diff --git a/packages/agent-bundle/tests/cli.test.ts b/packages/agent-bundle/tests/cli.test.ts
index 0d3b36410..1e828be26 100644
--- a/packages/agent-bundle/tests/cli.test.ts
+++ b/packages/agent-bundle/tests/cli.test.ts
@@ -7,6 +7,7 @@ import { promisify } from 'node:util';
 import { expect, it } from '@rstest/core';
 
 import { runCli as runSourceCli } from '../src/cli.ts';
+import { cachedNpmInstallArguments } from './support/shared-pack.ts';
 
 const execFile = promisify(executeFile);
 const workspaceRoot = process.cwd();
@@ -128,7 +129,7 @@ const createPackedConsumer = async (): Promise<{ readonly cli: string; readonly
   const [packed] = JSON.parse(stdout) as Array<{ readonly filename: string }>;
   await writeFile(join(root, 'package.json'), '{"type":"module"}\n');
   await execFile(
-    'npm', ['install', '--ignore-scripts', '--no-audit', '--no-fund', join(root, packed.filename)],
+    'npm', ['install', ...cachedNpmInstallArguments, join(root, packed.filename)],
     { cwd: root },
   );
   return { cli: join(root, 'node_modules', '.bin', 'agent-bundle'), root };
diff --git a/packages/agent-bundle/tests/dev-workbench-packaging.test.ts b/packages/agent-bundle/tests/dev-workbench-packaging.test.ts
index 326ffde08..6d12f3b70 100644
--- a/packages/agent-bundle/tests/dev-workbench-packaging.test.ts
+++ b/packages/agent-bundle/tests/dev-workbench-packaging.test.ts
@@ -7,7 +7,7 @@ import { promisify } from 'node:util';
 
 import { describe, expect, it } from '@rstest/core';
 
-import { installedEnvironment, npmInstallArguments, sharedPackedTarball } from './support/shared-pack.ts';
+import { cachedNpmInstallArguments, installedEnvironment, sharedPackedTarball } from './support/shared-pack.ts';
 
 const execFile = promisify(executeFile);
 const workspaceRoot = process.cwd();
@@ -83,7 +83,7 @@ it('serves prebuilt workbench assets from an installed tarball without the repos
     expect(listing.stdout).not.toMatch(/package\/dist\/workbench\/.*-[a-f0-9]{8,}/iu);
 
     await writeFile(join(consumer, 'package.json'), '{"type":"module"}\n');
-    await execFile('npm', ['install', ...npmInstallArguments, tarball], { cwd: consumer });
+    await execFile('npm', ['install', ...cachedNpmInstallArguments, tarball], { cwd: consumer });
     await mkdir(join(project, 'skills', 'review'), { recursive: true });
     await Promise.all([
       writeFile(join(project, 'package.json'), '{"type":"module"}\n'),
@@ -115,7 +115,7 @@ it('runs the Agent API from an omit-dev installed tarball with its runtime MCP d
   const project = join(consumer, 'project');
   try {
     await writeFile(join(consumer, 'package.json'), '{"type":"module"}\n');
-    await execFile('npm', ['install', '--omit=dev', ...npmInstallArguments, tarball], { cwd: consumer });
+    await execFile('npm', ['install', '--omit=dev', ...cachedNpmInstallArguments, tarball], { cwd: consumer });
     await mkdir(join(project, 'skills', 'review'), { recursive: true });
     await Promise.all([
       writeFile(join(project, 'package.json'), '{"type":"module"}\n'),
diff --git a/packages/agent-bundle/tests/packed-consumer.test.ts b/packages/agent-bundle/tests/packed-consumer.test.ts
index 10b639724..aec4d5f95 100644
--- a/packages/agent-bundle/tests/packed-consumer.test.ts
+++ b/packages/agent-bundle/tests/packed-consumer.test.ts
@@ -20,7 +20,7 @@ import { promisify } from 'node:util';
 import { expect, it } from '@rstest/core';
 
 import { sha256Hex } from '../src/core/digest.ts';
-import { installedEnvironment, npmInstallArguments } from './support/shared-pack.ts';
+import { cachedNpmInstallArguments, installedEnvironment } from './support/shared-pack.ts';
 
 const execFile = promisify(executeFile);
 const workspaceRoot = process.cwd();
@@ -110,7 +110,7 @@ it('uses only an installed tarball after source deletion', async () => {
     // The two consumers are disjoint directories; npm's cache handles the
     // concurrent installs (the scaffolder e2e relies on the same property).
     await Promise.all([projectRoot, scriptProjectRoot].map(async (consumer) =>
-      execFile('npm', ['install', ...npmInstallArguments, tarball], {
+      execFile('npm', ['install', ...cachedNpmInstallArguments, tarball], {
         cwd: consumer,
         env: installedEnvironment(),
       })));
@@ -331,7 +331,7 @@ it('uses only an installed tarball after source deletion', async () => {
         '',
       ].join('\n')),
     ]);
-    await execFile('npm', ['install', ...npmInstallArguments, tarball], {
+    await execFile('npm', ['install', ...cachedNpmInstallArguments, tarball], {
       cwd: frameworkRoot,
       env: installedEnvironment(),
     });
diff --git a/packages/agent-bundle/tests/public-api-packed.test.ts b/packages/agent-bundle/tests/public-api-packed.test.ts
index 5db4ae6bf..b8a68b99f 100644
--- a/packages/agent-bundle/tests/public-api-packed.test.ts
+++ b/packages/agent-bundle/tests/public-api-packed.test.ts
@@ -7,7 +7,7 @@ import { promisify } from 'node:util';
 import { expect, it } from '@rstest/core';
 
 import { writeFixtureManifest } from './support/manifest.ts';
-import { npmInstallArguments, sharedPackedTarball } from './support/shared-pack.ts';
+import { cachedNpmInstallArguments, sharedPackedTarball } from './support/shared-pack.ts';
 
 interface PackageManifest {
   bin: {
@@ -58,7 +58,7 @@ it('writes the package version as the producer of a packed CLI manifest', async
   try {
     await writeFile(join(consumerRoot, 'package.json'), '{"type":"module"}\n');
     await execFile(
-      'npm', ['install', ...npmInstallArguments, tarball],
+      'npm', ['install', ...cachedNpmInstallArguments, tarball],
       { cwd: consumerRoot },
     );
 
@@ -90,7 +90,7 @@ it('imports the externalized config entry from a packed npm consumer', async ()
     await writeFile(join(consumerRoot, 'package.json'), '{"type":"module"}\n');
     await execFile(
       'npm',
-      ['install', ...npmInstallArguments, tarball],
+      ['install', ...cachedNpmInstallArguments, tarball],
       { cwd: consumerRoot },
     );
 
@@ -198,7 +198,7 @@ it('invokes a prebuilt MCP server from a clean packed consumer', async () => {
     await writeFile(join(consumerRoot, 'package.json'), '{"type":"module"}\n');
     await execFile(
       'npm',
-      ['install', ...npmInstallArguments, tarball],
+      ['install', ...cachedNpmInstallArguments, tarball],
       { cwd: consumerRoot },
     );
     const { stdout } = await execFile(process.execPath, [
diff --git a/packages/agent-bundle/tests/rsc-runtime-optional-packaging.test.ts b/packages/agent-bundle/tests/rsc-runtime-optional-packaging.test.ts
index ee8477592..d0a996933 100644
--- a/packages/agent-bundle/tests/rsc-runtime-optional-packaging.test.ts
+++ b/packages/agent-bundle/tests/rsc-runtime-optional-packaging.test.ts
@@ -6,7 +6,7 @@ import { promisify } from 'node:util';
 
 import { describe, expect, it } from '@rstest/core';
 
-import { npmInstallArguments, sharedPackedTarball } from './support/shared-pack.ts';
+import { cachedNpmInstallArguments, sharedPackedTarball } from './support/shared-pack.ts';
 
 const execFile = promisify(executeFile);
 const workspaceRoot = process.cwd();
@@ -45,7 +45,7 @@ describe.sequential('optional RSC runtime package boundary', () => {
       const tarListing = (await execFile('tar', ['-tf', tarball])).stdout;
       expect(tarListing).not.toMatch(/examples\/rsc-agent-runtime|react-server-dom-rspack|rsbuild-plugin-rsc/u);
 
-      await execFile('npm', ['install', ...npmInstallArguments, tarball], { cwd: consumer });
+      await execFile('npm', ['install', ...cachedNpmInstallArguments, tarball], { cwd: consumer });
       const dependencyTree = JSON.parse((await execFile('npm', ['ls', '--all', '--json'], { cwd: consumer })).stdout) as InstalledDependencyTree;
       const installedNames = installedDependencyNames(dependencyTree);
       for (const name of ['react', 'react-dom', 'react-server-dom-rspack', 'rsbuild-plugin-rsc']) {
diff --git a/packages/agent-bundle/tests/support/packed-native-smoke.ts b/packages/agent-bundle/tests/support/packed-native-smoke.ts
index 99f38793c..00e244612 100644
--- a/packages/agent-bundle/tests/support/packed-native-smoke.ts
+++ b/packages/agent-bundle/tests/support/packed-native-smoke.ts
@@ -15,6 +15,10 @@ import { homedir, tmpdir } from 'node:os';
 import { join } from 'node:path';
 import { promisify } from 'node:util';
 
+// The native smoke installs the production closure a real consumer would get,
+// so it stays on npm's default metadata staleness checks.
+import { npmInstallArguments } from './shared-pack.ts';
+
 const execFile = promisify(executeFile);
 const workspaceRoot = process.cwd();
 const packageRoot = join(workspaceRoot, 'packages', 'agent-bundle');
@@ -236,9 +240,7 @@ export const runPackedNativeSmoke = async (options: {
     const installed = await runNodeEntrypoint(npmEntrypoint, [
       'install',
       '--omit=dev',
-      '--ignore-scripts',
-      '--no-audit',
-      '--no-fund',
+      ...npmInstallArguments,
       join(tarballs, listing[0].filename),
     ], { cwd: consumer, environment });
     if (installed.exitCode !== 0) throw new Error('Packed native smoke could not install the release tarball.');
diff --git a/packages/agent-bundle/tests/support/shared-pack.ts b/packages/agent-bundle/tests/support/shared-pack.ts
index 124584daf..131a1959f 100644
--- a/packages/agent-bundle/tests/support/shared-pack.ts
+++ b/packages/agent-bundle/tests/support/shared-pack.ts
@@ -26,9 +26,28 @@ export const installedEnvironment = (): NodeJS.ProcessEnv => {
   return environment;
 };
 
-/** Canonical flags for installing a packed tarball into a consumer fixture. */
+/**
+ * Canonical flags for installing a packed tarball into a consumer fixture.
+ * They keep npm's default metadata staleness checks, so the install resolves
+ * the tree a consumer would get today. That is the point of the proofs that
+ * stand in for a real consumer — release-audit's production entrypoint walk,
+ * the scaffolder template matrix, the native host smoke — and exact direct
+ * pins do not make it free: transitive ranges still move underneath them, and
+ * scripts/audit-packed-release.mjs audits the installed tree without ever
+ * exercising it.
+ */
 export const npmInstallArguments = ['--ignore-scripts', '--no-audit', '--no-fund'] as const;
 
+/**
+ * The same flags for suites that only prove the packed tarball resolves,
+ * imports, and runs, where the dependency tree is a means rather than the
+ * subject. `--prefer-offline` serves cached registry metadata without
+ * revalidating it: the tarball under test is always read from disk and
+ * uncached dependencies are still fetched, so only the staleness round-trips
+ * are skipped.
+ */
+export const cachedNpmInstallArguments = [...npmInstallArguments, '--prefer-offline'] as const;
+
 const packs = new Map<SharedPackPackage, Promise<SharedPack>>();
 let fallbackBuild: Promise<void> | undefined;
 
diff --git a/packages/create-agent-bundle/tests/support/scaffold-fixture.ts b/packages/create-agent-bundle/tests/support/scaffold-fixture.ts
index e321895a1..0ebcce5a8 100644
--- a/packages/create-agent-bundle/tests/support/scaffold-fixture.ts
+++ b/packages/create-agent-bundle/tests/support/scaffold-fixture.ts
@@ -6,7 +6,7 @@ import { promisify } from 'node:util';
 
 import { expect } from '@rstest/core';
 
-import { installedEnvironment, npmInstallArguments, sharedPackedTarball } from '../../../agent-bundle/tests/support/shared-pack.ts';
+import { cachedNpmInstallArguments, installedEnvironment, sharedPackedTarball } from '../../../agent-bundle/tests/support/shared-pack.ts';
 
 const execFile = promisify(executeFile);
 
@@ -36,7 +36,7 @@ const packFixture = async (): Promise<PackedFixture> => {
   const runnerRoot = join(root, 'runner');
   await mkdir(runnerRoot, { recursive: true });
   await writeFile(join(runnerRoot, 'package.json'), '{"name":"scaffold-runner","type":"module","private":true}\n');
-  await execFile('npm', ['install', ...npmInstallArguments, scaffolderTarball], {
+  await execFile('npm', ['install', ...cachedNpmInstallArguments, scaffolderTarball], {
     cwd: runnerRoot,
     env: installedEnvironment(),
   });
diff --git a/packages/workbench/tests/packed-release.e2e.test.ts b/packages/workbench/tests/packed-release.e2e.test.ts
index dfe352f39..83e0c8840 100644
--- a/packages/workbench/tests/packed-release.e2e.test.ts
+++ b/packages/workbench/tests/packed-release.e2e.test.ts
@@ -14,7 +14,7 @@ import {
   validateOutageLedger,
   type ConsoleErrorRecord,
 } from './support/packed-outage-ledger.ts';
-import { npmInstallArguments, sharedPackedTarball } from '../../agent-bundle/tests/support/shared-pack.ts';
+import { cachedNpmInstallArguments, sharedPackedTarball } from '../../agent-bundle/tests/support/shared-pack.ts';
 import { timeScale } from '../../agent-bundle/tests/support/time-scale.ts';
 import {
   availablePort,
@@ -83,7 +83,7 @@ e2e('runs every Agent API tool from the installed tarball', { timeout: 360_000 *
   let primaryFailure: Error | undefined;
   try {
     await writeFile(join(consumer, 'package.json'), '{"type":"module"}\n');
-    await execFile('npm', ['install', '--omit=dev', ...npmInstallArguments, tarball], {
+    await execFile('npm', ['install', '--omit=dev', ...cachedNpmInstallArguments, tarball], {
       cwd: consumer,
       env: installedEnvironment(),
     });
diff --git a/scripts/audit-packed-release.mjs b/scripts/audit-packed-release.mjs
index 744bd8eeb..4ae1ea5a9 100644
--- a/scripts/audit-packed-release.mjs
+++ b/scripts/audit-packed-release.mjs
@@ -157,6 +157,11 @@ const auditPackedRelease = async () => {
       '--pack-destination', tarballs,
     ], { cwd: packageRoot, env: productionEnvironment })).stdout);
     const tarball = join(tarballs, asString(filename, 'npm pack did not produce a tarball filename'));
+    // No `--prefer-offline` here (unlike the packed pool's
+    // cachedNpmInstallArguments): the tree this install produces is what
+    // `npm audit`, `npm audit signatures`, and `npm sbom` below report on, so
+    // it has to resolve against live registry metadata rather than whatever
+    // the cache last saw.
     await execNpm([
       'install',
       '--omit=dev',