diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0b61988375f..b92975f1054 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,6 +32,7 @@ Docs: https://docs.openclaw.ai
 - Channels/Yuanbao: register the Tencent Yuanbao external channel plugin (`openclaw-plugin-yuanbao`) in the official channel catalog, contract suites, and community plugin docs, with a new `docs/channels/yuanbao.md` quick-start guide for WebSocket bot DMs and group chats. (#72756) Thanks @loongfay.
 - Channels/QQBot: add full group chat support (history tracking, @-mention gating, activation modes, per-group config, FIFO message queue with deliver debounce), C2C `stream_messages` streaming with a `StreamingController` lifecycle manager, unified `sendMedia` with chunked upload for large files, and refactor the engine into pipeline stages, focused outbound submodules, builtin slash-command modules, and explicit DI ports via `createEngineAdapters()`. (#70624) Thanks @cxyhhhhh.
 - Plugins/startup: migrate bundled plugin manifests to explicit `activation.onStartup` declarations so Gateway startup imports only the bundled plugins that intentionally register startup-time runtime surfaces. Thanks @shakkernerd.
+- Plugins/startup: add an opt-in future-mode gate for disabling deprecated implicit startup sidecar loading while preserving explicit startup and narrower activation triggers. Thanks @shakkernerd.
 - Plugins/startup: add plugin compatibility warnings for deprecated implicit startup loading so authors can migrate to explicit `activation.onStartup` metadata. Thanks @shakkernerd.
 - Plugins/runtime: load bundled agent tool-result middleware from manifest contracts on demand so tokenjuice stays startup-lazy without losing Pi/Codex tool-output compaction. Thanks @shakkernerd.
 - Plugins/startup: add explicit `activation.onStartup` metadata so plugins can declare Gateway startup import behavior while the deprecated implicit sidecar fallback remains for legacy plugins. Thanks @shakkernerd.
diff --git a/docs/plugins/compatibility.md b/docs/plugins/compatibility.md
index 2f08bd886b9..b0359f47978 100644
--- a/docs/plugins/compatibility.md
+++ b/docs/plugins/compatibility.md
@@ -136,7 +136,8 @@ Current compatibility records include:
   move to `openclaw/plugin-sdk/channel-route`
 - activation hints that are being replaced by manifest contribution ownership
 - deprecated implicit startup sidecar loading for plugins that have not declared
-  `activation.onStartup`
+  `activation.onStartup`; maintainers can test the future stricter behavior with
+  `OPENCLAW_DISABLE_LEGACY_IMPLICIT_STARTUP_SIDECARS=1`
 - `setup-api` runtime fallback while setup descriptors move to cold
   `setup.requiresRuntime: false` metadata
 - provider `discovery` hooks while provider catalog hooks move to
diff --git a/docs/plugins/manifest.md b/docs/plugins/manifest.md
index 794d6bfcbfa..963163be27c 100644
--- a/docs/plugins/manifest.md
+++ b/docs/plugins/manifest.md
@@ -268,6 +268,12 @@ plugins unless they declare `activation.onStartup: true`. Plugin status and
 compatibility reports warn with `legacy-implicit-startup-sidecar` when a plugin
 still relies on that fallback.
 
+For migration testing, set
+`OPENCLAW_DISABLE_LEGACY_IMPLICIT_STARTUP_SIDECARS=1` to disable only that
+deprecated fallback. This opt-in mode does not block explicit
+`activation.onStartup: true` plugins or plugins loaded by channel, config,
+agent-harness, memory, or other narrower activation triggers.
+
 ```json
 {
   "activation": {
diff --git a/src/plugins/channel-plugin-ids.test.ts b/src/plugins/channel-plugin-ids.test.ts
index afc705ff0d8..d0432ba9d7b 100644
--- a/src/plugins/channel-plugin-ids.test.ts
+++ b/src/plugins/channel-plugin-ids.test.ts
@@ -662,6 +662,22 @@ describe("resolveGatewayStartupPluginIds", () => {
     });
   });
 
+  it("can disable deprecated implicit startup sidecar fallback for future-mode testing", () => {
+    expectStartupPluginIdsCase({
+      config: createStartupConfig({
+        enabledPluginIds: ["demo-global-sidecar"],
+        allowPluginIds: ["demo-global-sidecar"],
+        noConfiguredChannels: true,
+        memorySlot: "none",
+      }),
+      env: {
+        ...process.env,
+        OPENCLAW_DISABLE_LEGACY_IMPLICIT_STARTUP_SIDECARS: "1",
+      },
+      expected: [],
+    });
+  });
+
   it("skips deprecated implicit startup sidecar fallback when activation.onStartup is false", () => {
     expectStartupPluginIdsCase({
       config: createStartupConfig({
@@ -682,6 +698,10 @@ describe("resolveGatewayStartupPluginIds", () => {
         noConfiguredChannels: true,
         memorySlot: "none",
       }),
+      env: {
+        ...process.env,
+        OPENCLAW_DISABLE_LEGACY_IMPLICIT_STARTUP_SIDECARS: "1",
+      },
       expected: ["demo-global-explicit-startup"],
     });
   });
diff --git a/src/plugins/gateway-startup-plugin-ids.ts b/src/plugins/gateway-startup-plugin-ids.ts
index 13890c3d6c8..e930af24d53 100644
--- a/src/plugins/gateway-startup-plugin-ids.ts
+++ b/src/plugins/gateway-startup-plugin-ids.ts
@@ -20,6 +20,18 @@ import {
 } from "./plugin-registry-contributions.js";
 import { loadPluginRegistrySnapshot } from "./plugin-registry-snapshot.js";
 
+const DISABLE_LEGACY_IMPLICIT_STARTUP_SIDECARS_ENV =
+  "OPENCLAW_DISABLE_LEGACY_IMPLICIT_STARTUP_SIDECARS";
+
+function isTruthyEnvValue(value: string | undefined): boolean {
+  const normalized = value?.trim().toLowerCase();
+  return normalized === "1" || normalized === "true" || normalized === "yes" || normalized === "on";
+}
+
+function shouldDisableLegacyImplicitStartupSidecars(env: NodeJS.ProcessEnv): boolean {
+  return isTruthyEnvValue(env[DISABLE_LEGACY_IMPLICIT_STARTUP_SIDECARS_ENV]);
+}
+
 function listDisabledChannelIds(config: OpenClawConfig): Set<string> {
   const channels = config.channels;
   if (!channels || typeof channels !== "object" || Array.isArray(channels)) {
@@ -117,6 +129,7 @@ function resolveMemorySlotStartupPluginId(params: {
 function shouldConsiderForGatewayStartup(params: {
   plugin: InstalledPluginIndexRecord;
   manifest: PluginManifestRecord | undefined;
+  disableLegacyImplicitStartupSidecars: boolean;
   startupDreamingPluginIds: ReadonlySet<string>;
   memorySlotStartupPluginId?: string;
 }): boolean {
@@ -127,6 +140,9 @@ function shouldConsiderForGatewayStartup(params: {
     if (params.manifest?.activation?.onStartup === false) {
       return false;
     }
+    if (params.disableLegacyImplicitStartupSidecars) {
+      return false;
+    }
     // Deprecated compatibility fallback: plugins without explicit startup
     // activation metadata may still need startup import to register hooks or
     // services. All plugins should declare activation.onStartup explicitly as
@@ -383,6 +399,9 @@ export function resolveGatewayStartupPluginIdsFromRegistry(params: {
     collectConfiguredAgentHarnessRuntimes(activationSourceConfig, params.env),
   );
   const startupDreamingPluginIds = resolveGatewayStartupDreamingPluginIds(params.config);
+  const disableLegacyImplicitStartupSidecars = shouldDisableLegacyImplicitStartupSidecars(
+    params.env,
+  );
   const memorySlotStartupPluginId = resolveMemorySlotStartupPluginId({
     activationSourceConfig,
     activationSourcePlugins,
@@ -436,6 +455,7 @@ export function resolveGatewayStartupPluginIdsFromRegistry(params: {
         !shouldConsiderForGatewayStartup({
           plugin,
           manifest,
+          disableLegacyImplicitStartupSidecars,
           startupDreamingPluginIds,
           memorySlotStartupPluginId,
         })