diff --git a/build/story-workflow-buzz-bridge-gateway.ts b/build/story-workflow-buzz-bridge-gateway.ts
index 04117a2a5..67472e9b2 100644
--- a/build/story-workflow-buzz-bridge-gateway.ts
+++ b/build/story-workflow-buzz-bridge-gateway.ts
@@ -10,6 +10,7 @@ import {
   type StoryBridgeRequest,
 } from "../core/story-workflow/buzz-story-bridge-core.mjs";
 import { agentProfileById } from "../lib/agents/agent-profiles";
+import { prepareStoryBridgeRequest } from "../modules/story-workflow/buzz-story-bridge";
 import { ensurePrivateBuzzAgentMembership } from "./story-workflow/buzz-private-room-membership";
 
 const API = "/api/story-workflow/buzz-bridge";
@@ -38,6 +39,7 @@ type ResponsibilityRunSnapshot = {
   };
 };
 type LocalResponse<T> = T & { ok?: boolean; message?: string };
+type StoryBridgePreparationInput = Parameters<typeof prepareStoryBridgeRequest>[0];
 
 function requestMatchesLocalBridge(request: IncomingMessage, expectedPath: string) {
   if (!["127.0.0.1", "::1", "::ffff:127.0.0.1"].includes(request.socket.remoteAddress || "")) return false;
@@ -111,6 +113,15 @@ async function localJson<T>(request: IncomingMessage, route: string, init?: Requ
   return value as T;
 }
 
+function prepareRequest(body: Record<string, unknown>) {
+  return prepareStoryBridgeRequest({
+    project: body.project as StoryBridgePreparationInput["project"],
+    workItem: body.workItem as StoryBridgePreparationInput["workItem"],
+    run: body.run as StoryBridgePreparationInput["run"],
+    contextPacket: body.contextPacket as StoryBridgePreparationInput["contextPacket"],
+  });
+}
+
 function normalizeRequest(value: unknown): StoryBridgeRequest {
   if (!value || typeof value !== "object" || Array.isArray(value)) throw new Error("Story Bridge requires one bounded request envelope.");
   const input = value as StoryBridgeRequest;
@@ -383,6 +394,11 @@ export function storyWorkflowBuzzBridgeGateway(): Plugin {
             }
             const body = await readBridgeAction(request);
             const action = typeof body.action === "string" ? body.action : "";
+            if (action === "prepare") {
+              const bridge = prepareRequest(body);
+              writeBridgeResponse(response, 200, { ok: true, request: bridge }, bridge.requestId);
+              return;
+            }
             const bridge = normalizeRequest(body.request);
             if (action === "dispatch") {
               writeBridgeResponse(response, 200, await dispatch(request, bridge), bridge.requestId);
diff --git a/modules/story-workflow/ui/foundations-buzz-story-live-test.tsx b/modules/story-workflow/ui/foundations-buzz-story-live-test.tsx
index 655cd1307..c9a7d9833 100644
--- a/modules/story-workflow/ui/foundations-buzz-story-live-test.tsx
+++ b/modules/story-workflow/ui/foundations-buzz-story-live-test.tsx
@@ -5,7 +5,6 @@ import type { CurriculumLesson } from "../../../core/contracts/curriculum";
 import type { PPFProject } from "../../../core/project/project";
 import type { StoryWorkItem } from "../../../core/story-workflow/story-workflow-core.mjs";
 import { loadFoundationProject } from "../../../core/storage/foundation-project-browser";
-import { prepareStoryBridgeRequest } from "../buzz-story-bridge";
 import { createFoundationsStoryResponsibilityRun } from "../foundations-story-workflow";
 
 type RunResponse = {
@@ -21,12 +20,20 @@ type BridgeContribution = {
   readonly provenance?: { readonly eventId?: string; readonly signatureVerified?: boolean };
 };
 
+type PreparedBridgeRequest = Record<string, unknown> & {
+  readonly requestId?: string;
+  readonly state?: string;
+  readonly stateReason?: string;
+  readonly expectedAgentPubkey?: string;
+};
+
 type BridgeResponse = {
   readonly ok?: boolean;
   readonly message?: string;
   readonly state?: string;
   readonly executionPath?: string;
   readonly requestId?: string;
+  readonly request?: PreparedBridgeRequest;
   readonly idempotent?: boolean;
   readonly contributions?: readonly BridgeContribution[];
   readonly accepted?: readonly BridgeContribution[];
@@ -104,14 +111,16 @@ export default function FoundationsBuzzStoryLiveTest({
         contextCharacters: task.contextPacket.receipt.usedCharacters,
       });
 
-      const bridge = prepareStoryBridgeRequest({
+      const prepared = await bridgeRequest({
+        action: "prepare",
         project,
         workItem,
         run: task.run,
         contextPacket: task.contextPacket,
       });
-      if (bridge.state !== "ready" || !bridge.expectedAgentPubkey) {
-        throw new Error(bridge.stateReason || "Tamsin does not have a usable local BUZZ signer binding.");
+      const bridge = prepared.request;
+      if (!bridge || bridge.state !== "ready" || !bridge.expectedAgentPubkey) {
+        throw new Error(bridge?.stateReason || "Tamsin does not have a usable local BUZZ signer binding.");
       }
 
       onStatus("BUZZ Story Test · adding Tamsin to the private Story Room and dispatching the bounded task…");
@@ -163,7 +172,7 @@ export default function FoundationsBuzzStoryLiveTest({
         action: "proposal-ready",
         runId: task.run.runId,
         resultId: contribution.result.resultId,
-        ref: contribution.provenance?.eventId ? `buzz-event:${contribution.provenance.eventId}` : `buzz-story-bridge:${bridge.requestId}`,
+        ref: contribution.provenance?.eventId ? `buzz-event:${contribution.provenance.eventId}` : `buzz-story-bridge:${bridge.requestId || "unknown"}`,
         producedAt: new Date().toISOString(),
       });
       setState("pass");
diff --git a/tests/issue-1422-buzz-story-bridge-hardening.test.mjs b/tests/issue-1422-buzz-story-bridge-hardening.test.mjs
index 12f528f98..4179900ae 100644
--- a/tests/issue-1422-buzz-story-bridge-hardening.test.mjs
+++ b/tests/issue-1422-buzz-story-bridge-hardening.test.mjs
@@ -159,13 +159,15 @@ test("#1422 Story Bridge puts the exact approved BUZZ Agent in the private room
 });
 
 test("#1422 exposes a one-click Afterglow/Tamsin live proof without writing the PPF", async () => {
-  const [panel, liveTest] = await Promise.all([
+  const [panel, liveTest, gateway] = await Promise.all([
     read("modules/story-workflow/ui/foundations-story-workflow-panel.tsx"),
     read("modules/story-workflow/ui/foundations-buzz-story-live-test.tsx"),
+    read("build/story-workflow-buzz-bridge-gateway.ts"),
   ]);
   assert.ok(panel.includes("FoundationsBuzzStoryLiveTest"));
   for (const contract of [
     "Run BUZZ Story Test",
+    "action: \"prepare\"",
     "action: \"dispatch\"",
     "retry.idempotent !== true",
     "Waiting for Tamsin Hearthquill’s signed response",
@@ -176,5 +178,9 @@ test("#1422 exposes a one-click Afterglow/Tamsin live proof without writing the
     "BUZZ Story Test PASS",
   ]) assert.ok(liveTest.includes(contract), `Live Story Bridge UI is missing exit-proof behavior: ${contract}`);
 
+  assert.ok(gateway.includes('if (action === "prepare")') && gateway.includes("prepareStoryBridgeRequest"),
+    "Story Bridge request preparation must execute inside the localhost server gateway.");
+  assert.doesNotMatch(liveTest, /prepareStoryBridgeRequest|nostr-event-verification|node:crypto/,
+    "The client live-test component must not import server-only Story Bridge crypto or request preparation.");
   assert.doesNotMatch(liveTest, /saveFoundationProject|applyStoryCommand|foundations\.proposal\.store|writing-assistant\/chat/);
 });