diff --git a/docs/.generated/plugin-sdk-api-baseline.sha256 b/docs/.generated/plugin-sdk-api-baseline.sha256
index d1e94f5dc8ac..84f39904e287 100644
--- a/docs/.generated/plugin-sdk-api-baseline.sha256
+++ b/docs/.generated/plugin-sdk-api-baseline.sha256
@@ -78,7 +78,7 @@ d8ca27a737f235e09f1a9f8cd4b82ac0cde96f10c662347b6ac82e27b70b4a40  module/lazy-ru
 fd00374a91ab5b393152bbbaf90010f9140cf15827bde360d0c6c8724ed34e2e  module/logging-core
 7670808d8c6227a52b2cddb72121aed9767313dd674f294a1f426dc185c13046  module/matrix
 a5f59c9acbcaa3f82247bf806eb5ba08032373fb853719f0ec9457690f16fc70  module/media-mime
-7b30827ec2f616ae9de0c1d81348a2112a41e9b4a8aeb8f072cfb1480d2eb864  module/media-runtime
+0c3d926d16e44d200018330b708065e9190f12ff8bce8321ae7bae184fe9de59  module/media-runtime
 7a5a1de743fff9d5a86515b501ffd88e7fa49970c9f46a5153816e2ebaef7bb0  module/media-store
 c5e3eb1a584f4b8126d9d6c177a840ec9103671e8d1242634ee67db9b5b9e573  module/media-understanding
 c0ffaed532578cf33493992e1ff806b2268b8e3774a92edbaede5cf5bda162a6  module/media-understanding-runtime
diff --git a/extensions/whatsapp/src/auto-reply/deliver-reply.test.ts b/extensions/whatsapp/src/auto-reply/deliver-reply.test.ts
index d8b8bd800084..75ad797fd759 100644
--- a/extensions/whatsapp/src/auto-reply/deliver-reply.test.ts
+++ b/extensions/whatsapp/src/auto-reply/deliver-reply.test.ts
@@ -1,9 +1,9 @@
 // Whatsapp tests cover deliver reply plugin behavior.
-import fsSync from "node:fs";
 import {
   createMessageReceiptFromOutboundResults,
   listMessageReceiptPlatformIds,
 } from "openclaw/plugin-sdk/channel-outbound";
+import { MEDIA_FFMPEG_MAX_AUDIO_DURATION_SECS } from "openclaw/plugin-sdk/media-runtime";
 import { logVerbose } from "openclaw/plugin-sdk/runtime-env";
 import { beforeAll, describe, expect, it, vi } from "vitest";
 import { createAcceptedWhatsAppSendResult } from "../inbound/send-result.test-helper.js";
@@ -14,7 +14,7 @@ import { cacheInboundMessageMeta } from "../quoted-message.js";
 import { withWhatsAppSocketOperationTimeout } from "../socket-timing.js";
 
 const hoisted = vi.hoisted(() => ({
-  runFfmpeg: vi.fn(),
+  transcodeAudioBufferToOpus: vi.fn(),
 }));
 
 vi.mock("openclaw/plugin-sdk/media-runtime", async () => {
@@ -23,7 +23,7 @@ vi.mock("openclaw/plugin-sdk/media-runtime", async () => {
   );
   return {
     ...actual,
-    runFfmpeg: hoisted.runFfmpeg,
+    transcodeAudioBufferToOpus: hoisted.transcodeAudioBufferToOpus,
   };
 });
 
@@ -927,10 +927,7 @@ describe("deliverWebReply", () => {
 
   it("transcodes mp3 audio media before sending a ptt voice note", async () => {
     vi.clearAllMocks();
-    hoisted.runFfmpeg.mockImplementation(async (args: string[]) => {
-      fsSync.writeFileSync(args.at(-1) ?? "", Buffer.from("opus-output"));
-      return "";
-    });
+    hoisted.transcodeAudioBufferToOpus.mockResolvedValue(Buffer.from("opus-output"));
     const msg = makeMsg();
     (
       loadWebMedia as unknown as { mockResolvedValueOnce: (v: unknown) => void }
@@ -950,16 +947,16 @@ describe("deliverWebReply", () => {
       skipLog: true,
     });
 
-    const ffmpegArgs = mockCallArg(hoisted.runFfmpeg, 0, 0, "runFfmpeg");
-    expect(Array.isArray(ffmpegArgs)).toBe(true);
-    const ffmpegArgList = ffmpegArgs as unknown[];
-    expect(ffmpegArgList).toContain("-c:a");
-    expect(ffmpegArgList).toContain("libopus");
-    expect(ffmpegArgList).toContain("-ar");
-    expect(ffmpegArgList).toContain("48000");
-    expect(ffmpegArgList).toContain("-b:a");
-    expect(ffmpegArgList).toContain("64k");
-    expect(ffmpegArgList.slice(-3, -1)).toEqual(["-f", "ogg"]);
+    expect(hoisted.transcodeAudioBufferToOpus).toHaveBeenCalledWith({
+      audioBuffer: Buffer.from("mp3"),
+      inputFileName: "voice.mp3",
+      tempPrefix: "whatsapp-voice-",
+      outputFileName: "voice.ogg",
+      maxDurationSeconds: MEDIA_FFMPEG_MAX_AUDIO_DURATION_SECS,
+      sampleRateHz: 48000,
+      channels: 1,
+      bitrate: "64k",
+    });
     const mediaPayload = requireRecord(
       mockCallArg(msg.platform.sendMedia, 0, 0, "sendMedia"),
       "sendMedia payload",
diff --git a/extensions/whatsapp/src/channel-react-action.test.ts b/extensions/whatsapp/src/channel-react-action.test.ts
index c49c259b2ec3..ca6e48ae0b46 100644
--- a/extensions/whatsapp/src/channel-react-action.test.ts
+++ b/extensions/whatsapp/src/channel-react-action.test.ts
@@ -206,12 +206,12 @@ describe("whatsapp react action messageId resolution", () => {
     expect(hoisted.sendMessageWhatsApp).not.toHaveBeenCalled();
   });
 
-  it("sends upload-file from the hydrated buffer payload", async () => {
+  it("sends upload-file from a whitespace-heavy base64 data URL", async () => {
     await handleWhatsAppMessageAction({
       action: "upload-file",
       params: {
         to: "+1555",
-        buffer: Buffer.from("hello").toString("base64"),
+        buffer: " \n DATA:text/plain;BASE64, aG Vs\nbG8= \n ",
         contentType: "text/plain",
         filename: "hello.txt",
         filePath: "/tmp/hello.txt",
@@ -240,23 +240,46 @@ describe("whatsapp react action messageId resolution", () => {
     });
   });
 
+  it.each(["SGVsbG8=!", "data:text/plain,hello", "data:text/plain;base64"])(
+    "rejects malformed upload-file buffer %s",
+    async (buffer) => {
+      await expect(
+        handleWhatsAppMessageAction({
+          action: "upload-file",
+          params: { to: "+1555", buffer },
+          cfg: baseCfg,
+          accountId: "default",
+        }),
+      ).rejects.toThrow("must be valid base64 or a base64 data URL");
+      expect(hoisted.sendMessageWhatsApp).not.toHaveBeenCalled();
+    },
+  );
+
   it("rejects upload-file buffers above the WhatsApp media limit", async () => {
     hoisted.resolveWhatsAppMediaMaxBytes.mockReturnValueOnce(4);
+    const encoded = Buffer.from("hello").toString("base64");
+    const bufferFromSpy = vi.spyOn(Buffer, "from");
 
-    await expect(
-      handleWhatsAppMessageAction({
-        action: "upload-file",
-        params: {
-          to: "+1555",
-          buffer: Buffer.from("hello").toString("base64"),
-          contentType: "text/plain",
-          filename: "hello.txt",
-        },
-        cfg: baseCfg,
-        accountId: "default",
-      }),
-    ).rejects.toThrow("WhatsApp upload-file buffer exceeds configured media limit");
-    expect(hoisted.sendMessageWhatsApp).not.toHaveBeenCalled();
+    try {
+      await expect(
+        handleWhatsAppMessageAction({
+          action: "upload-file",
+          params: {
+            to: "+1555",
+            buffer: encoded,
+            contentType: "text/plain",
+            filename: "hello.txt",
+          },
+          cfg: baseCfg,
+          accountId: "default",
+        }),
+      ).rejects.toThrow("WhatsApp upload-file buffer exceeds configured media limit");
+      const bufferFromCalls = bufferFromSpy.mock.calls as unknown[][];
+      expect(bufferFromCalls.some((call) => call[1] === "base64")).toBe(false);
+      expect(hoisted.sendMessageWhatsApp).not.toHaveBeenCalled();
+    } finally {
+      bufferFromSpy.mockRestore();
+    }
   });
 
   it("requires upload-file media path input", async () => {
diff --git a/extensions/whatsapp/src/channel-react-action.ts b/extensions/whatsapp/src/channel-react-action.ts
index c2869d09ddb2..9b255627865c 100644
--- a/extensions/whatsapp/src/channel-react-action.ts
+++ b/extensions/whatsapp/src/channel-react-action.ts
@@ -1,6 +1,7 @@
 // Whatsapp plugin module implements channel react action behavior.
 import { readBooleanParam } from "openclaw/plugin-sdk/boolean-param";
 import { jsonResult } from "openclaw/plugin-sdk/channel-actions";
+import { canonicalizeBase64, estimateBase64DecodedBytes } from "openclaw/plugin-sdk/media-runtime";
 import {
   isWhatsAppGroupJid,
   resolveAuthorizedWhatsAppOutboundTarget,
@@ -75,18 +76,8 @@ function readWhatsAppActionChatJid(params: WhatsAppMessageActionParams): string
 }
 
 function extractBase64Payload(encoded: string): string {
-  const match = /^data:[^;]+;base64,(.*)$/i.exec(encoded.trim());
-  const payload = match?.[1];
-  return payload !== undefined ? payload : encoded;
-}
-
-function estimateBase64DecodedBytes(encoded: string): number {
-  const compact = extractBase64Payload(encoded).replace(/\s/g, "");
-  if (!compact) {
-    return 0;
-  }
-  const padding = compact.endsWith("==") ? 2 : compact.endsWith("=") ? 1 : 0;
-  return Math.max(0, Math.floor((compact.length * 3) / 4) - padding);
+  const match = /^data:[^;]+;base64,(.*)$/is.exec(encoded.trim());
+  return match?.[1] ?? encoded;
 }
 
 function decodeUploadFileMediaPayload(params: {
@@ -100,8 +91,11 @@ function decodeUploadFileMediaPayload(params: {
       fileName?: string;
     }
   | undefined {
+  const payload = extractBase64Payload(params.encoded);
   if (params.maxBytes !== undefined) {
-    const estimatedBytes = estimateBase64DecodedBytes(params.encoded);
+    // Enforce the budget before canonicalization and decode so hostile input cannot force an
+    // oversized Buffer allocation before rejection.
+    const estimatedBytes = estimateBase64DecodedBytes(payload);
     if (estimatedBytes > params.maxBytes) {
       throw new Error(
         `WhatsApp upload-file buffer exceeds configured media limit (${estimatedBytes} bytes > ${params.maxBytes} bytes).`,
@@ -112,7 +106,11 @@ function decodeUploadFileMediaPayload(params: {
     readStringParam(params.args, "contentType") ?? readStringParam(params.args, "mimeType");
   const fileName =
     readStringParam(params.args, "filename") ?? readStringParam(params.args, "fileName");
-  const buffer = Buffer.from(extractBase64Payload(params.encoded), "base64");
+  const canonicalPayload = canonicalizeBase64(payload);
+  if (!canonicalPayload) {
+    throw new Error("WhatsApp upload-file buffer must be valid base64 or a base64 data URL.");
+  }
+  const buffer = Buffer.from(canonicalPayload, "base64");
   if (params.maxBytes !== undefined && buffer.byteLength > params.maxBytes) {
     throw new Error(
       `WhatsApp upload-file buffer exceeds configured media limit (${buffer.byteLength} bytes > ${params.maxBytes} bytes).`,
diff --git a/extensions/whatsapp/src/outbound-media-contract.ts b/extensions/whatsapp/src/outbound-media-contract.ts
index 7bfe146b8373..e206dc195a2c 100644
--- a/extensions/whatsapp/src/outbound-media-contract.ts
+++ b/extensions/whatsapp/src/outbound-media-contract.ts
@@ -1,11 +1,13 @@
 // Whatsapp plugin module implements outbound media contract behavior.
 import path from "node:path";
 import { sanitizeForPlainText } from "openclaw/plugin-sdk/channel-outbound";
-import { MEDIA_FFMPEG_MAX_AUDIO_DURATION_SECS, runFfmpeg } from "openclaw/plugin-sdk/media-runtime";
+import { mediaKindFromMime, normalizeMimeType } from "openclaw/plugin-sdk/media-mime";
+import {
+  MEDIA_FFMPEG_MAX_AUDIO_DURATION_SECS,
+  transcodeAudioBufferToOpus,
+} from "openclaw/plugin-sdk/media-runtime";
 import { resolveOutboundMediaUrls } from "openclaw/plugin-sdk/reply-payload";
-import { writeExternalFileWithinRoot } from "openclaw/plugin-sdk/security-runtime";
 import { normalizeUniqueStringEntries } from "openclaw/plugin-sdk/string-coerce-runtime";
-import { resolvePreferredOpenClawTmpDir, withTempWorkspace } from "openclaw/plugin-sdk/temp-path";
 import { resolveWhatsAppDocumentFileName } from "./document-filename.js";
 import {
   sanitizeAssistantVisibleText,
@@ -123,17 +125,7 @@ function inferWhatsAppMediaKind(
   ) {
     return media.kind;
   }
-  const contentType = normalizeContentType(media.contentType);
-  if (contentType.startsWith("image/")) {
-    return "image";
-  }
-  if (contentType.startsWith("audio/")) {
-    return "audio";
-  }
-  if (contentType.startsWith("video/")) {
-    return "video";
-  }
-  return "document";
+  return mediaKindFromMime(normalizeMimeType(media.contentType)) ?? "document";
 }
 
 function normalizeWhatsAppLoadedMedia(
@@ -189,16 +181,12 @@ export async function prepareWhatsAppOutboundMedia(
   };
 }
 
-function normalizeContentType(value: string | undefined): string {
-  return value?.split(";", 1)[0]?.trim().toLowerCase() ?? "";
-}
-
 function isWhatsAppNativeVoiceAudio(params: {
   contentType?: string;
   fileName?: string;
   mediaUrl?: string;
 }): boolean {
-  const contentType = normalizeContentType(params.contentType);
+  const contentType = normalizeMimeType(params.contentType);
   if (contentType === "audio/ogg" || contentType === "audio/opus") {
     return true;
   }
@@ -211,45 +199,16 @@ async function transcodeToWhatsAppVoiceOpus(params: {
   buffer: Buffer;
   fileName: string;
 }): Promise<Buffer> {
-  return await withTempWorkspace(
-    { rootDir: resolvePreferredOpenClawTmpDir(), prefix: "whatsapp-voice-" },
-    async (workspace) => {
-      const ext = path.extname(params.fileName).toLowerCase();
-      const inputExt = ext && ext.length <= 12 ? ext : ".audio";
-      const inputPath = await workspace.write(`input${inputExt}`, params.buffer);
-      await writeExternalFileWithinRoot({
-        rootDir: workspace.dir,
-        path: WHATSAPP_VOICE_FILE_NAME,
-        write: async (outputPath) => {
-          await runFfmpeg([
-            "-hide_banner",
-            "-loglevel",
-            "error",
-            "-y",
-            "-i",
-            inputPath,
-            "-vn",
-            "-sn",
-            "-dn",
-            "-t",
-            String(MEDIA_FFMPEG_MAX_AUDIO_DURATION_SECS),
-            "-ar",
-            String(WHATSAPP_VOICE_SAMPLE_RATE_HZ),
-            "-ac",
-            "1",
-            "-c:a",
-            "libopus",
-            "-b:a",
-            WHATSAPP_VOICE_BITRATE,
-            "-f",
-            "ogg",
-            outputPath,
-          ]);
-        },
-      });
-      return await workspace.read(WHATSAPP_VOICE_FILE_NAME);
-    },
-  );
+  return await transcodeAudioBufferToOpus({
+    audioBuffer: params.buffer,
+    inputFileName: params.fileName,
+    tempPrefix: "whatsapp-voice-",
+    outputFileName: WHATSAPP_VOICE_FILE_NAME,
+    maxDurationSeconds: MEDIA_FFMPEG_MAX_AUDIO_DURATION_SECS,
+    sampleRateHz: WHATSAPP_VOICE_SAMPLE_RATE_HZ,
+    channels: 1,
+    bitrate: WHATSAPP_VOICE_BITRATE,
+  });
 }
 
 function deriveWhatsAppDocumentFileName(mediaUrl: string | undefined): string | undefined {
diff --git a/extensions/whatsapp/src/outbound-media.runtime.ts b/extensions/whatsapp/src/outbound-media.runtime.ts
deleted file mode 100644
index e042fdf2371c..000000000000
--- a/extensions/whatsapp/src/outbound-media.runtime.ts
+++ /dev/null
@@ -1,42 +0,0 @@
-// Whatsapp plugin module implements outbound media behavior.
-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>;
-    optimizeImages?: boolean;
-  } = {},
-) {
-  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;
-  const sharedOptions = {
-    ...(options.maxBytes !== undefined ? { maxBytes: options.maxBytes } : {}),
-    ...(options.optimizeImages !== undefined ? { optimizeImages: options.optimizeImages } : {}),
-  };
-  return await loadWebMedia(
-    mediaUrl,
-    readFile
-      ? {
-          ...sharedOptions,
-          localRoots: "any",
-          readFile,
-          hostReadCapability: true,
-        }
-      : {
-          ...sharedOptions,
-          ...(localRoots ? { localRoots } : {}),
-        },
-  );
-}
diff --git a/extensions/whatsapp/src/runtime-api.ts b/extensions/whatsapp/src/runtime-api.ts
index 4f784d4456a9..279be0958dfb 100644
--- a/extensions/whatsapp/src/runtime-api.ts
+++ b/extensions/whatsapp/src/runtime-api.ts
@@ -20,7 +20,6 @@ import type { OpenClawConfig as RuntimeOpenClawConfig } from "openclaw/plugin-sd
 import { loadWhatsAppChannelRuntime } from "./channel-runtime-loader.js";
 
 export { type ChannelMessageActionName } from "openclaw/plugin-sdk/channel-contract";
-export { loadOutboundMediaFromUrl } from "./outbound-media.runtime.js";
 export {
   resolveWhatsAppGroupRequireMention,
   resolveWhatsAppGroupToolPolicy,
diff --git a/extensions/whatsapp/src/send.test.ts b/extensions/whatsapp/src/send.test.ts
index aa57648f13c5..36df13069ec6 100644
--- a/extensions/whatsapp/src/send.test.ts
+++ b/extensions/whatsapp/src/send.test.ts
@@ -14,7 +14,7 @@ import type { ActiveWebListener } from "./inbound/types.js";
 const hoisted = vi.hoisted(() => ({
   loadOutboundMediaFromUrl: vi.fn(),
   controllerListeners: new Map<string, ActiveWebListener>(),
-  runFfmpeg: vi.fn(),
+  transcodeAudioBufferToOpus: vi.fn(),
 }));
 const loadWebMediaMock = vi.fn();
 let sendMessageWhatsApp: typeof import("./send.js").sendMessageWhatsApp;
@@ -45,9 +45,9 @@ vi.mock("./connection-controller-runtime-context.js", async () => {
   };
 });
 
-vi.mock("./outbound-media.runtime.js", async () => {
-  const actual = await vi.importActual<typeof import("./outbound-media.runtime.js")>(
-    "./outbound-media.runtime.js",
+vi.mock("openclaw/plugin-sdk/outbound-media", async () => {
+  const actual = await vi.importActual<typeof import("openclaw/plugin-sdk/outbound-media")>(
+    "openclaw/plugin-sdk/outbound-media",
   );
   return {
     ...actual,
@@ -61,7 +61,7 @@ vi.mock("openclaw/plugin-sdk/media-runtime", async () => {
   );
   return {
     ...actual,
-    runFfmpeg: hoisted.runFfmpeg,
+    transcodeAudioBufferToOpus: hoisted.transcodeAudioBufferToOpus,
   };
 });
 
@@ -92,10 +92,7 @@ describe("web outbound", () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
-    hoisted.runFfmpeg.mockReset().mockImplementation(async (args: string[]) => {
-      fsSync.writeFileSync(args.at(-1) ?? "", Buffer.from("opus-output"));
-      return "";
-    });
+    hoisted.transcodeAudioBufferToOpus.mockReset().mockResolvedValue(Buffer.from("opus-output"));
     hoisted.loadOutboundMediaFromUrl.mockReset().mockImplementation(
       async (
         mediaUrl: string,
@@ -361,6 +358,27 @@ describe("web outbound", () => {
     expect(sendMessage).toHaveBeenNthCalledWith(2, "+1555", "voice note", undefined, undefined);
   });
 
+  it("normalizes MIME parameters when inferring media kind", async () => {
+    const buf = Buffer.from("image");
+    loadWebMediaMock.mockResolvedValueOnce({
+      buffer: buf,
+      contentType: " Image/PNG; charset=binary ",
+    });
+
+    await sendMessageWhatsApp("+1555", "caption", {
+      verbose: false,
+      cfg: WHATSAPP_TEST_CFG,
+      mediaUrl: "/tmp/image.png",
+    });
+
+    expect(sendMessage).toHaveBeenLastCalledWith(
+      "+1555",
+      "caption",
+      buf,
+      " Image/PNG; charset=binary ",
+    );
+  });
+
   it("reports the accepted voice send before a caption failure", async () => {
     const buf = Buffer.from("audio");
     loadWebMediaMock.mockResolvedValueOnce({
@@ -390,6 +408,7 @@ describe("web outbound", () => {
 
   it.each([
     { name: "mp3", contentType: "audio/mpeg", fileName: "voice.mp3" },
+    { name: "m4a", contentType: "audio/mp4; codecs=mp4a.40.2", fileName: "voice.m4a" },
     { name: "webm", contentType: "audio/webm", fileName: "voice.webm" },
   ])("transcodes $name audio to Ogg Opus before sending a PTT voice note", async (media) => {
     const buf = Buffer.from(media.name);
@@ -406,30 +425,16 @@ describe("web outbound", () => {
       mediaUrl: `/tmp/${media.fileName}`,
     });
 
-    expect(hoisted.runFfmpeg).toHaveBeenCalledTimes(1);
-    const ffmpegArgs = hoisted.runFfmpeg.mock.calls.at(0)?.[0] as string[] | undefined;
-    expect(ffmpegArgs?.slice(0, 5)).toEqual(["-hide_banner", "-loglevel", "error", "-y", "-i"]);
-    expect(ffmpegArgs?.[5]).toContain(`/input.${media.name}`);
-    expect(ffmpegArgs?.slice(6, -1)).toEqual([
-      "-vn",
-      "-sn",
-      "-dn",
-      "-t",
-      String(MEDIA_FFMPEG_MAX_AUDIO_DURATION_SECS),
-      "-ar",
-      "48000",
-      "-ac",
-      "1",
-      "-c:a",
-      "libopus",
-      "-b:a",
-      "64k",
-      "-f",
-      "ogg",
-    ]);
-    const outputPath = ffmpegArgs?.at(-1);
-    expect(outputPath).toContain("/fs-safe-output-");
-    expect(outputPath).toContain("-voice.ogg.part");
+    expect(hoisted.transcodeAudioBufferToOpus).toHaveBeenCalledWith({
+      audioBuffer: buf,
+      inputFileName: media.fileName,
+      tempPrefix: "whatsapp-voice-",
+      outputFileName: "voice.ogg",
+      maxDurationSeconds: MEDIA_FFMPEG_MAX_AUDIO_DURATION_SECS,
+      sampleRateHz: 48000,
+      channels: 1,
+      bitrate: "64k",
+    });
     expect(sendMessage).toHaveBeenNthCalledWith(
       1,
       "+1555",
diff --git a/extensions/whatsapp/src/send.ts b/extensions/whatsapp/src/send.ts
index f004e0cddbfe..71de26ee7425 100644
--- a/extensions/whatsapp/src/send.ts
+++ b/extensions/whatsapp/src/send.ts
@@ -8,6 +8,7 @@ import {
   convertMarkdownTables,
   resolveMarkdownTableMode,
 } from "openclaw/plugin-sdk/markdown-table-runtime";
+import { loadOutboundMediaFromUrl } from "openclaw/plugin-sdk/outbound-media";
 import { requireRuntimeConfig } from "openclaw/plugin-sdk/plugin-config-runtime";
 import { normalizePollInput, type PollInput } from "openclaw/plugin-sdk/poll-runtime";
 import { createSubsystemLogger, getChildLogger } from "openclaw/plugin-sdk/runtime-env";
@@ -25,7 +26,6 @@ import {
   prepareWhatsAppOutboundMedia,
   resolveAdditiveWhatsAppMediaUrls,
 } from "./outbound-media-contract.js";
-import { loadOutboundMediaFromUrl } from "./outbound-media.runtime.js";
 import { markdownToWhatsApp, toWhatsappJid } from "./text-runtime.js";
 
 const outboundLog = createSubsystemLogger("gateway/channels/whatsapp").child("outbound");
@@ -198,6 +198,8 @@ export async function sendMessageWhatsApp(
     if (mediaPayload) {
       media = await prepareWhatsAppOutboundMedia(mediaPayload, primaryMediaUrl);
     } else if (primaryMediaUrl) {
+      // Injected readers must carry an explicit local-root boundary. The shared loader enforces
+      // that contract; never restore the former implicit `localRoots: "any"` widening here.
       media = await prepareWhatsAppOutboundMedia(
         await loadOutboundMediaFromUrl(primaryMediaUrl, {
           maxBytes: resolveWhatsAppMediaMaxBytes(account),
diff --git a/src/media/audio-transcode.test.ts b/src/media/audio-transcode.test.ts
index a7c3af9e8049..571ede0fa777 100644
--- a/src/media/audio-transcode.test.ts
+++ b/src/media/audio-transcode.test.ts
@@ -1,6 +1,6 @@
 // Audio transcode tests cover ffmpeg-backed audio conversion behavior.
 import { existsSync, realpathSync } from "node:fs";
-import { readFile } from "node:fs/promises";
+import { readFile, writeFile } from "node:fs/promises";
 import path from "node:path";
 import { afterEach, describe, expect, it, vi } from "vitest";
 import { resolvePreferredOpenClawTmpDir } from "../infra/tmp-openclaw-dir.js";
@@ -105,6 +105,24 @@ describe("transcodeAudioBufferToOpus", () => {
     });
   });
 
+  it("passes the maximum duration to ffmpeg when requested", async () => {
+    runFfmpegMock.mockImplementationOnce(async (args: string[]) => {
+      const outputPath = args.at(-1);
+      if (!outputPath) {
+        throw new Error("missing ffmpeg output path");
+      }
+      await writeFile(outputPath, Buffer.from("ogg-opus-output"));
+    });
+
+    await transcodeAudioBufferToOpus({
+      audioBuffer: Buffer.from("source-m4a"),
+      maxDurationSeconds: 300,
+    });
+
+    const ffmpegArgs = firstMockCall(runFfmpegMock, "runFfmpeg")[0] as string[];
+    expect(ffmpegArgs).toEqual(expect.arrayContaining(["-t", "300", "-c:a", "libopus"]));
+  });
+
   it("keeps temp prefixes and output names inside the preferred temp root", async () => {
     let capturedInputPath: string | undefined;
     let capturedOutputPath: string | undefined;
diff --git a/src/media/audio-transcode.ts b/src/media/audio-transcode.ts
index ec2e07a7cb78..191960db2eae 100644
--- a/src/media/audio-transcode.ts
+++ b/src/media/audio-transcode.ts
@@ -43,6 +43,16 @@ function normalizeOutputFileName(value?: string): string {
   return DEFAULT_OUTPUT_FILE_NAME;
 }
 
+function resolveMaxDurationSeconds(value?: number): number | undefined {
+  if (value === undefined) {
+    return undefined;
+  }
+  if (!Number.isFinite(value) || value <= 0) {
+    throw new Error("maxDurationSeconds must be a positive finite number");
+  }
+  return value;
+}
+
 /** Transcodes arbitrary audio input into mono Opus using a scoped temp workspace. */
 export async function transcodeAudioBufferToOpus(params: {
   audioBuffer: Buffer;
@@ -54,7 +64,10 @@ export async function transcodeAudioBufferToOpus(params: {
   sampleRateHz?: number;
   bitrate?: string;
   channels?: number;
+  /** Maximum output duration passed to ffmpeg's `-t` option. */
+  maxDurationSeconds?: number;
 }): Promise<Buffer> {
+  const maxDurationSeconds = resolveMaxDurationSeconds(params.maxDurationSeconds);
   return await withTempWorkspace(
     {
       rootDir: resolvePreferredOpenClawTmpDir(),
@@ -81,6 +94,7 @@ export async function transcodeAudioBufferToOpus(params: {
               "-vn",
               "-sn",
               "-dn",
+              ...(maxDurationSeconds === undefined ? [] : ["-t", String(maxDurationSeconds)]),
               "-c:a",
               "libopus",
               "-b:a",
diff --git a/src/plugin-sdk/outbound-media.test.ts b/src/plugin-sdk/outbound-media.test.ts
index d94e0522df88..0aee92f5e96c 100644
--- a/src/plugin-sdk/outbound-media.test.ts
+++ b/src/plugin-sdk/outbound-media.test.ts
@@ -34,7 +34,7 @@ beforeEach(() => {
 });
 
 describe("loadOutboundMediaFromUrl", () => {
-  it("forwards maxBytes and mediaLocalRoots to loadWebMedia", async () => {
+  it("forwards media limits, local roots, and image optimization to loadWebMedia", async () => {
     loadWebMediaMock.mockResolvedValueOnce({
       buffer: Buffer.from("x"),
       kind: "image",
@@ -44,11 +44,13 @@ describe("loadOutboundMediaFromUrl", () => {
     await loadOutboundMediaFromUrl("file:///tmp/image.png", {
       maxBytes: 1024,
       mediaLocalRoots: ["/tmp/workspace-agent"],
+      optimizeImages: false,
     });
 
     expect(loadWebMediaMock).toHaveBeenCalledWith("file:///tmp/image.png", {
       maxBytes: 1024,
       localRoots: ["/tmp/workspace-agent"],
+      optimizeImages: false,
     });
   });
 
diff --git a/src/plugin-sdk/outbound-media.ts b/src/plugin-sdk/outbound-media.ts
index c7cb3591af71..b941267f4c44 100644
--- a/src/plugin-sdk/outbound-media.ts
+++ b/src/plugin-sdk/outbound-media.ts
@@ -22,6 +22,8 @@ export type OutboundMediaLoadOptions = {
   fetchImpl?: (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>;
   /** Extra fetch options merged into remote media requests. */
   requestInit?: RequestInit;
+  /** Whether shared media loading may optimize image payloads. */
+  optimizeImages?: boolean;
   /** Allows explicit proxy DNS behavior to be trusted by the media fetch guard. */
   trustExplicitProxyDns?: boolean;
 };
@@ -42,6 +44,7 @@ export async function loadOutboundMediaFromUrl(
       proxyUrl: options.proxyUrl,
       fetchImpl: options.fetchImpl,
       requestInit: options.requestInit,
+      optimizeImages: options.optimizeImages,
       trustExplicitProxyDns: options.trustExplicitProxyDns,
     }),
   );