From 87d1f9c08578390ee0084021f1980798d94086eb Mon Sep 17 00:00:00 2001
From: Oliver Borchert <oliver.borchert@quantco.com>
Date: Mon, 12 Oct 2026 14:38:16 +0200
Subject: [PATCH] feat: Always check dependency licenses with conda-deny

---
 template/.github/workflows/ci.yml.jinja | 14 ++++++++++
 template/README.md.jinja                | 15 +++++++++++
 template/pixi.toml.jinja                | 36 +++++++++++++++++++++++++
 tests/test_template.py                  | 19 +++++++++++++
 4 files changed, 84 insertions(+)

diff --git a/template/.github/workflows/ci.yml.jinja b/template/.github/workflows/ci.yml.jinja
index d6c60ad..c225378 100644
--- a/template/.github/workflows/ci.yml.jinja
+++ b/template/.github/workflows/ci.yml.jinja
@@ -28,6 +28,20 @@ jobs:
         run: pixi run lint
         env:
           CLICOLOR_FORCE: 1
+
+  conda-deny:
+    name: Verify Software License Compliance
+    timeout-minutes: 30
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out branch
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Set up pixi
+        uses: prefix-dev/setup-pixi@9dabb60412d3d2d967a8d682f7ce01317af40514 # v0.11.0
+      - name: Run conda-deny
+        run: pixi run conda-deny-check
+        env:
+          CLICOLOR_FORCE: 1
 {%- endraw %}
 
   pytest:
diff --git a/template/README.md.jinja b/template/README.md.jinja
index d213251..181af49 100644
--- a/template/README.md.jinja
+++ b/template/README.md.jinja
@@ -21,3 +21,18 @@ cd {{ project_slug }}
 pixi run pre-commit-install
 pixi run test
 ```
+
+## Dependency licenses
+
+CI runs [conda-deny](https://github.com/Quantco/conda-deny) to check dependency
+licenses across all environments and platforms in `pixi.lock`. Run it locally with:
+
+```bash
+pixi run conda-deny-check
+```
+
+The starter allowlist in `[tool.conda-deny]` in `pixi.toml` covers the generated
+development and test environments, including their runtime dependencies.
+Review and customize it for your project's license policy. Dependencies with
+unlisted or missing licenses fail the check. The local project itself is excluded;
+set and review its license separately.
diff --git a/template/pixi.toml.jinja b/template/pixi.toml.jinja
index 96c6b81..d993897 100644
--- a/template/pixi.toml.jinja
+++ b/template/pixi.toml.jinja
@@ -47,10 +47,12 @@ tombi = "*"
 pre-commit-hooks = "*"
 typos = "*"
 zizmor = "*"
+conda-deny = "*"
 
 [feature.lint.tasks]
 pre-commit-install = "lefthook install"
 lint = "lefthook run pre-commit --all-files"
+conda-deny-check = "conda-deny check"
 {%- if minimal_python_version <= "py310" %}
 
 [feature.py310.dependencies]
@@ -94,3 +96,37 @@ py313 = ["py313", "test"]
 {%- if minimal_python_version <= "py314" %}
 py314 = ["py314", "test"]
 {%- endif %}
+
+[tool.conda-deny]
+# Starter allowlist for the generated development and test environments.
+# Review this list for your project before adding dependencies.
+safe-licenses = [
+  "0BSD",
+  "AFL-2.1",
+  "Apache-2.0",
+  "Apache-2.0 WITH LLVM-exception",
+  "BSD-2-Clause",
+  "BSD-3-Clause",
+  "EPL-2.0",
+  "GPL-3.0-only",
+  "GPL-3.0-only WITH GCC-exception-3.1",
+  "ISC",
+  "LGPL-2.1-only",
+  "LGPL-2.1-or-later",
+  "LGPL-3.0-only",
+  "MIT",
+  "MPL-2.0",
+  "PSF-2.0",
+  "Python-2.0",
+  "TCL",
+  "X11",
+  "Zlib",
+  "blessing",
+  "bzip2-1.0.6",
+  "LicenseRef-Public-Domain",
+  # Windows runtime dependencies distributed through conda-forge.
+  "LicenseRef-MicrosoftVisualCpp2015-2022Runtime",
+  "LicenseRef-MicrosoftWindowsSDK10",
+]
+# Exclude the local project; this check covers third-party dependencies.
+ignore-packages = [{ package = "{{ project_slug }}" }]
diff --git a/tests/test_template.py b/tests/test_template.py
index 5de2af4..2b79879 100644
--- a/tests/test_template.py
+++ b/tests/test_template.py
@@ -1,6 +1,8 @@
 import subprocess
+import tomllib
 
 import pytest
+from ruamel.yaml import YAML
 
 
 def test_generation(generated_project, project_slug):
@@ -106,3 +108,20 @@ def test_minimal_python_version(generate_project, minimal_python_version: str):
         else:
             assert env not in pixi_toml
             assert env not in ci
+
+
+def test_conda_deny(generated_project):
+    manifest = tomllib.loads((generated_project / "pixi.toml").read_text())
+    lint = manifest["feature"]["lint"]
+    assert "conda-deny" in lint["dependencies"]
+    task = lint["tasks"]["conda-deny-check"]
+    assert task == "conda-deny check"
+    policy = manifest["tool"]["conda-deny"]
+    assert "MIT" in policy["safe-licenses"]
+    assert policy["ignore-packages"] == [{"package": manifest["workspace"]["name"]}]
+    workflow = YAML(typ="safe").load(
+        (generated_project / ".github/workflows/ci.yml").read_text()
+    )
+    job = workflow["jobs"]["conda-deny"]
+    assert "if" not in job
+    assert any(step.get("run") == "pixi run conda-deny-check" for step in job["steps"])