {
+    if(newStyle.glyphs !== this.state.mapStyle.glyphs) {
+      this.updateFonts(newStyle.glyphs)
+    }
+    if(newStyle.sprite !== this.state.mapStyle.sprite) {
+      this.updateIcons(newStyle.sprite)
+    }
+
     const errors = validateStyleMin(newStyle, GlSpec)
     if(errors.length === 0) {
       this.revisionStore.addRevision(newStyle)
@@ -212,6 +245,7 @@ export default class App extends React.Component {
       layer={selectedLayer}
       sources={this.state.sources}
       vectorLayers={this.state.vectorLayers}
+      spec={this.state.spec}
       onLayerChanged={this.onLayerChanged.bind(this)}
       onLayerIdChange={this.onLayerIdChange.bind(this)}
     /> : null
diff --git a/src/components/fields/PropertyGroup.jsx b/src/components/fields/PropertyGroup.jsx
index 2a074b9..90b7b33 100644
--- a/src/components/fields/PropertyGroup.jsx
+++ b/src/components/fields/PropertyGroup.jsx
@@ -1,20 +1,34 @@
 import React from 'react'
-import GlSpec from 'mapbox-gl-style-spec/reference/latest.js'
 
 import ZoomSpecField from './ZoomSpecField'
 import colors from '../../config/colors'
 import { margins } from '../../config/scales'
 
+const iconProperties = ['background-pattern', 'fill-pattern', 'line-pattern', 'fill-extrusion-pattern', 'icon-image']
+
 /** Extract field spec by {@fieldName} from the {@layerType} in the
  * style specification from either the paint or layout group */
-function getFieldSpec(layerType, fieldName) {
-  const groupName = getGroupName(layerType, fieldName)
-  const group = GlSpec[groupName + '_' + layerType]
-  return group[fieldName]
+function getFieldSpec(spec, layerType, fieldName) {
+  const groupName = getGroupName(spec, layerType, fieldName)
+  const group = spec[groupName + '_' + layerType]
+  const fieldSpec = group[fieldName]
+  if(iconProperties.indexOf(fieldName) >= 0) {
+    return {
+      ...fieldSpec,
+      values: spec.$root.sprite.values
+    }
+  }
+  if(fieldName === 'text-font') {
+    return {
+      ...fieldSpec,
+      values: spec.$root.glyphs.values
+    }
+  }
+  return fieldSpec
 }
 
-function getGroupName(layerType, fieldName) {
-  const paint  = GlSpec['paint_' + layerType] || {}
+function getGroupName(spec, layerType, fieldName) {
+  const paint  = spec['paint_' + layerType] || {}
   if (fieldName in paint) {
     return 'paint'
   } else {
@@ -27,16 +41,17 @@ export default class PropertyGroup extends React.Component {
     layer: React.PropTypes.object.isRequired,
     groupFields: React.PropTypes.array.isRequired,
     onChange: React.PropTypes.func.isRequired,
+    spec: React.PropTypes.object.isRequired,
   }
 
   onPropertyChange(property, newValue) {
-    const group = getGroupName(this.props.layer.type, property)
+    const group = getGroupName(this.props.spec, this.props.layer.type, property)
     this.props.onChange(group , property, newValue)
   }
 
   render() {
     const fields = this.props.groupFields.map(fieldName => {
-      const fieldSpec = getFieldSpec(this.props.layer.type, fieldName)
+      const fieldSpec = getFieldSpec(this.props.spec, this.props.layer.type, fieldName)
 
       const paint = this.props.layer.paint || {}
       const layout = this.props.layer.layout || {}
diff --git a/src/components/fields/SpecField.jsx b/src/components/fields/SpecField.jsx
index 47e1c70..f51d43f 100644
--- a/src/components/fields/SpecField.jsx
+++ b/src/components/fields/SpecField.jsx
@@ -1,7 +1,6 @@
 import React from 'react'
 import color from 'color'
 
-import GlSpec from 'mapbox-gl-style-spec/reference/latest.min.js'
 import ColorField from './ColorField'
 import NumberInput from '../inputs/NumberInput'
 import CheckboxInput from '../inputs/CheckboxInput'
@@ -10,8 +9,10 @@ import SelectInput from '../inputs/SelectInput'
 import MultiButtonInput from '../inputs/MultiButtonInput'
 import ArrayInput from '../inputs/ArrayInput'
 import FontInput from '../inputs/FontInput'
+import IconInput from '../inputs/IconInput'
 import capitalize from 'lodash.capitalize'
 
+const iconProperties = ['background-pattern', 'fill-pattern', 'line-pattern', 'fill-extrusion-pattern', 'icon-image']
 
 import input from '../../config/input.js'
 
@@ -78,11 +79,17 @@ export default class SpecField extends React.Component {
             options={options}
           />
         }
-      case 'string': return (
-        <StringInput
-          {...commonProps}
-        />
-      )
+      case 'string':
+        if(iconProperties.indexOf(this.props.fieldName) >= 0) {
+          return <IconInput
+            {...commonProps}
+            icons={this.props.fieldSpec.values}
+          />
+        } else {
+          return <StringInput
+            {...commonProps}
+          />
+        }
       case 'color': return (
         <ColorField
           {...commonProps}
@@ -97,6 +104,7 @@ export default class SpecField extends React.Component {
         if(this.props.fieldName === 'text-font') {
           return <FontInput
             {...commonProps}
+            fonts={this.props.fieldSpec.values}
           />
         } else {
           return <ArrayInput
diff --git a/src/components/inputs/FontInput.jsx b/src/components/inputs/FontInput.jsx
index 573f4f9..2f8c311 100644
--- a/src/components/inputs/FontInput.jsx
+++ b/src/components/inputs/FontInput.jsx
@@ -9,10 +9,15 @@ import fontStacks from '../../config/fontstacks.json'
 class FontInput extends React.Component {
   static propTypes = {
     value: React.PropTypes.array.isRequired,
+    fonts: React.PropTypes.array,
     style: React.PropTypes.object,
     onChange: React.PropTypes.func.isRequired,
   }
 
+  static defaultProps = {
+    fonts: []
+  }
+
   get values() {
    return this.props.value || this.props.default.slice(1) || []
   }
@@ -28,7 +33,7 @@ class FontInput extends React.Component {
       return <AutocompleteInput
         key={i}
         value={value}
-        options={fontStacks.map(f => [f, f])}
+        options={this.props.fonts.map(f => [f, f])}
         onChange={this.changeFont.bind(this, i)}
         wrapperStyle={{
           display: 'block',
diff --git a/src/components/layers/LayerEditor.jsx b/src/components/layers/LayerEditor.jsx
index 1897c02..138ef06 100644
--- a/src/components/layers/LayerEditor.jsx
+++ b/src/components/layers/LayerEditor.jsx
@@ -1,6 +1,5 @@
 import React from 'react'
 
-import GlSpec from 'mapbox-gl-style-spec/reference/latest.js'
 import JSONEditor from './JSONEditor'
 import FilterEditor from '../filter/FilterEditor'
 import PropertyGroup from '../fields/PropertyGroup'
@@ -47,6 +46,7 @@ export default class LayerEditor extends React.Component {
     layer: React.PropTypes.object.isRequired,
     sources: React.PropTypes.object,
     vectorLayers: React.PropTypes.object,
+    spec: React.PropTypes.object.isRequired,
     onLayerChanged: React.PropTypes.func,
     onLayerIdChange: React.PropTypes.func,
   }
@@ -146,6 +146,7 @@ export default class LayerEditor extends React.Component {
       case 'properties': return <PropertyGroup
         layer={this.props.layer}
         groupFields={fields}
+        spec={this.props.spec}
         onChange={this.changeProperty.bind(this)}
       />
       case 'jsoneditor': return <JSONEditor