diff --git a/swh/indexer/metadata_dictionary.py b/swh/indexer/metadata_dictionary.py
--- a/swh/indexer/metadata_dictionary.py
+++ b/swh/indexer/metadata_dictionary.py
@@ -166,24 +166,26 @@
     def normalize_repository(self, d):
         """https://docs.npmjs.com/files/package.json#repository"""
         if isinstance(d, dict):
-            return '{type}+{url}'.format(**d)
+            url = '{type}+{url}'.format(**d)
         elif isinstance(d, str):
             if '://' in d:
-                return d
+                url = d
             elif ':' in d:
                 (schema, rest) = d.split(':', 1)
                 if schema in self._schema_shortcuts:
-                    return self._schema_shortcuts[schema] + rest
+                    url = self._schema_shortcuts[schema] + rest
                 else:
                     return None
             else:
-                return self._schema_shortcuts['github'] + d
+                url = self._schema_shortcuts['github'] + d
 
         else:
             return None
 
+        return {'@id': url}
+
     def normalize_bugs(self, d):
-        return '{url}'.format(**d)
+        return {'@id': '{url}'.format(**d)}
 
     _parse_author = re.compile(r'^ *'
                                r'(?P<name>.*?)'
@@ -211,8 +213,14 @@
         if email:
             author[SCHEMA_URI+'email'] = email
         if url:
-            author[SCHEMA_URI+'url'] = url
-        return author
+            author[SCHEMA_URI+'url'] = {'@id': url}
+        return {"@list": [author]}
+
+    def normalize_license(self, s):
+        return {"@id": "https://spdx.org/licenses/" + s}
+
+    def normalize_homepage(self, s):
+        return {"@id": s}
 
 
 @register_mapping
@@ -265,7 +273,10 @@
             url = os.path.join(url, *d['groupId'].split('.'))
             if d['artifactId']:
                 url = os.path.join(url, d['artifactId'])
-        return url
+        return {"@id": url}
+
+    def normalize_groupId(self, id_):
+        return {"@id": id_}
 
 
 def main():
diff --git a/swh/indexer/tests/test_metadata.py b/swh/indexer/tests/test_metadata.py
--- a/swh/indexer/tests/test_metadata.py
+++ b/swh/indexer/tests/test_metadata.py
@@ -130,13 +130,13 @@
             'name': 'test_metadata',
             'version': '0.0.2',
             'description': 'Simple package.json test for indexer',
-            'schema:codeRepository':
+            'codeRepository':
                 'git+https://github.com/moranegg/metadata_test',
-            'schema:author': {
+            'author': [{
                 'type': 'Person',
                 'name': 'Morane G',
                 'email': 'moranegg@example.com',
-            },
+            }],
         }
 
         # when
@@ -154,20 +154,20 @@
             'name': 'test_1',
             'version': '0.0.2',
             'description': 'Simple package.json test for indexer',
-            'schema:codeRepository':
+            'codeRepository':
                 'git+https://github.com/moranegg/metadata_test',
         }, {
             '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
             'name': 'test_0_1',
             'version': '0.0.2',
             'description': 'Simple package.json test for indexer',
-            'schema:codeRepository':
+            'codeRepository':
                 'git+https://github.com/moranegg/metadata_test'
         }, {
             '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
             'name': 'test_metadata',
             'version': '0.0.2',
-            'schema:author': 'moranegg',
+            'author': 'moranegg',
         }]
 
         # when
@@ -179,8 +179,8 @@
             "version": '0.0.2',
             "description": 'Simple package.json test for indexer',
             "name": ['test_1', 'test_0_1', 'test_metadata'],
-            "schema:author": 'moranegg',
-            "schema:codeRepository":
+            "author": ['moranegg'],
+            "codeRepository":
                 'git+https://github.com/moranegg/metadata_test',
         }
         self.assertEqual(expected_results, results)
@@ -213,7 +213,7 @@
             'translated_metadata': {
                 '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
                 'type': 'SoftwareSourceCode',
-                'schema:codeRepository':
+                'codeRepository':
                     'git+https://github.com/moranegg/metadata_test',
                 'description': 'Simple package.json test for indexer',
                 'name': 'test_metadata',
@@ -224,18 +224,18 @@
             'translated_metadata': {
                 '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
                 'type': 'SoftwareSourceCode',
-                'codemeta:issueTracker':
+                'issueTracker':
                     'https://github.com/npm/npm/issues',
-                'schema:author': {
+                'author': [{
                     'type': 'Person',
                     'name': 'Isaac Z. Schlueter',
                     'email': 'i@izs.me',
-                    'schema:url': 'http://blog.izs.me',
-                },
-                'schema:codeRepository':
+                    'url': 'http://blog.izs.me',
+                }],
+                'codeRepository':
                     'git+https://github.com/npm/npm',
                 'description': 'a package manager for JavaScript',
-                'schema:license': 'Artistic-2.0',
+                'license': 'https://spdx.org/licenses/Artistic-2.0',
                 'version': '5.0.3',
                 'name': 'npm',
                 'keywords': [
@@ -244,7 +244,7 @@
                     'package manager',
                     'package.json'
                 ],
-                'schema:url': 'https://docs.npmjs.com/'
+                'url': 'https://docs.npmjs.com/'
             },
             'id': hash_to_bytes('d4c647f0fc257591cc9ba1722484229780d1c607')
             }, {
@@ -432,9 +432,9 @@
             '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
             'type': 'SoftwareSourceCode',
             'name': 'Maven Default Project',
-            'schema:identifier': 'com.mycompany.app',
+            'identifier': 'com.mycompany.app',
             'version': '1.2.3',
-            'schema:codeRepository':
+            'codeRepository':
                 'http://repo1.maven.org/maven2/com/mycompany/app/my-app',
             })
 
@@ -453,17 +453,17 @@
             'translated_metadata': {
                 '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
                 'type': 'SoftwareSourceCode',
-                'codemeta:issueTracker':
+                'issueTracker':
                     'https://github.com/librariesio/yarn-parser/issues',
                 'version': '1.0.0',
                 'name': 'yarn-parser',
-                'schema:author': 'Andrew Nesbitt',
+                'author': ['Andrew Nesbitt'],
                 'url':
                     'https://github.com/librariesio/yarn-parser#readme',
                 'processorRequirements': {'node': '7.5'},
                 'license': 'AGPL-3.0',
                 'keywords': ['yarn', 'parse', 'lock', 'dependencies'],
-                'schema:codeRepository':
+                'codeRepository':
                     'git+https://github.com/librariesio/yarn-parser.git',
                 'description':
                     'Tiny web service for parsing yarn.lock files',
@@ -485,14 +485,14 @@
                 '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
                 'url':
                     'https://github.com/librariesio/yarn-parser#readme',
-                'schema:codeRepository':
+                'codeRepository':
                     'git+https://github.com/librariesio/yarn-parser.git',
-                'schema:author': 'Andrew Nesbitt',
+                'author': ['Andrew Nesbitt'],
                 'license': 'AGPL-3.0',
                 'version': '1.0.0',
                 'description':
                     'Tiny web service for parsing yarn.lock files',
-                'codemeta:issueTracker':
+                'issueTracker':
                     'https://github.com/librariesio/yarn-parser/issues',
                 'name': 'yarn-parser',
                 'keywords': ['yarn', 'parse', 'lock', 'dependencies'],