[no-ci] Add CI check to enforce labels and milestone on PRs

.github/workflows/pr-metadata-check.yml

@@ -0,0 +1,56 @@
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+name: "CI: Enforce label/milestone on PRs"
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - synchronize
+      - labeled
+      - unlabeled
+      # - milestoned
+      # - demilestoned
+
+jobs:
+  check-metadata:
+    name: PR has labels and milestone
+    if: github.repository_owner == 'NVIDIA'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check for labels and milestone
+        env:
+          LABELS: ${{ toJson(github.event.pull_request.labels) }}
+          MILESTONE: ${{ github.event.pull_request.milestone && github.event.pull_request.milestone.title || '' }}
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          IS_BOT: ${{ github.actor == 'dependabot[bot]' || github.actor == 'pre-commit-ci[bot]' || github.actor == 'copy-pr-bot[bot]' }}
+          IS_DRAFT: ${{ github.event.pull_request.draft }}
+        run: |
+          if [ "$IS_BOT" = "true" ] || [ "$IS_DRAFT" = "true" ]; then
+            echo "Skipping check for bot or draft PR."
+            exit 0
+          fi
+
+          LABEL_COUNT=$(echo "$LABELS" | jq 'length')
+          ERRORS=""
+
+          if [ "$LABEL_COUNT" -eq 0 ]; then
+            ERRORS="${ERRORS}  - Missing labels: add at least one label to categorize this PR.\n"
+          fi
+
+          if [ -z "$MILESTONE" ]; then
+            ERRORS="${ERRORS}  - Missing milestone: assign a milestone to this PR.\n"
+          fi
+
+          if [ -n "$ERRORS" ]; then
+            echo "::error::This PR is missing required metadata:"
+            printf "$ERRORS"
+            echo ""
+            echo "Please update the PR at: $PR_URL"
+            exit 1
+          fi
+
+          echo "PR has $LABEL_COUNT label(s) and milestone '$MILESTONE'."

AGENTS.md

@@ -12,6 +12,22 @@ guide for package-specific conventions and workflows.
 - `cuda_core/`: High-level Pythonic CUDA APIs built on top of bindings.
 - `cuda_python/`: Metapackage and docs aggregation.
 
+# Pull requests
+
+When creating pull requests with `gh pr create`, always assign at least one
+label and a milestone. CI enforces this via the `pr-metadata-check` workflow
+and will block PRs that are missing labels or a milestone. Use `--label` and
+`--milestone` flags, for example:
+
+```
+gh pr create --title "..." --body "..." --label "bug" --milestone "v1.0"
+```
+
+If you are unsure which label or milestone to use, check the existing labels
+and milestones on the repository with `gh label list` and `gh api
+repos/{owner}/{repo}/milestones --jq '.[].title'`, and pick the best match.
+
+
 # General
 
 - When searching for text or files, prefer using `rg` or `rg --files`