{"data":{"slug":"harper","name":"Harper","tagline":"Apache-2.0 offline privacy grammar checker — Rust (Automattic)","category":"rust","categoryName":"Rust","url":"https://writewithharper.com","github":"https://github.com/Automattic/harper","pricing":"open-source","hook":"Harper is Automattic’s offline, privacy-first grammar checker — fast, open-source, Rust-powered, no document phone-home.","whatsGood":"Apache-2.0 (Automattic/harper). Local grammar/style checking with editor/LSP/Obsidian integrations. Docs and product at writewithharper.com. Runs on your machine; aimed at writers who refuse to paste drafts into SaaS grammar boxes.","theCatch":"Vs Grammarly SaaS: Harper is offline Rust grammar, not a cloud writing coach with tone/generative rewrites and team admin. Rule coverage and language support differ from Grammarly’s product surface — try it on your real prose. Not an LLM writing agent.","verdict":"Apache-2.0 offline grammar. Privacy-local vs Grammarly cloud.","addedAt":"2026-09-15","featured":false,"domain":"Rust","subSpecialty":"Editors","subcategory":"Editors","tags":["self-host","local-first","permissive","active"],"capabilities":["grammar","lsp","offline"],"surfaces":["Self-host","Hosted"],"ecosystem":["Rust","Multi-platform"],"licenseModel":"Apache-2.0","githubStars":16721,"starsPerWeek":107,"access":"free","archived":false,"repo":{"createdAt":"2023-10-22","pushedAt":"2026-10-19","license":"Apache-2.0","archived":false,"checkedAt":"2026-10-19"}},"related":[{"slug":"rust-lang","name":"Rust","tagline":"Systems programming without the footguns"},{"slug":"tokio","name":"Tokio","tagline":"Async runtime for Rust"},{"slug":"axum","name":"Axum","tagline":"Web framework from the Tokio team"},{"slug":"actix-web","name":"Actix Web","tagline":"Fast Rust web framework"},{"slug":"serde","name":"Serde","tagline":"Serialization framework for Rust"}],"links":{"self":"/api/gems/harper","html":"/gems/harper","markdown":"/gems/harper.md","category":"/api/gems?category=rust","categoryPage":"/stacks/rust"}}