feat(packaging): gate the leiden extra by interpreter so Leiden works on 3.13+

README.md

@@ -255,7 +255,7 @@ Codex users also need `multi_agent = true` under `[features]` in `~/.codex/confi
 | `neo4j` | Neo4j push support | `uv tool install "graphifyy[neo4j]"` |
 | `falkordb` | FalkorDB push support | `uv tool install "graphifyy[falkordb]"` |
 | `svg` | SVG graph export | `uv tool install "graphifyy[svg]"` |
-| `leiden` | Leiden community detection (Python < 3.13 only) | `uv tool install "graphifyy[leiden]"` |
+| `leiden` | Leiden community detection (Python < 3.13: graspologic; 3.13+: the native abi3 wheel) | `uv tool install "graphifyy[leiden]"` |
 | `ollama` | Ollama local inference | `uv tool install "graphifyy[ollama]"` |
 | `openai` | OpenAI / OpenAI-compatible APIs | `uv tool install "graphifyy[openai]"` |
 | `gemini` | Google Gemini API | `uv tool install "graphifyy[gemini]"` |

pyproject.toml

@@ -62,7 +62,19 @@ falkordb = ["falkordb"]
 pdf = ["pypdf>=6.12.0", "markdownify"]
 watch = ["watchdog"]
 svg = ["matplotlib", "numpy>=2.0; python_version >= '3.13'"]
-leiden = ["graspologic; python_version < '3.13'"]
+# _partition() calls graspologic_native.leiden() directly (#3104). Below 3.13 the
+# graspologic distribution supplies that binding as a dependency of its own; from 3.13
+# graspologic's metadata excludes the interpreter, so name the binding directly there
+# and Leiden keeps working instead of silently falling back to NetworkX Louvain. The
+# arms are exhaustive, so `[leiden]` installs a working backend on every supported
+# interpreter. Ceiling: _native_leiden() passes eight exact keyword arguments and
+# swallows every exception, so a breaking major would return None and degrade to
+# Louvain silently -- the bug this gate exists to fix. It also keeps the arms
+# symmetric, since graspologic caps the same package below 2.0 on the other arm.
+leiden = [
+    "graspologic; python_version < '3.13'",
+    "graspologic-native>=1.2.1,<2.0.0; python_version >= '3.13'",
+]
 office = ["python-docx", "openpyxl"]
 google = ["openpyxl"]
 # --postgres reconstructs DDL and feeds it to extract_sql(), which needs the
@@ -98,7 +110,7 @@ commonlisp = ["tree-sitter-commonlisp"]
 # every platform, no C toolchain; optional because Robot Framework corpora are
 # QA-automation specific.
 robot = ["robotframework>=4.0"]
-all = ["mcp>=1,<3", "starlette>=1.3.1,<2", "neo4j", "falkordb", "pypdf>=6.12.0", "markdownify", "watchdog", "graspologic; python_version < '3.13'", "python-docx", "openpyxl", "faster-whisper; python_version >= '3.11'", "yt-dlp>=2026.6.9", "matplotlib", "numpy>=2.0; python_version >= '3.13'", "openai", "tiktoken", "boto3", "anthropic", "tree-sitter-sql", "jieba", "tree-sitter-dm", "tree-sitter-hcl", "tree-sitter-pascal", "tree-sitter-ocaml", "tree-sitter-commonlisp", "robotframework>=4.0"]
+all = ["mcp>=1,<3", "starlette>=1.3.1,<2", "neo4j", "falkordb", "pypdf>=6.12.0", "markdownify", "watchdog", "graspologic; python_version < '3.13'", "graspologic-native>=1.2.1,<2.0.0; python_version >= '3.13'", "python-docx", "openpyxl", "faster-whisper; python_version >= '3.11'", "yt-dlp>=2026.6.9", "matplotlib", "numpy>=2.0; python_version >= '3.13'", "openai", "tiktoken", "boto3", "anthropic", "tree-sitter-sql", "jieba", "tree-sitter-dm", "tree-sitter-hcl", "tree-sitter-pascal", "tree-sitter-ocaml", "tree-sitter-commonlisp", "robotframework>=4.0"]
 
 [project.scripts]
 graphify = "graphify.__main__:main"

tests/test_backend_extras.py

@@ -39,3 +39,28 @@ def test_backend_pkg_hint_points_at_uv_tool_and_extra():
     assert "uv tool install" in msg
     assert 'graphifyy[anthropic]' in msg
     assert "pip install anthropic" in msg  # pip/venv fallback still mentioned
+
+
+def _leiden_arms(extras: dict) -> dict[str, str]:
+    """Map each `leiden` requirement to its interpreter marker."""
+    return {dep.split(";")[0].strip(): dep.partition(";")[2].strip() for dep in extras["leiden"]}
+
+
+def test_leiden_extra_installs_a_working_backend_on_every_supported_python():
+    """`_partition()` calls graspologic_native.leiden() first and falls back to
+    NetworkX Louvain when the binding is absent. graspologic's own metadata stops at
+    3.13, so below that it supplies the binding and from 3.13 the extra must name it
+    directly -- otherwise `[leiden]` installs nothing on a current interpreter and
+    clustering silently loses Leiden. The two arms must stay complementary and
+    exhaustive, or some interpreter is left with no backend."""
+    arms = _leiden_arms(_extras())
+    assert arms.get("graspologic") == "python_version < '3.13'", f"below-3.13 arm: {arms}"
+    native = [pkg for pkg in arms if pkg.startswith("graspologic-native")]
+    assert len(native) == 1, f"expected exactly one graspologic-native arm, got {arms}"
+    assert arms[native[0]] == "python_version >= '3.13'", f"3.13+ arm: {arms}"
+    assert len(arms) == 2, f"a third arm leaves the gate ambiguous: {arms}"
+
+
+def test_all_extra_gates_leiden_the_same_way():
+    extras = _extras()
+    assert set(extras["leiden"]) <= set(extras["all"]), "[all] must carry both leiden arms"