diff --git a/src/cli/lab.ts b/src/cli/lab.ts
index 013b96327a..5071404eb9 100644
--- a/src/cli/lab.ts
+++ b/src/cli/lab.ts
@@ -36,6 +36,7 @@ import {
   queryPassiveProductionSignals,
   type PassiveProductionQueryResultV1,
 } from "../lab/query";
+import { isLabRouteSubjectId } from "../usage/log";
 import {
   CliUsageError,
   RuntimeApiError,
@@ -243,6 +244,9 @@ export async function handleLabCommand(argv: string[], deps: LabCliDeps = {}): P
           const limit = takeIntegerOption(rest, "--limit", { min: 1 });
           rejectArgs(rest, USAGE);
           if (!subjectId) throw new CliUsageError("--subject is required", USAGE);
+          if (!isLabRouteSubjectId(subjectId)) {
+            throw new CliUsageError("--subject must be an exact Lab route subject id", USAGE);
+          }
           const result = queryPassiveProductionSignals(subjectId, limit, configDir);
           printData(result, wantsJson, passiveProductionLines(result));
           return;
diff --git a/src/server/management/lab-routes.ts b/src/server/management/lab-routes.ts
index 5c0929e47f..efd80ff43a 100644
--- a/src/server/management/lab-routes.ts
+++ b/src/server/management/lab-routes.ts
@@ -30,6 +30,7 @@ import {
   LabProjectionIncompatibleError,
   LabProjectionUnavailableError,
   LAB_QUERY_MAX_PAGE_SIZE,
+  PASSIVE_PRODUCTION_MAX_LIMIT,
   queryLabArtifactByDigest,
   queryLabArtifacts,
   queryLabCatalogEntries,
@@ -75,20 +76,24 @@ function projectionErrorResponse(err: unknown, ctx: ManagementContext): Response
   return null;
 }
 
-function parseLimit(raw: string | null, ctx: ManagementContext): number | undefined | Response {
+function parseLimit(
+  raw: string | null,
+  ctx: ManagementContext,
+  max = LAB_QUERY_MAX_PAGE_SIZE,
+): number | undefined | Response {
   const parsed = raw === null ? undefined : parseQueryInt(raw);
   if (parsed === "invalid") {
     return errorResponse(
       "invalid_limit",
-      `limit must be an integer from 1 to ${LAB_QUERY_MAX_PAGE_SIZE}`,
+      `limit must be an integer from 1 to ${max}`,
       400,
       ctx,
     );
   }
-  if (parsed !== undefined && (parsed < 1 || parsed > LAB_QUERY_MAX_PAGE_SIZE)) {
+  if (parsed !== undefined && (parsed < 1 || parsed > max)) {
     return errorResponse(
       "invalid_limit",
-      `limit must be an integer from 1 to ${LAB_QUERY_MAX_PAGE_SIZE}`,
+      `limit must be an integer from 1 to ${max}`,
       400,
       ctx,
     );
@@ -198,7 +203,7 @@ export async function handleLabRoutes(ctx: ManagementContext): Promise<Response
   if (url.pathname === "/api/lab/production-signals") {
     const subjectId = url.searchParams.get("subjectId")?.trim();
     if (!subjectId) return errorResponse("invalid_subject", "subjectId is required", 400, ctx);
-    const limit = parseLimit(url.searchParams.get("limit"), ctx);
+    const limit = parseLimit(url.searchParams.get("limit"), ctx, PASSIVE_PRODUCTION_MAX_LIMIT);
     if (limit instanceof Response) return limit;
     try {
       return jsonResponse(queryPassiveProductionSignals(subjectId, limit), 200, req, config);
@@ -398,4 +403,4 @@ export async function handleLabRoutes(ctx: ManagementContext): Promise<Response
   }
 
   return null;
-}
+}
\ No newline at end of file
diff --git a/tests/lab-passive-production-surfaces.test.ts b/tests/lab-passive-production-surfaces.test.ts
new file mode 100644
index 0000000000..66ae81fc53
--- /dev/null
+++ b/tests/lab-passive-production-surfaces.test.ts
@@ -0,0 +1,95 @@
+import { afterEach, describe, expect, test } from "bun:test";
+import { mkdirSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { handleLabCommand } from "../src/cli/lab";
+import {
+  LAB_QUERY_MAX_PAGE_SIZE,
+  PASSIVE_PRODUCTION_MAX_LIMIT,
+} from "../src/lab/query";
+import { handleManagementAPI } from "../src/server/management-api";
+import type { OcxConfig } from "../src/types";
+import { ManagementRequest } from "./helpers/management-auth";
+
+const HOMES: string[] = [];
+const originalOpenCodexHome = process.env.OPENCODEX_HOME;
+
+function tempHome(): string {
+  const dir = join(tmpdir(), `ocx-lab-passive-surfaces-${process.pid}-${Math.random().toString(16).slice(2)}`);
+  mkdirSync(dir, { recursive: true, mode: 0o700 });
+  HOMES.push(dir);
+  return dir;
+}
+
+afterEach(() => {
+  for (const dir of HOMES.splice(0)) {
+    rmSync(dir, { recursive: true, force: true });
+  }
+  if (originalOpenCodexHome === undefined) delete process.env.OPENCODEX_HOME;
+  else process.env.OPENCODEX_HOME = originalOpenCodexHome;
+});
+
+function config(): OcxConfig {
+  return { providers: {} } as OcxConfig;
+}
+
+async function apiGet(home: string, path: string): Promise<Response> {
+  process.env.OPENCODEX_HOME = home;
+  const req = new ManagementRequest(`http://127.0.0.1${path}`, { method: "GET" });
+  const response = await handleManagementAPI(req, new URL(req.url), config(), {
+    refreshCodexCatalog: async () => {},
+  });
+  expect(response).not.toBeNull();
+  return response!;
+}
+
+describe("CL-09 passive production read surfaces", () => {
+  test("management API uses the passive query limit without widening generic Lab pages", async () => {
+    const home = tempHome();
+    const subjectId = "a".repeat(64);
+
+    const accepted = await apiGet(
+      home,
+      `/api/lab/production-signals?subjectId=${subjectId}&limit=${PASSIVE_PRODUCTION_MAX_LIMIT}`,
+    );
+    expect(accepted.status).toBe(200);
+    const acceptedBody = await accepted.json() as {
+      signals: unknown[];
+      summary: { recentProductionAttempts: number };
+    };
+    expect(acceptedBody.signals).toEqual([]);
+    expect(acceptedBody.summary.recentProductionAttempts).toBe(0);
+
+    const tooHigh = await apiGet(
+      home,
+      `/api/lab/production-signals?subjectId=${subjectId}&limit=${PASSIVE_PRODUCTION_MAX_LIMIT + 1}`,
+    );
+    expect(tooHigh.status).toBe(400);
+    const tooHighBody = await tooHigh.json() as { error: { code: string; message: string } };
+    expect(tooHighBody.error.code).toBe("invalid_limit");
+    expect(tooHighBody.error.message).toContain(`1 to ${PASSIVE_PRODUCTION_MAX_LIMIT}`);
+
+    const generic = await apiGet(home, `/api/lab/verdicts?limit=${LAB_QUERY_MAX_PAGE_SIZE + 1}`);
+    expect(generic.status).toBe(400);
+    const genericBody = await generic.json() as { error: { code: string; message: string } };
+    expect(genericBody.error.code).toBe("invalid_limit");
+    expect(genericBody.error.message).toContain(`1 to ${LAB_QUERY_MAX_PAGE_SIZE}`);
+  });
+
+  test("CLI reports malformed passive subject ids as the actual usage error", async () => {
+    const home = tempHome();
+    const errors: string[] = [];
+    const originalError = console.error;
+    console.error = (...args: unknown[]) => { errors.push(args.join(" ")); };
+    try {
+      expect(await handleLabCommand(
+        ["production-signals", "--subject", "not-a-subject-id"],
+        { configDir: home },
+      )).toBe(2);
+      expect(errors.join("\n")).toContain("--subject must be an exact Lab route subject id");
+      expect(errors.join("\n")).not.toContain("lab read failed");
+    } finally {
+      console.error = originalError;
+    }
+  });
+});