diff --git a/extensions/whatsapp/src/outbound-media.runtime.ts b/extensions/whatsapp/src/outbound-media.runtime.ts
new file mode 100644
index 00000000000..5163b3c66df
--- /dev/null
+++ b/extensions/whatsapp/src/outbound-media.runtime.ts
@@ -0,0 +1,36 @@
+import { loadWebMedia } from "openclaw/plugin-sdk/web-media";
+
+export async function loadOutboundMediaFromUrl(
+  mediaUrl: string,
+  options: {
+    maxBytes?: number;
+    mediaAccess?: {
+      localRoots?: readonly string[];
+      readFile?: (filePath: string) => Promise<Buffer>;
+    };
+    mediaLocalRoots?: readonly string[];
+    mediaReadFile?: (filePath: string) => Promise<Buffer>;
+  } = {},
+) {
+  const readFile = options.mediaAccess?.readFile ?? options.mediaReadFile;
+  const localRoots =
+    options.mediaAccess?.localRoots?.length && options.mediaAccess.localRoots.length > 0
+      ? options.mediaAccess.localRoots
+      : options.mediaLocalRoots && options.mediaLocalRoots.length > 0
+        ? options.mediaLocalRoots
+        : undefined;
+  return await loadWebMedia(
+    mediaUrl,
+    readFile
+      ? {
+          ...(options.maxBytes !== undefined ? { maxBytes: options.maxBytes } : {}),
+          localRoots: "any",
+          readFile,
+          hostReadCapability: true,
+        }
+      : {
+          ...(options.maxBytes !== undefined ? { maxBytes: options.maxBytes } : {}),
+          ...(localRoots ? { localRoots } : {}),
+        },
+  );
+}
diff --git a/extensions/whatsapp/src/runtime-api.ts b/extensions/whatsapp/src/runtime-api.ts
index 269c72fd32d..65117feb430 100644
--- a/extensions/whatsapp/src/runtime-api.ts
+++ b/extensions/whatsapp/src/runtime-api.ts
@@ -18,7 +18,7 @@ export type { DmPolicy, GroupPolicy } from "openclaw/plugin-sdk/config-runtime";
 import type { OpenClawConfig as RuntimeOpenClawConfig } from "openclaw/plugin-sdk/config-runtime";
 
 export { type ChannelMessageActionName } from "openclaw/plugin-sdk/channel-contract";
-import { loadWebMedia } from "openclaw/plugin-sdk/web-media";
+export { loadOutboundMediaFromUrl } from "./outbound-media.runtime.js";
 export {
   resolveWhatsAppGroupRequireMention,
   resolveWhatsAppGroupToolPolicy,
@@ -58,38 +58,3 @@ export async function monitorWebChannel(
   const { monitorWebChannel } = await loadChannelRuntime();
   return await monitorWebChannel(...args);
 }
-
-export async function loadOutboundMediaFromUrl(
-  mediaUrl: string,
-  options: {
-    maxBytes?: number;
-    mediaAccess?: {
-      localRoots?: readonly string[];
-      readFile?: (filePath: string) => Promise<Buffer>;
-    };
-    mediaLocalRoots?: readonly string[];
-    mediaReadFile?: (filePath: string) => Promise<Buffer>;
-  } = {},
-) {
-  const readFile = options.mediaAccess?.readFile ?? options.mediaReadFile;
-  const localRoots =
-    options.mediaAccess?.localRoots?.length && options.mediaAccess.localRoots.length > 0
-      ? options.mediaAccess.localRoots
-      : options.mediaLocalRoots && options.mediaLocalRoots.length > 0
-        ? options.mediaLocalRoots
-        : undefined;
-  return await loadWebMedia(
-    mediaUrl,
-    readFile
-      ? {
-          ...(options.maxBytes !== undefined ? { maxBytes: options.maxBytes } : {}),
-          localRoots: "any",
-          readFile,
-          hostReadCapability: true,
-        }
-      : {
-          ...(options.maxBytes !== undefined ? { maxBytes: options.maxBytes } : {}),
-          ...(localRoots ? { localRoots } : {}),
-        },
-  );
-}
diff --git a/extensions/whatsapp/src/send.test.ts b/extensions/whatsapp/src/send.test.ts
index d4d4c403aba..b84fc7f0957 100644
--- a/extensions/whatsapp/src/send.test.ts
+++ b/extensions/whatsapp/src/send.test.ts
@@ -17,8 +17,10 @@ let setActiveWebListener: typeof import("./active-listener.js").setActiveWebList
 let resetLogger: typeof import("openclaw/plugin-sdk/runtime-env").resetLogger;
 let setLoggerOverride: typeof import("openclaw/plugin-sdk/runtime-env").setLoggerOverride;
 
-vi.mock("./runtime-api.js", async () => {
-  const actual = await vi.importActual<typeof import("./runtime-api.js")>("./runtime-api.js");
+vi.mock("./outbound-media.runtime.js", async () => {
+  const actual = await vi.importActual<typeof import("./outbound-media.runtime.js")>(
+    "./outbound-media.runtime.js",
+  );
   return {
     ...actual,
     loadOutboundMediaFromUrl: hoisted.loadOutboundMediaFromUrl,
diff --git a/extensions/whatsapp/src/send.ts b/extensions/whatsapp/src/send.ts
index 42c25b95289..5ae65fb59fb 100644
--- a/extensions/whatsapp/src/send.ts
+++ b/extensions/whatsapp/src/send.ts
@@ -12,7 +12,7 @@ import {
   resolveWhatsAppMediaMaxBytes,
 } from "./accounts.js";
 import { type ActiveWebSendOptions, requireActiveWebListener } from "./active-listener.js";
-import { loadOutboundMediaFromUrl } from "./runtime-api.js";
+import { loadOutboundMediaFromUrl } from "./outbound-media.runtime.js";
 import { markdownToWhatsApp, toWhatsappJid } from "./text-runtime.js";
 
 const outboundLog = createSubsystemLogger("gateway/channels/whatsapp").child("outbound");