macOS App

The SwiftUI shell in apps/macos embeds the node core through crates/inseam-ffi. It proves the integration end to end: open the node, index a chosen folder, and query — all business logic in Rust, only UI in Swift.

The FFI boundary (crates/inseam-ffi)

A C ABI static library (libinseam_ffi.a) with a hand-maintained header at crates/inseam-ffi/include/inseam_ffi.h (keep header and src/lib.rs in sync). Surface:

Function	Does
inseam_version	Core version string
inseam_node_open	Open the node under a data dir; optional composition path, otherwise <data_dir>/composition.toml layered over the built-in base
inseam_node_query	Finder query → QueryResponse JSON
inseam_node_index_dir	Index a local directory → IndexReport JSON
inseam_node_free / inseam_string_free	Release handles/strings the library allocated

Conventions: calls that can fail take char **error_out (null return + owned message on failure); every returned string is freed with inseam_string_free. The handle owns a booted kernel and its tokio runtime, so calls block — app shells run them off the main thread. Responses are the same serde types ops serializes everywhere else.

The Swift side (apps/macos)

A SwiftPM package, no Xcode project:

• Sources/CInseamFFI/module.modulemap — system-library target exposing the FFI header and linking inseam_ffi.
• Sources/Inseam/InseamCore.swift — CoreNode: RAII wrapper over the handle, JSON decoding into Swift structs (snake_case converted).
• Sources/Inseam/ContentView.swift — the UI: open node on launch (data dir ~/Library/Application Support/inseam, shared with the CLI), Index Folder… button, query field, results list.

Building

apps/macos/build.sh            # → /Applications/Inseam.app
apps/macos/build.sh /tmp/out   # → any other destination dir

The script builds inseam-ffi in release, runs swift build -c release with -L target/release, assembles the .app bundle from apps/macos/Info.plist (including the app icon from assets/icon-macos.icns — see docs/assets.md), ad-hoc codesigns, and copies to the destination — default /Applications, so the finished app is directly launchable. Requires only the Xcode Command Line Tools (swift).

Known cosmetic warning: the Rust objects target the host macOS version while the app declares LSMinimumSystemVersion 14.0, so ld prints version-mismatch warnings. Harmless for local builds; set MACOSX_DEPLOYMENT_TARGET=14.0 when building the Rust side for distribution.