@@ -0,0 +1,62 @@
+name: Label external contributions
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - reopened
+      - ready_for_review
+
+permissions: {}
+
+jobs:
+  label:
+    if: >-
+      github.event.pull_request.draft == false &&
+      github.event.pull_request.user.type == 'User' &&
+      github.event.pull_request.author_association != 'MEMBER' &&
+      github.event.pull_request.author_association != 'OWNER'
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    permissions:
+      issues: write
+    concurrency:
+      group: label-external-contribution-${{ github.event.pull_request.number }}
+      cancel-in-progress: false
+
+    steps:
+      - name: Add external contribution label
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          github-token: ${{ github.token }}
+          script: |
+            const label = 'external-contribution';
+            const pullRequest = context.payload.pull_request;
+
+            if (pullRequest.labels.some(({ name }) => name === label)) {
+              return;
+            }
+
+            if (context.payload.action !== 'opened') {
+              const events = await github.paginate(
+                github.rest.issues.listEvents,
+                {
+                  ...context.repo,
+                  issue_number: pullRequest.number,
+                  per_page: 100,
+                },
+              );
+              if (
+                events.some(({ event, label: eventLabel }) =>
+                  event === 'unlabeled' && eventLabel?.name === label
+                )
+              ) {
+                return;
+              }
+            }
+
+            await github.rest.issues.addLabels({
+              ...context.repo,
+              issue_number: pullRequest.number,
+              labels: [label],
+            });