Last updated: 2026-07-01
RewriteCmd is a macOS menu bar app by Hyperstack Studio that rewrites selected text in any application using a keyboard shortcut. It connects to Claude, OpenAI, or Mistral with your own API key and stores those credentials in the macOS Keychain instead of on disk. Custom rewrite instructions scale from one on Free to unlimited for teams.
About RewriteCmd
RewriteCmd is a macOS-native AI writing assistant built by Hyperstack Studio that rewrites text directly inside whatever application is currently open. Rather than switching to a separate writing tool or browser tab, users select text in any macOS application, press a customizable keyboard shortcut, and the selected text is rewritten in place. The workflow interruption is near-zero. The application sits in the macOS menu bar with no dock icon, keeping it accessible without cluttering the desktop. It uses the user's own API keys from Anthropic (Claude), OpenAI, or Mistral, meaning all rewrites go directly to the chosen provider without passing through a third-party server beyond the AI provider itself. API keys are stored in the macOS Keychain rather than written to disk, providing native macOS-level security for credentials. Users create custom instructions that define specific rewrite styles: make it more formal, shorten it, convert to bullet points, improve clarity, adopt a specific voice. The free plan includes one custom instruction, Pro includes five, and the Business plan provides unlimited instructions with team features. All plans support unlimited rewrites using the user's own API key, so the subscription cost covers the app features while AI compute costs are billed directly from the user's provider account. RewriteCmd works on macOS 13 Ventura and later, supporting both Apple Silicon and Intel processors. It targets Mac users who write across multiple applications daily: email in Apple Mail or Gmail in Safari, messages in Slack or Teams, code comments in VS Code, and documents in Pages or Notion, all without leaving each app to run AI-assisted rewrites. The model is relatively unique in the writing assistant space: a system-level native integration rather than a browser extension or standalone web app, making it faster and more universal across macOS applications.
Pricing
Free plan: basic rewriting, 1 custom instruction. Pro: $10/month (5 custom instructions, priority support). Business: $20/month (unlimited instructions, team features). All plans: unlimited rewrites using your own API key.
Key Features
- System-Wide In-App Rewriting: Works in any macOS application via keyboard shortcut, rewriting selected text in place without switching apps or opening a separate AI tool.
- Multi-Provider API Support: Connects to Claude (Anthropic), OpenAI, and Mistral using the user's own API keys, giving model choice without per-request platform markup.
- Custom Rewrite Instructions: Users create named instruction presets (formal, casual, shorter, bullet points) that apply different rewrite styles on demand via separate keyboard shortcuts.
- macOS Keychain Security: Stores API keys in the native macOS Keychain rather than application files, preventing credential exposure through disk access or app data breaches.
- Menu Bar Native Integration: Runs as a macOS menu bar app with no dock icon or external dependencies, maintaining system-level accessibility without desktop clutter.
Pros
- System-level universal compatibility means it works in every macOS application without requiring a browser extension or copy-paste workflow, unlike web-based writing tools.
- Bring-your-own-API-key model means unlimited rewrites without paying per-rewrite markups, with subscription cost covering app features only.
- macOS Keychain storage for API keys is significantly more secure than browser-based tools that store credentials in browser storage or cookies.
Cons
- macOS-only platform excludes Windows and Linux users entirely, and requires macOS 13 Ventura or later, which cuts off users on older Macs that cannot upgrade.
- API key requirement means users must create accounts and manage billing with Anthropic, OpenAI, or Mistral separately, adding setup friction compared to subscription-only tools.
- Free plan limited to one custom instruction significantly restricts workflow flexibility for users who write across multiple contexts with different style requirements.
Frequently Asked Questions
How much do you pay for RewriteCmd?
RewriteCmd has three tiers: Free with 1 custom instruction, Pro at $10/month with 5 instructions and priority support, and Business at $20/month with unlimited instructions and team features. Every tier, including Free, allows unlimited rewrites because usage runs through your own Anthropic, OpenAI, or Mistral key rather than a metered allowance from RewriteCmd.
Can you use RewriteCmd without paying?
Yes, the Free plan includes basic text rewriting and 1 custom instruction, with rewrites unlimited since the app bills usage to your own API key. Free does not include the extra custom instructions, priority support, or team features that come with Pro and Business.
What should you use instead of RewriteCmd?
Grammarly suits users who want cross-platform grammar and clarity checking through a browser extension rather than a native macOS app. ProWritingAid fits writers who want a dedicated style-coaching editor with deep grammar analysis. QuillBot works well when paraphrasing, summarizing, and plagiarism or AI detection matter more than in-place, system-wide rewriting.
What separates RewriteCmd from Grammarly?
Grammarly runs as a browser extension and standalone app across Windows, Mac, and web, and bundles its own AI model rather than requiring an API key. RewriteCmd instead lives in the macOS menu bar and rewrites text inside any application via a keyboard shortcut, using your own Claude, OpenAI, or Mistral key. Mac users who already pay for an API key and want native, in-place rewriting over a browser-based checker get a more direct fit from RewriteCmd.
How do you set up RewriteCmd?
Download RewriteCmd from rewritecmd.com, then create an API key at console.anthropic.com, platform.openai.com, or console.mistral.ai depending on the provider you want. Enter that key in RewriteCmd's settings, since even the Free plan requires it before any rewrite will work. From there, select text in any macOS app, press your configured keyboard shortcut, and the rewrite replaces the selection in place.
Top Alternatives
- Grammarly: Grammarly runs as a cross-platform browser extension with its own bundled AI model. RewriteCmd instead lives natively in the macOS menu bar, rewriting text inside any app through a keyboard shortcut using your own API key.
- ProWritingAid: A dedicated style-coaching editor with deep grammar analysis is ProWritingAid's strength. RewriteCmd skips the editor entirely and rewrites in place, triggered by a keyboard shortcut inside whatever app you're already using.
- QuillBot: QuillBot covers paraphrasing, summarizing, and plagiarism or AI detection. RewriteCmd stays narrower: system-wide keyboard-shortcut rewriting, nothing more, inside any macOS app.