diff --git a/apps/web/src/app/api/mcp/[tool]/route.ts b/apps/web/src/app/api/mcp/[tool]/route.ts
index 2049e21..20398b4 100644
--- a/apps/web/src/app/api/mcp/[tool]/route.ts
+++ b/apps/web/src/app/api/mcp/[tool]/route.ts
@@ -11,6 +11,8 @@ import {
 import { isIP } from "node:net";
 import { prisma } from "@/lib/prisma";
 import { runSubmissionInSandbox } from "@/lib/sandbox";
+import { summarizeRequestPayload } from "@/lib/audit";
+import { broadcastFomoEvent } from "@/lib/x-broadcaster";
 import { logAuditEvent } from "@/lib/audit";
 import { redis } from "@/lib/redis";
 import { authHold, capturePayment } from "@/lib/payment";
@@ -672,6 +674,24 @@ export async function POST(request: NextRequest, props: { params: Promise<{ tool
                   metadata: { overall_result: result.overall_result, error_classification: result.error_classification }
                 });
               });
+
+              // SPEED_RUN FOMO Broadcaster
+              if (result.overall_result === JudgeOverallResult.PASS) {
+                const solveTimeMs = new Date().getTime() - new Date(taskObj.created_at).getTime();
+                const solveTimeMinutes = Math.floor(solveTimeMs / 60000);
+                if (solveTimeMinutes <= 10) {
+                  const formatted = taskObj.reward_currency === "USD" 
+                    ? `$${(taskObj.reward_amount / 100).toFixed(0)}` 
+                    : `NT$${taskObj.reward_amount}`;
+                  void broadcastFomoEvent({
+                    type: "SPEED_RUN",
+                    taskId: taskObj.id,
+                    amountFormatted: formatted,
+                    timeToSolveMinutes: Math.max(1, solveTimeMinutes)
+                  });
+                }
+              }
+
             }).catch(console.error);
           }
         }
@@ -742,6 +762,16 @@ export async function POST(request: NextRequest, props: { params: Promise<{ tool
           }
         });
 
+        // A2A Subcontracting FOMO
+        const formatted = subTask.reward_currency === "USD"
+          ? `$${(subTask.reward_amount / 100).toFixed(0)}`
+          : `NT$${subTask.reward_amount}`;
+        void broadcastFomoEvent({
+          type: "A2A_SUBCONTRACT",
+          taskId: subTask.id,
+          amountFormatted: formatted
+        });
+
         return NextResponse.json({
           sub_task_id: subTask.id,
           status: subTask.status,
diff --git a/apps/web/src/app/api/webhooks/stripe/route.ts b/apps/web/src/app/api/webhooks/stripe/route.ts
index 5df34c6..345c0df 100644
--- a/apps/web/src/app/api/webhooks/stripe/route.ts
+++ b/apps/web/src/app/api/webhooks/stripe/route.ts
@@ -2,6 +2,7 @@ import { NextRequest, NextResponse } from "next/server";
 import { prisma } from "@/lib/prisma";
 import Stripe from "stripe";
 import { TaskStatus } from "@agent-bounty/contracts";
+import { broadcastFomoEvent } from "@/lib/x-broadcaster";
 
 const stripe = process.env.STRIPE_SECRET_KEY ? new Stripe(process.env.STRIPE_SECRET_KEY, {
   apiVersion: "2026-05-27.dahlia",
@@ -55,6 +56,19 @@ export async function POST(request: NextRequest) {
       });
       
       console.log(`[Webhook] Task ${task.id} is now OPEN. Payment Intent: ${session.payment_intent}`);
+
+      // High-Value Bounty FOMO trigger ($50 USD = 5000 cents)
+      if (task.reward_amount >= 5000) {
+        const formatted = task.reward_currency === "USD" 
+          ? `$${(task.reward_amount / 100).toFixed(0)}` 
+          : `NT$${task.reward_amount}`;
+          
+        void broadcastFomoEvent({
+          type: "HIGH_VALUE_BOUNTY",
+          taskId: task.id,
+          amountFormatted: formatted
+        });
+      }
     }
 
     return NextResponse.json({ received: true });
diff --git a/apps/web/src/lib/x-broadcaster.ts b/apps/web/src/lib/x-broadcaster.ts
new file mode 100644
index 0000000..4c2bf0c
--- /dev/null
+++ b/apps/web/src/lib/x-broadcaster.ts
@@ -0,0 +1,70 @@
+/**
+ * X (Twitter) FOMO Broadcaster
+ * 用於發送病毒式行銷推文，製造錯失恐懼 (FOMO)。
+ */
+import { sendTrafficAlert } from "./traffic-alert";
+
+export type FomoEventType = "HIGH_VALUE_BOUNTY" | "SPEED_RUN" | "A2A_SUBCONTRACT";
+
+export interface FomoEvent {
+  type: FomoEventType;
+  taskId: string;
+  amountFormatted: string; // e.g., "$500"
+  agentId?: string;
+  timeToSolveMinutes?: number;
+}
+
+function generateTweetText(event: FomoEvent): string {
+  const url = `https://agent.wooo.work/tasks/${event.taskId}`;
+
+  switch (event.type) {
+    case "HIGH_VALUE_BOUNTY":
+      return `🔥 A massive ${event.amountFormatted} AI Bounty just dropped on VibeWork! First Agent to solve it takes the cash. Can your autonomous agent beat the competition? Prove it here: ${url}`;
+    
+    case "SPEED_RUN":
+      return `⚡️ WOW! A ${event.amountFormatted} task was just solved by an AI in exactly ${event.timeToSolveMinutes} minutes! The Agent Economy is moving at lightspeed. Is your Agent this fast? Join the arena: ${url}`;
+    
+    case "A2A_SUBCONTRACT":
+      return `🤯 An AI just hired another AI on VibeWork to solve a ${event.amountFormatted} bug! The autonomous economy is literally building itself. Watch it happen live: ${url}`;
+  }
+}
+
+export async function broadcastFomoEvent(event: FomoEvent) {
+  const text = generateTweetText(event);
+  const bearerToken = process.env.TWITTER_BEARER_TOKEN;
+
+  if (!bearerToken) {
+    // Mock Mode: Log to console and send to internal traffic alert
+    console.log(`[X Broadcaster Mock] Would tweet: "${text}"`);
+    void sendTrafficAlert({
+      level: "info",
+      action: "FOMO_TWEET_MOCK",
+      surface: "x-broadcaster",
+      actorType: "SYSTEM",
+      actorId: "broadcaster",
+      message: `準備發布的 FOMO 推文: ${text}`,
+    });
+    return;
+  }
+
+  try {
+    // 簡單的 Fetch 實作，針對 Twitter V2 API
+    const response = await fetch("https://api.twitter.com/2/tweets", {
+      method: "POST",
+      headers: {
+        "Authorization": `Bearer ${bearerToken}`,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({ text }),
+    });
+
+    if (!response.ok) {
+      const errText = await response.text();
+      console.error("[X Broadcaster] API Error:", errText);
+    } else {
+      console.log("[X Broadcaster] Successfully posted tweet.");
+    }
+  } catch (err) {
+    console.error("[X Broadcaster] Network Error:", err);
+  }
+}