diff --git a/tests/test_codebase_genome_status.py b/tests/test_codebase_genome_status.py
new file mode 100644
index 0000000..3c94fdf
--- /dev/null
+++ b/tests/test_codebase_genome_status.py
@@ -0,0 +1,113 @@
+from __future__ import annotations
+
+import importlib.util
+import json
+import pathlib
+import sys
+import tempfile
+import unittest
+
+ROOT = pathlib.Path(__file__).resolve().parents[1]
+SCRIPT = ROOT / 'scripts' / 'codebase_genome_status.py'
+
+spec = importlib.util.spec_from_file_location('codebase_genome_status', str(SCRIPT))
+mod = importlib.util.module_from_spec(spec)
+sys.modules['codebase_genome_status'] = mod
+spec.loader.exec_module(mod)
+
+
+class TestCodebaseGenomeStatus(unittest.TestCase):
+    def test_fetch_org_repo_names_ignores_archived_and_dot_repos(self):
+        payloads = [
+            [
+                {'name': 'timmy-home', 'archived': False},
+                {'name': '.profile', 'archived': False},
+                {'name': 'old-repo', 'archived': True},
+            ],
+            [],
+        ]
+
+        class FakeResponse:
+            def __init__(self, payload):
+                self.payload = json.dumps(payload).encode('utf-8')
+            def read(self):
+                return self.payload
+            def __enter__(self):
+                return self
+            def __exit__(self, exc_type, exc, tb):
+                return False
+
+        def fake_urlopen(req, timeout=30):
+            return FakeResponse(payloads.pop(0))
+
+        with tempfile.TemporaryDirectory() as tmp:
+            token_file = pathlib.Path(tmp) / 'token'
+            token_file.write_text('demo-token')
+            from unittest.mock import patch
+            with patch('codebase_genome_status.urllib.request.urlopen', side_effect=fake_urlopen):
+                repos = mod.fetch_org_repo_names('Timmy_Foundation', 'https://forge.example.com', token_file)
+        self.assertEqual(repos, ['timmy-home'])
+
+    def test_collects_artifacts_tests_and_duplicates(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            root = pathlib.Path(tmp)
+            (root / 'GENOME.md').write_text('# host genome\n')
+            (root / 'the-door-GENOME.md').write_text('# the-door\n')
+            (root / 'genomes' / 'the-nexus').mkdir(parents=True)
+            (root / 'genomes' / 'the-nexus' / 'GENOME.md').write_text('# the-nexus\n')
+            (root / 'genomes' / 'burn-fleet').mkdir(parents=True)
+            (root / 'genomes' / 'burn-fleet' / 'GENOME.md').write_text('# burn-fleet\n')
+            (root / 'genomes' / 'burn-fleet-GENOME.md').write_text('# burn-fleet duplicate\n')
+            (root / 'tests' / 'docs').mkdir(parents=True)
+            (root / 'tests' / 'docs' / 'test_the_door_genome.py').write_text('')
+            (root / 'tests' / 'test_the_nexus_genome.py').write_text('')
+            (root / 'tests' / 'test_codebase_genome_pipeline.py').write_text('')
+
+            summary = mod.build_status_summary(
+                repo_root=root,
+                expected_repos=['timmy-home', 'the-door', 'the-nexus', 'burn-fleet', 'wolf'],
+                state={'last_repo': 'the-nexus'},
+            )
+
+            self.assertEqual(summary['total_expected_repos'], 5)
+            self.assertEqual(summary['artifact_count'], 4)
+            self.assertEqual(summary['tested_artifact_count'], 3)
+            self.assertEqual(summary['next_uncovered_repo'], 'wolf')
+            self.assertEqual(summary['last_repo'], 'the-nexus')
+            self.assertEqual(summary['artifacts']['the-door']['has_test'], True)
+            self.assertEqual(summary['artifacts']['the-nexus']['has_test'], True)
+            self.assertEqual(summary['artifacts']['timmy-home']['has_test'], True)
+            self.assertIn('burn-fleet', summary['duplicates'])
+            self.assertEqual(summary['missing_repos'], ['wolf'])
+
+    def test_render_markdown_contains_required_sections(self):
+        summary = {
+            'generated_at': '2026-04-17T10:00:00Z',
+            'total_expected_repos': 3,
+            'artifact_count': 2,
+            'tested_artifact_count': 1,
+            'last_repo': 'the-door',
+            'next_uncovered_repo': 'wolf',
+            'missing_repos': ['wolf'],
+            'duplicates': {'burn-fleet': ['genomes/burn-fleet/GENOME.md', 'genomes/burn-fleet-GENOME.md']},
+            'artifacts': {
+                'timmy-home': {'artifact_paths': ['GENOME.md'], 'has_test': True},
+                'the-door': {'artifact_paths': ['the-door-GENOME.md'], 'has_test': False},
+            },
+        }
+        rendered = mod.render_markdown(summary)
+        for snippet in [
+            '# Codebase Genome Status',
+            '## Summary',
+            '## Coverage Matrix',
+            '## Missing Repo Artifacts',
+            '## Duplicate Artifact Paths',
+            'the-door-GENOME.md',
+            'genomes/burn-fleet/GENOME.md',
+            'wolf',
+        ]:
+            self.assertIn(snippet, rendered)
+
+
+if __name__ == '__main__':
+    unittest.main()