An open protocol for portable, agent-backed personal software.
Snug is an open protocol (MIT) for small, user-built apps that think through their host's AI agent at runtime —
while the app and its accumulated state — code, data, chats — live in one portable file the user keeps.
snugprotocol.org · Try the Playground · Docs · Spec 1.0 · Download for macOS
- The app's brain is the host agent. A Snug chess game doesn't embed a chess engine — it sends the board to the LLM over a standard envelope and animates the reply. The app is a body; the agent is the mind.
- Users own their apps and their data — everything lives in one portable
.snugfile (real SQLite), exportable, movable, optionally passphrase-sealed. - It's embeddable and secure by construction — any product can drop in the runner + SDK; apps run in a hard sandbox with no network of their own, and credentials never enter the app, the LLM, or anyone's cloud.
| Repository | What it is |
|---|---|
snug |
The reference implementation — protocol bindings, sandboxed runner, SDK, portable database, agent adapters, the Playground, the macOS desktop app, and starter apps |
spec |
Specification 1.0 (normative) — the spec, JSON schemas for every message type, and the whitepaper |
- Curious? What is Snug? → try it in five minutes
- Building a product? Implementor quickstart — let your users build micro apps against your assistant
- Security-minded? The whitepaper — design rationale, threat model, security properties
Security contact: security@snugprotocol.org · MIT