Lexa
Lexa is a small open-source Grammarly alternative for macOS under MIT. Select text in any app, press Option plus Command plus G, and Lexa shows the correction, a tone change or a translation into 15 languages. It supports OpenRouter, Groq, Cerebras, Gemini, Mistral, GitHub Models, Ollama, LM Studio and your ChatGPT or Claude subscription through the official CLIs, with keys kept in the macOS Keychain.
What does Lexa do?
Lexa's README calls it "a small Grammarly alternative for macOS" and lists its workflow: select text in an app, press Option plus Command plus G, read the highlighted changes, press Return to replace the selected text. The command panel has Correct, which fixes grammar, spelling and punctuation; Make Clear, which rewrites the text in ASD-STE100 Simplified Technical English; Tone, which changes the text to Formal, Friendly, Short or Confident; and Translate, which translates into one of 15 languages. Copy, retry and close are their own shortcuts.
Lexa is wide on providers for its size. The README lists OpenRouter, Nous Portal, GitHub Models, Groq, Cerebras, Google Gemini, Mistral, Ollama, LM Studio, ChatGPT and Claude. The two subscriptions use the official codex and claude CLIs, so Lexa does not read their credentials directly; the README warns "use your subscription only for your work, and obey the terms of your plan." A Custom provider accepts any server with an OpenAI-compatible /chat/completions endpoint. Keys and tokens are stored in the macOS Keychain.
Key facts
- Licence: MIT, per the README and the LICENSE file.
- macOS 26 or newer.
- Install with Homebrew:
brew install --cask sasuke40/tap/lexa, or download Lexa-x.y.z.zip from Releases. - The app is not notarised by Apple; the first launch needs Open Anyway in System Settings.
- Accessibility access is required so Lexa can copy and paste the selected text.
- Shortcuts: Option plus Command plus G to open the correction, Command plus 1 for Correct, Command plus 2 for Make Clear, Command plus C for Copy, Command plus R for Try again, Escape to close.
- Providers the README names: OpenRouter, Nous Portal, GitHub Models, Groq, Cerebras, Gemini, Mistral, Ollama, LM Studio, ChatGPT (via Codex CLI), Claude (via claude CLI), Custom.
- Updates: Lexa checks on launch and once a day. Install the update from Settings, General; a Homebrew install uses
brew upgrade --cask lexa. - A support note in the README: the Nous Portal sign-in uses the Hermes Agent client ID and may stop at any time.
What does it replace, and where does it fall short?
Lexa replaces Grammarly for a Mac user who wants a system-wide "fix this selection" box with a wide provider choice, keeping the text local when Ollama or LM Studio is picked. It is a candidate on the open-source alternatives to Grammarly page.
Where it falls short: macOS 26 or newer only, so older Macs are out. Lexa is a trigger-based rewriter rather than an inline grammar underliner; if you want "live checks" as you type, Nogrammerly and Harper do that. The Nous Portal sign-in borrows another project's client ID without permission, per the README; expect it to break at any time. The README names no Windows or Linux build.
How does Lexa run?
Install Lexa through the Homebrew cask or by moving the zip's Lexa.app to Applications. Grant Accessibility access, then open the menu bar icon to pick a provider. Each provider has its own path: paste an OpenRouter or Gemini key, sign in with GitHub for GitHub Models, or point Lexa at Ollama or LM Studio on localhost. ChatGPT and Claude subscriptions require the codex and claude CLIs on the machine.
The README describes no paid or hosted version of Lexa itself.
Who is Lexa for?
A Mac user on a recent macOS who wants Grammarly-style corrections, tone changes and translations across every app, with the flexibility to route to a local model, a free hosted API or a paid subscription they already own. A reader on Windows or an older Mac should pick a different project.
What limits does the README state?
- macOS 26 or newer only.
- The app is not notarised; the first launch needs the Open Anyway step.
- Accessibility access is required.
- "The Nous Portal sign-in uses the public client ID of Hermes Agent. Nous Research did not give Lexa permission for this sign-in, and it can stop at any time."
- Subscription routes read keys through the
codexandclaudeCLIs; Lexa does not touch their credentials.
Questions people ask
Is Lexa open source?
Yes. The LICENSE file is MIT, verified on the date on this page. MIT is an OSI-approved licence with no added conditions. The project has no paid build.
Does Lexa work offline?
With Ollama or LM Studio, yes: the README says "with Ollama or LM Studio, your text stays on your Mac." Every other provider sends the selection over the internet to the provider you picked.
Can I use my ChatGPT or Claude plan with Lexa?
The README says yes, through the codex and claude CLIs. Lexa does not read the CLIs' credentials directly; it runs the CLI and reads its output. The README adds a note to use the plan only for your own work and to follow the plan's terms.
How does Lexa compare with Grammarly?
Grammarly is a hosted writing service with its own model and a browser extension. Lexa is an MIT macOS trigger that calls a provider you pick, including local models, and runs on any text in any app. The open-source alternatives to Grammarly page compares Lexa with other candidates.
How many languages does Lexa translate into?
Fifteen, per the README's shortcut table. The exact list is not reproduced in the README; the Translate menu names them when open.
Sources
- Lexa README and MIT LICENSE: github.com/SASUKE40/Lexa, read 2026-10-19.
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Added October 19, 2026. Every claim above comes from the project's README, LICENSE or model card, read on October 19, 2026, or from the GitHub API on the date shown in the panel. Found an error? Write to reveneau@licheo.com and it is fixed in the next weekly pass. Repository: github.com/SASUKE40/Lexa.
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