Case study · 2024 — Present
Hone Intelligence — AI Clipboard for macOS
Local-first clipboard history with a Rust core and dual-process AI safety
Independent builder · Independent
The problem
The problem
Clipboard history tools either spy in the cloud or lack AI transforms. Power users need both speed and privacy, plus a safety net so secrets never leak to a model.
Outcomes
- Unlimited history with SQLite FTS5 search, Smart Context ranking, and a Cmd+K command palette
- AI features (OpenAI, Anthropic, Perplexity) via BYOK or an optional WorkOS-gated Go proxy for orgs
- Two-layer content safety: Swift-side policy plus Rust-side regex redaction before anything reaches a model
Architecture
SwiftUI app bridged to a Rust core (`hone_lib`) over a C FFI boundary — Rust owns SQLite (WAL + FTS5, 12 migrations), clipboard capture (NSPasteboard/NSEvent via objc2), and AI provider calls (reqwest + SSE streaming).
Secrets live in the macOS Keychain; sensitive-content detection (SSN/credit-card/API-key patterns) runs before paste and before any AI call. A separate Go service (`hone-auth`) handles WorkOS magic-code sign-in and role-based access for the optional org proxy.
Product
Tags, pinboards, favorites, snippets with placeholder expansion, paste queue, copy-merge, and paste transforms.
Chat workspace with vision analysis and cited Perplexity web search; a plugin marketplace with permission tiers; 30+ themes on a Liquid Glass design system.
Key tradeoffs
Platform
Chose: Native macOS first (Swift + Rust)
Rejected: Electron cross-platform v1
Clipboard capture, performance, and OS permissions are better as a native citizen; Rust keeps the data/AI core portable if a Windows port ever happens.
AI safety boundary
Chose: Redact before the model, not after
Rejected: Trust the provider / client-side warning only
Clipboard content routinely contains secrets — the redaction has to sit between capture and any network call, not as a post-hoc check.
What was hard
- Permission model and silent capture reliability
- Keeping the Swift/Rust FFI boundary safe under concurrent clipboard events
What I would change
- Windows when macOS retention is proven
Artifacts
