diff --git a/README.md b/README.md
index a46b9a6..5f99be2 100644
--- a/README.md
+++ b/README.md
@@ -12,54 +12,12 @@ The endpoint MUST return a reference to a single image.
 
 ---
 
-Mapbox Styles require the properties [`sources`](https://docs.mapbox.com/mapbox-gl-js/style-spec/#root-sources) (root property) and [`source`](https://docs.mapbox.com/mapbox-gl-js/style-spec/#layer-source) (layers property). geostyler-mapbox-parser only parses style related properties to keep a clear separation between style and data. Thus, `sources` and `source` have to be added to the created styleobject after parsing, manually. See code snippet below for an example implementation of a wrapper function.
-
-```javascript
-/**
- * Example wrapper function that maps a source to the corresponding
- * layer based on layer id. Expects a mapper object with key value
- * pairs in the format of "layerId:'sourceName'".
-**/
-function wrapper(sources, mapper, style) {
-  if (typeof style === 'undefined') {
-    return;
-  }
-  if (typeof mapper === 'undefined') {
-    return style;
-  }
-  if (typeof sources === 'undefined') {
-    return style;
-  }
-
-  style.sources = sources;
-  style.layers.forEach(l => {
-    l.source = mapper[l.id];
-  });
-  return style;
-}
-
-// required mapper object where the key refers to the layer id
-// and the value to the source name.
-var mapper = {
-  "water": "mapbox-streets"
-};
-
-// mapbox sources object
-var sources = {
-  "mapbox-streets": {
-    "type": "vector",
-    "url": "mapbox://mapbox.mapbox-streets-v6"
-  }
-};
-
-// mapbox style object
-var mbStyle = {
-  version: 8,
-  layers: [...]
-};
-
-var wrappedStyle = wrapper(sources, mapper, style);
-```
+Mapbox styles require the properties [`sources`](https://docs.mapbox.com/mapbox-gl-js/style-spec/#root-sources) (root property)
+and [`source`](https://docs.mapbox.com/mapbox-gl-js/style-spec/#layer-source) (layers property).
+In order to keep a clear separation between style and data, geostyler-mapbox-parser puts the source-related attributes into the metadata block of
+a geostyler-style under `mapbox:ref`. There, the original sources object, as well as the mappings between layers and sources will be stored
+(properties `sources`, `sourceMapping` and `layerSourceMapping`). Applications can then use these mappings for re-creating the same layer structure
+using their map library of choice (e.g. OpenLayers, etc.).
 
 ### How to use
 
diff --git a/data/mapbox/circle_simplecircle.ts b/data/mapbox/circle_simplecircle.ts
index 3370bb5..55e8c03 100644
--- a/data/mapbox/circle_simplecircle.ts
+++ b/data/mapbox/circle_simplecircle.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const circleSimpleCircle: Omit<MbStyle, 'sources'> = {
+const circleSimpleCircle: MbStyle = {
   version: 8,
   name: 'Simple Circle',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Simple Circle',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': '#000000',
diff --git a/data/mapbox/expression_case.ts b/data/mapbox/expression_case.ts
index a35bf26..b839d97 100644
--- a/data/mapbox/expression_case.ts
+++ b/data/mapbox/expression_case.ts
@@ -1,13 +1,20 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const expression_case: Omit<MbStyle, 'sources'> = {
+const expression_case: MbStyle = {
   version: 8,
   name: 'Expression Case',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'earthquake_circle',
       type: 'circle',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'circle-color': [
           'case',
diff --git a/data/mapbox/expression_get.ts b/data/mapbox/expression_get.ts
index 8373c92..8d1dcf0 100644
--- a/data/mapbox/expression_get.ts
+++ b/data/mapbox/expression_get.ts
@@ -1,12 +1,19 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const expression_get: Omit<MbStyle, 'sources'> = {
+const expression_get: MbStyle = {
   version: 8,
   name: 'Expression Get',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Expression Get',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': '#000000',
diff --git a/data/mapbox/fill_patternfill.ts b/data/mapbox/fill_patternfill.ts
index 807c05a..9dd9bef 100644
--- a/data/mapbox/fill_patternfill.ts
+++ b/data/mapbox/fill_patternfill.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const fillSimpleFill: Omit<MbStyle, 'sources'> = {
+const fillSimpleFill: MbStyle = {
   version: 8,
   name: 'Pattern Fill',
   sprite: 'https://testurl.com',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Pattern Fill',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'fill',
       paint: {
         'fill-color': '#000000',
diff --git a/data/mapbox/fill_simple_outline.ts b/data/mapbox/fill_simple_outline.ts
index e2818f7..b44c1c0 100644
--- a/data/mapbox/fill_simple_outline.ts
+++ b/data/mapbox/fill_simple_outline.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const fillSimpleFillOutline: Omit<MbStyle, 'sources'> = {
+const fillSimpleFillOutline: MbStyle = {
   version: 8,
   name: 'Simple Fill With outline',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [{
     id: 'r0_sy0_st0',
     type: 'fill',
+    source: 'testsource',
+    'source-layer': 'foo',
     paint: {
       'fill-color': '#ff0000'
     }
@@ -13,6 +20,8 @@ const fillSimpleFillOutline: Omit<MbStyle, 'sources'> = {
   {
     id: 'r0_sy0_st1',
     type: 'line',
+    source: 'testsource',
+    'source-layer': 'foo',
     paint: {
       'line-opacity': 0.5,
       'line-color': '#00ff00',
diff --git a/data/mapbox/fill_simplefill.ts b/data/mapbox/fill_simplefill.ts
index 6f7a2e0..1fc0af8 100644
--- a/data/mapbox/fill_simplefill.ts
+++ b/data/mapbox/fill_simplefill.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const fillSimpleFill: Omit<MbStyle, 'sources'> = {
+const fillSimpleFill: MbStyle = {
   version: 8,
   name: 'Simple Fill',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Simple Fill',
       type: 'fill',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'fill-color': '#000000',
         'fill-opacity': 1
diff --git a/data/mapbox/icon_simpleicon.ts b/data/mapbox/icon_simpleicon.ts
index 6d9759d..41463ca 100644
--- a/data/mapbox/icon_simpleicon.ts
+++ b/data/mapbox/icon_simpleicon.ts
@@ -1,13 +1,20 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const iconSimpleIcon: Omit<MbStyle, 'sources'> = {
+const iconSimpleIcon: MbStyle = {
   version: 8,
   name: 'Simple Icon',
   sprite: 'https://testurl.com',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Simple Icon',
       type: 'symbol',
+      source: 'testsource',
+      'source-layer': 'foo',
       layout: {
         'icon-image': 'poi'
       }
diff --git a/data/mapbox/icon_simpleicon_mapboxapi.ts b/data/mapbox/icon_simpleicon_mapboxapi.ts
index d1e8f0c..967ae5b 100644
--- a/data/mapbox/icon_simpleicon_mapboxapi.ts
+++ b/data/mapbox/icon_simpleicon_mapboxapi.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const iconSimpleIcon: Omit<MbStyle, 'sources'> = {
+const iconSimpleIcon: MbStyle = {
   version: 8,
   name: 'Simple Icon',
   sprite: 'mapbox://sprites/mapbox/streets-v8',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Simple Icon',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'icon-image': 'poi'
diff --git a/data/mapbox/icontext_symbolizer.ts b/data/mapbox/icontext_symbolizer.ts
index 4ff3423..539ec73 100644
--- a/data/mapbox/icontext_symbolizer.ts
+++ b/data/mapbox/icontext_symbolizer.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const iconTextSymbolizer: Omit<MbStyle, 'sources'> = {
+const iconTextSymbolizer: MbStyle = {
   version: 8,
   name: 'icontext symbolizer',
   sprite: 'https://testurl.com',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       type: 'symbol',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'text-color': 'rgba(45, 45, 45, 1)',
       },
diff --git a/data/mapbox/line_patternline.ts b/data/mapbox/line_patternline.ts
index a193b81..65ecc69 100644
--- a/data/mapbox/line_patternline.ts
+++ b/data/mapbox/line_patternline.ts
@@ -1,13 +1,20 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const linePatternLine: Omit<MbStyle, 'sources'> = {
+const linePatternLine: MbStyle = {
   version: 8,
   name: 'Pattern Line',
   sprite: 'https://testurl.com',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Pattern Line',
       type: 'line',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'line-color': '#000000',
         'line-width': 3,
diff --git a/data/mapbox/line_simpleline.ts b/data/mapbox/line_simpleline.ts
index 29c6d7b..4f89b58 100644
--- a/data/mapbox/line_simpleline.ts
+++ b/data/mapbox/line_simpleline.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const lineSimpleLine: Omit<MbStyle, 'sources'> = {
+const lineSimpleLine: MbStyle = {
   version: 8,
   name: 'Simple Line',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Simple Line',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'line',
       paint: {
         'line-color': '#000000',
diff --git a/data/mapbox/line_simpleline_basefilter.ts b/data/mapbox/line_simpleline_basefilter.ts
index 69f9c64..f3f3eef 100644
--- a/data/mapbox/line_simpleline_basefilter.ts
+++ b/data/mapbox/line_simpleline_basefilter.ts
@@ -1,10 +1,17 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const lineSimpleLine: Omit<MbStyle, 'sources'> = {
+const lineSimpleLine: MbStyle = {
   version: 8,
   name: 'Small populated New Yorks',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [{
     id: 'Small populated New Yorks',
+    source: 'testsource',
+    'source-layer': 'foo',
     type: 'line',
     filter: ['all',
       ['==', 'NAME', 'New York'],
diff --git a/data/mapbox/line_simpleline_expression.ts b/data/mapbox/line_simpleline_expression.ts
index 9717aad..8393719 100644
--- a/data/mapbox/line_simpleline_expression.ts
+++ b/data/mapbox/line_simpleline_expression.ts
@@ -1,10 +1,17 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const lineSimpleLine: Omit<MbStyle, 'sources'> = {
+const lineSimpleLine: MbStyle = {
   version: 8,
   name: 'Simple Line Filter',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [{
     id: 'Small populated New Yorks',
+    source: 'testsource',
+    'source-layer': 'foo',
     type: 'line',
     paint: {
       'line-color': '#FF0000',
diff --git a/data/mapbox/line_simpleline_zoom.ts b/data/mapbox/line_simpleline_zoom.ts
index 8d42289..45a63e3 100644
--- a/data/mapbox/line_simpleline_zoom.ts
+++ b/data/mapbox/line_simpleline_zoom.ts
@@ -1,10 +1,17 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const lineSimpleLine: Omit<MbStyle, 'sources'> = {
+const lineSimpleLine: MbStyle = {
   version: 8,
   name: 'Simple Line Filter',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [{
     id: 'Small populated New Yorks',
+    source: 'testsource',
+    'source-layer': 'foo',
     type: 'line',
     minzoom: 5.5,
     maxzoom: 10,
diff --git a/data/mapbox/multi_rule_line_fill.ts b/data/mapbox/multi_rule_line_fill.ts
index dbfd1a1..cd86b28 100644
--- a/data/mapbox/multi_rule_line_fill.ts
+++ b/data/mapbox/multi_rule_line_fill.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const multiRuleLineFill: Omit<MbStyle, 'sources'> = {
+const multiRuleLineFill: MbStyle = {
   version: 8,
   name: 'Rule Line Fill',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Line Rule',
       type: 'line',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'line-color': '#000000',
         'line-width': 3,
@@ -19,6 +26,8 @@ const multiRuleLineFill: Omit<MbStyle, 'sources'> = {
     }, {
       id: 'Fill Rule',
       type: 'fill',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'fill-color': '#000000',
         'fill-opacity': 1
diff --git a/data/mapbox/multi_simpleline_simplefill.ts b/data/mapbox/multi_simpleline_simplefill.ts
index 5da5a90..d489bc3 100644
--- a/data/mapbox/multi_simpleline_simplefill.ts
+++ b/data/mapbox/multi_simpleline_simplefill.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const multiSimpleLineSimpleFill: Omit<MbStyle, 'sources'> = {
+const multiSimpleLineSimpleFill: MbStyle = {
   version: 8,
   name: 'Simple Line Simple Fill',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Simple Line Simple Fill',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'line',
       paint: {
         'line-color': '#000000',
@@ -18,6 +25,8 @@ const multiSimpleLineSimpleFill: Omit<MbStyle, 'sources'> = {
       }
     }, {
       id: 'Simple Line Simple Fill',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'fill',
       paint: {
         'fill-color': '#000000',
diff --git a/data/mapbox/point_placeholderText.ts b/data/mapbox/point_placeholderText.ts
index e59f9d7..e8e0f4b 100644
--- a/data/mapbox/point_placeholderText.ts
+++ b/data/mapbox/point_placeholderText.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const pointPlaceholderText: Omit<MbStyle, 'sources'> = {
+const pointPlaceholderText: MbStyle = {
   version: 8,
   name: 'Placeholder Text',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Placeholder Text',
       type: 'symbol',
+      source: 'testsource',
+      'source-layer': 'foo',
       layout: {
         'text-field': ['format',
           'Area: ', {},
diff --git a/data/mapbox/point_placeholderText_simple.ts b/data/mapbox/point_placeholderText_simple.ts
index fdbc21a..d5345ce 100644
--- a/data/mapbox/point_placeholderText_simple.ts
+++ b/data/mapbox/point_placeholderText_simple.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const pointPlaceholderText: Omit<MbStyle, 'sources'> = {
+const pointPlaceholderText: MbStyle = {
   version: 8,
   name: 'Placeholder Text',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Placeholder Text',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'text-field': '{River}'
diff --git a/data/mapbox/point_simpletext.ts b/data/mapbox/point_simpletext.ts
index 7aff41e..b22a277 100644
--- a/data/mapbox/point_simpletext.ts
+++ b/data/mapbox/point_simpletext.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const pointSimpleText: Omit<MbStyle, 'sources'> = {
+const pointSimpleText: MbStyle = {
   version: 8,
   name: 'Simple Text',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'Simple Text',
       type: 'symbol',
+      source: 'testsource',
+      'source-layer': 'foo',
       layout: {
         'text-field': 'River'
       },
diff --git a/data/mapbox/source_layer_mapping.ts b/data/mapbox/source_layer_mapping.ts
new file mode 100644
index 0000000..9989d3c
--- /dev/null
+++ b/data/mapbox/source_layer_mapping.ts
@@ -0,0 +1,43 @@
+import { MbStyle } from '../../src/MapboxStyleParser';
+
+const sourceLayerMapping: MbStyle = {
+  version: 8,
+  name: 'SourceLayerMapping',
+  sources: {
+    first: {
+      type: 'vector'
+    }
+  },
+  layers: [
+    {
+      id: 'Simple Circle 1',
+      source: 'first',
+      'source-layer': 'foo',
+      type: 'circle',
+      paint: {
+        'circle-color': '#000000',
+        'circle-radius': 5,
+        'circle-opacity': 1,
+        'circle-stroke-width': 2,
+        'circle-stroke-color': '#FF0000',
+        'circle-stroke-opacity': 0.5
+      }
+    },
+    {
+      id: 'Simple Circle 2',
+      source: 'first',
+      'source-layer': 'bar',
+      type: 'circle',
+      paint: {
+        'circle-color': '#000000',
+        'circle-radius': 5,
+        'circle-opacity': 1,
+        'circle-stroke-width': 2,
+        'circle-stroke-color': '#FF0000',
+        'circle-stroke-opacity': 0.5
+      }
+    }
+  ]
+};
+
+export default sourceLayerMapping;
diff --git a/data/mapbox/source_mapping.ts b/data/mapbox/source_mapping.ts
new file mode 100644
index 0000000..0beacc4
--- /dev/null
+++ b/data/mapbox/source_mapping.ts
@@ -0,0 +1,46 @@
+import { MbStyle } from '../../src/MapboxStyleParser';
+
+const sourceMapping: MbStyle = {
+  version: 8,
+  name: 'SourceMapping',
+  sources: {
+    first: {
+      type: 'vector'
+    },
+    second: {
+      type: 'vector'
+    }
+  },
+  layers: [
+    {
+      id: 'Simple Circle 1',
+      source: 'first',
+      'source-layer': 'foo',
+      type: 'circle',
+      paint: {
+        'circle-color': '#000000',
+        'circle-radius': 5,
+        'circle-opacity': 1,
+        'circle-stroke-width': 2,
+        'circle-stroke-color': '#FF0000',
+        'circle-stroke-opacity': 0.5
+      }
+    },
+    {
+      id: 'Simple Circle 2',
+      source: 'second',
+      'source-layer': 'foo',
+      type: 'circle',
+      paint: {
+        'circle-color': '#000000',
+        'circle-radius': 5,
+        'circle-opacity': 1,
+        'circle-stroke-width': 2,
+        'circle-stroke-color': '#FF0000',
+        'circle-stroke-opacity': 0.5
+      }
+    }
+  ]
+};
+
+export default sourceMapping;
diff --git a/data/mapbox_metadata/circle_simplecircle.ts b/data/mapbox_metadata/circle_simplecircle.ts
index e84ce33..4978304 100644
--- a/data/mapbox_metadata/circle_simplecircle.ts
+++ b/data/mapbox_metadata/circle_simplecircle.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const circleSimpleCircle: Omit<MbStyle, 'sources'> = {
+const circleSimpleCircle: MbStyle = {
   version: 8,
   name: 'Simple Circle',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': '#000000',
diff --git a/data/mapbox_metadata/expression_case.ts b/data/mapbox_metadata/expression_case.ts
index de9c076..eab7ddb 100644
--- a/data/mapbox_metadata/expression_case.ts
+++ b/data/mapbox_metadata/expression_case.ts
@@ -1,12 +1,19 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const expression_case: Omit<MbStyle, 'sources'> = {
+const expression_case: MbStyle = {
   version: 8,
   name: 'Expression Case',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
diff --git a/data/mapbox_metadata/expression_decisions.ts b/data/mapbox_metadata/expression_decisions.ts
index 94389ed..80a9543 100644
--- a/data/mapbox_metadata/expression_decisions.ts
+++ b/data/mapbox_metadata/expression_decisions.ts
@@ -1,12 +1,19 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const expression_decisions: Omit<MbStyle, 'sources'> = {
+const expression_decisions: MbStyle = {
   version: 8,
   name: 'Expression Decisions',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
@@ -19,6 +26,8 @@ const expression_decisions: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r1_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
@@ -31,6 +40,8 @@ const expression_decisions: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r2_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
@@ -43,6 +54,8 @@ const expression_decisions: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r3_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
@@ -55,6 +68,8 @@ const expression_decisions: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r4_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
@@ -67,6 +82,8 @@ const expression_decisions: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r5_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
@@ -79,6 +96,8 @@ const expression_decisions: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r6_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
@@ -91,6 +110,8 @@ const expression_decisions: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r7_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
@@ -106,6 +127,8 @@ const expression_decisions: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r8_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': [
diff --git a/data/mapbox_metadata/expression_get.ts b/data/mapbox_metadata/expression_get.ts
index c026638..837b441 100644
--- a/data/mapbox_metadata/expression_get.ts
+++ b/data/mapbox_metadata/expression_get.ts
@@ -1,12 +1,19 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const expression_get: Omit<MbStyle, 'sources'> = {
+const expression_get: MbStyle = {
   version: 8,
   name: 'Expression Get',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-color': '#000000',
diff --git a/data/mapbox_metadata/expression_lookup.ts b/data/mapbox_metadata/expression_lookup.ts
index a7dc1ea..516c592 100644
--- a/data/mapbox_metadata/expression_lookup.ts
+++ b/data/mapbox_metadata/expression_lookup.ts
@@ -1,12 +1,19 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const expression_lookup: Omit<MbStyle, 'sources'> = {
+const expression_lookup: MbStyle = {
   version: 8,
   name: 'Expression Lookup',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['length', 'peter']
@@ -14,6 +21,8 @@ const expression_lookup: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r1_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'text-field': ['slice', 'peter', 0, 2]
diff --git a/data/mapbox_metadata/expression_math.ts b/data/mapbox_metadata/expression_math.ts
index 506a634..b009295 100644
--- a/data/mapbox_metadata/expression_math.ts
+++ b/data/mapbox_metadata/expression_math.ts
@@ -1,12 +1,19 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const expression_math: Omit<MbStyle, 'sources'> = {
+const expression_math: MbStyle = {
   version: 8,
   name: 'Expression Math',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['+', 13, 3, 7]
@@ -14,6 +21,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r1_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['abs', -12]
@@ -21,6 +30,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r2_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['acos', 4]
@@ -28,6 +39,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r3_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['asin', 4]
@@ -35,6 +48,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r4_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['atan', 4]
@@ -42,6 +57,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r5_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['ceil', 3.4]
@@ -49,6 +66,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r6_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['cos', 3.4]
@@ -56,6 +75,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r7_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['/', 100, 2]
@@ -63,6 +84,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r8_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['e']
@@ -70,6 +93,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r9_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['floor', 3.5]
@@ -77,6 +102,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r10_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['ln', 4.6]
@@ -84,6 +111,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r11_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['max', 13, 37, 0, 8, 15]
@@ -91,6 +120,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r12_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['min', 13, 37, 0, 8, 15]
@@ -98,6 +129,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r13_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['%', 3, 2]
@@ -105,6 +138,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r14_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['*', 2, 2.5, 10]
@@ -112,6 +147,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r15_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['pi']
@@ -119,6 +156,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r16_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['^', 2, 4]
@@ -126,6 +165,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r17_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['round', 13.37]
@@ -133,6 +174,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r18_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['sin', 1]
@@ -140,6 +183,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r19_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['sqrt', 1]
@@ -147,6 +192,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r20_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['-', 5, 6]
@@ -154,6 +201,8 @@ const expression_math: Omit<MbStyle, 'sources'> = {
     },
     {
       id: 'r21_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'circle',
       paint: {
         'circle-radius': ['tan', 1]
diff --git a/data/mapbox_metadata/expression_string.ts b/data/mapbox_metadata/expression_string.ts
index 88610a1..8f29b0c 100644
--- a/data/mapbox_metadata/expression_string.ts
+++ b/data/mapbox_metadata/expression_string.ts
@@ -1,12 +1,19 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const expression_string: Omit<MbStyle, 'sources'> = {
+const expression_string: MbStyle = {
   version: 8,
   name: 'Expression String',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'text-field': [
@@ -18,6 +25,8 @@ const expression_string: Omit<MbStyle, 'sources'> = {
       }
     }, {
       id: 'r1_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'text-field': [
@@ -27,6 +36,8 @@ const expression_string: Omit<MbStyle, 'sources'> = {
       }
     }, {
       id: 'r2_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'text-field': [
diff --git a/data/mapbox_metadata/fill_patternfill.ts b/data/mapbox_metadata/fill_patternfill.ts
index 7c33d61..352ca16 100644
--- a/data/mapbox_metadata/fill_patternfill.ts
+++ b/data/mapbox_metadata/fill_patternfill.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const fillSimpleFill: Omit<MbStyle, 'sources'> = {
+const fillSimpleFill: MbStyle = {
   version: 8,
   name: 'Pattern Fill',
   sprite: 'https://testurl.com',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'fill',
       paint: {
         'fill-color': '#000000',
diff --git a/data/mapbox_metadata/fill_simple_outline.ts b/data/mapbox_metadata/fill_simple_outline.ts
index 643555d..ebc92f1 100644
--- a/data/mapbox_metadata/fill_simple_outline.ts
+++ b/data/mapbox_metadata/fill_simple_outline.ts
@@ -1,10 +1,17 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const fillSimpleFillOutline: Omit<MbStyle, 'sources'> = {
+const fillSimpleFillOutline: MbStyle = {
   version: 8,
   name: 'Simple Fill With outline',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [{
     id: 'r0_sy0_st0',
+    source: 'testsource',
+    'source-layer': 'foo',
     type: 'fill',
     paint: {
       'fill-color': '#ff0000'
@@ -12,6 +19,8 @@ const fillSimpleFillOutline: Omit<MbStyle, 'sources'> = {
   },
   {
     id: 'r0_sy0_st1',
+    source: 'testsource',
+    'source-layer': 'foo',
     type: 'line',
     paint: {
       'line-opacity': 0.5,
diff --git a/data/mapbox_metadata/fill_simplefill.ts b/data/mapbox_metadata/fill_simplefill.ts
index 37a2a87..ed30054 100644
--- a/data/mapbox_metadata/fill_simplefill.ts
+++ b/data/mapbox_metadata/fill_simplefill.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const fillSimpleFill: Omit<MbStyle, 'sources'> = {
+const fillSimpleFill: MbStyle = {
   version: 8,
   name: 'Simple Fill',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'fill',
       paint: {
         'fill-color': '#000000',
diff --git a/data/mapbox_metadata/icon_simpleicon.ts b/data/mapbox_metadata/icon_simpleicon.ts
index ac647c1..391e9a8 100644
--- a/data/mapbox_metadata/icon_simpleicon.ts
+++ b/data/mapbox_metadata/icon_simpleicon.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const iconSimpleIcon: Omit<MbStyle, 'sources'> = {
+const iconSimpleIcon: MbStyle = {
   version: 8,
   name: 'Simple Icon',
   sprite: 'https://testurl.com',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'icon-image': 'poi'
diff --git a/data/mapbox_metadata/icon_simpleicon_mapboxapi.ts b/data/mapbox_metadata/icon_simpleicon_mapboxapi.ts
index 4d70eb8..97e700b 100644
--- a/data/mapbox_metadata/icon_simpleicon_mapboxapi.ts
+++ b/data/mapbox_metadata/icon_simpleicon_mapboxapi.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const iconSimpleIcon: Omit<MbStyle, 'sources'> = {
+const iconSimpleIcon: MbStyle = {
   version: 8,
   name: 'Simple Icon',
   sprite: 'mapbox://sprites/mapbox/streets-v8',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'icon-image': 'poi'
diff --git a/data/mapbox_metadata/icontext_symbolizer.ts b/data/mapbox_metadata/icontext_symbolizer.ts
index 7481fec..ee3d154 100644
--- a/data/mapbox_metadata/icontext_symbolizer.ts
+++ b/data/mapbox_metadata/icontext_symbolizer.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const iconTextSymbolizer: Omit<MbStyle, 'sources'> = {
+const iconTextSymbolizer: MbStyle = {
   version: 8,
   name: 'icontext symbolizer',
   sprite: 'https://testurl.com',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       type: 'symbol',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'text-color': 'rgba(45, 45, 45, 1)',
       },
diff --git a/data/mapbox_metadata/line_patternline.ts b/data/mapbox_metadata/line_patternline.ts
index 09a5707..8808595 100644
--- a/data/mapbox_metadata/line_patternline.ts
+++ b/data/mapbox_metadata/line_patternline.ts
@@ -1,13 +1,20 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const linePatternLine: Omit<MbStyle, 'sources'> = {
+const linePatternLine: MbStyle = {
   version: 8,
   name: 'Pattern Line',
   sprite: 'https://testurl.com',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
       type: 'line',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'line-color': '#000000',
         'line-width': 3,
diff --git a/data/mapbox_metadata/line_simpleline.ts b/data/mapbox_metadata/line_simpleline.ts
index ee43e18..ae314ba 100644
--- a/data/mapbox_metadata/line_simpleline.ts
+++ b/data/mapbox_metadata/line_simpleline.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const lineSimpleLine: Omit<MbStyle, 'sources'> = {
+const lineSimpleLine: MbStyle = {
   version: 8,
   name: 'Simple Line',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
       type: 'line',
+      source: 'testsource',
+      'source-layer': 'foo',
       paint: {
         'line-color': '#000000',
         'line-width': 3,
diff --git a/data/mapbox_metadata/line_simpleline_basefilter.ts b/data/mapbox_metadata/line_simpleline_basefilter.ts
index ebf5c14..f971751 100644
--- a/data/mapbox_metadata/line_simpleline_basefilter.ts
+++ b/data/mapbox_metadata/line_simpleline_basefilter.ts
@@ -1,10 +1,17 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const lineSimpleLine: Omit<MbStyle, 'sources'> = {
+const lineSimpleLine: MbStyle = {
   version: 8,
   name: 'Small populated New Yorks',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [{
     id: 'r0_sy0_st0',
+    source: 'testsource',
+    'source-layer': 'foo',
     type: 'line',
     filter: ['all',
       ['==', 'NAME', 'New York'],
diff --git a/data/mapbox_metadata/line_simpleline_expression.ts b/data/mapbox_metadata/line_simpleline_expression.ts
index 704983e..ea2af6f 100644
--- a/data/mapbox_metadata/line_simpleline_expression.ts
+++ b/data/mapbox_metadata/line_simpleline_expression.ts
@@ -1,10 +1,17 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const lineSimpleLine: Omit<MbStyle, 'sources'> = {
+const lineSimpleLine: MbStyle = {
   version: 8,
   name: 'Simple Line Filter',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [{
     id: 'r0_sy0_st0',
+    source: 'testsource',
+    'source-layer': 'foo',
     type: 'line',
     paint: {
       'line-color': '#FF0000',
diff --git a/data/mapbox_metadata/line_simpleline_zoom.ts b/data/mapbox_metadata/line_simpleline_zoom.ts
index 35334a0..6af96d4 100644
--- a/data/mapbox_metadata/line_simpleline_zoom.ts
+++ b/data/mapbox_metadata/line_simpleline_zoom.ts
@@ -1,10 +1,17 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const lineSimpleLine: Omit<MbStyle, 'sources'> = {
+const lineSimpleLine: MbStyle = {
   version: 8,
   name: 'Simple Line Filter',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [{
     id: 'r0_sy0_st0',
+    source: 'testsource',
+    'source-layer': 'foo',
     type: 'line',
     minzoom: 5.5,
     maxzoom: 10,
diff --git a/data/mapbox_metadata/multi_rule_line_fill.ts b/data/mapbox_metadata/multi_rule_line_fill.ts
index d0a46ed..e48f019 100644
--- a/data/mapbox_metadata/multi_rule_line_fill.ts
+++ b/data/mapbox_metadata/multi_rule_line_fill.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const multiRuleLineFill: Omit<MbStyle, 'sources'> = {
+const multiRuleLineFill: MbStyle = {
   version: 8,
   name: 'Rule Line Fill',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'line',
       paint: {
         'line-color': '#000000',
@@ -18,6 +25,8 @@ const multiRuleLineFill: Omit<MbStyle, 'sources'> = {
       }
     }, {
       id: 'r1_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'fill',
       paint: {
         'fill-color': '#000000',
diff --git a/data/mapbox_metadata/multi_simpleline_simplefill.ts b/data/mapbox_metadata/multi_simpleline_simplefill.ts
index b22272c..6f0c196 100644
--- a/data/mapbox_metadata/multi_simpleline_simplefill.ts
+++ b/data/mapbox_metadata/multi_simpleline_simplefill.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const multiSimpleLineSimpleFill: Omit<MbStyle, 'sources'> = {
+const multiSimpleLineSimpleFill: MbStyle = {
   version: 8,
   name: 'Simple Line Simple Fill',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'line',
       paint: {
         'line-color': '#000000',
@@ -18,6 +25,8 @@ const multiSimpleLineSimpleFill: Omit<MbStyle, 'sources'> = {
       }
     }, {
       id: 'r1_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'fill',
       paint: {
         'fill-color': '#000000',
diff --git a/data/mapbox_metadata/point_placeholderText.ts b/data/mapbox_metadata/point_placeholderText.ts
index 3fda64a..6016a86 100644
--- a/data/mapbox_metadata/point_placeholderText.ts
+++ b/data/mapbox_metadata/point_placeholderText.ts
@@ -1,12 +1,19 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const pointPlaceholderText: Omit<MbStyle, 'sources'> = {
+const pointPlaceholderText: MbStyle = {
   version: 8,
   name: 'Placeholder Text',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
       type: 'symbol',
+      source: 'testsource',
+      'source-layer': 'foo',
       layout: {
         'text-field': ['format',
           'Area: ', {},
diff --git a/data/mapbox_metadata/point_placeholderText_simple.ts b/data/mapbox_metadata/point_placeholderText_simple.ts
index 8a9c93c..e305038 100644
--- a/data/mapbox_metadata/point_placeholderText_simple.ts
+++ b/data/mapbox_metadata/point_placeholderText_simple.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const pointPlaceholderText: Omit<MbStyle, 'sources'> = {
+const pointPlaceholderText: MbStyle = {
   version: 8,
   name: 'Placeholder Text',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'text-field': '{River}'
diff --git a/data/mapbox_metadata/point_simpletext.ts b/data/mapbox_metadata/point_simpletext.ts
index d6c92cc..0c3181a 100644
--- a/data/mapbox_metadata/point_simpletext.ts
+++ b/data/mapbox_metadata/point_simpletext.ts
@@ -1,11 +1,18 @@
 import { MbStyle } from '../../src/MapboxStyleParser';
 
-const pointSimpleText: Omit<MbStyle, 'sources'> = {
+const pointSimpleText: MbStyle = {
   version: 8,
   name: 'Simple Text',
+  sources: {
+    testsource: {
+      type: 'vector'
+    }
+  },
   layers: [
     {
       id: 'r0_sy0_st0',
+      source: 'testsource',
+      'source-layer': 'foo',
       type: 'symbol',
       layout: {
         'text-field': 'River'
diff --git a/data/mapbox_metadata/source_layer_mapping.ts b/data/mapbox_metadata/source_layer_mapping.ts
new file mode 100644
index 0000000..af5ba22
--- /dev/null
+++ b/data/mapbox_metadata/source_layer_mapping.ts
@@ -0,0 +1,58 @@
+import { MbStyle } from '../../src/MapboxStyleParser';
+
+const sourceLayerMapping: MbStyle = {
+  version: 8,
+  name: 'SourceLayerMapping',
+  sources: {
+    first: {
+      type: 'vector'
+    }
+  },
+  layers: [
+    {
+      id: 'r0_sy0_st0',
+      source: 'first',
+      'source-layer': 'foo',
+      type: 'circle',
+      paint: {
+        'circle-color': '#000000',
+        'circle-radius': 5,
+        'circle-opacity': 1,
+        'circle-stroke-width': 2,
+        'circle-stroke-color': '#FF0000',
+        'circle-stroke-opacity': 0.5
+      }
+    },
+    {
+      id: 'r1_sy0_st0',
+      source: 'first',
+      'source-layer': 'bar',
+      type: 'circle',
+      paint: {
+        'circle-color': '#000000',
+        'circle-radius': 5,
+        'circle-opacity': 1,
+        'circle-stroke-width': 2,
+        'circle-stroke-color': '#FF0000',
+        'circle-stroke-opacity': 0.5
+      }
+    }
+  ],
+  metadata: {
+    'geostyler:ref': {
+      rules: [{
+        name: 'Simple Circle 1',
+        symbolizers: [[
+          'r0_sy0_st0'
+        ]]
+      }, {
+        name: 'Simple Circle 2',
+        symbolizers: [[
+          'r1_sy0_st0'
+        ]]
+      }]
+    }
+  }
+};
+
+export default sourceLayerMapping;
diff --git a/data/mapbox_metadata/source_mapping.ts b/data/mapbox_metadata/source_mapping.ts
new file mode 100644
index 0000000..5320d7a
--- /dev/null
+++ b/data/mapbox_metadata/source_mapping.ts
@@ -0,0 +1,61 @@
+import { MbStyle } from '../../src/MapboxStyleParser';
+
+const sourceMapping: MbStyle = {
+  version: 8,
+  name: 'SourceMapping',
+  sources: {
+    first: {
+      type: 'vector'
+    },
+    second: {
+      type: 'vector'
+    }
+  },
+  layers: [
+    {
+      id: 'r0_sy0_st0',
+      source: 'first',
+      'source-layer': 'foo',
+      type: 'circle',
+      paint: {
+        'circle-color': '#000000',
+        'circle-radius': 5,
+        'circle-opacity': 1,
+        'circle-stroke-width': 2,
+        'circle-stroke-color': '#FF0000',
+        'circle-stroke-opacity': 0.5
+      }
+    },
+    {
+      id: 'r1_sy0_st0',
+      source: 'second',
+      'source-layer': 'foo',
+      type: 'circle',
+      paint: {
+        'circle-color': '#000000',
+        'circle-radius': 5,
+        'circle-opacity': 1,
+        'circle-stroke-width': 2,
+        'circle-stroke-color': '#FF0000',
+        'circle-stroke-opacity': 0.5
+      }
+    }
+  ],
+  metadata: {
+    'geostyler:ref': {
+      rules: [{
+        name: 'Simple Circle 1',
+        symbolizers: [[
+          'r0_sy0_st0'
+        ]]
+      }, {
+        name: 'Simple Circle 2',
+        symbolizers: [[
+          'r1_sy0_st0'
+        ]]
+      }]
+    }
+  }
+};
+
+export default sourceMapping;
diff --git a/data/styles/circle_simplecircle.ts b/data/styles/circle_simplecircle.ts
index 3698a17..3baa7cc 100644
--- a/data/styles/circle_simplecircle.ts
+++ b/data/styles/circle_simplecircle.ts
@@ -14,7 +14,22 @@ const circleSimpleCircle: Style = {
       strokeColor: '#FF0000',
       strokeOpacity: 0.5
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default circleSimpleCircle;
diff --git a/data/styles/fill_patternfill.ts b/data/styles/fill_patternfill.ts
index 4118b30..d8d364d 100644
--- a/data/styles/fill_patternfill.ts
+++ b/data/styles/fill_patternfill.ts
@@ -13,7 +13,22 @@ const fillPatternFill: Style = {
         image: '/sprites/?name=poi&baseurl=' + encodeURIComponent('https://testurl.com')
       }
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default fillPatternFill;
diff --git a/data/styles/fill_simple_outline.ts b/data/styles/fill_simple_outline.ts
index f365a26..7bafa7c 100644
--- a/data/styles/fill_simple_outline.ts
+++ b/data/styles/fill_simple_outline.ts
@@ -13,7 +13,22 @@ const fillSimpleFillOutline: Style = {
       outlineCap: 'butt',
       outlineJoin: 'round'
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default fillSimpleFillOutline;
diff --git a/data/styles/fill_simplefill.ts b/data/styles/fill_simplefill.ts
index 027cf9b..d0ea754 100644
--- a/data/styles/fill_simplefill.ts
+++ b/data/styles/fill_simplefill.ts
@@ -9,7 +9,22 @@ const fillSimpleFill: Style = {
       color: '#000000',
       opacity: 1
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default fillSimpleFill;
diff --git a/data/styles/gs_expression_case.ts b/data/styles/gs_expression_case.ts
index 0c1fdbc..6ee46c4 100644
--- a/data/styles/gs_expression_case.ts
+++ b/data/styles/gs_expression_case.ts
@@ -86,7 +86,22 @@ const gs_expression_case: Style = {
       radius: 12,
       fillOpacity: 0.6
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default gs_expression_case;
diff --git a/data/styles/gs_expression_decisions.ts b/data/styles/gs_expression_decisions.ts
index d716190..54d0659 100644
--- a/data/styles/gs_expression_decisions.ts
+++ b/data/styles/gs_expression_decisions.ts
@@ -228,7 +228,22 @@ const gs_expression_decisions: Style = {
         ]
       }
     }]
-  },]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0, 1, 2, 3, 4, 5, 6, 7, 8]
+      },
+      sourceLayerMapping: {
+        foo: [0, 1, 2, 3, 4, 5, 6, 7, 8]
+      }
+    }
+  }
 };
 
 export default gs_expression_decisions;
diff --git a/data/styles/gs_expression_lookup.ts b/data/styles/gs_expression_lookup.ts
index 0b6a044..0473902 100644
--- a/data/styles/gs_expression_lookup.ts
+++ b/data/styles/gs_expression_lookup.ts
@@ -22,7 +22,22 @@ const gs_expression_lookup: Style = {
         args: ['peter', 0, 2]
       }
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0, 1]
+      },
+      sourceLayerMapping: {
+        foo: [0, 1]
+      }
+    }
+  }
 };
 
 export default gs_expression_lookup;
diff --git a/data/styles/gs_expression_math.ts b/data/styles/gs_expression_math.ts
index be4e851..ce2b665 100644
--- a/data/styles/gs_expression_math.ts
+++ b/data/styles/gs_expression_math.ts
@@ -222,7 +222,22 @@ const gs_expression_math: Style = {
         args: [1]
       }
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21]
+      },
+      sourceLayerMapping: {
+        foo: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21]
+      }
+    }
+  }
 };
 
 export default gs_expression_math;
diff --git a/data/styles/gs_expression_property.ts b/data/styles/gs_expression_property.ts
index 21c9fce..6716e80 100644
--- a/data/styles/gs_expression_property.ts
+++ b/data/styles/gs_expression_property.ts
@@ -21,7 +21,22 @@ const gs_expression_property: Style = {
       strokeColor: '#FF0000',
       strokeOpacity: 0.5
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default gs_expression_property;
diff --git a/data/styles/gs_expression_string.ts b/data/styles/gs_expression_string.ts
index e057e3b..c60e7c1 100644
--- a/data/styles/gs_expression_string.ts
+++ b/data/styles/gs_expression_string.ts
@@ -30,7 +30,22 @@ const gs_expression_string: Style = {
         args: ['peter']
       }
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0, 1, 2]
+      },
+      sourceLayerMapping: {
+        foo: [0, 1, 2]
+      }
+    }
+  }
 };
 
 export default gs_expression_string;
diff --git a/data/styles/icon_simpleicon.ts b/data/styles/icon_simpleicon.ts
index 41df89a..589825e 100644
--- a/data/styles/icon_simpleicon.ts
+++ b/data/styles/icon_simpleicon.ts
@@ -8,7 +8,22 @@ const iconSimpleIcon: Style = {
       kind: 'Icon',
       image: '/sprites/?name=poi&baseurl=' + encodeURIComponent('https://testurl.com')
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default iconSimpleIcon;
diff --git a/data/styles/icon_simpleicon_mapboxapi.ts b/data/styles/icon_simpleicon_mapboxapi.ts
index 09f0adb..1fb28a0 100644
--- a/data/styles/icon_simpleicon_mapboxapi.ts
+++ b/data/styles/icon_simpleicon_mapboxapi.ts
@@ -8,7 +8,22 @@ const iconSimpleIcon: Style = {
       kind: 'Icon',
       image: '/sprites/?name=poi&baseurl=' + encodeURIComponent('https://api.mapbox.com/sprites/mapbox/streets-v8')
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default iconSimpleIcon;
diff --git a/data/styles/line_patternline.ts b/data/styles/line_patternline.ts
index 551c498..75125f3 100644
--- a/data/styles/line_patternline.ts
+++ b/data/styles/line_patternline.ts
@@ -16,7 +16,22 @@ const linePatternLine: Style = {
         image: '/sprites/?name=poi&baseurl=' + encodeURIComponent('https://testurl.com')
       }
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default linePatternLine;
diff --git a/data/styles/line_simpleline.ts b/data/styles/line_simpleline.ts
index d99d572..a0b9282 100644
--- a/data/styles/line_simpleline.ts
+++ b/data/styles/line_simpleline.ts
@@ -12,7 +12,22 @@ const lineSimpleLine: Style = {
       cap: 'round',
       join: 'miter'
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default lineSimpleLine;
diff --git a/data/styles/line_simpleline_basefilter.ts b/data/styles/line_simpleline_basefilter.ts
index e10523d..5198aa3 100644
--- a/data/styles/line_simpleline_basefilter.ts
+++ b/data/styles/line_simpleline_basefilter.ts
@@ -21,7 +21,22 @@ const lineSimpleLine: Style = {
       color: '#FF0000',
       width: 3
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default lineSimpleLine;
diff --git a/data/styles/line_simpleline_expression.ts b/data/styles/line_simpleline_expression.ts
index 6e2ac9e..ae26c9e 100644
--- a/data/styles/line_simpleline_expression.ts
+++ b/data/styles/line_simpleline_expression.ts
@@ -12,7 +12,22 @@ const lineSimpleLine: Style = {
         name: 'random'
       }
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default lineSimpleLine;
diff --git a/data/styles/line_simpleline_zoom.ts b/data/styles/line_simpleline_zoom.ts
index 0737737..b1a4307 100644
--- a/data/styles/line_simpleline_zoom.ts
+++ b/data/styles/line_simpleline_zoom.ts
@@ -13,7 +13,22 @@ const lineSimpleLine: Style = {
       color: '#FF0000',
       width: 5
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default lineSimpleLine;
diff --git a/data/styles/multi_rule_line_fill.ts b/data/styles/multi_rule_line_fill.ts
index 9ad49db..5182ed8 100644
--- a/data/styles/multi_rule_line_fill.ts
+++ b/data/styles/multi_rule_line_fill.ts
@@ -20,7 +20,22 @@ const multiRuleLineFill: Style = {
       color: '#000000',
       opacity: 1
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0, 1]
+      },
+      sourceLayerMapping: {
+        foo: [0, 1]
+      }
+    }
+  }
 };
 
 export default multiRuleLineFill;
diff --git a/data/styles/multi_simpleline_simplefill.ts b/data/styles/multi_simpleline_simplefill.ts
index 461c74e..a57a904 100644
--- a/data/styles/multi_simpleline_simplefill.ts
+++ b/data/styles/multi_simpleline_simplefill.ts
@@ -19,7 +19,22 @@ const multiSimpleLineSimpleFill: Style = {
       color: '#000000',
       opacity: 1
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0, 1]
+      },
+      sourceLayerMapping: {
+        foo: [0, 1]
+      }
+    }
+  }
 };
 
 export default multiSimpleLineSimpleFill;
diff --git a/data/styles/point_placeholderText.ts b/data/styles/point_placeholderText.ts
index e16d790..8875fa5 100644
--- a/data/styles/point_placeholderText.ts
+++ b/data/styles/point_placeholderText.ts
@@ -10,7 +10,22 @@ const pointPlaceholderText: Style = {
       color: '#000000',
       opacity: 1
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default pointPlaceholderText;
diff --git a/data/styles/point_placeholderText_simple.ts b/data/styles/point_placeholderText_simple.ts
index 49c6493..80d764e 100644
--- a/data/styles/point_placeholderText_simple.ts
+++ b/data/styles/point_placeholderText_simple.ts
@@ -10,7 +10,22 @@ const pointPlaceholderText: Style = {
       color: '#000000',
       opacity: 1
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default pointPlaceholderText;
diff --git a/data/styles/point_simpletext.ts b/data/styles/point_simpletext.ts
index cbe8c49..c69fd15 100644
--- a/data/styles/point_simpletext.ts
+++ b/data/styles/point_simpletext.ts
@@ -10,7 +10,22 @@ const pointSimpleText: Style = {
       color: '#000000',
       opacity: 1
     }]
-  }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
+    }
+  }
 };
 
 export default pointSimpleText;
diff --git a/data/styles/source_layer_mapping.ts b/data/styles/source_layer_mapping.ts
new file mode 100644
index 0000000..e625d02
--- /dev/null
+++ b/data/styles/source_layer_mapping.ts
@@ -0,0 +1,48 @@
+import { Style } from 'geostyler-style';
+
+const sourceLayerMapping: Style = {
+  name: 'SourceLayerMapping',
+  rules: [{
+    name: 'Simple Circle 1',
+    symbolizers: [{
+      kind: 'Mark',
+      wellKnownName: 'circle',
+      color: '#000000',
+      radius: 5,
+      fillOpacity: 1,
+      strokeWidth: 2,
+      strokeColor: '#FF0000',
+      strokeOpacity: 0.5
+    }]
+  }, {
+    name: 'Simple Circle 2',
+    symbolizers: [{
+      kind: 'Mark',
+      wellKnownName: 'circle',
+      color: '#000000',
+      radius: 5,
+      fillOpacity: 1,
+      strokeWidth: 2,
+      strokeColor: '#FF0000',
+      strokeOpacity: 0.5
+    }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        first: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        first: [0, 1]
+      },
+      sourceLayerMapping: {
+        foo: [0],
+        bar: [1]
+      }
+    }
+  }
+};
+
+export default sourceLayerMapping;
diff --git a/data/styles/source_mapping.ts b/data/styles/source_mapping.ts
new file mode 100644
index 0000000..3676c9c
--- /dev/null
+++ b/data/styles/source_mapping.ts
@@ -0,0 +1,51 @@
+import { Style } from 'geostyler-style';
+
+const sourceMapping: Style = {
+  name: 'SourceMapping',
+  rules: [{
+    name: 'Simple Circle 1',
+    symbolizers: [{
+      kind: 'Mark',
+      wellKnownName: 'circle',
+      color: '#000000',
+      radius: 5,
+      fillOpacity: 1,
+      strokeWidth: 2,
+      strokeColor: '#FF0000',
+      strokeOpacity: 0.5
+    }]
+  }, {
+    name: 'Simple Circle 2',
+    symbolizers: [{
+      kind: 'Mark',
+      wellKnownName: 'circle',
+      color: '#000000',
+      radius: 5,
+      fillOpacity: 1,
+      strokeWidth: 2,
+      strokeColor: '#FF0000',
+      strokeOpacity: 0.5
+    }]
+  }],
+  metadata: {
+    'mapbox:ref': {
+      sources: {
+        first: {
+          type: 'vector'
+        },
+        second: {
+          type: 'vector'
+        }
+      },
+      sourceMapping: {
+        first: [0],
+        second: [1]
+      },
+      sourceLayerMapping: {
+        foo: [0, 1]
+      }
+    }
+  }
+};
+
+export default sourceMapping;
diff --git a/data/styles_metadata/icontext_symbolizer.ts b/data/styles_metadata/icontext_symbolizer.ts
index 20f9f2e..b16d4e7 100644
--- a/data/styles_metadata/icontext_symbolizer.ts
+++ b/data/styles_metadata/icontext_symbolizer.ts
@@ -23,10 +23,21 @@ const iconTextSymbolizer: Style = {
   ],
   metadata: {
     'mapbox:ref': {
+      sources: {
+        testsource: {
+          type: 'vector'
+        }
+      },
       splitSymbolizers: [{
         rule: 0,
         symbolizers: [0, 1]
-      }]
+      }],
+      sourceMapping: {
+        testsource: [0]
+      },
+      sourceLayerMapping: {
+        foo: [0]
+      }
     }
   }
 };
diff --git a/src/MapboxStyleParser.spec.ts b/src/MapboxStyleParser.spec.ts
index 2318734..395d9ed 100644
--- a/src/MapboxStyleParser.spec.ts
+++ b/src/MapboxStyleParser.spec.ts
@@ -51,6 +51,12 @@ import mb_point_placeholdertext_simple_metadata from '../data/mapbox_metadata/po
 import icontext_symbolizer_metadata from '../data/styles_metadata/icontext_symbolizer';
 import mb_icontext_symbolizer from '../data/mapbox/icontext_symbolizer';
 import mb_icontext_symbolizer_metadata from '../data/mapbox_metadata/icontext_symbolizer';
+import source_mapping from '../data/styles/source_mapping';
+import mb_source_mapping from '../data/mapbox/source_mapping';
+import mb_source_mapping_metadata from '../data/mapbox_metadata/source_mapping';
+import source_layer_mapping from '../data/styles/source_layer_mapping';
+import mb_source_layer_mapping from '../data/mapbox/source_layer_mapping';
+import mb_source_layer_mapping_metadata from '../data/mapbox_metadata/source_layer_mapping';
 import { CustomLayerInterface } from 'mapbox-gl';
 import { AnyLayer } from 'mapbox-gl';
 
@@ -195,6 +201,18 @@ describe('MapboxStyleParser implements StyleParser', () => {
       expect(geoStylerStyle).toBeDefined();
       expect(geoStylerStyle).toEqual(icontext_symbolizer_metadata);
     });
+
+    it('can keep track of a mapbox style sources', async () => {
+      const { output: geoStylerStyle } = await styleParser.readStyle(mb_source_mapping);
+      expect(geoStylerStyle).toBeDefined();
+      expect(geoStylerStyle).toEqual(source_mapping);
+    });
+
+    it('can keep track of a mapbox style layer source', async () => {
+      const { output: geostylerStyle } = await styleParser.readStyle(mb_source_layer_mapping);
+      expect(geostylerStyle).toBeDefined();
+      expect(geostylerStyle).toEqual(source_layer_mapping);
+    });
   });
 
   describe('#writeStyle', () => {
@@ -304,5 +322,17 @@ describe('MapboxStyleParser implements StyleParser', () => {
       expect(mbStyle).toBeDefined();
       expect(mbStyle).toEqual(mb_icontext_symbolizer_metadata);
     });
+
+    it('can properly resolve the source mapping', async () => {
+      const { output: mbStyle } = await styleParser.writeStyle(source_mapping);
+      expect(mbStyle).toBeDefined();
+      expect(mbStyle).toEqual(mb_source_mapping_metadata);
+    });
+
+    it('can properly resolve the source layer mapping', async () => {
+      const { output: mbStyle } = await styleParser.writeStyle(source_layer_mapping);
+      expect(mbStyle).toBeDefined();
+      expect(mbStyle).toEqual(mb_source_layer_mapping_metadata);
+    });
   });
 });
diff --git a/src/MapboxStyleParser.ts b/src/MapboxStyleParser.ts
index afbfefb..21797b5 100644
--- a/src/MapboxStyleParser.ts
+++ b/src/MapboxStyleParser.ts
@@ -48,7 +48,8 @@ import {
   SymbolPaint,
   Style as MapboxStyle,
   Sources,
-  Expression
+  Expression,
+  Layer
 } from 'mapbox-gl';
 import { gs2mbExpression, mb2gsExpression } from './Expressions';
 import { isBoolean, isString, isUndefined, omitBy, set } from 'lodash';
@@ -57,7 +58,7 @@ import { isBoolean, isString, isUndefined, omitBy, set } from 'lodash';
  * The style representation of mapbox-gl but with optional sources, as these are
  * not required for reading the style and get stripped when writing.
  */
-export type MbStyle = Omit<MapboxStyle, 'sources'> & { sources?: Sources };
+export type MbStyle = MapboxStyle;
 
 type NoneCustomLayer = Exclude<AnyLayer, CustomLayerInterface>;
 
@@ -82,6 +83,13 @@ type MapboxRef = {
     rule: number;
     symbolizers: number[];
   }[];
+  sources: Sources;
+  sourceMapping?: {
+    [source: keyof Sources]: number[];
+  };
+  sourceLayerMapping?: {
+    [key: string]: number[];
+  };
 };
 
 type SymbolType = {
@@ -654,6 +662,8 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
     const gsRules: Rule[] = [];
     const splitSymbolizers: MapboxRef['splitSymbolizers'] = [];
     const mapboxRef = structuredClone(mbRef);
+    const sourceMapping: MapboxRef['sourceMapping'] = {};
+    const sourceLayerMapping: MapboxRef['sourceLayerMapping'] = {};
 
     if (geoStylerRef) {
       geoStylerRef.rules.forEach((rule, ruleIndex) => {
@@ -661,6 +671,8 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
         let symbolizers: Symbolizer[] = [];
         let filter: Filter | undefined;
         let scaleDenominator: ScaleDenominator | undefined;
+        let source: Layer['source'];
+        let sourceLayer: Layer['source-layer'];
         rule.symbolizers?.forEach((layerIds, symbolizerIndex) => {
           const matchingLayers = layers.filter(layer => layerIds.includes(layer.id));
           const flattenedSymbolizers = matchingLayers
@@ -687,6 +699,21 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
               matchingLayers[0].minzoom,
               matchingLayers[0].maxzoom,
             );
+            source = matchingLayers[0].source;
+            sourceLayer = matchingLayers[0]['source-layer'];
+
+            if (source && typeof source === 'string') {
+              if (!sourceMapping[source]) {
+                sourceMapping[source] = [];
+              }
+              sourceMapping[source].push(ruleIndex);
+            }
+            if (sourceLayer) {
+              if (!sourceLayerMapping[sourceLayer]) {
+                sourceLayerMapping[sourceLayer] = [];
+              }
+              sourceLayerMapping[sourceLayer].push(ruleIndex);
+            }
           }
           // TODO: care about layers not configured in the metadata
           // const noneMatchingLayes = layers.filter(layer => !layerIds.includes(layer.id));
@@ -718,6 +745,18 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
           symbolizers
         };
         gsRules.push(rule);
+        if (layer.source && typeof layer.source === 'string') {
+          if (!sourceMapping[layer.source]) {
+            sourceMapping[layer.source] = [];
+          }
+          sourceMapping[layer.source].push(gsRules.length - 1);
+        }
+        if (layer['source-layer']) {
+          if (!sourceLayerMapping[layer['source-layer']]) {
+            sourceLayerMapping[layer['source-layer']] = [];
+          }
+          sourceLayerMapping[layer['source-layer']].push(gsRules.length - 1);
+        }
         if (symbolizers.length > 1) {
           splitSymbolizers.push({
             rule: gsRules.length - 1,
@@ -730,6 +769,12 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
     if (splitSymbolizers.length) {
       mapboxRef.splitSymbolizers = splitSymbolizers;
     }
+    if (Object.keys(sourceMapping).length) {
+      mapboxRef.sourceMapping = sourceMapping;
+    }
+    if (Object.keys(sourceLayerMapping).length) {
+      mapboxRef.sourceLayerMapping = sourceLayerMapping;
+    }
 
     return {
       rules: gsRules,
@@ -747,7 +792,9 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
     let style: Style = {} as Style;
     style.name = mapboxStyle.name || '';
     style.rules = [];
-    let mapboxRef: MapboxRef = {};
+    let mapboxRef: MapboxRef = {
+      sources: mapboxStyle.sources || {}
+    };
     this.mbMetadata = mapboxStyle.metadata;
     if (mapboxStyle.sprite) {
       this.spriteBaseUrl = MapboxStyleUtil.getUrlForMbPlaceholder(mapboxStyle.sprite);
@@ -763,11 +810,9 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
       style.rules = style.rules.concat(rules);
     }
 
-    if (Object.keys(mapboxRef).length) {
-      style.metadata = {
-        'mapbox:ref': mapboxRef
-      };
-    }
+    style.metadata = {
+      'mapbox:ref': mapboxRef
+    };
     return style;
   }
 
@@ -801,12 +846,12 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
    * @param geoStylerStyle A GeoStylerStyle-Style
    * @return The Promise resolving with a GeoStylerStyle-WriteStyleResult
    */
-  writeStyle(geoStylerStyle: Style): Promise<WriteStyleResult<Omit<MbStyle, 'sources'>>> {
-    return new Promise<WriteStyleResult<Omit<MbStyle, 'sources'>>>(resolve => {
+  writeStyle(geoStylerStyle: Style): Promise<WriteStyleResult<MbStyle>> {
+    return new Promise<WriteStyleResult<MbStyle>>(resolve => {
       const unsupportedProperties = this.checkForUnsupportedProperties(geoStylerStyle);
       try {
         const gsStyle = structuredClone(geoStylerStyle);
-        const output: Omit<MbStyle, 'sources'> = this.geoStylerStyleToMapboxObject(gsStyle);
+        const output: MbStyle = this.geoStylerStyleToMapboxObject(gsStyle);
         resolve({
           output,
           unsupportedProperties,
@@ -826,12 +871,12 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
    * @param geoStylerStyle A GeoStylerStyle-Style
    * @return A Mapbox Style object
    */
-  geoStylerStyleToMapboxObject(geoStylerStyle: Style): Omit<MbStyle, 'sources'> {
+  geoStylerStyleToMapboxObject(geoStylerStyle: Style): MbStyle {
     // Mapbox Style version
     const version = 8;
     const name = geoStylerStyle.name;
-    const metadata = geoStylerStyle.metadata?.['mapbox:ref'];
-    const {layers, geoStylerRef} = this.getMapboxLayersFromRules(geoStylerStyle.rules, metadata);
+    const mapboxRef = geoStylerStyle.metadata?.['mapbox:ref'];
+    const {layers, geoStylerRef} = this.getMapboxLayersFromRules(geoStylerStyle.rules, mapboxRef);
     const sprite = MapboxStyleUtil.getMbPlaceholderForUrl(this.spriteBaseUrl);
 
     let mapboxObject = omitBy({
@@ -839,7 +884,8 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
       name,
       layers,
       sprite,
-    }, isUndefined) as Omit<MbStyle, 'sources'>;
+      sources: mapboxRef?.sources || {}
+    }, isUndefined) as MbStyle;
 
     if (geoStylerRef){
       mapboxObject = {
@@ -934,6 +980,25 @@ export class MapboxStyleParser implements StyleParser<Omit<MbStyle, 'sources'>>
           }
           lyrClone.id = `r${ruleIndex}_sy${symbolizerIndex}_st${styleIndex}`;
 
+          const sourceMapping = mapboxRef?.sourceMapping;
+          if (sourceMapping) {
+            const matchingSource = Object.keys(sourceMapping)
+              .filter(source => sourceMapping[source].includes(ruleIndex))
+              .pop();
+            if (matchingSource !== undefined) {
+              lyrClone.source = matchingSource;
+            }
+          }
+          const sourceLayerMapping = mapboxRef?.sourceLayerMapping;
+          if (sourceLayerMapping) {
+            const matchingSourceLayer = Object.keys(sourceLayerMapping)
+              .filter(sourceLayer => sourceLayerMapping[sourceLayer].includes(ruleIndex))
+              .pop();
+            if (matchingSourceLayer !== undefined) {
+              lyrClone['source-layer'] = matchingSourceLayer;
+            }
+          }
+
           layers.push(omitBy(lyrClone, isUndefined) as NoneCustomLayer);
 
           let symbs = geoStylerRef.rules[ruleIndex].symbolizers;