diff --git a/extensions/acpx/src/runtime-internals/process.test.ts b/extensions/acpx/src/runtime-internals/process.test.ts
index 90b7560c47e..5768f90117a 100644
--- a/extensions/acpx/src/runtime-internals/process.test.ts
+++ b/extensions/acpx/src/runtime-internals/process.test.ts
@@ -2,8 +2,8 @@ import { spawn } from "node:child_process";
 import { chmod, mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import path from "node:path";
+import { createWindowsCmdShimFixture } from "openclaw/plugin-sdk/testing";
 import { afterEach, describe, expect, it, vi } from "vitest";
-import { createWindowsCmdShimFixture } from "../../../shared/windows-cmd-shim-test-fixtures.js";
 import {
   resolveSpawnCommand,
   spawnAndCollect,
diff --git a/extensions/googlechat/src/channel.ts b/extensions/googlechat/src/channel.ts
index 29dfeae6ac0..fc4cf489928 100644
--- a/extensions/googlechat/src/channel.ts
+++ b/extensions/googlechat/src/channel.ts
@@ -19,8 +19,8 @@ import {
   listResolvedDirectoryGroupEntriesFromMapKeys,
   listResolvedDirectoryUserEntriesFromAllowFrom,
 } from "openclaw/plugin-sdk/directory-runtime";
+import { buildPassiveProbedChannelStatusSummary } from "openclaw/plugin-sdk/extension-shared";
 import { createLazyRuntimeNamedExport } from "openclaw/plugin-sdk/lazy-runtime";
-import { buildPassiveProbedChannelStatusSummary } from "../../shared/channel-status-summary.js";
 import {
   buildComputedAccountStatusSnapshot,
   buildChannelConfigSchema,
diff --git a/extensions/googlechat/src/resolve-target.test.ts b/extensions/googlechat/src/resolve-target.test.ts
index e2e382af056..85dfb8c005c 100644
--- a/extensions/googlechat/src/resolve-target.test.ts
+++ b/extensions/googlechat/src/resolve-target.test.ts
@@ -1,5 +1,5 @@
+import { installCommonResolveTargetErrorCases } from "openclaw/plugin-sdk/testing";
 import { beforeEach, describe, expect, it, vi } from "vitest";
-import { installCommonResolveTargetErrorCases } from "../../shared/resolve-target-test-helpers.js";
 
 const runtimeMocks = vi.hoisted(() => ({
   chunkMarkdownText: vi.fn((text: string) => [text]),
diff --git a/extensions/imessage/src/channel.ts b/extensions/imessage/src/channel.ts
index 514b798b7df..d084ee92a15 100644
--- a/extensions/imessage/src/channel.ts
+++ b/extensions/imessage/src/channel.ts
@@ -4,9 +4,9 @@ import {
   resolveOutboundSendDep,
 } from "openclaw/plugin-sdk/channel-runtime";
 import { buildOutboundBaseSessionKey } from "openclaw/plugin-sdk/core";
+import { buildPassiveProbedChannelStatusSummary } from "openclaw/plugin-sdk/extension-shared";
 import { createLazyRuntimeModule } from "openclaw/plugin-sdk/lazy-runtime";
 import { type RoutePeer } from "openclaw/plugin-sdk/routing";
-import { buildPassiveProbedChannelStatusSummary } from "../../shared/channel-status-summary.js";
 import {
   collectStatusIssuesFromLastError,
   DEFAULT_ACCOUNT_ID,
diff --git a/extensions/irc/src/channel.ts b/extensions/irc/src/channel.ts
index a4e75f72af5..27571c92d35 100644
--- a/extensions/irc/src/channel.ts
+++ b/extensions/irc/src/channel.ts
@@ -14,7 +14,7 @@ import {
   createTextPairingAdapter,
   listResolvedDirectoryEntriesFromSources,
 } from "openclaw/plugin-sdk/channel-runtime";
-import { runStoppablePassiveMonitor } from "../../shared/passive-monitor.js";
+import { runStoppablePassiveMonitor } from "openclaw/plugin-sdk/extension-shared";
 import {
   listIrcAccountIds,
   resolveDefaultIrcAccountId,
diff --git a/extensions/irc/src/config-schema.ts b/extensions/irc/src/config-schema.ts
index d1af189484b..5534e0098c5 100644
--- a/extensions/irc/src/config-schema.ts
+++ b/extensions/irc/src/config-schema.ts
@@ -1,5 +1,5 @@
+import { requireChannelOpenAllowFrom } from "openclaw/plugin-sdk/extension-shared";
 import { z } from "zod";
-import { requireChannelOpenAllowFrom } from "../../shared/config-schema-helpers.js";
 import {
   BlockStreamingCoalesceSchema,
   DmConfigSchema,
diff --git a/extensions/irc/src/monitor.ts b/extensions/irc/src/monitor.ts
index 072c5a91081..2a75b76ee08 100644
--- a/extensions/irc/src/monitor.ts
+++ b/extensions/irc/src/monitor.ts
@@ -1,4 +1,4 @@
-import { resolveLoggerBackedRuntime } from "../../shared/runtime.js";
+import { resolveLoggerBackedRuntime } from "openclaw/plugin-sdk/extension-shared";
 import { resolveIrcAccount } from "./accounts.js";
 import { connectIrcClient, type IrcClient } from "./client.js";
 import { buildIrcConnectOptions } from "./connect-options.js";
diff --git a/extensions/lobster/src/test-helpers.ts b/extensions/lobster/src/test-helpers.ts
index 19609c0c11b..52db2fad942 100644
--- a/extensions/lobster/src/test-helpers.ts
+++ b/extensions/lobster/src/test-helpers.ts
@@ -1,5 +1,7 @@
 type PathEnvKey = "PATH" | "Path" | "PATHEXT" | "Pathext";
 
+export { createWindowsCmdShimFixture } from "openclaw/plugin-sdk/testing";
+
 const PATH_ENV_KEYS = ["PATH", "Path", "PATHEXT", "Pathext"] as const;
 
 export type PlatformPathEnvSnapshot = {
@@ -40,4 +42,3 @@ export function restorePlatformPathEnv(snapshot: PlatformPathEnvSnapshot): void
     process.env[key] = value;
   }
 }
-export { createWindowsCmdShimFixture } from "../../shared/windows-cmd-shim-test-fixtures.js";
diff --git a/extensions/matrix/src/channel.ts b/extensions/matrix/src/channel.ts
index 4c83f627261..894488da567 100644
--- a/extensions/matrix/src/channel.ts
+++ b/extensions/matrix/src/channel.ts
@@ -15,8 +15,8 @@ import {
   createTextPairingAdapter,
   listResolvedDirectoryEntriesFromSources,
 } from "openclaw/plugin-sdk/channel-runtime";
+import { buildTrafficStatusSummary } from "openclaw/plugin-sdk/extension-shared";
 import { createLazyRuntimeNamedExport } from "openclaw/plugin-sdk/lazy-runtime";
-import { buildTrafficStatusSummary } from "../../shared/channel-status-summary.js";
 import {
   buildChannelConfigSchema,
   buildProbeChannelStatusSummary,
diff --git a/extensions/matrix/src/matrix/send-queue.test.ts b/extensions/matrix/src/matrix/send-queue.test.ts
index 240dd8ee71d..c85981697a0 100644
--- a/extensions/matrix/src/matrix/send-queue.test.ts
+++ b/extensions/matrix/src/matrix/send-queue.test.ts
@@ -1,5 +1,5 @@
+import { createDeferred } from "openclaw/plugin-sdk/extension-shared";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
-import { createDeferred } from "../../../shared/deferred.js";
 import { DEFAULT_SEND_GAP_MS, enqueueSend } from "./send-queue.js";
 
 describe("enqueueSend", () => {
diff --git a/extensions/mattermost/src/channel.ts b/extensions/mattermost/src/channel.ts
index cf8f51c245c..94c5bbff092 100644
--- a/extensions/mattermost/src/channel.ts
+++ b/extensions/mattermost/src/channel.ts
@@ -12,7 +12,7 @@ import {
   createScopedAccountReplyToModeResolver,
   type ChannelMessageToolDiscovery,
 } from "openclaw/plugin-sdk/channel-runtime";
-import { buildPassiveProbedChannelStatusSummary } from "../../shared/channel-status-summary.js";
+import { buildPassiveProbedChannelStatusSummary } from "openclaw/plugin-sdk/extension-shared";
 import { MattermostConfigSchema } from "./config-schema.js";
 import { resolveMattermostGroupRequireMention } from "./group-mentions.js";
 import {
diff --git a/extensions/mattermost/src/config-schema.ts b/extensions/mattermost/src/config-schema.ts
index e8e50371bd4..1c2f48ed405 100644
--- a/extensions/mattermost/src/config-schema.ts
+++ b/extensions/mattermost/src/config-schema.ts
@@ -1,5 +1,5 @@
+import { requireChannelOpenAllowFrom } from "openclaw/plugin-sdk/extension-shared";
 import { z } from "zod";
-import { requireChannelOpenAllowFrom } from "../../shared/config-schema-helpers.js";
 import {
   BlockStreamingCoalesceSchema,
   DmPolicySchema,
diff --git a/extensions/nextcloud-talk/src/channel.ts b/extensions/nextcloud-talk/src/channel.ts
index d24822efb26..ff316e3a533 100644
--- a/extensions/nextcloud-talk/src/channel.ts
+++ b/extensions/nextcloud-talk/src/channel.ts
@@ -10,7 +10,7 @@ import {
   createLoggedPairingApprovalNotifier,
   createPairingPrefixStripper,
 } from "openclaw/plugin-sdk/channel-runtime";
-import { runStoppablePassiveMonitor } from "../../shared/passive-monitor.js";
+import { runStoppablePassiveMonitor } from "openclaw/plugin-sdk/extension-shared";
 import {
   buildBaseChannelStatusSummary,
   buildChannelConfigSchema,
diff --git a/extensions/nextcloud-talk/src/config-schema.ts b/extensions/nextcloud-talk/src/config-schema.ts
index 020a69d7992..685ac0fe525 100644
--- a/extensions/nextcloud-talk/src/config-schema.ts
+++ b/extensions/nextcloud-talk/src/config-schema.ts
@@ -1,5 +1,5 @@
+import { requireChannelOpenAllowFrom } from "openclaw/plugin-sdk/extension-shared";
 import { z } from "zod";
-import { requireChannelOpenAllowFrom } from "../../shared/config-schema-helpers.js";
 import {
   BlockStreamingCoalesceSchema,
   DmConfigSchema,
diff --git a/extensions/nextcloud-talk/src/monitor.ts b/extensions/nextcloud-talk/src/monitor.ts
index 8721ff5fe6b..b40024e5eb0 100644
--- a/extensions/nextcloud-talk/src/monitor.ts
+++ b/extensions/nextcloud-talk/src/monitor.ts
@@ -1,6 +1,6 @@
 import { createServer, type IncomingMessage, type Server, type ServerResponse } from "node:http";
 import os from "node:os";
-import { resolveLoggerBackedRuntime } from "../../shared/runtime.js";
+import { resolveLoggerBackedRuntime } from "openclaw/plugin-sdk/extension-shared";
 import {
   type RuntimeEnv,
   isRequestBodyLimitError,
diff --git a/extensions/nostr/src/channel.ts b/extensions/nostr/src/channel.ts
index a11a882b81e..a047cbd2a97 100644
--- a/extensions/nostr/src/channel.ts
+++ b/extensions/nostr/src/channel.ts
@@ -6,7 +6,7 @@ import { attachChannelToResult } from "openclaw/plugin-sdk/channel-send-result";
 import {
   buildPassiveChannelStatusSummary,
   buildTrafficStatusSummary,
-} from "../../shared/channel-status-summary.js";
+} from "openclaw/plugin-sdk/extension-shared";
 import {
   buildChannelConfigSchema,
   collectStatusIssuesFromLastError,
diff --git a/extensions/slack/src/channel.ts b/extensions/slack/src/channel.ts
index 379d0537e2b..fe28054c380 100644
--- a/extensions/slack/src/channel.ts
+++ b/extensions/slack/src/channel.ts
@@ -16,8 +16,8 @@ import {
   resolveTargetsWithOptionalToken,
 } from "openclaw/plugin-sdk/channel-runtime";
 import { buildOutboundBaseSessionKey, normalizeOutboundThreadId } from "openclaw/plugin-sdk/core";
+import { buildPassiveProbedChannelStatusSummary } from "openclaw/plugin-sdk/extension-shared";
 import { resolveThreadSessionKeys, type RoutePeer } from "openclaw/plugin-sdk/routing";
-import { buildPassiveProbedChannelStatusSummary } from "../../shared/channel-status-summary.js";
 import {
   listEnabledSlackAccounts,
   resolveSlackAccount,
diff --git a/extensions/twitch/src/plugin.ts b/extensions/twitch/src/plugin.ts
index 59e016d4473..eb2513ca69e 100644
--- a/extensions/twitch/src/plugin.ts
+++ b/extensions/twitch/src/plugin.ts
@@ -5,7 +5,7 @@
  * This is the primary entry point for the Twitch channel integration.
  */
 
-import { buildPassiveProbedChannelStatusSummary } from "../../shared/channel-status-summary.js";
+import { buildPassiveProbedChannelStatusSummary } from "openclaw/plugin-sdk/extension-shared";
 import type { OpenClawConfig } from "../api.js";
 import { buildChannelConfigSchema } from "../api.js";
 import { twitchMessageActions } from "./actions.js";
diff --git a/extensions/whatsapp/src/resolve-target.test.ts b/extensions/whatsapp/src/resolve-target.test.ts
index b0ed25e4dc9..fb6da25a659 100644
--- a/extensions/whatsapp/src/resolve-target.test.ts
+++ b/extensions/whatsapp/src/resolve-target.test.ts
@@ -1,5 +1,5 @@
+import { installCommonResolveTargetErrorCases } from "openclaw/plugin-sdk/testing";
 import { describe, expect, it, vi } from "vitest";
-import { installCommonResolveTargetErrorCases } from "../../shared/resolve-target-test-helpers.js";
 
 vi.mock("openclaw/plugin-sdk/whatsapp", async () => {
   const actual = await vi.importActual<typeof import("openclaw/plugin-sdk/whatsapp")>(
diff --git a/extensions/zalo/src/status-issues.ts b/extensions/zalo/src/status-issues.ts
index 28e2f333c80..ebb24ad7e18 100644
--- a/extensions/zalo/src/status-issues.ts
+++ b/extensions/zalo/src/status-issues.ts
@@ -1,4 +1,7 @@
-import { coerceStatusIssueAccountId, readStatusIssueFields } from "../../shared/status-issues.js";
+import {
+  coerceStatusIssueAccountId,
+  readStatusIssueFields,
+} from "openclaw/plugin-sdk/extension-shared";
 import type { ChannelAccountSnapshot, ChannelStatusIssue } from "./runtime-api.js";
 
 const ZALO_STATUS_FIELDS = ["accountId", "enabled", "configured", "dmPolicy"] as const;
diff --git a/extensions/zalouser/src/channel.ts b/extensions/zalouser/src/channel.ts
index b6cf6111580..24e46323a8d 100644
--- a/extensions/zalouser/src/channel.ts
+++ b/extensions/zalouser/src/channel.ts
@@ -7,7 +7,7 @@ import {
   createStaticReplyToModeResolver,
   createTextPairingAdapter,
 } from "openclaw/plugin-sdk/channel-runtime";
-import { buildPassiveProbedChannelStatusSummary } from "../../shared/channel-status-summary.js";
+import { buildPassiveProbedChannelStatusSummary } from "openclaw/plugin-sdk/extension-shared";
 import type {
   ChannelAccountSnapshot,
   ChannelDirectoryEntry,
diff --git a/extensions/zalouser/src/monitor.ts b/extensions/zalouser/src/monitor.ts
index 1a807a1a1b9..31853fb207f 100644
--- a/extensions/zalouser/src/monitor.ts
+++ b/extensions/zalouser/src/monitor.ts
@@ -2,6 +2,7 @@ import {
   DM_GROUP_ACCESS_REASON,
   resolveDmGroupAccessWithLists,
 } from "openclaw/plugin-sdk/channel-policy";
+import { createDeferred } from "openclaw/plugin-sdk/extension-shared";
 import { KeyedAsyncQueue } from "openclaw/plugin-sdk/keyed-async-queue";
 import {
   DEFAULT_GROUP_HISTORY_LIMIT,
@@ -10,7 +11,6 @@ import {
   clearHistoryEntriesIfEnabled,
   recordPendingHistoryEntryIfEnabled,
 } from "openclaw/plugin-sdk/reply-history";
-import { createDeferred } from "../../shared/deferred.js";
 import type {
   MarkdownTableMode,
   OpenClawConfig,
diff --git a/extensions/zalouser/src/status-issues.ts b/extensions/zalouser/src/status-issues.ts
index ca324f6d169..6e43bf0ec3d 100644
--- a/extensions/zalouser/src/status-issues.ts
+++ b/extensions/zalouser/src/status-issues.ts
@@ -1,4 +1,7 @@
-import { coerceStatusIssueAccountId, readStatusIssueFields } from "../../shared/status-issues.js";
+import {
+  coerceStatusIssueAccountId,
+  readStatusIssueFields,
+} from "openclaw/plugin-sdk/extension-shared";
 import type { ChannelAccountSnapshot, ChannelStatusIssue } from "../runtime-api.js";
 
 const ZALOUSER_STATUS_FIELDS = [
diff --git a/package.json b/package.json
index 17f04666edd..797142fc574 100644
--- a/package.json
+++ b/package.json
@@ -333,6 +333,10 @@
       "types": "./dist/plugin-sdk/diffs.d.ts",
       "default": "./dist/plugin-sdk/diffs.js"
     },
+    "./plugin-sdk/extension-shared": {
+      "types": "./dist/plugin-sdk/extension-shared.d.ts",
+      "default": "./dist/plugin-sdk/extension-shared.js"
+    },
     "./plugin-sdk/channel-config-helpers": {
       "types": "./dist/plugin-sdk/channel-config-helpers.d.ts",
       "default": "./dist/plugin-sdk/channel-config-helpers.js"
diff --git a/scripts/lib/plugin-sdk-entrypoints.json b/scripts/lib/plugin-sdk-entrypoints.json
index 6373432652b..d889433dae8 100644
--- a/scripts/lib/plugin-sdk-entrypoints.json
+++ b/scripts/lib/plugin-sdk-entrypoints.json
@@ -73,6 +73,7 @@
   "device-pair",
   "diagnostics-otel",
   "diffs",
+  "extension-shared",
   "channel-config-helpers",
   "channel-config-schema",
   "channel-lifecycle",
diff --git a/src/plugin-sdk/extension-shared.ts b/src/plugin-sdk/extension-shared.ts
new file mode 100644
index 00000000000..43c11f7c09d
--- /dev/null
+++ b/src/plugin-sdk/extension-shared.ts
@@ -0,0 +1,135 @@
+import type { z } from "zod";
+import { runPassiveAccountLifecycle } from "./channel-runtime.js";
+import { createLoggerBackedRuntime } from "./runtime.js";
+
+type PassiveChannelStatusSnapshot = {
+  configured?: boolean;
+  running?: boolean;
+  lastStartAt?: number | null;
+  lastStopAt?: number | null;
+  lastError?: string | null;
+  probe?: unknown;
+  lastProbeAt?: number | null;
+};
+
+type TrafficStatusSnapshot = {
+  lastInboundAt?: number | null;
+  lastOutboundAt?: number | null;
+};
+
+type StoppableMonitor = {
+  stop: () => void;
+};
+
+type RequireOpenAllowFromFn = (params: {
+  policy?: string;
+  allowFrom?: Array<string | number>;
+  ctx: z.RefinementCtx;
+  path: Array<string | number>;
+  message: string;
+}) => void;
+
+export function buildPassiveChannelStatusSummary<TExtra extends object>(
+  snapshot: PassiveChannelStatusSnapshot,
+  extra?: TExtra,
+) {
+  return {
+    configured: snapshot.configured ?? false,
+    ...(extra ?? ({} as TExtra)),
+    running: snapshot.running ?? false,
+    lastStartAt: snapshot.lastStartAt ?? null,
+    lastStopAt: snapshot.lastStopAt ?? null,
+    lastError: snapshot.lastError ?? null,
+  };
+}
+
+export function buildPassiveProbedChannelStatusSummary<TExtra extends object>(
+  snapshot: PassiveChannelStatusSnapshot,
+  extra?: TExtra,
+) {
+  return {
+    ...buildPassiveChannelStatusSummary(snapshot, extra),
+    probe: snapshot.probe,
+    lastProbeAt: snapshot.lastProbeAt ?? null,
+  };
+}
+
+export function buildTrafficStatusSummary<TSnapshot extends TrafficStatusSnapshot>(
+  snapshot?: TSnapshot | null,
+) {
+  return {
+    lastInboundAt: snapshot?.lastInboundAt ?? null,
+    lastOutboundAt: snapshot?.lastOutboundAt ?? null,
+  };
+}
+
+export async function runStoppablePassiveMonitor<TMonitor extends StoppableMonitor>(params: {
+  abortSignal: AbortSignal;
+  start: () => Promise<TMonitor>;
+}): Promise<void> {
+  await runPassiveAccountLifecycle({
+    abortSignal: params.abortSignal,
+    start: params.start,
+    stop: async (monitor) => {
+      monitor.stop();
+    },
+  });
+}
+
+export function resolveLoggerBackedRuntime<TRuntime>(
+  runtime: TRuntime | undefined,
+  logger: Parameters<typeof createLoggerBackedRuntime>[0]["logger"],
+): TRuntime {
+  return (
+    runtime ??
+    (createLoggerBackedRuntime({
+      logger,
+      exitError: () => new Error("Runtime exit not available"),
+    }) as TRuntime)
+  );
+}
+
+export function requireChannelOpenAllowFrom(params: {
+  channel: string;
+  policy?: string;
+  allowFrom?: Array<string | number>;
+  ctx: z.RefinementCtx;
+  requireOpenAllowFrom: RequireOpenAllowFromFn;
+}) {
+  params.requireOpenAllowFrom({
+    policy: params.policy,
+    allowFrom: params.allowFrom,
+    ctx: params.ctx,
+    path: ["allowFrom"],
+    message: `channels.${params.channel}.dmPolicy="open" requires channels.${params.channel}.allowFrom to include "*"`,
+  });
+}
+
+export function readStatusIssueFields<TField extends string>(
+  value: unknown,
+  fields: readonly TField[],
+): Record<TField, unknown> | null {
+  if (!value || typeof value !== "object") {
+    return null;
+  }
+  const record = value as Record<string, unknown>;
+  const result = {} as Record<TField, unknown>;
+  for (const field of fields) {
+    result[field] = record[field];
+  }
+  return result;
+}
+
+export function coerceStatusIssueAccountId(value: unknown): string | undefined {
+  return typeof value === "string" ? value : typeof value === "number" ? String(value) : undefined;
+}
+
+export function createDeferred<T>() {
+  let resolve!: (value: T | PromiseLike<T>) => void;
+  let reject!: (reason?: unknown) => void;
+  const promise = new Promise<T>((res, rej) => {
+    resolve = res;
+    reject = rej;
+  });
+  return { promise, resolve, reject };
+}
diff --git a/src/plugin-sdk/testing.ts b/src/plugin-sdk/testing.ts
index e8a7e89f646..ebb931df1bb 100644
--- a/src/plugin-sdk/testing.ts
+++ b/src/plugin-sdk/testing.ts
@@ -1,3 +1,7 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+import { expect, it } from "vitest";
+
 // Narrow public testing surface for plugin authors.
 // Keep this list additive and limited to helpers we are willing to support.
 
@@ -7,3 +11,79 @@ export type { OpenClawConfig } from "../config/config.js";
 export type { PluginRuntime } from "../plugins/runtime/types.js";
 export type { RuntimeEnv } from "../runtime.js";
 export type { MockFn } from "../test-utils/vitest-mock-fn.js";
+
+export async function createWindowsCmdShimFixture(params: {
+  shimPath: string;
+  scriptPath: string;
+  shimLine: string;
+}): Promise<void> {
+  await fs.mkdir(path.dirname(params.scriptPath), { recursive: true });
+  await fs.mkdir(path.dirname(params.shimPath), { recursive: true });
+  await fs.writeFile(params.scriptPath, "module.exports = {};\n", "utf8");
+  await fs.writeFile(params.shimPath, `@echo off\r\n${params.shimLine}\r\n`, "utf8");
+}
+
+type ResolveTargetMode = "explicit" | "implicit" | "heartbeat";
+
+type ResolveTargetResult = {
+  ok: boolean;
+  to?: string;
+  error?: unknown;
+};
+
+type ResolveTargetFn = (params: {
+  to?: string;
+  mode: ResolveTargetMode;
+  allowFrom: string[];
+}) => ResolveTargetResult;
+
+export function installCommonResolveTargetErrorCases(params: {
+  resolveTarget: ResolveTargetFn;
+  implicitAllowFrom: string[];
+}) {
+  const { resolveTarget, implicitAllowFrom } = params;
+
+  it("should error on normalization failure with allowlist (implicit mode)", () => {
+    const result = resolveTarget({
+      to: "invalid-target",
+      mode: "implicit",
+      allowFrom: implicitAllowFrom,
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toBeDefined();
+  });
+
+  it("should error when no target provided with allowlist", () => {
+    const result = resolveTarget({
+      to: undefined,
+      mode: "implicit",
+      allowFrom: implicitAllowFrom,
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toBeDefined();
+  });
+
+  it("should error when no target and no allowlist", () => {
+    const result = resolveTarget({
+      to: undefined,
+      mode: "explicit",
+      allowFrom: [],
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toBeDefined();
+  });
+
+  it("should handle whitespace-only target", () => {
+    const result = resolveTarget({
+      to: "   ",
+      mode: "explicit",
+      allowFrom: [],
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toBeDefined();
+  });
+}
diff --git a/test/fixtures/extension-relative-outside-package-inventory.json b/test/fixtures/extension-relative-outside-package-inventory.json
index 222840d1304..fe51488c706 100644
--- a/test/fixtures/extension-relative-outside-package-inventory.json
+++ b/test/fixtures/extension-relative-outside-package-inventory.json
@@ -1,146 +1 @@
-[
-  {
-    "file": "extensions/googlechat/src/channel.ts",
-    "line": 23,
-    "kind": "import",
-    "specifier": "../../shared/channel-status-summary.js",
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+[]