diff --git a/.github/scripts/cla/manage-label.mjs b/.github/scripts/cla/manage-label.mjs
new file mode 100644
index 00000000000..a899f1fc4dd
--- /dev/null
+++ b/.github/scripts/cla/manage-label.mjs
@@ -0,0 +1,83 @@
+// Invoked from .github/workflows/ci-cla-check.yml via actions/github-script.
+//
+// Adds the `cla-signed` label when every contributor has signed, and
+// removes it otherwise. Idempotent: re-runs safely without duplicating
+// the label or erroring if it's already in the desired state. Creates
+// the label on first use so the workflow is self-contained.
+
+/**
+ * @typedef { InstanceType<typeof import("@actions/github/lib/utils").GitHub> } GitHubInstance
+ * @typedef { import("@actions/github/lib/context").Context } Context
+ * @typedef { typeof import("@actions/core") } Core
+ */
+
+const LABEL_NAME = 'cla-signed';
+const LABEL_COLOR = '0e8a16'; // GitHub's standard green
+const LABEL_DESCRIPTION = 'All contributors on this PR have signed the CLA';
+
+/**
+ * @param {{ github: GitHubInstance, context: Context, core: Core }} params
+ */
+export default async function manageClaLabel({ github, context, core }) {
+	const { owner, repo } = context.repo;
+	const issue_number = Number(process.env.PR_NUMBER);
+	const allSigned = process.env.ALL_SIGNED === 'true';
+
+	if (allSigned) {
+		// Make sure the label exists before trying to apply it — addLabels
+		// errors if the label is missing from the repo.
+		try {
+			await github.rest.issues.getLabel({ owner, repo, name: LABEL_NAME });
+		} catch (e) {
+			if (errorStatus(e) === 404) {
+				try {
+					await github.rest.issues.createLabel({
+						owner,
+						repo,
+						name: LABEL_NAME,
+						color: LABEL_COLOR,
+						description: LABEL_DESCRIPTION,
+					});
+				} catch (createErr) {
+					// 422 = race with a parallel run that just created it. Fine.
+					if (errorStatus(createErr) !== 422) throw createErr;
+				}
+			} else {
+				throw e;
+			}
+		}
+
+		await github.rest.issues.addLabels({
+			owner,
+			repo,
+			issue_number,
+			labels: [LABEL_NAME],
+		});
+		core.info(`Applied "${LABEL_NAME}" label to PR #${issue_number}`);
+	} else {
+		// 404 just means the label wasn't on the PR — nothing to undo.
+		try {
+			await github.rest.issues.removeLabel({
+				owner,
+				repo,
+				issue_number,
+				name: LABEL_NAME,
+			});
+			core.info(`Removed "${LABEL_NAME}" label from PR #${issue_number}`);
+		} catch (e) {
+			if (errorStatus(e) !== 404) throw e;
+		}
+	}
+}
+
+/**
+ * Octokit's request errors carry an HTTP `status` field, but TypeScript
+ * sees catch parameters as `unknown`. This guard narrows safely.
+ * @param {unknown} e
+ * @returns {number | undefined}
+ */
+function errorStatus(e) {
+	return typeof e === 'object' && e !== null && 'status' in e && typeof e.status === 'number'
+		? e.status
+		: undefined;
+}
diff --git a/.github/scripts/cla/update-pr-comment.mjs b/.github/scripts/cla/update-pr-comment.mjs
index 50b87da0b2c..5a16bca25e8 100644
--- a/.github/scripts/cla/update-pr-comment.mjs
+++ b/.github/scripts/cla/update-pr-comment.mjs
@@ -51,9 +51,7 @@ export default async function updatePRComment({ github, context }) {
 	} else {
 		const lines = [MARKER, '## CLA signatures required', ''];
 		lines.push(`Thank you for your submission! We really appreciate it.
-Like many open source projects, we ask that you sign our [Contributor License Agreement](${process.env.CLA_SIGN_URL}) before we can accept your contribution.
-
-After signing, please comment \`\`\`/cla-check\`\`\` to re-check signature status.`);
+Like many open source projects, we ask that you sign our [Contributor License Agreement](${process.env.CLA_SIGN_URL}) before we can accept your contribution.`);
 		lines.push('');
 
 		if (unsigned.length > 0) {
diff --git a/.github/workflows/ci-cla-check.yml b/.github/workflows/ci-cla-check.yml
index 9d233d038d1..37448dfd8fe 100644
--- a/.github/workflows/ci-cla-check.yml
+++ b/.github/workflows/ci-cla-check.yml
@@ -148,6 +148,22 @@ jobs:
             const mod = await import('${{ github.workspace }}/.github/scripts/cla/update-pr-comment.mjs');
             await mod.default({ github, context, core });
 
+      - name: Manage cla-signed label
+        # Skip on merge_group (no PR) and when the check produced no result.
+        if: >-
+          always() &&
+          steps.context.outputs.pr_number != '' &&
+          steps.check.outputs.all_signed != ''
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
+        env:
+          PR_NUMBER: ${{ steps.context.outputs.pr_number }}
+          ALL_SIGNED: ${{ steps.check.outputs.all_signed }}
+        with:
+          github-token: ${{ steps.generate-token.outputs.token }}
+          script: |
+            const mod = await import('${{ github.workspace }}/.github/scripts/cla/manage-label.mjs');
+            await mod.default({ github, context, core });
+
       - name: React to /cla-check comment
         if: always() && github.event_name == 'issue_comment' && steps.check.outputs.all_signed != ''
         uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8