tolaria/docs/IPAD-PROTOTYPE.md

iPad Prototype — Tauri v2 iOS Feasibility Report

Date: 2026-03-27 Status: Prototype — Rust cross-compiles to iOS, Xcode project generated, awaiting simulator runtime

Summary

Laputa can be ported to iPad using Tauri v2 iOS (beta) with minimal code changes. The React frontend stays identical. The Rust backend compiles for iOS with conditional compilation to gate desktop-only features (git CLI, menu bar, MCP, Claude CLI). Vault read/write operations work without changes.

What Works

Feature	Status	Notes
Rust backend cross-compilation	Compiles cleanly for aarch64-apple-ios-sim	Zero errors, zero warnings
Desktop build (no regressions)	581 Rust tests pass, 2201 frontend tests pass	Lint and type check clean
Tauri iOS project generation	Xcode project generated via tauri ios init	CocoaPods, xcodegen, libimobiledevice installed
Vault file read/write	Expected to work	Pure filesystem operations, no process spawning
AI chat (Anthropic API)	Expected to work	Uses reqwest HTTP, no CLI dependency
Search	Expected to work	Pure Rust in-memory search
Settings persistence	Expected to work	JSON file read/write
React UI in WebView	Expected to work	Tauri v2 uses WKWebView on iOS

What Doesn't Work (Yet)

Feature	Blocker	Recommended Solution
Git operations	No git binary on iOS	Option B (Working Copy) for prototype; Option A (isomorphic-git) for production
GitHub clone/push/pull	Depends on git CLI	Same as above
Claude CLI streaming	No claude binary on iOS	Use Anthropic API directly (already available via ai_chat)
MCP server / WS bridge	Spawns Node.js child process	Skip for mobile; explore in-process MCP later
macOS menu bar	Desktop-only API	Touch-native navigation (already handled by React)
Updater plugin	Desktop-only	Use TestFlight for updates
File open dialog	Different on iOS	tauri-plugin-dialog supports iOS — needs testing

Changes Made

src-tauri/src/lib.rs

• Gated WsBridgeChild, run_startup_tasks, spawn_ws_bridge, log_startup_result behind #[cfg(desktop)]
• Mobile build skips MCP registration, WS bridge, and vault migrations at startup
• Run event handler gated for desktop (child process cleanup)

src-tauri/src/commands.rs

• Git commands: desktop implementations remain unchanged; mobile stubs return graceful errors or empty results
• GitHub commands: desktop-only; mobile stubs return errors
• Claude CLI commands: desktop-only; mobile stubs return installed: false
• MCP commands: desktop-only; mobile stubs return NotInstalled
• Menu commands: desktop-only; mobile stub is a no-op
• Vault, frontmatter, search, AI chat, settings: unchanged (work on both platforms)

src-tauri/src/lib.rs

• pub mod menu gated behind #[cfg(desktop)]

src-tauri/capabilities/

• default.json: scoped to desktop platforms (linux, macOS, windows)
• mobile.json: new file with iOS/Android permissions (core, dialog)

src-tauri/gen/apple/

• Full Xcode project generated by tauri ios init
• iPad support: all orientations enabled, arm64 architecture

Architecture: How Mobile Stubs Work

Frontend (React) ──invoke──> Tauri Commands ──> Rust Backend
                                 │
                      ┌──────────┴──────────┐
                  #[cfg(desktop)]       #[cfg(mobile)]
                      │                     │
                  Real impl            Stub (error/empty)
                  (git CLI,            (graceful degradation)
                   menu, MCP)

The frontend code doesn't change at all. Commands that aren't available on mobile return errors that the UI can handle gracefully (e.g., hiding the git sync panel, disabling commit buttons).

Git Strategy for iPad

Phase 1: Working Copy (Recommended for prototype)

• User manages vault with Working Copy (git client for iPad)
• Laputa opens the vault via iOS Files API / FileProvider
• Zero git code needed in Laputa — Working Copy handles sync
• Pro: Works immediately, robust git implementation
• Con: Requires separate app, split UX for sync

Phase 2: isomorphic-git (Production)

• Pure JS git implementation running in the WebView
• Replace invoke("git_commit") etc. with JS-side git operations
• Pro: Integrated UX, no external dependency
• Con: Slower on large vaults (~9200 files), limited advanced git features

Phase 3: git2-rs / gitoxide (Future)

• Pure Rust git library compiled into the Tauri binary
• Best performance, no JS bridge overhead
• Con: Larger binary size, more integration work

Next Steps

1. Install iOS simulator runtime — xcodebuild -downloadPlatform iOS (downloading ~7GB)
2. Full Xcode build — npx tauri ios build --target aarch64-sim
3. Launch on iPad simulator — npx tauri ios dev
4. Test vault read/write — open a vault, read/edit a note
5. Test AI chat — verify Anthropic API calls work from iOS WebView
6. Evaluate touch UX — identify layout issues on iPad screen size
7. File Provider integration — test opening vaults from Working Copy via iOS Files

Prerequisites Installed

• Rust iOS targets: aarch64-apple-ios, aarch64-apple-ios-sim, x86_64-apple-ios
• Xcode 16.2 with iOS 18.3.1 simulator runtime (downloading)
• CocoaPods 1.16.2, xcodegen 2.45.3, libimobiledevice 1.4.0
• Tauri CLI 2.10.0 with iOS support