diff --git a/libs/backend-apisix-standalone/e2e/resources/global-rule.e2e-spec.ts b/libs/backend-apisix-standalone/e2e/resources/global-rule.e2e-spec.ts
new file mode 100644
index 00000000..ebb334c0
--- /dev/null
+++ b/libs/backend-apisix-standalone/e2e/resources/global-rule.e2e-spec.ts
@@ -0,0 +1,105 @@
+import { Differ } from '@api7/adc-differ';
+import * as ADCSDK from '@api7/adc-sdk';
+import axios from 'axios';
+
+import { BackendAPISIXStandalone } from '../../src';
+import { defaultBackendOptions, server1, token1 } from '../support/constants';
+import { dumpConfiguration, restartAPISIX, syncEvents } from '../support/utils';
+
+describe('Global Rule E2E', () => {
+  let backend: BackendAPISIXStandalone;
+
+  beforeAll(async () => {
+    await restartAPISIX();
+    backend = new BackendAPISIXStandalone({
+      server: server1,
+      token: token1,
+      cacheKey: 'default',
+      ...defaultBackendOptions,
+    });
+  });
+
+  describe('Sync and dump global rules', () => {
+    const plugin1Name = 'request-id';
+    const plugin1 = {} as ADCSDK.GlobalRule;
+    const plugin2Name = 'prometheus';
+    const plugin2 = { prefer_name: true } as unknown as ADCSDK.GlobalRule;
+
+    it('Initialize cache', () =>
+      expect(dumpConfiguration(backend)).resolves.not.toThrow());
+
+    it('Create global rules', async () => {
+      const events = Differ.diff(
+        { global_rules: { [plugin1Name]: plugin1, [plugin2Name]: plugin2 } },
+        {},
+      );
+      expect(events).toHaveLength(2);
+      expect(events.every((e) => e.type === ADCSDK.EventType.CREATE)).toBe(true);
+      await syncEvents(backend, events);
+    });
+
+    it('Dump', async () => {
+      const result = (await dumpConfiguration(backend)) as ADCSDK.Configuration;
+      expect(Object.keys(result.global_rules!)).toHaveLength(2);
+      expect(result.global_rules![plugin1Name]).toMatchObject(plugin1);
+      expect(result.global_rules![plugin2Name]).toMatchObject(plugin2);
+    });
+
+    it('Second sync is a no-op (idempotency regression test for #489)', async () => {
+      const { global_rules_conf_version: versionBefore } = (
+        await axios.get(`${server1}/apisix/admin/configs`, {
+          headers: { 'X-API-KEY': token1 },
+        })
+      ).data;
+
+      const events = Differ.diff(
+        { global_rules: { [plugin1Name]: plugin1, [plugin2Name]: plugin2 } },
+        await dumpConfiguration(backend),
+      );
+      expect(events).toHaveLength(0);
+      await syncEvents(backend, events);
+
+      const { global_rules_conf_version: versionAfter } = (
+        await axios.get(`${server1}/apisix/admin/configs`, {
+          headers: { 'X-API-KEY': token1 },
+        })
+      ).data;
+      expect(versionAfter).toEqual(versionBefore);
+    });
+
+    it('Update plugin1', async () => {
+      const updatedPlugin1 = { enable: false } as unknown as ADCSDK.GlobalRule;
+      const events = Differ.diff(
+        {
+          global_rules: {
+            [plugin1Name]: updatedPlugin1,
+            [plugin2Name]: plugin2,
+          },
+        },
+        await dumpConfiguration(backend),
+      );
+      expect(events).toHaveLength(1);
+      expect(events[0].type).toBe(ADCSDK.EventType.UPDATE);
+      expect(events[0].resourceId).toBe(plugin1Name);
+      await syncEvents(backend, events);
+    });
+
+    it('Dump again (plugin1 updated)', async () => {
+      const result = (await dumpConfiguration(backend)) as ADCSDK.Configuration;
+      expect(result.global_rules![plugin1Name]).toMatchObject({ enable: false });
+      expect(result.global_rules![plugin2Name]).toMatchObject(plugin2);
+    });
+
+    it('Delete all global rules', async () => {
+      const events = Differ.diff({}, await dumpConfiguration(backend));
+      expect(events).toHaveLength(2);
+      expect(events.every((e) => e.type === ADCSDK.EventType.DELETE)).toBe(true);
+      await syncEvents(backend, events);
+    });
+
+    it('Dump again (all global rules removed)', async () => {
+      const result = (await dumpConfiguration(backend)) as ADCSDK.Configuration;
+      expect(Object.keys(result.global_rules!)).toHaveLength(0);
+    });
+  });
+});
diff --git a/libs/backend-apisix-standalone/src/transformer.ts b/libs/backend-apisix-standalone/src/transformer.ts
index c776dfcc..74495496 100644
--- a/libs/backend-apisix-standalone/src/transformer.ts
+++ b/libs/backend-apisix-standalone/src/transformer.ts
@@ -170,17 +170,18 @@ export const toADC = (input: typing.APISIXStandalone) => {
         }))
         .map(ADCSDK.utils.recursiveOmitUndefined) ?? [],
     global_rules: Object.fromEntries(
-      input.global_rules
-        ?.map((globalRule) => [globalRule.id, globalRule.plugins![0]])
-        .map(ADCSDK.utils.recursiveOmitUndefined) ?? [],
+      input.global_rules?.flatMap((gr) =>
+        Object.entries(gr.plugins ?? {}).map(([k, v]) => [
+          k,
+          ADCSDK.utils.recursiveOmitUndefined(v as Record<string, unknown>),
+        ]),
+      ) ?? [],
     ),
     plugin_metadata: Object.fromEntries(
-      input.plugin_metadata
-        ?.map((pluginMetadata) => {
-          const { id, ...rest } = pluginMetadata;
-          return [id, rest];
-        })
-        .map(ADCSDK.utils.recursiveOmitUndefined) ?? [],
+      input.plugin_metadata?.map((pluginMetadata) => {
+        const { id, ...rest } = pluginMetadata;
+        return [id, ADCSDK.utils.recursiveOmitUndefined(rest)];
+      }) ?? [],
     ),
   } satisfies ADCSDK.Configuration as ADCSDK.Configuration;
 };