diff --git a/extensions/browser/src/browser-proxy-upload.ts b/extensions/browser/src/browser-proxy-upload.ts
index 590ae3499c4f..7fa7c1221c4d 100644
--- a/extensions/browser/src/browser-proxy-upload.ts
+++ b/extensions/browser/src/browser-proxy-upload.ts
@@ -16,6 +16,7 @@ import {
   type BrowserProxyUploadV1,
 } from "./browser-proxy-envelope.js";
 import { DEFAULT_UPLOAD_DIR, resolveExistingUploadPaths } from "./browser/paths.js";
+import { asRecord } from "./record-shared.js";
 
 const logger = createSubsystemLogger("browser");
 const BROWSER_PROXY_UPLOAD_ROOT_NAME = ".proxy-uploads";
@@ -76,12 +77,6 @@ export function isBrowserProxyUploadRequest(params: {
   return Boolean(body && Array.isArray(body.paths) && body.paths.length > 0);
 }
 
-function asRecord(value: unknown): Record<string, unknown> | null {
-  return value && typeof value === "object" && !Array.isArray(value)
-    ? (value as Record<string, unknown>)
-    : null;
-}
-
 function readUploadPaths(body: Record<string, unknown>): string[] | null {
   if (!Array.isArray(body.paths) || body.paths.length === 0) {
     return null;
diff --git a/extensions/browser/src/browser/chrome.graphics.ts b/extensions/browser/src/browser/chrome.graphics.ts
index 680665fa4298..5f24e38c8753 100644
--- a/extensions/browser/src/browser/chrome.graphics.ts
+++ b/extensions/browser/src/browser/chrome.graphics.ts
@@ -5,6 +5,7 @@
  * exact RunningChrome instance that owns the process.
  */
 import type { SsrFPolicy } from "../infra/net/ssrf.js";
+import { asRecord, isRecord } from "../record-shared.js";
 import { redactCdpErrorText, withCdpSocket } from "./cdp.helpers.js";
 import { getChromeWebSocketUrl, type RunningChrome } from "./chrome.js";
 import type {
@@ -15,8 +16,6 @@ import type {
   BrowserVideoEncodeCapability,
 } from "./client.types.js";
 
-type UnknownRecord = Record<string, unknown>;
-
 type ChromeGraphicsProbeOptions = {
   httpTimeoutMs?: number;
   handshakeTimeoutMs?: number;
@@ -24,12 +23,6 @@ type ChromeGraphicsProbeOptions = {
   ssrfPolicy?: SsrFPolicy;
 };
 
-function asRecord(value: unknown): UnknownRecord | null {
-  return value !== null && typeof value === "object" && !Array.isArray(value)
-    ? (value as UnknownRecord)
-    : null;
-}
-
 function readString(value: unknown): string {
   return typeof value === "string" ? value.trim() : "";
 }
@@ -63,65 +56,36 @@ function readSize(value: unknown): { width: number; height: number } {
   };
 }
 
+function readRecordArray(value: unknown): Record<string, unknown>[] {
+  return Array.isArray(value) ? value.filter(isRecord) : [];
+}
+
 function readDevices(value: unknown): BrowserGraphicsDevice[] {
-  if (!Array.isArray(value)) {
-    return [];
-  }
-  return value.flatMap((item) => {
-    const device = asRecord(item);
-    if (!device) {
-      return [];
-    }
-    return [
-      {
-        vendorId: readNumber(device.vendorId),
-        deviceId: readNumber(device.deviceId),
-        vendor: readString(device.vendorString),
-        device: readString(device.deviceString),
-        driverVendor: readString(device.driverVendor),
-        driverVersion: readString(device.driverVersion),
-      },
-    ];
-  });
+  return readRecordArray(value).map((device) => ({
+    vendorId: readNumber(device.vendorId),
+    deviceId: readNumber(device.deviceId),
+    vendor: readString(device.vendorString),
+    device: readString(device.deviceString),
+    driverVendor: readString(device.driverVendor),
+    driverVersion: readString(device.driverVersion),
+  }));
 }
 
 function readVideoDecoding(value: unknown): BrowserVideoDecodeCapability[] {
-  if (!Array.isArray(value)) {
-    return [];
-  }
-  return value.flatMap((item) => {
-    const capability = asRecord(item);
-    if (!capability) {
-      return [];
-    }
-    return [
-      {
-        profile: readString(capability.profile),
-        minResolution: readSize(capability.minResolution),
-        maxResolution: readSize(capability.maxResolution),
-      },
-    ];
-  });
+  return readRecordArray(value).map((capability) => ({
+    profile: readString(capability.profile),
+    minResolution: readSize(capability.minResolution),
+    maxResolution: readSize(capability.maxResolution),
+  }));
 }
 
 function readVideoEncoding(value: unknown): BrowserVideoEncodeCapability[] {
-  if (!Array.isArray(value)) {
-    return [];
-  }
-  return value.flatMap((item) => {
-    const capability = asRecord(item);
-    if (!capability) {
-      return [];
-    }
-    return [
-      {
-        profile: readString(capability.profile),
-        maxResolution: readSize(capability.maxResolution),
-        maxFramerateNumerator: readNumber(capability.maxFramerateNumerator),
-        maxFramerateDenominator: readNumber(capability.maxFramerateDenominator),
-      },
-    ];
-  });
+  return readRecordArray(value).map((capability) => ({
+    profile: readString(capability.profile),
+    maxResolution: readSize(capability.maxResolution),
+    maxFramerateNumerator: readNumber(capability.maxFramerateNumerator),
+    maxFramerateDenominator: readNumber(capability.maxFramerateDenominator),
+  }));
 }
 
 function firstAttribute(
diff --git a/extensions/browser/src/browser/chrome.profile-decoration.ts b/extensions/browser/src/browser/chrome.profile-decoration.ts
index c1da5846feb1..47a78f7583f1 100644
--- a/extensions/browser/src/browser/chrome.profile-decoration.ts
+++ b/extensions/browser/src/browser/chrome.profile-decoration.ts
@@ -7,6 +7,7 @@
 import fs from "node:fs";
 import path from "node:path";
 import { loadJsonFile, saveJsonFile } from "openclaw/plugin-sdk/json-store";
+import { asRecord } from "../record-shared.js";
 import {
   DEFAULT_OPENCLAW_BROWSER_COLOR,
   DEFAULT_OPENCLAW_BROWSER_PROFILE_NAME,
@@ -19,22 +20,13 @@ function decoratedMarkerPath(userDataDir: string) {
 }
 
 function safeReadJson(filePath: string): Record<string, unknown> | null {
-  const parsed = loadJsonFile(filePath);
-  return typeof parsed === "object" && parsed !== null && !Array.isArray(parsed)
-    ? (parsed as Record<string, unknown>)
-    : null;
+  return asRecord(loadJsonFile(filePath));
 }
 
 function safeWriteJson(filePath: string, data: Record<string, unknown>) {
   saveJsonFile(filePath, data);
 }
 
-function asRecord(value: unknown): Record<string, unknown> | null {
-  return typeof value === "object" && value !== null && !Array.isArray(value)
-    ? (value as Record<string, unknown>)
-    : null;
-}
-
 function readNestedRecord(root: unknown, key: string): Record<string, unknown> | null {
   return asRecord(asRecord(root)?.[key]);
 }
diff --git a/extensions/browser/src/cli/browser-cli-actions-input/register.navigation.ts b/extensions/browser/src/cli/browser-cli-actions-input/register.navigation.ts
index 1af2360107ef..0fe65f91b842 100644
--- a/extensions/browser/src/cli/browser-cli-actions-input/register.navigation.ts
+++ b/extensions/browser/src/cli/browser-cli-actions-input/register.navigation.ts
@@ -3,12 +3,13 @@
  */
 import type { Command } from "commander";
 import { normalizeOptionalString } from "openclaw/plugin-sdk/string-coerce-runtime";
-import { ACT_MAX_VIEWPORT_DIMENSION } from "../../browser/act-policy.js";
-import { runBrowserResizeWithOutput } from "../browser-cli-resize.js";
+import {
+  parseBrowserViewportDimension,
+  runBrowserResizeWithOutput,
+} from "../browser-cli-resize.js";
 import {
   BROWSER_TAB_REFERENCE_HELP,
   callBrowserRequest,
-  parseBrowserPositiveIntegerValue,
   type BrowserParentOpts,
 } from "../browser-cli-shared.js";
 import { danger, defaultRuntime } from "../core-api.js";
@@ -19,21 +20,6 @@ export function registerBrowserNavigationCommands(
   browser: Command,
   parentOpts: (cmd: Command) => BrowserParentOpts,
 ) {
-  const parsePositiveInteger = (value: unknown, label: string): number | undefined => {
-    const parsed = parseBrowserPositiveIntegerValue(value);
-    if (parsed === undefined) {
-      defaultRuntime.error(danger(`Invalid ${label}: must be a positive integer`));
-      defaultRuntime.exit(1);
-      return undefined;
-    }
-    if (parsed > ACT_MAX_VIEWPORT_DIMENSION) {
-      defaultRuntime.error(danger(`Invalid ${label}: maximum is ${ACT_MAX_VIEWPORT_DIMENSION}`));
-      defaultRuntime.exit(1);
-      return undefined;
-    }
-    return parsed;
-  };
-
   browser
     .command("navigate")
     .description("Navigate the current tab to a URL")
@@ -73,8 +59,8 @@ export function registerBrowserNavigationCommands(
     .argument("<height>", "Viewport height")
     .option("--target-id <id>", BROWSER_TAB_REFERENCE_HELP)
     .action(async (width: string, height: string, opts, cmd) => {
-      const normalizedWidth = parsePositiveInteger(width, "width");
-      const normalizedHeight = parsePositiveInteger(height, "height");
+      const normalizedWidth = parseBrowserViewportDimension(width, "width");
+      const normalizedHeight = parseBrowserViewportDimension(height, "height");
       if (normalizedWidth === undefined || normalizedHeight === undefined) {
         return;
       }
diff --git a/extensions/browser/src/cli/browser-cli-actions-observe.ts b/extensions/browser/src/cli/browser-cli-actions-observe.ts
index 654786ba06a0..5a7ab1890690 100644
--- a/extensions/browser/src/cli/browser-cli-actions-observe.ts
+++ b/extensions/browser/src/cli/browser-cli-actions-observe.ts
@@ -9,7 +9,6 @@ import {
   resolveBrowserExtractTimeoutMs,
   validateBrowserExtractSchema,
 } from "../browser-extract.js";
-import { runCommandWithRuntime } from "../core-api.js";
 import {
   completeWithPreparedSimpleCompletionModel,
   extractAssistantText,
@@ -23,9 +22,11 @@ import {
   BROWSER_TAB_REFERENCE_HELP,
   callBrowserRequest,
   parseBrowserPositiveIntegerOption,
+  printBrowserJsonResult,
+  runBrowserCliCommand as runBrowserObserve,
   type BrowserParentOpts,
 } from "./browser-cli-shared.js";
-import { danger, defaultRuntime, getRuntimeConfig, shortenHomePath } from "./core-api.js";
+import { defaultRuntime, getRuntimeConfig, shortenHomePath } from "./core-api.js";
 
 const browserCliExtractDeps = {
   completeWithPreparedSimpleCompletionModel,
@@ -58,13 +59,6 @@ function parseSchemaOption(value: string | undefined): JsonSchemaObject | undefi
   return parsed as JsonSchemaObject;
 }
 
-function runBrowserObserve(action: () => Promise<void>) {
-  return runCommandWithRuntime(defaultRuntime, action, (err) => {
-    defaultRuntime.error(danger(String(err)));
-    defaultRuntime.exit(1);
-  });
-}
-
 /** Registers Browser commands that observe current page state without direct input. */
 export function registerBrowserActionObserveCommands(
   browser: Command,
@@ -140,8 +134,7 @@ export function registerBrowserActionObserveCommands(
           const text = result.content.find((block) => block.type === "text")?.text;
           throw new Error(text || "Browser extract failed");
         }
-        if (parent?.json) {
-          defaultRuntime.writeJson(result);
+        if (printBrowserJsonResult(parent, result)) {
           return;
         }
         const text = result.content.find((block) => block.type === "text")?.text;
@@ -173,8 +166,7 @@ export function registerBrowserActionObserveCommands(
           },
           { timeoutMs: 20000 },
         );
-        if (parent?.json) {
-          defaultRuntime.writeJson(result);
+        if (printBrowserJsonResult(parent, result)) {
           return;
         }
         defaultRuntime.writeJson(result.messages);
@@ -199,8 +191,7 @@ export function registerBrowserActionObserveCommands(
           },
           { timeoutMs: 20000 },
         );
-        if (parent?.json) {
-          defaultRuntime.writeJson(result);
+        if (printBrowserJsonResult(parent, result)) {
           return;
         }
         defaultRuntime.log(`PDF: ${shortenHomePath(result.path)}`);
@@ -241,8 +232,7 @@ export function registerBrowserActionObserveCommands(
           },
           { timeoutMs: timeoutMs ?? 20000 },
         );
-        if (parent?.json) {
-          defaultRuntime.writeJson(result);
+        if (printBrowserJsonResult(parent, result)) {
           return;
         }
         defaultRuntime.log(result.response.body);
diff --git a/extensions/browser/src/cli/browser-cli-debug.ts b/extensions/browser/src/cli/browser-cli-debug.ts
index f824d3841c89..3d5ad0228bed 100644
--- a/extensions/browser/src/cli/browser-cli-debug.ts
+++ b/extensions/browser/src/cli/browser-cli-debug.ts
@@ -3,13 +3,15 @@
  */
 import type { Command } from "commander";
 import { normalizeOptionalString } from "openclaw/plugin-sdk/string-coerce-runtime";
-import { runCommandWithRuntime } from "../core-api.js";
 import {
   BROWSER_TAB_REFERENCE_HELP,
   callBrowserRequest,
+  printBrowserJsonResult as printJsonResult,
+  resolveBrowserProfileQuery as resolveProfileQuery,
+  runBrowserCliCommand,
   type BrowserParentOpts,
 } from "./browser-cli-shared.js";
-import { danger, defaultRuntime, shortenHomePath } from "./core-api.js";
+import { defaultRuntime, shortenHomePath } from "./core-api.js";
 
 const BROWSER_DEBUG_TIMEOUT_MS = 20000;
 
@@ -20,20 +22,13 @@ type DebugContext = {
   profile?: string;
 };
 
-function runBrowserDebug(action: () => Promise<void>) {
-  return runCommandWithRuntime(defaultRuntime, action, (err) => {
-    defaultRuntime.error(danger(String(err)));
-    defaultRuntime.exit(1);
-  });
-}
-
 async function withDebugContext(
   cmd: Command,
   parentOpts: (cmd: Command) => BrowserParentOpts,
   action: (context: DebugContext) => Promise<void>,
 ) {
   const parent = parentOpts(cmd);
-  await runBrowserDebug(() =>
+  await runBrowserCliCommand(() =>
     action({
       parent,
       profile: parent.browserProfile,
@@ -41,14 +36,6 @@ async function withDebugContext(
   );
 }
 
-function printJsonResult(parent: BrowserParentOpts, result: unknown): boolean {
-  if (!parent.json) {
-    return false;
-  }
-  defaultRuntime.writeJson(result);
-  return true;
-}
-
 async function callDebugRequest<T>(
   parent: BrowserParentOpts,
   params: BrowserRequestParams,
@@ -56,10 +43,6 @@ async function callDebugRequest<T>(
   return callBrowserRequest<T>(parent, params, { timeoutMs: BROWSER_DEBUG_TIMEOUT_MS });
 }
 
-function resolveProfileQuery(profile?: string) {
-  return profile ? { profile } : undefined;
-}
-
 function resolveDebugQuery(params: {
   targetId?: unknown;
   clear?: unknown;
diff --git a/extensions/browser/src/cli/browser-cli-manage.ts b/extensions/browser/src/cli/browser-cli-manage.ts
index a383349cf546..99fcc1db4d58 100644
--- a/extensions/browser/src/cli/browser-cli-manage.ts
+++ b/extensions/browser/src/cli/browser-cli-manage.ts
@@ -4,11 +4,13 @@
  */
 import type { Command } from "commander";
 import { formatBrowserGraphicsSummary } from "../browser/chrome.graphics.js";
-import { runCommandWithRuntime } from "../core-api.js";
 import {
   BROWSER_TAB_REFERENCE_HELP,
   callBrowserRequest,
   parseBrowserPositiveIntegerValue,
+  printBrowserJsonResult as printJsonResult,
+  resolveBrowserProfileQuery as resolveProfileQuery,
+  runBrowserCliCommand as runBrowserCommand,
   type BrowserParentOpts,
 } from "./browser-cli-shared.js";
 import {
@@ -37,28 +39,6 @@ type BrowserDoctorCheck = {
   warning?: boolean;
 };
 
-function resolveProfileQuery(
-  profile?: string,
-  extra?: Record<string, string | number | boolean | undefined>,
-) {
-  const query: Record<string, string | number | boolean | undefined> = {};
-  if (profile) {
-    query.profile = profile;
-  }
-  if (extra) {
-    Object.assign(query, extra);
-  }
-  return Object.keys(query).length > 0 ? query : undefined;
-}
-
-function printJsonResult(parent: BrowserParentOpts, payload: unknown): boolean {
-  if (!parent?.json) {
-    return false;
-  }
-  defaultRuntime.writeJson(payload);
-  return true;
-}
-
 function sanitizeTableCell(value: string): string {
   // Strip C0/C1 control characters (Unicode Cc) so profile names cannot inject
   // terminal escapes into the printed table.
@@ -124,13 +104,6 @@ async function runBrowserToggle(
   defaultRuntime.log(info(`🦞 browser [${name}] running: ${status.running}${headlessLabel}`));
 }
 
-function runBrowserCommand(action: () => Promise<void>) {
-  return runCommandWithRuntime(defaultRuntime, action, (err) => {
-    defaultRuntime.error(danger(String(err)));
-    defaultRuntime.exit(1);
-  });
-}
-
 function parseTabIndex(value: string): number {
   return parseBrowserPositiveIntegerValue(value) ?? Number.NaN;
 }
diff --git a/extensions/browser/src/cli/browser-cli-resize.ts b/extensions/browser/src/cli/browser-cli-resize.ts
index 20cd6f160de8..2fdc0531dc80 100644
--- a/extensions/browser/src/cli/browser-cli-resize.ts
+++ b/extensions/browser/src/cli/browser-cli-resize.ts
@@ -2,9 +2,28 @@
  * Shared Browser CLI resize runner used by resize and set viewport commands.
  */
 import { ACT_MAX_VIEWPORT_DIMENSION } from "../browser/act-policy.js";
-import { callBrowserResize, type BrowserParentOpts } from "./browser-cli-shared.js";
+import {
+  callBrowserResize,
+  parseBrowserPositiveIntegerValue,
+  type BrowserParentOpts,
+} from "./browser-cli-shared.js";
 import { danger, defaultRuntime } from "./core-api.js";
 
+/** Parses a bounded viewport dimension for both Browser resize commands. */
+export function parseBrowserViewportDimension(value: unknown, label: string): number | undefined {
+  const parsed = parseBrowserPositiveIntegerValue(value);
+  if (parsed !== undefined && parsed <= ACT_MAX_VIEWPORT_DIMENSION) {
+    return parsed;
+  }
+  const reason =
+    parsed === undefined
+      ? "must be a positive integer"
+      : `maximum is ${ACT_MAX_VIEWPORT_DIMENSION}`;
+  defaultRuntime.error(danger(`Invalid ${label}: ${reason}`));
+  defaultRuntime.exit(1);
+  return undefined;
+}
+
 /** Validates viewport dimensions, sends resize action, and writes CLI output. */
 export async function runBrowserResizeWithOutput(params: {
   parent: BrowserParentOpts;
diff --git a/extensions/browser/src/cli/browser-cli-shared.ts b/extensions/browser/src/cli/browser-cli-shared.ts
index a819a868539b..9b9b66412e49 100644
--- a/extensions/browser/src/cli/browser-cli-shared.ts
+++ b/extensions/browser/src/cli/browser-cli-shared.ts
@@ -11,6 +11,7 @@ import {
   BROWSER_REQUEST_GATEWAY_SCOPES,
 } from "../browser-gateway-contract.js";
 import { normalizeBrowserTimerDelayMs } from "../browser/timer-delay.js";
+import { danger, defaultRuntime, runCommandWithRuntime } from "../core-api.js";
 import { callGatewayFromCli, type GatewayRpcOpts } from "./core-api.js";
 
 /** Parent Browser CLI options inherited by subcommands. */
@@ -30,6 +31,32 @@ type BrowserRequestParams = {
   body?: unknown;
 };
 
+/** Runs a Browser CLI command with the standard runtime error handling. */
+export function runBrowserCliCommand(action: () => Promise<void>) {
+  return runCommandWithRuntime(defaultRuntime, action, (error) => {
+    defaultRuntime.error(danger(String(error)));
+    defaultRuntime.exit(1);
+  });
+}
+
+/** Writes a Browser command result when structured output was requested. */
+export function printBrowserJsonResult(parent: BrowserParentOpts, payload: unknown): boolean {
+  if (!parent?.json) {
+    return false;
+  }
+  defaultRuntime.writeJson(payload);
+  return true;
+}
+
+/** Combines the selected Browser profile with optional request query fields. */
+export function resolveBrowserProfileQuery(
+  profile?: string,
+  extra?: BrowserRequestParams["query"],
+): BrowserRequestParams["query"] {
+  const query = { ...(profile ? { profile } : {}), ...extra };
+  return Object.keys(query).length > 0 ? query : undefined;
+}
+
 function normalizeQuery(query: BrowserRequestParams["query"]): Record<string, string> | undefined {
   if (!query) {
     return undefined;
@@ -78,17 +105,13 @@ export async function callBrowserRequest<T>(
   params: BrowserRequestParams,
   extra?: { timeoutMs?: number; progress?: boolean },
 ): Promise<T> {
-  const resolvedTimeoutMs =
+  const resolvedTimeout =
     typeof extra?.timeoutMs === "number" && Number.isFinite(extra.timeoutMs)
       ? normalizeBrowserTimerDelayMs(extra.timeoutMs)
       : typeof opts.timeout === "string"
         ? normalizeBrowserTimerDelayMs(parseBrowserPositiveIntegerOption(opts.timeout, "--timeout"))
         : undefined;
-  const resolvedTimeout =
-    typeof resolvedTimeoutMs === "number" && Number.isFinite(resolvedTimeoutMs)
-      ? resolvedTimeoutMs
-      : undefined;
-  const timeout = typeof resolvedTimeout === "number" ? String(resolvedTimeout) : opts.timeout;
+  const timeout = resolvedTimeout === undefined ? opts.timeout : String(resolvedTimeout);
   const payload = await callGatewayFromCli(
     BROWSER_REQUEST_GATEWAY_METHOD,
     { ...opts, timeout },
diff --git a/extensions/browser/src/cli/browser-cli-state.ts b/extensions/browser/src/cli/browser-cli-state.ts
index 301293eb45b6..6f670183523f 100644
--- a/extensions/browser/src/cli/browser-cli-state.ts
+++ b/extensions/browser/src/cli/browser-cli-state.ts
@@ -3,17 +3,17 @@
  * HTTP context settings.
  */
 import type { Command } from "commander";
+import { parseStrictFiniteNumber } from "openclaw/plugin-sdk/number-runtime";
 import {
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
 } from "openclaw/plugin-sdk/string-coerce-runtime";
-import { ACT_MAX_VIEWPORT_DIMENSION } from "../browser/act-policy.js";
-import { runCommandWithRuntime } from "../core-api.js";
-import { runBrowserResizeWithOutput } from "./browser-cli-resize.js";
+import { parseBrowserViewportDimension, runBrowserResizeWithOutput } from "./browser-cli-resize.js";
 import {
   BROWSER_TAB_REFERENCE_HELP,
   callBrowserRequest,
-  parseBrowserPositiveIntegerValue,
+  printBrowserJsonResult,
+  runBrowserCliCommand as runBrowserCommand,
   type BrowserParentOpts,
 } from "./browser-cli-shared.js";
 import { registerBrowserCookiesAndStorageCommands } from "./browser-cli-state.cookies-storage.js";
@@ -24,30 +24,12 @@ function parseOnOff(raw: string): boolean | null {
   return parsed === undefined ? null : parsed;
 }
 
-function parsePositiveInteger(value: unknown, label: string): number | undefined {
-  const parsed = parseBrowserPositiveIntegerValue(value);
-  if (parsed === undefined) {
-    defaultRuntime.error(danger(`Invalid ${label}: must be a positive integer`));
-    defaultRuntime.exit(1);
-    return undefined;
-  }
-  if (parsed > ACT_MAX_VIEWPORT_DIMENSION) {
-    defaultRuntime.error(danger(`Invalid ${label}: maximum is ${ACT_MAX_VIEWPORT_DIMENSION}`));
-    defaultRuntime.exit(1);
-    return undefined;
-  }
-  return parsed;
-}
-
 function parseFiniteNumberOption(value: string | undefined, label: string): number | undefined {
   if (value === undefined) {
     return undefined;
   }
-  const raw = value.trim();
-  const parsed = /^[+-]?(?:(?:\d+\.?\d*)|(?:\.\d+))(?:e[+-]?\d+)?$/i.test(raw)
-    ? Number(raw)
-    : Number.NaN;
-  if (!Number.isFinite(parsed)) {
+  const parsed = parseStrictFiniteNumber(value);
+  if (parsed === undefined) {
     defaultRuntime.error(danger(`Invalid ${label}: must be a finite number`));
     defaultRuntime.exit(1);
     return undefined;
@@ -55,13 +37,6 @@ function parseFiniteNumberOption(value: string | undefined, label: string): numb
   return parsed;
 }
 
-function runBrowserCommand(action: () => Promise<void>) {
-  return runCommandWithRuntime(defaultRuntime, action, (err) => {
-    defaultRuntime.error(danger(String(err)));
-    defaultRuntime.exit(1);
-  });
-}
-
 async function runBrowserSetRequest(params: {
   parent: BrowserParentOpts;
   path: string;
@@ -80,8 +55,7 @@ async function runBrowserSetRequest(params: {
       },
       { timeoutMs: 20000 },
     );
-    if (params.parent?.json) {
-      defaultRuntime.writeJson(result);
+    if (printBrowserJsonResult(params.parent, result)) {
       return;
     }
     defaultRuntime.log(params.successMessage);
@@ -104,8 +78,8 @@ export function registerBrowserStateCommands(
     .argument("<height>", "Viewport height")
     .option("--target-id <id>", BROWSER_TAB_REFERENCE_HELP)
     .action(async (widthRaw: string, heightRaw: string, opts, cmd) => {
-      const width = parsePositiveInteger(widthRaw, "width");
-      const height = parsePositiveInteger(heightRaw, "height");
+      const width = parseBrowserViewportDimension(widthRaw, "width");
+      const height = parseBrowserViewportDimension(heightRaw, "height");
       if (width === undefined || height === undefined) {
         return;
       }
@@ -186,8 +160,7 @@ export function registerBrowserStateCommands(
           },
           { timeoutMs: 20000 },
         );
-        if (parent?.json) {
-          defaultRuntime.writeJson(result);
+        if (printBrowserJsonResult(parent, result)) {
           return;
         }
         defaultRuntime.log("headers set");