diff --git a/docs/.generated/plugin-sdk-api-baseline.sha256 b/docs/.generated/plugin-sdk-api-baseline.sha256
index 36aee4f0383..f6d2da78785 100644
--- a/docs/.generated/plugin-sdk-api-baseline.sha256
+++ b/docs/.generated/plugin-sdk-api-baseline.sha256
@@ -1,2 +1,2 @@
-15505f02306eb9920e350babf1b290d8fcc1b2338b4fccf65d3525de83d9bbcb  plugin-sdk-api-baseline.json
-06fc58082be4c2e1df1030fa9e8d965c6d5947984c4aed360c0474c1639a0a84  plugin-sdk-api-baseline.jsonl
+db3c843947298c9af4b5f5fa7ecde6656dba32189ec386c29192fe498d64e5e5  plugin-sdk-api-baseline.json
+c14586fd393a1375ee02ba507ffc83a2886d97632e323e5661b618c71624d26b  plugin-sdk-api-baseline.jsonl
diff --git a/extensions/discord/src/outbound-payload.contract.test.ts b/extensions/discord/src/outbound-payload.contract.test.ts
new file mode 100644
index 00000000000..f954036f4f3
--- /dev/null
+++ b/extensions/discord/src/outbound-payload.contract.test.ts
@@ -0,0 +1,38 @@
+import {
+  installChannelOutboundPayloadContractSuite,
+  primeChannelOutboundSendMock,
+  type OutboundPayloadHarnessParams,
+} from "openclaw/plugin-sdk/testing";
+import { describe, vi } from "vitest";
+import { discordOutbound } from "./outbound-adapter.js";
+
+function createDiscordHarness(params: OutboundPayloadHarnessParams) {
+  const sendDiscord = vi.fn();
+  primeChannelOutboundSendMock(
+    sendDiscord,
+    { messageId: "dc-1", channelId: "123456" },
+    params.sendResults,
+  );
+  const ctx = {
+    cfg: {},
+    to: "channel:123456",
+    text: "",
+    payload: params.payload,
+    deps: {
+      sendDiscord,
+    },
+  };
+  return {
+    run: async () => await discordOutbound.sendPayload!(ctx),
+    sendMock: sendDiscord,
+    to: ctx.to,
+  };
+}
+
+describe("Discord outbound payload contract", () => {
+  installChannelOutboundPayloadContractSuite({
+    channel: "discord",
+    chunking: { mode: "passthrough", longTextLength: 3000 },
+    createHarness: createDiscordHarness,
+  });
+});
diff --git a/extensions/slack/src/outbound-payload.contract.test.ts b/extensions/slack/src/outbound-payload.contract.test.ts
new file mode 100644
index 00000000000..b555d3ff74d
--- /dev/null
+++ b/extensions/slack/src/outbound-payload.contract.test.ts
@@ -0,0 +1,11 @@
+import { installChannelOutboundPayloadContractSuite } from "openclaw/plugin-sdk/testing";
+import { describe } from "vitest";
+import { createSlackOutboundPayloadHarness } from "./outbound-payload.test-harness.js";
+
+describe("Slack outbound payload contract", () => {
+  installChannelOutboundPayloadContractSuite({
+    channel: "slack",
+    chunking: { mode: "passthrough", longTextLength: 5000 },
+    createHarness: createSlackOutboundPayloadHarness,
+  });
+});
diff --git a/extensions/whatsapp/src/outbound-payload.contract.test.ts b/extensions/whatsapp/src/outbound-payload.contract.test.ts
new file mode 100644
index 00000000000..7f961066415
--- /dev/null
+++ b/extensions/whatsapp/src/outbound-payload.contract.test.ts
@@ -0,0 +1,34 @@
+import {
+  installChannelOutboundPayloadContractSuite,
+  primeChannelOutboundSendMock,
+  type OutboundPayloadHarnessParams,
+} from "openclaw/plugin-sdk/testing";
+import { describe, vi } from "vitest";
+import { whatsappOutbound } from "./outbound-adapter.js";
+
+function createWhatsAppHarness(params: OutboundPayloadHarnessParams) {
+  const sendWhatsApp = vi.fn();
+  primeChannelOutboundSendMock(sendWhatsApp, { messageId: "wa-1" }, params.sendResults);
+  const ctx = {
+    cfg: {},
+    to: "5511999999999@c.us",
+    text: "",
+    payload: params.payload,
+    deps: {
+      whatsapp: sendWhatsApp,
+    },
+  };
+  return {
+    run: async () => await whatsappOutbound.sendPayload!(ctx),
+    sendMock: sendWhatsApp,
+    to: ctx.to,
+  };
+}
+
+describe("WhatsApp outbound payload contract", () => {
+  installChannelOutboundPayloadContractSuite({
+    channel: "whatsapp",
+    chunking: { mode: "split", longTextLength: 5000, maxChunkLength: 4000 },
+    createHarness: createWhatsAppHarness,
+  });
+});
diff --git a/extensions/zalo/src/outbound-payload.contract.test.ts b/extensions/zalo/src/outbound-payload.contract.test.ts
new file mode 100644
index 00000000000..8367c38d1b7
--- /dev/null
+++ b/extensions/zalo/src/outbound-payload.contract.test.ts
@@ -0,0 +1,45 @@
+import {
+  installChannelOutboundPayloadContractSuite,
+  primeChannelOutboundSendMock,
+  type OutboundPayloadHarnessParams,
+} from "openclaw/plugin-sdk/testing";
+import { describe, vi } from "vitest";
+import { zaloPlugin } from "./channel.js";
+
+const { sendZaloTextMock } = vi.hoisted(() => ({
+  sendZaloTextMock: vi.fn(),
+}));
+
+vi.mock("./channel.runtime.js", () => ({
+  sendZaloText: sendZaloTextMock,
+}));
+
+function createZaloHarness(params: OutboundPayloadHarnessParams) {
+  const sendZalo = vi.fn();
+  primeChannelOutboundSendMock(sendZalo, { ok: true, messageId: "zl-1" }, params.sendResults);
+  sendZaloTextMock.mockReset().mockImplementation(
+    async (nextCtx: { to: string; text: string; mediaUrl?: string }) =>
+      await sendZalo(nextCtx.to, nextCtx.text, {
+        mediaUrl: nextCtx.mediaUrl,
+      }),
+  );
+  const ctx = {
+    cfg: {},
+    to: "123456789",
+    text: "",
+    payload: params.payload,
+  };
+  return {
+    run: async () => await zaloPlugin.outbound!.sendPayload!(ctx),
+    sendMock: sendZalo,
+    to: ctx.to,
+  };
+}
+
+describe("Zalo outbound payload contract", () => {
+  installChannelOutboundPayloadContractSuite({
+    channel: "zalo",
+    chunking: { mode: "split", longTextLength: 3000, maxChunkLength: 2000 },
+    createHarness: createZaloHarness,
+  });
+});
diff --git a/extensions/zalouser/src/channel.sendpayload.test.ts b/extensions/zalouser/src/channel.sendpayload.test.ts
index d39bc5b547d..1407ecb5418 100644
--- a/extensions/zalouser/src/channel.sendpayload.test.ts
+++ b/extensions/zalouser/src/channel.sendpayload.test.ts
@@ -1,4 +1,8 @@
-import { primeChannelOutboundSendMock } from "openclaw/plugin-sdk/testing";
+import {
+  installChannelOutboundPayloadContractSuite,
+  primeChannelOutboundSendMock,
+  type OutboundPayloadHarnessParams,
+} from "openclaw/plugin-sdk/testing";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import "./accounts.test-mocks.js";
 import "./zalo-js.test-mocks.js";
@@ -109,6 +113,38 @@ describe("zalouserPlugin outbound sendPayload", () => {
   });
 });
 
+describe("zalouserPlugin outbound payload contract", () => {
+  function createZalouserHarness(params: OutboundPayloadHarnessParams) {
+    const mockedSend = vi.mocked(sendModule.sendMessageZalouser);
+    setZalouserRuntime({
+      channel: {
+        text: {
+          resolveChunkMode: vi.fn(() => "length"),
+          resolveTextChunkLimit: vi.fn(() => 1200),
+        },
+      },
+    } as never);
+    primeChannelOutboundSendMock(mockedSend, { ok: true, messageId: "zlu-1" }, params.sendResults);
+    const ctx = {
+      cfg: {},
+      to: "user:987654321",
+      text: "",
+      payload: params.payload,
+    };
+    return {
+      run: async () => await zalouserPlugin.outbound!.sendPayload!(ctx),
+      sendMock: mockedSend,
+      to: "987654321",
+    };
+  }
+
+  installChannelOutboundPayloadContractSuite({
+    channel: "zalouser",
+    chunking: { mode: "passthrough", longTextLength: 3000 },
+    createHarness: createZalouserHarness,
+  });
+});
+
 describe("zalouserPlugin messaging target normalization", () => {
   it("normalizes user/group aliases to canonical targets", () => {
     const normalize = zalouserPlugin.messaging?.normalizeTarget;
diff --git a/src/channels/plugins/contracts/outbound-payload-testkit.ts b/src/channels/plugins/contracts/outbound-payload-testkit.ts
new file mode 100644
index 00000000000..53169bb885a
--- /dev/null
+++ b/src/channels/plugins/contracts/outbound-payload-testkit.ts
@@ -0,0 +1,134 @@
+import { beforeEach, expect, it, type Mock } from "vitest";
+import type { ReplyPayload } from "../../../plugin-sdk/reply-payload.js";
+import { resetGlobalHookRunner } from "../../../plugins/hook-runner-global.js";
+
+type PayloadLike = Pick<ReplyPayload, "mediaUrl" | "mediaUrls" | "text">;
+
+type SendResultLike = {
+  messageId: string;
+  [key: string]: unknown;
+};
+
+type ChunkingMode =
+  | {
+      longTextLength: number;
+      maxChunkLength: number;
+      mode: "split";
+    }
+  | {
+      longTextLength: number;
+      mode: "passthrough";
+    };
+
+type OutboundPayloadHarness = {
+  run: () => Promise<Record<string, unknown>>;
+  sendMock: Mock;
+  to: string;
+};
+
+export type OutboundPayloadHarnessParams = {
+  payload: PayloadLike;
+  sendResults?: SendResultLike[];
+};
+
+export function installChannelOutboundPayloadContractSuite(params: {
+  channel: string;
+  chunking: ChunkingMode;
+  createHarness: (
+    params: OutboundPayloadHarnessParams,
+  ) => OutboundPayloadHarness | Promise<OutboundPayloadHarness>;
+}) {
+  beforeEach(() => {
+    resetGlobalHookRunner();
+  });
+
+  it("text-only delegates to sendText", async () => {
+    const { run, sendMock, to } = await params.createHarness({
+      payload: { text: "hello" },
+    });
+    const result = await run();
+
+    expect(sendMock).toHaveBeenCalledTimes(1);
+    expect(sendMock).toHaveBeenCalledWith(to, "hello", expect.any(Object));
+    expect(result).toMatchObject({ channel: params.channel });
+  });
+
+  it("single media delegates to sendMedia", async () => {
+    const { run, sendMock, to } = await params.createHarness({
+      payload: { text: "cap", mediaUrl: "https://example.com/a.jpg" },
+    });
+    const result = await run();
+
+    expect(sendMock).toHaveBeenCalledTimes(1);
+    expect(sendMock).toHaveBeenCalledWith(
+      to,
+      "cap",
+      expect.objectContaining({ mediaUrl: "https://example.com/a.jpg" }),
+    );
+    expect(result).toMatchObject({ channel: params.channel });
+  });
+
+  it("multi-media iterates URLs with caption on first", async () => {
+    const { run, sendMock, to } = await params.createHarness({
+      payload: {
+        text: "caption",
+        mediaUrls: ["https://example.com/1.jpg", "https://example.com/2.jpg"],
+      },
+      sendResults: [{ messageId: "m-1" }, { messageId: "m-2" }],
+    });
+    const result = await run();
+
+    expect(sendMock).toHaveBeenCalledTimes(2);
+    expect(sendMock).toHaveBeenNthCalledWith(
+      1,
+      to,
+      "caption",
+      expect.objectContaining({ mediaUrl: "https://example.com/1.jpg" }),
+    );
+    expect(sendMock).toHaveBeenNthCalledWith(
+      2,
+      to,
+      "",
+      expect.objectContaining({ mediaUrl: "https://example.com/2.jpg" }),
+    );
+    expect(result).toMatchObject({ channel: params.channel, messageId: "m-2" });
+  });
+
+  it("empty payload returns no-op", async () => {
+    const { run, sendMock } = await params.createHarness({ payload: {} });
+    const result = await run();
+
+    expect(sendMock).not.toHaveBeenCalled();
+    expect(result).toEqual({ channel: params.channel, messageId: "" });
+  });
+
+  if (params.chunking.mode === "passthrough") {
+    it("text exceeding chunk limit is sent as-is when chunker is null", async () => {
+      const text = "a".repeat(params.chunking.longTextLength);
+      const { run, sendMock, to } = await params.createHarness({ payload: { text } });
+      const result = await run();
+
+      expect(sendMock).toHaveBeenCalledTimes(1);
+      expect(sendMock).toHaveBeenCalledWith(to, text, expect.any(Object));
+      expect(result).toMatchObject({ channel: params.channel });
+    });
+    return;
+  }
+
+  const chunking = params.chunking;
+
+  it("chunking splits long text", async () => {
+    const text = "a".repeat(chunking.longTextLength);
+    const { run, sendMock } = await params.createHarness({
+      payload: { text },
+      sendResults: [{ messageId: "c-1" }, { messageId: "c-2" }],
+    });
+    const result = await run();
+
+    expect(sendMock.mock.calls.length).toBeGreaterThanOrEqual(2);
+    for (const call of sendMock.mock.calls) {
+      expect((call[1] as string).length).toBeLessThanOrEqual(chunking.maxChunkLength);
+    }
+    expect(result).toMatchObject({ channel: params.channel });
+  });
+}
diff --git a/src/channels/plugins/contracts/outbound-payload.contract.test.ts b/src/channels/plugins/contracts/outbound-payload.contract.test.ts
index 1a0f1de8e5d..e0025a76ef7 100644
--- a/src/channels/plugins/contracts/outbound-payload.contract.test.ts
+++ b/src/channels/plugins/contracts/outbound-payload.contract.test.ts
@@ -1,35 +1,40 @@
-import { describe } from "vitest";
+import { describe, vi } from "vitest";
+import { createDirectTextMediaOutbound } from "../outbound/direct-text-media.js";
 import {
-  installDirectTextMediaOutboundPayloadContractSuite,
-  installDiscordOutboundPayloadContractSuite,
-  installSlackOutboundPayloadContractSuite,
-  installWhatsAppOutboundPayloadContractSuite,
-  installZaloOutboundPayloadContractSuite,
-  installZalouserOutboundPayloadContractSuite,
-} from "../../../../test/helpers/channels/outbound-payload-contract.js";
+  installChannelOutboundPayloadContractSuite,
+  type OutboundPayloadHarnessParams,
+} from "./outbound-payload-testkit.js";
+import { primeChannelOutboundSendMock } from "./test-helpers.js";
+
+function createDirectTextMediaHarness(params: OutboundPayloadHarnessParams) {
+  const sendFn = vi.fn();
+  primeChannelOutboundSendMock(sendFn, { messageId: "m1" }, params.sendResults);
+  const outbound = createDirectTextMediaOutbound({
+    channel: "direct-text-media",
+    resolveSender: () => sendFn,
+    resolveMaxBytes: () => undefined,
+    buildTextOptions: (opts) => opts as never,
+    buildMediaOptions: (opts) => opts as never,
+  });
+  const ctx = {
+    cfg: {},
+    to: "user1",
+    text: "",
+    payload: params.payload,
+  };
+  return {
+    run: async () => await outbound.sendPayload!(ctx),
+    sendMock: sendFn,
+    to: ctx.to,
+  };
+}
 
 describe("outbound payload contracts", () => {
-  describe("discord", () => {
-    installDiscordOutboundPayloadContractSuite();
-  });
-
-  describe("imessage", () => {
-    installDirectTextMediaOutboundPayloadContractSuite();
-  });
-
-  describe("slack", () => {
-    installSlackOutboundPayloadContractSuite();
-  });
-
-  describe("whatsapp", () => {
-    installWhatsAppOutboundPayloadContractSuite();
-  });
-
-  describe("zalo", () => {
-    installZaloOutboundPayloadContractSuite();
-  });
-
-  describe("zalouser", () => {
-    installZalouserOutboundPayloadContractSuite();
+  describe("direct text/media", () => {
+    installChannelOutboundPayloadContractSuite({
+      channel: "direct-text-media",
+      chunking: { mode: "split", longTextLength: 5000, maxChunkLength: 4000 },
+      createHarness: createDirectTextMediaHarness,
+    });
   });
 });
diff --git a/src/plugin-sdk/testing.ts b/src/plugin-sdk/testing.ts
index f2fc5290e92..69556c5a8e6 100644
--- a/src/plugin-sdk/testing.ts
+++ b/src/plugin-sdk/testing.ts
@@ -6,6 +6,10 @@ export {
   expectChannelInboundContextContract,
   primeChannelOutboundSendMock,
 } from "../channels/plugins/contracts/test-helpers.js";
+export {
+  installChannelOutboundPayloadContractSuite,
+  type OutboundPayloadHarnessParams,
+} from "../channels/plugins/contracts/outbound-payload-testkit.js";
 export { buildDispatchInboundCaptureMock } from "../channels/plugins/contracts/inbound-testkit.js";
 export {
   createCliRuntimeCapture,
diff --git a/test/helpers/channels/outbound-payload-contract.ts b/test/helpers/channels/outbound-payload-contract.ts
deleted file mode 100644
index ffe676709b3..00000000000
--- a/test/helpers/channels/outbound-payload-contract.ts
+++ /dev/null
@@ -1,409 +0,0 @@
-import { beforeEach, expect, it, type Mock, vi } from "vitest";
-import type { ReplyPayload } from "../../../src/auto-reply/types.js";
-import { primeChannelOutboundSendMock } from "../../../src/channels/plugins/contracts/test-helpers.js";
-import { createDirectTextMediaOutbound } from "../../../src/channels/plugins/outbound/direct-text-media.js";
-import type { ChannelOutboundAdapter } from "../../../src/channels/plugins/types.js";
-import { sendPayloadWithChunkedTextAndMedia } from "../../../src/plugin-sdk/reply-payload.js";
-import { chunkTextForOutbound } from "../../../src/plugin-sdk/text-chunking.js";
-import { resetGlobalHookRunner } from "../../../src/plugins/hook-runner-global.js";
-import { resolveRelativeBundledPluginPublicModuleId } from "../../../src/test-utils/bundled-plugin-public-surface.js";
-type CreateSlackOutboundPayloadHarness = (params: PayloadHarnessParams) => {
-  run: () => Promise<Record<string, unknown>>;
-  sendMock: Mock;
-  to: string;
-};
-
-const discordOutboundAdapterModuleId = resolveRelativeBundledPluginPublicModuleId({
-  fromModuleUrl: import.meta.url,
-  pluginId: "discord",
-  artifactBasename: "src/outbound-adapter.js",
-});
-const slackTestApiModuleId = resolveRelativeBundledPluginPublicModuleId({
-  fromModuleUrl: import.meta.url,
-  pluginId: "slack",
-  artifactBasename: "outbound-payload-test-api.js",
-});
-const whatsappTestApiModuleId = resolveRelativeBundledPluginPublicModuleId({
-  fromModuleUrl: import.meta.url,
-  pluginId: "whatsapp",
-  artifactBasename: "outbound-payload-test-api.js",
-});
-
-let discordOutboundCache: Promise<ChannelOutboundAdapter> | undefined;
-let slackTestApiPromise:
-  | Promise<{
-      createSlackOutboundPayloadHarness: CreateSlackOutboundPayloadHarness;
-    }>
-  | undefined;
-let whatsappTestApiPromise:
-  | Promise<{
-      whatsappOutbound: ChannelOutboundAdapter;
-    }>
-  | undefined;
-
-async function getDiscordOutbound(): Promise<ChannelOutboundAdapter> {
-  discordOutboundCache ??= (async () => {
-    const module = (await import(discordOutboundAdapterModuleId)) as {
-      discordOutbound: ChannelOutboundAdapter;
-    };
-    return module.discordOutbound;
-  })();
-  return await discordOutboundCache;
-}
-
-async function getCreateSlackOutboundPayloadHarness(): Promise<CreateSlackOutboundPayloadHarness> {
-  slackTestApiPromise ??= import(slackTestApiModuleId) as Promise<{
-    createSlackOutboundPayloadHarness: CreateSlackOutboundPayloadHarness;
-  }>;
-  const { createSlackOutboundPayloadHarness } = await slackTestApiPromise;
-  return createSlackOutboundPayloadHarness;
-}
-
-async function getWhatsAppOutboundAsync(): Promise<ChannelOutboundAdapter> {
-  whatsappTestApiPromise ??= import(whatsappTestApiModuleId) as Promise<{
-    whatsappOutbound: ChannelOutboundAdapter;
-  }>;
-  const { whatsappOutbound } = await whatsappTestApiPromise;
-  return whatsappOutbound;
-}
-
-type PayloadHarnessParams = {
-  payload: ReplyPayload;
-  sendResults?: Array<{ messageId: string }>;
-};
-
-type PayloadLike = {
-  mediaUrl?: string;
-  mediaUrls?: string[];
-  text?: string;
-};
-
-type SendResultLike = {
-  messageId: string;
-  [key: string]: unknown;
-};
-
-type ChunkingMode =
-  | {
-      longTextLength: number;
-      maxChunkLength: number;
-      mode: "split";
-    }
-  | {
-      longTextLength: number;
-      mode: "passthrough";
-    };
-
-function installChannelOutboundPayloadContractSuite(params: {
-  channel: string;
-  chunking: ChunkingMode;
-  createHarness: (params: { payload: PayloadLike; sendResults?: SendResultLike[] }) =>
-    | {
-        run: () => Promise<Record<string, unknown>>;
-        sendMock: Mock;
-        to: string;
-      }
-    | Promise<{
-        run: () => Promise<Record<string, unknown>>;
-        sendMock: Mock;
-        to: string;
-      }>;
-}) {
-  beforeEach(() => {
-    resetGlobalHookRunner();
-  });
-
-  it("text-only delegates to sendText", async () => {
-    const { run, sendMock, to } = await params.createHarness({
-      payload: { text: "hello" },
-    });
-    const result = await run();
-
-    expect(sendMock).toHaveBeenCalledTimes(1);
-    expect(sendMock).toHaveBeenCalledWith(to, "hello", expect.any(Object));
-    expect(result).toMatchObject({ channel: params.channel });
-  });
-
-  it("single media delegates to sendMedia", async () => {
-    const { run, sendMock, to } = await params.createHarness({
-      payload: { text: "cap", mediaUrl: "https://example.com/a.jpg" },
-    });
-    const result = await run();
-
-    expect(sendMock).toHaveBeenCalledTimes(1);
-    expect(sendMock).toHaveBeenCalledWith(
-      to,
-      "cap",
-      expect.objectContaining({ mediaUrl: "https://example.com/a.jpg" }),
-    );
-    expect(result).toMatchObject({ channel: params.channel });
-  });
-
-  it("multi-media iterates URLs with caption on first", async () => {
-    const { run, sendMock, to } = await params.createHarness({
-      payload: {
-        text: "caption",
-        mediaUrls: ["https://example.com/1.jpg", "https://example.com/2.jpg"],
-      },
-      sendResults: [{ messageId: "m-1" }, { messageId: "m-2" }],
-    });
-    const result = await run();
-
-    expect(sendMock).toHaveBeenCalledTimes(2);
-    expect(sendMock).toHaveBeenNthCalledWith(
-      1,
-      to,
-      "caption",
-      expect.objectContaining({ mediaUrl: "https://example.com/1.jpg" }),
-    );
-    expect(sendMock).toHaveBeenNthCalledWith(
-      2,
-      to,
-      "",
-      expect.objectContaining({ mediaUrl: "https://example.com/2.jpg" }),
-    );
-    expect(result).toMatchObject({ channel: params.channel, messageId: "m-2" });
-  });
-
-  it("empty payload returns no-op", async () => {
-    const { run, sendMock } = await params.createHarness({ payload: {} });
-    const result = await run();
-
-    expect(sendMock).not.toHaveBeenCalled();
-    expect(result).toEqual({ channel: params.channel, messageId: "" });
-  });
-
-  if (params.chunking.mode === "passthrough") {
-    it("text exceeding chunk limit is sent as-is when chunker is null", async () => {
-      const text = "a".repeat(params.chunking.longTextLength);
-      const { run, sendMock, to } = await params.createHarness({ payload: { text } });
-      const result = await run();
-
-      expect(sendMock).toHaveBeenCalledTimes(1);
-      expect(sendMock).toHaveBeenCalledWith(to, text, expect.any(Object));
-      expect(result).toMatchObject({ channel: params.channel });
-    });
-    return;
-  }
-
-  const chunking = params.chunking;
-
-  it("chunking splits long text", async () => {
-    const text = "a".repeat(chunking.longTextLength);
-    const { run, sendMock } = await params.createHarness({
-      payload: { text },
-      sendResults: [{ messageId: "c-1" }, { messageId: "c-2" }],
-    });
-    const result = await run();
-
-    expect(sendMock.mock.calls.length).toBeGreaterThanOrEqual(2);
-    for (const call of sendMock.mock.calls) {
-      expect((call[1] as string).length).toBeLessThanOrEqual(chunking.maxChunkLength);
-    }
-    expect(result).toMatchObject({ channel: params.channel });
-  });
-}
-
-function buildChannelSendResult(channel: string, result: Record<string, unknown>) {
-  return {
-    channel,
-    messageId: typeof result.messageId === "string" ? result.messageId : "",
-  };
-}
-
-function createDiscordHarness(params: PayloadHarnessParams) {
-  const sendDiscord = vi.fn();
-  primeChannelOutboundSendMock(
-    sendDiscord,
-    { messageId: "dc-1", channelId: "123456" },
-    params.sendResults,
-  );
-  const ctx = {
-    cfg: {},
-    to: "channel:123456",
-    text: "",
-    payload: params.payload,
-    deps: {
-      sendDiscord,
-    },
-  };
-  return {
-    run: async () => await (await getDiscordOutbound()).sendPayload!(ctx),
-    sendMock: sendDiscord,
-    to: ctx.to,
-  };
-}
-
-function createWhatsAppHarness(params: PayloadHarnessParams) {
-  const sendWhatsApp = vi.fn();
-  primeChannelOutboundSendMock(sendWhatsApp, { messageId: "wa-1" }, params.sendResults);
-  const ctx = {
-    cfg: {},
-    to: "5511999999999@c.us",
-    text: "",
-    payload: params.payload,
-    deps: {
-      whatsapp: sendWhatsApp,
-    },
-  };
-  return {
-    run: async () => await (await getWhatsAppOutboundAsync()).sendPayload!(ctx),
-    sendMock: sendWhatsApp,
-    to: ctx.to,
-  };
-}
-
-function createDirectTextMediaHarness(params: PayloadHarnessParams) {
-  const sendFn = vi.fn();
-  primeChannelOutboundSendMock(sendFn, { messageId: "m1" }, params.sendResults);
-  const outbound = createDirectTextMediaOutbound({
-    channel: "imessage",
-    resolveSender: () => sendFn,
-    resolveMaxBytes: () => undefined,
-    buildTextOptions: (opts) => opts as never,
-    buildMediaOptions: (opts) => opts as never,
-  });
-  const ctx = {
-    cfg: {},
-    to: "user1",
-    text: "",
-    payload: params.payload,
-  };
-  return {
-    run: async () => await outbound.sendPayload!(ctx),
-    sendMock: sendFn,
-    to: ctx.to,
-  };
-}
-
-function createZaloHarness(params: PayloadHarnessParams) {
-  const sendZalo = vi.fn();
-  primeChannelOutboundSendMock(sendZalo, { ok: true, messageId: "zl-1" }, params.sendResults);
-  const ctx = {
-    cfg: {},
-    to: "123456789",
-    text: "",
-    payload: params.payload,
-  };
-  return {
-    run: async () =>
-      await sendPayloadWithChunkedTextAndMedia({
-        ctx,
-        textChunkLimit: 2000,
-        chunker: chunkTextForOutbound,
-        sendText: async (nextCtx) =>
-          buildChannelSendResult(
-            "zalo",
-            await sendZalo(nextCtx.to, nextCtx.text, {
-              accountId: undefined,
-              cfg: nextCtx.cfg,
-            }),
-          ),
-        sendMedia: async (nextCtx) =>
-          buildChannelSendResult(
-            "zalo",
-            await sendZalo(nextCtx.to, nextCtx.text, {
-              accountId: undefined,
-              cfg: nextCtx.cfg,
-              mediaUrl: nextCtx.mediaUrl,
-            }),
-          ),
-        emptyResult: { channel: "zalo", messageId: "" },
-      }),
-    sendMock: sendZalo,
-    to: ctx.to,
-  };
-}
-
-function createZalouserHarness(params: PayloadHarnessParams) {
-  const sendZalouser = vi.fn();
-  primeChannelOutboundSendMock(sendZalouser, { ok: true, messageId: "zlu-1" }, params.sendResults);
-  const ctx = {
-    cfg: {},
-    to: "987654321",
-    text: "",
-    payload: params.payload,
-  };
-  return {
-    run: async () =>
-      await sendPayloadWithChunkedTextAndMedia({
-        ctx,
-        sendText: async (nextCtx) => {
-          return buildChannelSendResult(
-            "zalouser",
-            await sendZalouser(nextCtx.to, nextCtx.text, {
-              profile: "default",
-              isGroup: false,
-              textMode: "markdown",
-              textChunkMode: "length",
-              textChunkLimit: 1200,
-            }),
-          );
-        },
-        sendMedia: async (nextCtx) => {
-          return buildChannelSendResult(
-            "zalouser",
-            await sendZalouser(nextCtx.to, nextCtx.text, {
-              profile: "default",
-              isGroup: false,
-              mediaUrl: nextCtx.mediaUrl,
-              textMode: "markdown",
-              textChunkMode: "length",
-              textChunkLimit: 1200,
-            }),
-          );
-        },
-        emptyResult: { channel: "zalouser", messageId: "" },
-      }),
-    sendMock: sendZalouser,
-    to: ctx.to,
-  };
-}
-
-export function installSlackOutboundPayloadContractSuite() {
-  installChannelOutboundPayloadContractSuite({
-    channel: "slack",
-    chunking: { mode: "passthrough", longTextLength: 5000 },
-    createHarness: async (params) => (await getCreateSlackOutboundPayloadHarness())(params),
-  });
-}
-
-export function installDiscordOutboundPayloadContractSuite() {
-  installChannelOutboundPayloadContractSuite({
-    channel: "discord",
-    chunking: { mode: "passthrough", longTextLength: 3000 },
-    createHarness: createDiscordHarness,
-  });
-}
-
-export function installWhatsAppOutboundPayloadContractSuite() {
-  installChannelOutboundPayloadContractSuite({
-    channel: "whatsapp",
-    chunking: { mode: "split", longTextLength: 5000, maxChunkLength: 4000 },
-    createHarness: createWhatsAppHarness,
-  });
-}
-
-export function installZaloOutboundPayloadContractSuite() {
-  installChannelOutboundPayloadContractSuite({
-    channel: "zalo",
-    chunking: { mode: "split", longTextLength: 3000, maxChunkLength: 2000 },
-    createHarness: createZaloHarness,
-  });
-}
-
-export function installZalouserOutboundPayloadContractSuite() {
-  installChannelOutboundPayloadContractSuite({
-    channel: "zalouser",
-    chunking: { mode: "passthrough", longTextLength: 3000 },
-    createHarness: createZalouserHarness,
-  });
-}
-
-export function installDirectTextMediaOutboundPayloadContractSuite() {
-  installChannelOutboundPayloadContractSuite({
-    channel: "imessage",
-    chunking: { mode: "split", longTextLength: 5000, maxChunkLength: 4000 },
-    createHarness: createDirectTextMediaHarness,
-  });
-}