diff --git a/extensions/imessage/package.json b/extensions/imessage/package.json
index 860617e5d42..7b6ca03b4d6 100644
--- a/extensions/imessage/package.json
+++ b/extensions/imessage/package.json
@@ -2,7 +2,7 @@
   "name": "@openclaw/imessage",
   "version": "2026.5.6",
   "private": true,
-  "description": "OpenClaw iMessage channel plugin",
+  "description": "OpenClaw iMessage channel plugin using imsg on a signed-in Mac",
   "type": "module",
   "devDependencies": {
     "@openclaw/plugin-sdk": "workspace:*"
@@ -19,7 +19,7 @@
       "detailLabel": "iMessage",
       "docsPath": "/channels/imessage",
       "docsLabel": "imessage",
-      "blurb": "this is still a work in progress.",
+      "blurb": "iMessage via the imsg CLI on a signed-in Mac or SSH wrapper.",
       "aliases": [
         "imsg"
       ],
diff --git a/extensions/imessage/src/probe.ts b/extensions/imessage/src/probe.ts
index 740ea3335fc..055f86768b3 100644
--- a/extensions/imessage/src/probe.ts
+++ b/extensions/imessage/src/probe.ts
@@ -1,3 +1,4 @@
+import path from "node:path";
 import type { BaseProbeResult } from "openclaw/plugin-sdk/channel-contract";
 import { runCommandWithTimeout } from "openclaw/plugin-sdk/process-runtime";
 import { getRuntimeConfig } from "openclaw/plugin-sdk/runtime-config-snapshot";
@@ -17,6 +18,7 @@ export type IMessageProbe = BaseProbeResult & {
 export type IMessageProbeOptions = {
   cliPath?: string;
   dbPath?: string;
+  platform?: NodeJS.Platform;
   runtime?: RuntimeEnv;
 };
 
@@ -28,6 +30,21 @@ type RpcSupportResult = {
 
 const rpcSupportCache = new Map<string, RpcSupportResult>();
 
+function isDefaultLocalIMessageCliPath(cliPath: string): boolean {
+  const trimmed = cliPath.trim();
+  return trimmed === "imsg" || (!trimmed.includes("/") && path.basename(trimmed) === "imsg");
+}
+
+export function resolveIMessageNonMacHostError(
+  cliPath: string,
+  platform: NodeJS.Platform = process.platform,
+): string | undefined {
+  if (platform === "darwin" || !isDefaultLocalIMessageCliPath(cliPath)) {
+    return undefined;
+  }
+  return "iMessage via the default imsg CLI must run on macOS. Run OpenClaw on the signed-in Messages Mac, or set channels.imessage.cliPath to an SSH wrapper that runs imsg on that Mac.";
+}
+
 async function probeRpcSupport(cliPath: string, timeoutMs: number): Promise<RpcSupportResult> {
   const cached = rpcSupportCache.get(cliPath);
   if (cached) {
@@ -76,6 +93,11 @@ export async function probeIMessage(
   const effectiveTimeout =
     timeoutMs ?? cfg?.channels?.imessage?.probeTimeoutMs ?? DEFAULT_IMESSAGE_PROBE_TIMEOUT_MS;
 
+  const nonMacHostError = resolveIMessageNonMacHostError(cliPath, opts.platform);
+  if (nonMacHostError) {
+    return { ok: false, fatal: true, error: nonMacHostError };
+  }
+
   const detected = await detectBinary(cliPath);
   if (!detected) {
     return { ok: false, error: `imsg not found (${cliPath})` };
diff --git a/extensions/imessage/src/setup-core.ts b/extensions/imessage/src/setup-core.ts
index 74032d75e98..c8d1ca3488e 100644
--- a/extensions/imessage/src/setup-core.ts
+++ b/extensions/imessage/src/setup-core.ts
@@ -169,7 +169,8 @@ export function createIMessageCliPathTextInput(
 export const imessageCompletionNote = {
   title: "iMessage next steps",
   lines: [
-    "This is still a work in progress.",
+    "Run OpenClaw on the Mac signed into Messages, or set cliPath to an SSH wrapper that runs imsg on that Mac.",
+    "Linux/Windows hosts cannot run the default local imsg path directly.",
     "Ensure OpenClaw has Full Disk Access to Messages DB.",
     "Grant Automation permission for Messages when prompted.",
     "List chats with: imsg chats --limit 20",
diff --git a/extensions/imessage/src/status.test.ts b/extensions/imessage/src/status.test.ts
index cbfa9615ef5..99ec98ff37d 100644
--- a/extensions/imessage/src/status.test.ts
+++ b/extensions/imessage/src/status.test.ts
@@ -169,6 +169,24 @@ describe("probeIMessage", () => {
     expect(createIMessageRpcClientMock).not.toHaveBeenCalled();
   });
 
+  it("fails fast for default local imsg probes on non-mac hosts", async () => {
+    const createIMessageRpcClientMock = vi
+      .spyOn(clientModule, "createIMessageRpcClient")
+      .mockResolvedValue({
+        request: vi.fn(),
+        stop: vi.fn(),
+      } as unknown as Awaited<ReturnType<typeof clientModule.createIMessageRpcClient>>);
+
+    const result = await probeIMessage(1000, { cliPath: "imsg", platform: "linux" });
+
+    expect(result.ok).toBe(false);
+    expect(result.fatal).toBe(true);
+    expect(result.error).toMatch(/macOS/i);
+    expect(result.error).toMatch(/SSH wrapper/i);
+    expect(setupRuntime.detectBinary).not.toHaveBeenCalled();
+    expect(createIMessageRpcClientMock).not.toHaveBeenCalled();
+  });
+
   it("status probe uses account-scoped cliPath and dbPath", async () => {
     const probeSpy = vi.spyOn(channelRuntimeModule, "probeIMessageAccount").mockResolvedValue({
       ok: true,