diff --git a/src/mapping.ts b/src/mapping.ts
index 72ef7109..e849555f 100644
--- a/src/mapping.ts
+++ b/src/mapping.ts
@@ -41,7 +41,10 @@ const dynamicTemplates: ElasticsearchDynamicTemplate[] = [];
 let errors: string[] = [];
 let showErrors = true;
 
+let aggregatablePaths: string[] = [];
+
 const indexableTag = 'indexable';
+const aggregatableTag = 'aggregatable';
 
 let ignoredTagsList = ['indexable', 'validatable'];
 
@@ -86,12 +89,13 @@ export function getAllIndexableInterfaces(projectReflection: ProjectReflection):
  * Composes error messages, that are readable and contain a certain minumum of information
  *
  * @param path the path where the error took place
+ * @param topTypeName the name of the SCThingType
  * @param typeName the name of the object, with which something went wrong
  * @param object the object or name
  * @param message the error message
  */
-function composeErrorMessage(path: string, typeName: string, object: string, message: string) {
-  const error = `At "${path.substr(0, path.length - 1)}" for ${typeName} "${object}": ${message}`;
+function composeErrorMessage(path: string, topTypeName: string, typeName: string, object: string, message: string) {
+  const error = `At "${topTypeName}::${path.substr(0, path.length - 1)}" for ${typeName} "${object}": ${message}`;
   errors.push(error);
   if (showErrors) {
     // tslint:disable-next-line:no-floating-promises
@@ -108,11 +112,12 @@ function composeErrorMessage(path: string, typeName: string, object: string, mes
  * @param type the ReferenceType of a DeclarationReflection
  * @param out the previous reflection, it then overrides all parameters or keeps old ones
  * @param path the current path to the object we are in
+ * @param topTypeName the name of the SCThingType
  * @param tags any tags attached to the type
  */
 function getReflectionGeneric(type: ReferenceType,
                               out: ReflectionGeneric[],
-                              path: string, tags: CommentTag[]): ReflectionGeneric[] {
+                              path: string, topTypeName: string, tags: CommentTag[]): ReflectionGeneric[] {
   if (typeof type.typeArguments !== 'undefined'
     && type.reflection instanceof DeclarationReflection
     && typeof type.reflection.typeParameters !== 'undefined'
@@ -121,14 +126,14 @@ function getReflectionGeneric(type: ReferenceType,
       let replaced = false;
       for (const old of out) {
         if (old.name === type.reflection.typeParameters[i].name) {
-          old.value = handleType(type.typeArguments[i], out, path, tags);
+          old.value = handleType(type.typeArguments[i], out, path, topTypeName, tags);
           replaced = true;
         }
       }
       if (!replaced) {
         out.push({
           name: type.reflection.typeParameters[i].name,
-          value: handleType(type.typeArguments[i], out, path, tags),
+          value: handleType(type.typeArguments[i], out, path, topTypeName, tags),
         });
       }
     }
@@ -143,25 +148,27 @@ function getReflectionGeneric(type: ReferenceType,
  * @param ref the ReferenceType
  * @param generics the generics from levels above, so we can use them without having access to the parent
  * @param path the current path to the object we are in
+ * @param topTypeName the name of the SCThingType
  * @param tags any tags attached to the type
  */
 function handleRefWithoutReflection(ref: ReferenceType, generics: ReflectionGeneric[],
-                                    path: string, tags: CommentTag[]): ElasticsearchValue {
+                                    path: string, topTypeName: string, tags: CommentTag[]): ElasticsearchValue {
   for (const premap in premaps) {
     if (premap === ref.name) {
-      return readFieldTags(premaps[premap], path, tags);
+      return readFieldTags(premaps[premap], path, topTypeName, tags);
     }
   }
 
   if (ref.name === 'Array') { // basically an external type, but Array is quite common, especially with generics
     if (typeof ref.typeArguments === 'undefined' || typeof ref.typeArguments[0] === 'undefined') {
-      composeErrorMessage(path, 'Array with generics', 'array', 'Failed to parse');
+      composeErrorMessage(path, topTypeName, 'Array with generics', 'array', 'Failed to parse');
 
       return {type: ElasticsearchDataType.parse_error};
     }
 
-    return readFieldTags(handleType(ref.typeArguments[0], getReflectionGeneric(ref, generics, path, tags), path, tags),
-      path, tags);
+    return readFieldTags(handleType(ref.typeArguments[0], getReflectionGeneric(ref, generics, path, topTypeName, tags),
+      path, topTypeName, tags),
+      path, topTypeName, tags);
   }
   if (ref.name === '__type') { // empty object
     return {
@@ -170,9 +177,9 @@ function handleRefWithoutReflection(ref: ReferenceType, generics: ReflectionGene
     };
   }
 
-  composeErrorMessage(path, 'external type', ref.name, 'Missing pre-map');
+  composeErrorMessage(path, topTypeName, 'external type', ref.name, 'Missing pre-map');
 
-  return readFieldTags({type: ElasticsearchDataType.missing_premap}, path, tags);
+  return readFieldTags({type: ElasticsearchDataType.missing_premap}, path, topTypeName, tags);
 }
 
 /**
@@ -181,15 +188,17 @@ function handleRefWithoutReflection(ref: ReferenceType, generics: ReflectionGene
  * @param decl the DeclarationReflection of the object
  * @param generics the generics from levels above, so we can use them without having access to the parent
  * @param path the current path to the object we are in
+ * @param topTypeName the name of the SCThingType
  */
 function handleDeclarationReflection(decl: DeclarationReflection,
                                      generics: ReflectionGeneric[],
-                                     path: string):
+                                     path: string,
+                                     topTypeName: string):
   ElasticsearchValue {
   // check if we have an object referencing a generic
   for (const gRefl of generics) {
     if (gRefl.name === decl.name) { // if the object name is the same as the generic name
-      return readFieldTags(gRefl.value, path,
+      return readFieldTags(gRefl.value, path, topTypeName,
         typeof decl.comment !== 'undefined' ? typeof decl.comment.tags !== 'undefined' ? decl.comment.tags : [] : []);
       // use the value defined by the generic
     }
@@ -208,7 +217,7 @@ function handleDeclarationReflection(decl: DeclarationReflection,
       empty = false;
       const template: ElasticsearchDynamicTemplate = {};
       template[decl.name] = {
-        mapping: handleDeclarationReflection(param as DeclarationReflection, generics, path),
+        mapping: handleDeclarationReflection(param as DeclarationReflection, generics, path, topTypeName),
         match: '*',
         match_mapping_type: '*',
         path_match: `${path}*`,
@@ -221,21 +230,21 @@ function handleDeclarationReflection(decl: DeclarationReflection,
   if (typeof decl.children !== 'undefined' && decl.children.length > 0) {
     for (const child of decl.children) {
       empty = false;
-      out.properties[child.name] = handleDeclarationReflection(child, generics, `${path}${child.name}.`);
+      out.properties[child.name] = handleDeclarationReflection(child, generics, `${path}${child.name}.`, topTypeName);
     }
   } else if (decl.type instanceof Type) { // if the object is a type, so we are dealing with a PROPERTY
-    return handleType(decl.type, generics, path,
+    return handleType(decl.type, generics, path, topTypeName,
       typeof decl.comment !== 'undefined' ? typeof decl.comment.tags !== 'undefined' ? decl.comment.tags : [] : []);
   } else if (decl.kindString === 'Enumeration member') {
-    return readTypeTags(typeof decl.defaultValue, path,
+    return readTypeTags(typeof decl.defaultValue, path, topTypeName,
       typeof decl.comment !== 'undefined' ? typeof decl.comment.tags !== 'undefined' ? decl.comment.tags : [] : []);
   }
 
   if (empty) {
-    composeErrorMessage(path, 'object', decl.name, 'Empty object');
+    composeErrorMessage(path, topTypeName, 'object', decl.name, 'Empty object');
   }
 
-  return readFieldTags(out, path,
+  return readFieldTags(out, path, topTypeName,
     typeof decl.comment !== 'undefined' ? typeof decl.comment.tags !== 'undefined' ? decl.comment.tags : [] : []);
 }
 
@@ -248,11 +257,13 @@ function handleDeclarationReflection(decl: DeclarationReflection,
  * @param type the type object
  * @param generics the generics from levels above, so we can use them without having access to the parent
  * @param path the current path to the object we are in
+ * @param topTypeName the name of the SCThingType
  * @param tags any tags attached to the type
  */
 function handleUnionType(type: UnionType,
                          generics: ReflectionGeneric[],
                          path: string,
+                         topTypeName: string,
                          tags: CommentTag[]): ElasticsearchValue {
   const list: ElasticsearchValue[] = [];
 
@@ -260,7 +271,7 @@ function handleUnionType(type: UnionType,
     if (subType instanceof IntrinsicType && subType.name === 'undefined') {
       continue;
     }
-    list.push(handleType(subType, generics, path, tags));
+    list.push(handleType(subType, generics, path, topTypeName, tags));
   }
 
   if (list.length > 0) {
@@ -273,7 +284,8 @@ function handleUnionType(type: UnionType,
     return out;
   }
 
-  composeErrorMessage(path, 'Union Type', stringify(list), 'Empty union type. This is likely not a user error.');
+  composeErrorMessage(path, topTypeName, 'Union Type', stringify(list),
+    'Empty union type. This is likely not a user error.');
 
   return {type: ElasticsearchDataType.parse_error};
 }
@@ -284,30 +296,32 @@ function handleUnionType(type: UnionType,
  * @param type the type object
  * @param generics the generics from levels above, so we can use them without having access to the parent
  * @param path the current path to the object we are in
+ * @param topTypeName the name of the SCThingType
  * @param tags any tags attached to the type
  */
-function handleType(type: Type, generics: ReflectionGeneric[], path: string, tags: CommentTag[]): ElasticsearchValue {
+function handleType(type: Type, generics: ReflectionGeneric[], path: string, topTypeName: string, tags: CommentTag[]):
+  ElasticsearchValue {
   // logger.log((type as any).name);
   if (type instanceof ArrayType) { // array is irrelevant in Elasticsearch, so just go with the element type
-    return handleType(type.elementType, generics, path, tags);
+    return handleType(type.elementType, generics, path, topTypeName, tags);
   }
   if (type.type === 'stringLiteral') { // a string literal, usually for type
-    return readTypeTags(type.type, path, tags);
+    return readTypeTags(type.type, path, topTypeName, tags);
   }
   if (type instanceof IntrinsicType) { // the absolute default type, like strings
-    return readTypeTags(type.name, path, tags);
+    return readTypeTags(type.name, path, topTypeName, tags);
   }
   if (type instanceof UnionType) { // the union type...
-    return handleUnionType(type, generics, path, tags);
+    return handleUnionType(type, generics, path, topTypeName, tags);
   }
   if (type instanceof ReferenceType) {
     if (typeof type.reflection !== 'undefined') {
       // there is really no way to make this typesafe, every element in DeclarationReflection is optional.
       return handleDeclarationReflection(type.reflection as DeclarationReflection,
-        getReflectionGeneric(type, generics, path, tags), path);
+        getReflectionGeneric(type, generics, path, topTypeName, tags), path, topTypeName);
     }
 
-    return handleRefWithoutReflection(type, generics, path, tags);
+    return handleRefWithoutReflection(type, generics, path, topTypeName, tags);
   }
   if (type instanceof TypeParameterType) {
     // check if we have an object referencing a generic
@@ -316,16 +330,17 @@ function handleType(type: Type, generics: ReflectionGeneric[], path: string, tag
         return gRefl.value; // use the value defined by the generic
       }
     }
-    composeErrorMessage(path, 'Generic', type.name, 'Missing reflection, please report!');
+    composeErrorMessage(path, topTypeName, 'Generic', type.name, 'Missing reflection, please report!');
 
     return {type: ElasticsearchDataType.parse_error};
 
   }
   if (type instanceof ReflectionType) {
-    return readFieldTags(handleDeclarationReflection(type.declaration, generics, path), path, tags);
+    return readFieldTags(handleDeclarationReflection(type.declaration, generics, path, topTypeName),
+      path, topTypeName, tags);
   }
 
-  composeErrorMessage(path, 'type', stringify(type), 'Not implemented type');
+  composeErrorMessage(path, topTypeName, 'type', stringify(type), 'Not implemented type');
 
   return {type: ElasticsearchDataType.parse_error};
 }
@@ -335,14 +350,21 @@ function handleType(type: Type, generics: ReflectionGeneric[], path: string, tag
  *
  * @param prev the previous ElasticsearchValue, for example and object
  * @param path the current path to the object we are in
+ * @param topTypeName the name of the SCThingType
  * @param tags tags attached to the value
  * @param dataType the ElasticsearchDataType, for checking if a tag is a type tag
  */
 function readFieldTags(prev: ElasticsearchValue,
                        path: string,
+                       topTypeName: string,
                        tags: CommentTag[],
                        dataType?: string): ElasticsearchValue {
   for (const tag of tags) {
+    if (tag.tagName === aggregatableTag) {
+      // push type.path and remove the '.' at the end of the path
+      aggregatablePaths.push(`${topTypeName}.${path.slice(0, -1)}`);
+    }
+
     if (!ignoredTagsList.includes(tag.tagName)) {
       if (typeof fieldmap[tag.tagName] !== 'undefined') {
         if (typeof prev.fields === 'undefined') {
@@ -357,7 +379,7 @@ function readFieldTags(prev: ElasticsearchValue,
           prev.fields = {...prev.fields, ...fieldmap[tag.tagName][tag.text.trim()]};
         } else if (!fieldmap[tag.tagName].ignore.includes(tag.text.trim())) {
           // when there is an unidentified tag
-          composeErrorMessage(path, 'tag', tag.tagName, `Not implemented tag param "${tag.text.trim()}"`);
+          composeErrorMessage(path, topTypeName, 'tag', tag.tagName, `Not implemented tag param "${tag.text.trim()}"`);
         }
       } else if (tag.tagName === filterableTagName) {
         if (typeof prev.fields === 'undefined') {
@@ -369,13 +391,13 @@ function readFieldTags(prev: ElasticsearchValue,
             // merge fields
             prev.fields = {...prev.fields, ...{raw: {type: type}}};
           } else {
-            composeErrorMessage(path, 'tag', tag.tagName, `Not implemented for ${prev.type}`);
+            composeErrorMessage(path, topTypeName, 'tag', tag.tagName, `Not implemented for ${prev.type}`);
           }
         } else {
-          composeErrorMessage(path, 'tag', tag.tagName, 'Not applicable for object types');
+          composeErrorMessage(path, topTypeName, 'tag', tag.tagName, 'Not applicable for object types');
         }
       } else if (typeof dataType === 'undefined' || typeof typemap[dataType][tag.tagName] === 'undefined') {
-        composeErrorMessage(path, 'tag', tag.tagName, `Not implemented tag`);
+        composeErrorMessage(path, topTypeName, 'tag', tag.tagName, `Not implemented tag`);
       }
     }
   }
@@ -388,9 +410,10 @@ function readFieldTags(prev: ElasticsearchValue,
  *
  * @param type the type of the value
  * @param path the current path to the object we are in
+ * @param topTypeName the name of the SCThingType
  * @param tags tags attached to the value
  */
-function readTypeTags(type: string, path: string, tags: CommentTag[]): ElasticsearchValue {
+function readTypeTags(type: string, path: string, topTypeName: string, tags: CommentTag[]): ElasticsearchValue {
   let out: ElasticsearchValue = {type: ElasticsearchDataType.parse_error};
 
   if (typeof typemap[type] !== 'undefined') { // first look if the value has a definition in the typemap
@@ -398,8 +421,8 @@ function readTypeTags(type: string, path: string, tags: CommentTag[]): Elasticse
       if (!ignoredTagsList.includes(tags[i].tagName) && typeof typemap[type][tags[i].tagName] !== 'undefined') {
         // if we have a tag that indicates a type
         if (out.type !== ElasticsearchDataType.parse_error) {
-          composeErrorMessage(path, 'type', type, `Type conflict; "${typemap[type][tags[i].tagName]}" would` +
-            ` override "${out.type}"`);
+          composeErrorMessage(path, topTypeName, 'type', type,
+            `Type conflict; "${typemap[type][tags[i].tagName]}" would override "${out.type}"`);
           out.type = ElasticsearchDataType.type_conflict;
           continue;
         }
@@ -411,7 +434,7 @@ function readTypeTags(type: string, path: string, tags: CommentTag[]): Elasticse
       out.type = typemap[type].default;
     }
 
-    out = readFieldTags(out, path, tags, type);
+    out = readFieldTags(out, path, topTypeName, tags, type);
 
     return out;
   }
@@ -422,7 +445,7 @@ function readTypeTags(type: string, path: string, tags: CommentTag[]): Elasticse
     };
   }
 
-  composeErrorMessage(path, 'type', type, 'Not implemented type');
+  composeErrorMessage(path, topTypeName, 'type', type, 'Not implemented type');
 
   return out;
 }
@@ -440,8 +463,9 @@ function readTypeTags(type: string, path: string, tags: CommentTag[]): Elasticse
  */
 export function generateTemplate(projectReflection: ProjectReflection, ignoredTags: string[], showErrorOutput = true):
 // tslint:disable-next-line:completed-docs
-  { errors: string[]; template: ElasticsearchTemplate; } {
+  { aggregations: string[]; errors: string[]; template: ElasticsearchTemplate; } {
   errors = [];
+  aggregatablePaths = [];
   showErrors = showErrorOutput;
 
   ignoredTagsList = ['indexable', 'validatable'];
@@ -498,10 +522,10 @@ export function generateTemplate(projectReflection: ProjectReflection, ignoredTa
     }
 
     out.mappings._default_.properties[typeName] =
-      handleDeclarationReflection(_interface, [], '') as ElasticsearchObject;
+      handleDeclarationReflection(_interface, [], '', typeName) as ElasticsearchObject;
   }
 
   out.mappings._default_.dynamic_templates = dynamicTemplates;
 
-  return {template: out, errors};
+  return {aggregations: aggregatablePaths, template: out, errors};
 }