Cotabby is a genuinely good free, open-source beta — a local LLM predicts your next words as ghost text in any field, and Tab accepts. If you love importing your own GGUF models and don’t mind beta software, keep using it. But if you’d rather run a finished, notarized tool — also free and open source, with no daily cap and optional screen recording — Shadowtype is built for you.
Both are free, open source, and import custom models — we mark that honestly. Where they tie, we say so. Shadowtype wins on a stable notarized release, a homegrown auto-updater, optional screen recording, and built-in personalization.
| Capability | Shadowtype | Cotabby |
|---|---|---|
| System-wide inline ghost-text completion | Yes | Yes |
| On-device LLM · offline · no account | Yes | Yes |
| Tab-to-accept · zero telemetry | Yes | Yes |
| Open source (AGPL-3.0) | Source-available roadmap | Yes |
| Import your own custom GGUF model | Curated catalog | Yes |
| Apple Foundation Models engine | llama.cpp + Metal | Optional |
| Release maturity | Stable · notarized | Beta (v0.4.x) |
| Support | Dedicated email | GitHub issues |
| Per-app instructions & personalization | Yes | Length presets only |
| Selection rewrite (⌥⌘K, on-device) | Yes | Completion only |
| Local API + MCP server (OpenAI-compatible) | Yes | No |
| Screen Recording permission | Optional | Required |
| Price | Free & open source | Free · AGPL |
| Requirements | macOS 14+ · Apple Silicon | macOS 15+ · Apple Silicon |
Cotabby ships as a beta you build from source or grab from GitHub releases. Shadowtype is a stable, notarized macOS app with a homegrown auto-updater — install it once and it just keeps working, no Xcode and no open-issue triage required.
Both are open source, but Cotabby is still beta software. Shadowtype is a stable, notarized, signed release that just keeps working — free, with no daily cap and no account. Read the code and file issues any time.
Cotabby requires Accessibility, Input Monitoring and Screen Recording. Shadowtype keeps screen-aware OCR optional, adds per-app instructions, personalization, and on-device selection rewrite with ⌥⌘K — free, on as many of your Macs as you like.
An OpenAI-compatible HTTP endpoint runs on 127.0.0.1 so your scripts, editors, and agents can call the same on-device model — no key, no cloud. A built-in MCP bridge plugs into Claude Code and other MCP clients, and the BYOM picker loads any GGUF.
127.0.0.1 with no key required, so your terminal, editor plugins, and AI agents can call /v1/chat/completions against the same on-device model. A built-in MCP server plugs into Claude Code and other MCP clients, and the BYOM picker loads any GGUF you drop in. Everything is bound to localhost — nothing leaves your Mac. Cotabby doesn’t offer a local API or MCP server.Download Shadowtype free, accept your first word with Tab, and upgrade once when you’re ready.