diff --git a/gates/profiles.py b/gates/profiles.py
index 17d4051..069ee4c 100644
--- a/gates/profiles.py
+++ b/gates/profiles.py
@@ -80,3 +80,21 @@ def delete_profile(base, pid):
     if d.exists():
         shutil.rmtree(d)
     return reg
+
+
+def duplicate_profile(base, src_id, name, new_id, ts=0):
+    reg = read_registry(base)
+    if not find_by_id(reg, src_id):
+        raise KeyError(src_id)
+    if find_by_name(reg, name):
+        raise ValueError(f"profile name already exists: {name}")
+    src = Path(base) / src_id
+    dst = Path(base) / new_id
+    if src.exists():
+        shutil.copytree(src, dst)
+    else:
+        dst.mkdir(parents=True, exist_ok=True)
+    entry = {"id": new_id, "name": name, "created": ts}
+    reg["profiles"].append(entry)
+    write_registry(base, reg)
+    return entry
diff --git a/tests/test_profiles.py b/tests/test_profiles.py
index 62f9a6f..40ecd1a 100644
--- a/tests/test_profiles.py
+++ b/tests/test_profiles.py
@@ -54,3 +54,16 @@ def test_delete_profile_removes_dir_and_entry(tmp_path):
     pr.delete_profile(str(tmp_path), "id1")
     assert not (tmp_path / "id1").exists()
     assert pr.find_by_id(pr.read_registry(str(tmp_path)), "id1") is None
+
+def test_duplicate_copies_images(tmp_path):
+    pr.create_profile(str(tmp_path), "src", "id1")
+    (tmp_path / "id1" / "img_0001.png").write_bytes(b"abc")
+    e = pr.duplicate_profile(str(tmp_path), "id1", "copy", "id2", ts=5)
+    assert e == {"id": "id2", "name": "copy", "created": 5}
+    assert (tmp_path / "id2" / "img_0001.png").read_bytes() == b"abc"
+
+def test_duplicate_duplicate_name_raises(tmp_path):
+    import pytest
+    pr.create_profile(str(tmp_path), "src", "id1")
+    with pytest.raises(ValueError):
+        pr.duplicate_profile(str(tmp_path), "id1", "src", "id2")