How to Set Up a Writing Assistant on Mac

The simplest way to set up a writing assistant on Mac is to install Charm, grant one Accessibility permission, and it starts correcting in every app immediately. For most users, this means spelling correction, grammar fixing, and word prediction across Mail, Notes, Slack, VS Code, and any other Mac app - with no configuration required and no subscription to manage.

Step-by-step: setting up Charm as your writing assistant

The whole process takes under 2 minutes. Here is exactly what to do.

Step 1: Download Charm. Go to theodorehq.com/charm and download the app. Open the downloaded file to start the installer.

Step 2: Move Charm to your Applications folder. Drag the Charm icon into your Applications folder when prompted. This is a standard macOS installation step. Once it is in Applications, open it from there rather than from your Downloads folder.

Step 3: Grant Accessibility permission. When Charm launches for the first time, it will prompt you to grant Accessibility access. Click the button to open System Settings, then navigate to Privacy & Security > Accessibility, and toggle Charm on.

This permission is the only one Charm needs. It does not ask for microphone access, camera access, or network permissions for its correction features. Accessibility is what allows Charm to read and modify text in any app - the same mechanism that powers screen readers and other assistive tools built into macOS.

Step 4: Test it. Open any app - Mail, Notes, Slack, whatever you use most - and type a word with a deliberate typo. Charm should correct it as you finish the word, marked by a brief cyan glow. If you see the glow, everything is working.

That is the complete setup. No account, no configuration wizard, no onboarding flow. From download to first correction in under two minutes.

What Charm does and how to use each feature

Charm ships with three features turned on by default. You do not need to configure any of them - they are active from the moment you grant Accessibility permission.

Spells handles real-time spelling correction. As you type, Charm monitors each word. When it detects a misspelling, it silently replaces it with the correct version the moment you finish the word. The correction is marked by a brief cyan glow so you know it happened - but it does not interrupt your flow. No red squiggles, no popups.

Polish handles grammar. It fires when you reach the end of a sentence - typically at a period, question mark, or comma - and corrects grammatical errors in the text you just wrote. Corrections from Polish appear with a blue glow rather than cyan, so you can tell which feature acted.

Oracle handles word prediction. As you type, Oracle predicts the most likely next word and shows it as a greyed-out suggestion after your cursor. Press Tab to accept the suggestion and move on. If you keep typing instead, the suggestion disappears. Oracle uses a purple indicator when it activates. This feature tends to be most noticeable when you are writing common phrases or finishing a sentence you have started many times before.

All three features work in every text field on your Mac, simultaneously, in the background.

Configuring Charm to fit your workflow

Charm works well out of the box, but there are a few things worth knowing once you have used it for a day or two.

Per-app settings. If you want Charm to behave differently in a specific app - for example, disabling word prediction in your code editor while keeping it active in Mail - you can set per-app preferences from the Charm menu bar icon. This is useful for apps where prediction suggestions might clash with autocomplete from another tool.

Personal dictionary. Charm learns from corrections over time, but you can also manually add words to your personal dictionary. This is where you add proper nouns, brand names, technical terms, or any word that Charm keeps flagging as a misspelling. Adding a word once means it is never corrected again.

Complement Charm with macOS Text Replacements. Charm focuses on spelling and grammar - it does not expand abbreviations or insert boilerplate phrases. macOS has a built-in Text Replacements feature (System Settings > Keyboard > Text Replacements) that handles this. Set up shortcuts like "addr" for your full address or "sig1" for a common email sign-off, and they will expand everywhere on your Mac. Used together, Charm and Text Replacements cover nearly every friction point in everyday typing.

What about AI drafting tools and other writing assistants?

The term "writing assistant" covers a lot of ground. It helps to draw a clear line between two distinct categories.

Real-time correction tools like Charm work invisibly as you type. They fix what you have already written - catching a typo before it leaves your keyboard, tightening a grammatical slip before you send it. The output is still entirely your own. You are writing; Charm is just removing the friction.

AI drafting tools like ChatGPT, Claude, and Notion AI generate text from a prompt. You describe what you want and the tool writes it. These are different use cases, not competing products. Many people use both: an AI tool to draft or brainstorm, and a correction tool like Charm to clean up their own writing everywhere else.

If you have looked at Grammarly as an alternative, the key differences are worth knowing. Grammarly on Mac is a browser extension - it only works inside Chrome, Safari, Firefox, and Edge. It does not function in Mail, Slack, Notes, VS Code, or any native Mac app. It also uses cloud processing, which means your text is sent to Grammarly's servers for analysis. And it costs $144 per year on the Premium plan.

Charm is system-wide (every Mac app, not just browsers), on-device (your text never leaves your Mac), and costs $9.99 once. For most Mac users who want real-time correction across their full workflow, Charm covers more ground at a fraction of the price.

Frequently asked questions

What is the best writing assistant for Mac in 2026?

For real-time correction across every Mac app, Charm is the best option in 2026. It corrects spelling, fixes grammar, and predicts words system-wide - in Mail, Slack, Notes, VS Code, and anywhere else you type - for a one-time $9.99 payment. If you want AI-generated drafts rather than real-time correction, tools like ChatGPT or Claude serve a different but complementary purpose.

How long does it take to set up a writing assistant on Mac?

With Charm, under 2 minutes. Download the app, move it to Applications, launch it, and grant one Accessibility permission. After that, Charm is active everywhere with no further setup.

Does a writing assistant work in every Mac app?

Charm does. It uses the macOS Accessibility API to work in every text field across all applications - Mail, Notes, Slack, VS Code, Pages, Obsidian, and any other Mac app. Browser-only tools like Grammarly do not work in native Mac apps, which covers the majority of where most people actually type.

Do I need to pay a subscription for a writing assistant on Mac?

Not with Charm. It costs $9.99 as a one-time purchase - no subscription, no renewal. One licence covers up to 3 Macs and includes updates. Grammarly Premium, by comparison, costs $144 per year.