diff --git a/blenderpack.py b/blenderpack.py
index 68f7d41..1972a3b 100755
--- a/blenderpack.py
+++ b/blenderpack.py
@@ -14,13 +14,22 @@ import logging
 
 log = logging.getLogger(__name__)
 
-def report(msg):
-    # if __name__ == '__main__':
-    print("blenderpack:", msg)
+REQUIRED_KEYS = set(['name', 'blender'])
+SCHEMA_VERSION = 1
+
+def report(msg):
+    print("blenderpack:", msg, file=sys.stderr)
+
+def fatal_report(msg, code=1, ex=None):
+    if __name__ == '__main__':
+        # report("fatal: %s" % msg)
+        log.fatal(msg)
+        exit(code)
+    elif ex is not None:
+        raise Exception(msg) from ex
+    else:
+        raise RuntimeError("blenderpack: Unhandled fatal exception: %s" % msg)
 
-def fatal_report(msg, code=1):
-    report(msg)
-    exit(code)
 
 def fetch(url):
     # TODO: do conditional request
@@ -81,13 +90,42 @@ def extract_blinfo(path):
 
 
 
-def make_repo(path):
-    """Make repo.json for files in directory 'path'"""
-    # try:
-    for addon in os.listdir(path):
-        extract_blinfo(os.path.join(path, addon))
-    # except FileNotFoundError:
-    #     fatal_report("No such file or directory: '%s'" % path)
+def make_repo(outpath):
+    """Make repo.json for files in directory 'outpath'"""
+
+    repo_data = {}
+    package_data = []
+
+    try:
+        for addon in os.listdir(outpath):
+            package_datum = {}
+            addon_path = os.path.join(outpath, addon)
+
+            try:
+                bl_info = extract_blinfo(addon_path)
+                if not bl_info:
+                    raise Exception("No bl_info found in %s" % addon)
+            except Exception as err:
+                fatal_report('Could not extract bl_info from {}: {}'.format(addon_path, err))
+
+            if not REQUIRED_KEYS.issubset(set(bl_info)):
+                fatal_report(
+                        "Required key(s) '{}' not found in bl_info of '{}'".format(
+                            "', '".join(REQUIRED_KEYS.difference(set(bl_info))), addon),
+                        ex=Exception()
+                        )
+
+            package_datum['bl_info'] = bl_info
+            package_datum['type'] = 'addon'
+            package_data.append(package_datum)
+
+        repo_data['packages'] = package_data
+        with open(os.path.join(outpath, "repo.json"), 'w', encoding='utf-8') as repo_file:
+            json.dump(repo_data, repo_file, indent=4, sort_keys=True)
+
+
+    except FileNotFoundError:
+        fatal_report("No such file or directory: '%s'" % outpath)
 
 
 
diff --git a/tests/test_blenderpack.py b/tests/test_blenderpack.py
index f595f64..fd11cac 100644
--- a/tests/test_blenderpack.py
+++ b/tests/test_blenderpack.py
@@ -36,7 +36,9 @@ class test_blenderpack_make_repo(unittest.TestCase):
                 )
 
 
-    # def test_validpath(self):
-    #     blenderpack.make_repo(os.path.join('test_helpers', 'addons'))
+    def test_make_repo_valid(self):
+        blenderpack.make_repo(os.path.join(self.helper_path, 'addons'))
 
 
+    def test_make_repo_from_nonexistent(self):
+        blenderpack.make_repo(os.path.join(self.helper_path, 'addons'))