diff --git a/src/lib/onboard/command.test.ts b/src/lib/onboard/command.test.ts
index 0f9f166f298..82257f55204 100644
--- a/src/lib/onboard/command.test.ts
+++ b/src/lib/onboard/command.test.ts
@@ -9,6 +9,7 @@ import { describe, expect, it, vi } from "vitest";
 
 import { resolveOnboardOptions, runOnboardCommand } from "./command";
 import type { OnboardFlags } from "./command-support";
+import { invalidGatewayManagementDeclarationError } from "./gateway-management";
 
 function exitWithCode(code: number): never {
   throw new Error(`exit:${code}`);
@@ -261,6 +262,68 @@ describe("onboard command options", () => {
     expect(errors.join("\n")).toContain("Installation cancelled");
   });
 
+  it("prints a clean CLI error for an invalid gateway management contract (#7627)", async () => {
+    const errors: string[] = [];
+    await expect(
+      runOnboardCommand({
+        flags: {},
+        env: {},
+        runOnboard: async () => {
+          throw invalidGatewayManagementDeclarationError(
+            "unsupported gateway-management contract version; this NemoClaw build supports version 1",
+          );
+        },
+        error: (message = "") => errors.push(message),
+        exit: exitWithCode,
+      }),
+    ).rejects.toThrow("exit:1");
+    const output = errors.join("\n");
+    expect(output).toContain("Invalid gateway management declaration");
+    expect(output).toContain("unsupported gateway-management contract version");
+    // No stack frames leaked into the user-facing output.
+    expect(output).not.toContain(".js:");
+    expect(output).not.toContain("    at ");
+  });
+
+  it("escapes terminal controls in gateway declaration errors before printing (#7627)", async () => {
+    const errors: string[] = [];
+    await expect(
+      runOnboardCommand({
+        flags: {},
+        env: {},
+        runOnboard: async () => {
+          throw invalidGatewayManagementDeclarationError(
+            "unknown declaration field(s): forged\n\u001b[31mError: \u202efake failure",
+          );
+        },
+        error: (message = "") => errors.push(message),
+        exit: exitWithCode,
+      }),
+    ).rejects.toThrow("exit:1");
+
+    expect(errors).toEqual([
+      "  Invalid gateway management declaration: unknown declaration field(s): forged\\u000a\\u001b[31mError: \\u202efake failure",
+    ]);
+    expect(errors[0]?.split(/\r?\n/u)).toHaveLength(1);
+    expect(errors[0]).not.toMatch(
+      /[\u0000-\u001f\u007f-\u009f\u061c\u200e\u200f\u2028-\u202e\u2066-\u2069]/u,
+    );
+  });
+
+  it("re-throws a non-cancellation, non-gateway error so genuine bugs still surface (#7627)", async () => {
+    await expect(
+      runOnboardCommand({
+        flags: {},
+        env: {},
+        runOnboard: async () => {
+          throw new Error("unexpected boom");
+        },
+        error: () => {},
+        exit: exitWithCode,
+      }),
+    ).rejects.toThrow("unexpected boom");
+  });
+
   it("returns without rethrowing when a prompt rejects with SIGINT (#7439)", async () => {
     const exit = vi.fn<(code: number) => never>();
     await expect(
diff --git a/src/lib/onboard/command.ts b/src/lib/onboard/command.ts
index dcc7c62b143..cba531b5573 100644
--- a/src/lib/onboard/command.ts
+++ b/src/lib/onboard/command.ts
@@ -12,6 +12,7 @@ import {
 } from "../tool-disclosure";
 import { applyAgentsManifestEnv } from "./agents-manifest";
 import type { OnboardFlags } from "./command-support";
+import { GatewayManagementDeclarationError } from "./gateway-management";
 import { managedSandboxFeatureIssue } from "./managed-sandbox-feature";
 import { DCODE_OBSERVABILITY_FEATURE } from "./observability-policy-presets";
 import { isOpenclawAgent } from "./openclaw-otel-policy-presets";
@@ -208,6 +209,13 @@ export async function runOnboardCommand(deps: RunOnboardCommandDeps): Promise<vo
       // oclif as a raw stack trace (#7439).
       return;
     }
+    // A rejected NEMOCLAW_GATEWAY_MANAGEMENT contract is operator input error,
+    // not a crash: print the validation reason as a clean single-line CLI error
+    // and exit nonzero instead of re-throwing it into a Node.js stack trace
+    // (#7627). `fail` sets exit code 1.
+    if (error instanceof GatewayManagementDeclarationError) {
+      fail(deps, `  ${error.message}`);
+    }
     // Stdin EOF at any onboarding prompt is a cancellation, not a failure:
     // print a clear message and exit non-zero instead of either crashing with
     // a stack trace or — as in the original bug — exiting 0 silently (#5976).
diff --git a/src/lib/onboard/gateway-host-runtime.test.ts b/src/lib/onboard/gateway-host-runtime.test.ts
index 5d4fbde19b6..9cd74ecaaf2 100644
--- a/src/lib/onboard/gateway-host-runtime.test.ts
+++ b/src/lib/onboard/gateway-host-runtime.test.ts
@@ -4,7 +4,10 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 import { createGatewayHostRuntime, type GatewayHostRuntimeDeps } from "./gateway-host-runtime";
-import { GATEWAY_MANAGEMENT_ENV_VAR } from "./gateway-management";
+import {
+  GATEWAY_MANAGEMENT_ENV_VAR,
+  GatewayManagementDeclarationError,
+} from "./gateway-management";
 import { evaluateGatewayAttachment } from "./gateway-ownership";
 import type { PortProbeResult } from "./preflight";
 
@@ -116,6 +119,14 @@ describe("gateway host runtime ownership", () => {
     );
   });
 
+  it("throws a recognized GatewayManagementDeclarationError so the CLI can present it cleanly (#7627)", () => {
+    declareExternalSupervision({ ...DECLARATION, version: 99 });
+
+    expect(() => createGatewayHostRuntime(createDeps()).getGatewayOwner()).toThrow(
+      GatewayManagementDeclarationError,
+    );
+  });
+
   it("fails closed on unsupported capabilities before probing an external listener (#6576)", () => {
     declareExternalSupervision({
       ...DECLARATION,
diff --git a/src/lib/onboard/gateway-host-runtime.ts b/src/lib/onboard/gateway-host-runtime.ts
index 92035564e1c..3418a90db9d 100644
--- a/src/lib/onboard/gateway-host-runtime.ts
+++ b/src/lib/onboard/gateway-host-runtime.ts
@@ -23,7 +23,10 @@ import {
   isGatewayHttpReady,
   waitForGatewayHttpReady,
 } from "./gateway-http-readiness";
-import { loadGatewayManagementDeclaration } from "./gateway-management";
+import {
+  invalidGatewayManagementDeclarationError,
+  loadGatewayManagementDeclaration,
+} from "./gateway-management";
 import {
   assertGatewayEffectAllowed,
   cgroupBelongsToUnit,
@@ -113,7 +116,7 @@ export function createGatewayHostRuntime(deps: GatewayHostRuntimeDeps): GatewayH
   function resolveCurrentGatewayOwner(gatewayName: string, gatewayPort: number): GatewayOwner {
     const loaded = loadGatewayManagementDeclaration();
     if (!loaded.ok) {
-      throw new Error(`Invalid gateway management declaration: ${loaded.reason}`);
+      throw invalidGatewayManagementDeclarationError(loaded.reason);
     }
     return resolveGatewayOwner({
       gatewayName,
diff --git a/src/lib/onboard/gateway-management.ts b/src/lib/onboard/gateway-management.ts
index 703cc266656..8e845e95e70 100644
--- a/src/lib/onboard/gateway-management.ts
+++ b/src/lib/onboard/gateway-management.ts
@@ -76,6 +76,37 @@ export type GatewayManagementParseResult =
   | { ok: true; declaration: GatewayManagementDeclaration }
   | { ok: false; reason: string };
 
+/**
+ * A rejected NEMOCLAW_GATEWAY_MANAGEMENT contract is user-input error, not a
+ * NemoClaw bug: the operator pointed the env var at a declaration file that
+ * fails contract validation (bad version, unknown field, non-loopback / DNS
+ * endpoint, embedded credentials, query string, path, …). Command boundaries
+ * recognize this class to print a clean single-line CLI error and exit nonzero
+ * instead of leaking a Node.js stack trace (#7627). Every rejection reason
+ * funnels through `reason`, so this one class covers the whole class of
+ * contract-validation failures.
+ */
+export class GatewayManagementDeclarationError extends Error {}
+
+const GATEWAY_MANAGEMENT_ERROR_CONTROL_RE =
+  /[\u0000-\u001f\u007f-\u009f\u061c\u200e\u200f\u2028-\u202e\u2066-\u2069]/gu;
+
+function escapeGatewayManagementErrorReason(reason: string): string {
+  return reason.replace(
+    GATEWAY_MANAGEMENT_ERROR_CONTROL_RE,
+    (character) => `\\u${character.charCodeAt(0).toString(16).padStart(4, "0")}`,
+  );
+}
+
+/** Build the user-facing error for an invalid gateway management declaration. */
+export function invalidGatewayManagementDeclarationError(
+  reason: string,
+): GatewayManagementDeclarationError {
+  return new GatewayManagementDeclarationError(
+    `Invalid gateway management declaration: ${escapeGatewayManagementErrorReason(reason)}`,
+  );
+}
+
 const DECLARATION_KEYS = new Set([
   "version",
   "mode",
diff --git a/src/lib/onboard/gateway-teardown-authority.ts b/src/lib/onboard/gateway-teardown-authority.ts
index ebc8b4c5792..1db805ca6d4 100644
--- a/src/lib/onboard/gateway-teardown-authority.ts
+++ b/src/lib/onboard/gateway-teardown-authority.ts
@@ -21,6 +21,7 @@ import { gatewayOwnerFromCheckpoint } from "./gateway-authority-checkpoint";
 import { resolveGatewayName } from "./gateway-binding";
 import {
   type GatewayManagementLoadResult,
+  invalidGatewayManagementDeclarationError,
   loadGatewayManagementDeclaration,
 } from "./gateway-management";
 import {
@@ -87,7 +88,7 @@ function resolveGatewayEffectAuthority(
     ? deps.loadDeclaration(env)
     : loadGatewayManagementDeclaration({ env });
   if (!loaded.ok) {
-    throw new Error(`Invalid gateway management declaration: ${loaded.reason}`);
+    throw invalidGatewayManagementDeclarationError(loaded.reason);
   }
   const hasPackagedService =
     loaded.declaration === null &&