| 1 | --- |
| 2 | name: sdk-swift-package |
| 3 | description: Build the Onde Swift package (XCFramework) from Rust source using UniFFI and distribute it via a remote-binary Package.swift for Swift Package Index. Covers xcframework assembly, App Group shared container, models/hub cache convention, and the onde-swift release workflow. |
| 4 | allowed-tools: Read, Write, Edit, Glob, Grep, Bash |
| 5 | user-invocable: true |
| 6 | --- |
| 7 | |
| 8 | # Skill: Swift Package (XCFramework Distribution) |
| 9 | |
| 10 | ## What this skill covers |
| 11 | |
| 12 | Building the `Onde` Swift package from Rust source using UniFFI, assembling an |
| 13 | `XCFramework`, and distributing it via a remote-binary `Package.swift` for |
| 14 | Swift Package Index. |
| 15 | |
| 16 | --- |
| 17 | |
| 18 | ## Repository layout |
| 19 | |
| 20 | ``` |
| 21 | onde/ |
| 22 | ├── src/ # Rust source (lib.rs, inference/, hf_cache.rs) |
| 23 | ├── sdk/Onde/ # Output: generated Swift package (git-ignored locally) |
| 24 | │ ├── Package.swift |
| 25 | │ ├── Sources/Onde/ # UniFFI-generated onde.swift glue + header |
| 26 | │ └── OndeFramework.xcframework |
| 27 | ├── uniffi-bindgen/ # onde's own uniffi-bindgen CLI binary |
| 28 | │ ├── Cargo.toml |
| 29 | │ └── uniffi-bindgen.rs # fn main() { uniffi::uniffi_bindgen_main() } |
| 30 | ├── uniffi.toml # UniFFI binding config (package_name, cdylib_name) |
| 31 | ├── build.rs # Provides tvOS ___chkstk_darwin stub via cc |
| 32 | └── Cargo.toml # uniffi = "=0.31.0" — version MUST stay pinned |
| 33 | ``` |
| 34 | |
| 35 | --- |
| 36 | |
| 37 | ## Key constraints |
| 38 | |
| 39 | | Constraint | Detail | |
| 40 | |---|---| |
| 41 | | UniFFI version | Pinned to **`=0.31.0`** in `Cargo.toml` and `uniffi-bindgen/Cargo.toml`. Never bump without coordinating with the Kotlin and Python SDKs. | |
| 42 | | tvOS targets | Tier-3 — require `cargo +nightly -Z build-std`. Stable toolchain is used for iOS/macOS. | |
| 43 | | tvOS linker | `___chkstk_darwin` is missing from tvOS libSystem. `build.rs` compiles `tvos_chkstk.s` as a no-op stub. This is automatic — do not remove it. | |
| 44 | | `cargo-swift` | **Not required.** The project owns its own `uniffi-bindgen` binary. Use it directly (same as `build-kotlin.sh` does for Android). | |
| 45 | | `.xcframework` in `Package.swift` | Published `Package.swift` must use **remote** `url:` + `checksum:` — never a local `path:`. | |
| 46 | | Swift package name | `Onde` (PascalCase). Git repo slug: `onde-swift` under the `ondeinference` org. | |
| 47 | | App Group ID | `group.com.ondeinference.apps` — shared across all Onde-powered apps (Flutter, Tauri, native Swift). | |
| 48 | | HF cache subdirectory | `<container>/models/hub/` — NOT `huggingface/hub/`. Must match the Tauri and Dart SDK convention. | |
| 49 | |
| 50 | --- |
| 51 | |
| 52 | ## Apple target triples |
| 53 | |
| 54 | | Slice | Triple | Toolchain | |
| 55 | |---|---|---| |
| 56 | | iOS device | `aarch64-apple-ios` | stable | |
| 57 | | iOS simulator (Intel) | `x86_64-apple-ios` | stable | |
| 58 | | iOS simulator (Apple Silicon) | `aarch64-apple-ios-sim` | stable | |
| 59 | | tvOS device | `aarch64-apple-tvos` | nightly + `-Z build-std` | |
| 60 | | tvOS simulator (Intel) | `x86_64-apple-tvos` | nightly + `-Z build-std` | |
| 61 | | tvOS simulator (Apple Silicon) | `aarch64-apple-tvos-sim` | nightly + `-Z build-std` | |
| 62 | | macOS (Apple Silicon) | `aarch64-apple-darwin` | stable | |
| 63 | | macOS (Intel) | `x86_64-apple-darwin` | stable | |
| 64 | |
| 65 | --- |
| 66 | |
| 67 | ## Build sequence (manual / CI) |
| 68 | |
| 69 | ### 1. Build the `uniffi-bindgen` CLI (host) |
| 70 | |
| 71 | ```bash |
| 72 | cargo build --manifest-path uniffi-bindgen/Cargo.toml --release |
| 73 | BINDGEN=uniffi-bindgen/target/release/uniffi-bindgen # or workspace target/ |
| 74 | ``` |
| 75 | |
| 76 | ### 2. Compile Rust staticlibs per Apple target |
| 77 | |
| 78 | ```bash |
| 79 | # Stable targets (iOS, macOS) |
| 80 | cargo build --target aarch64-apple-ios --release |
| 81 | cargo build --target x86_64-apple-ios --release |
| 82 | cargo build --target aarch64-apple-ios-sim --release |
| 83 | cargo build --target aarch64-apple-darwin --release |
| 84 | cargo build --target x86_64-apple-darwin --release |
| 85 | |
| 86 | # Nightly targets (tvOS — tier 3) |
| 87 | cargo +nightly build -Z build-std \ |
| 88 | --target aarch64-apple-tvos --release |
| 89 | cargo +nightly build -Z build-std \ |
| 90 | --target x86_64-apple-tvos --release |
| 91 | cargo +nightly build -Z build-std \ |
| 92 | --target aarch64-apple-tvos-sim --release |
| 93 | ``` |
| 94 | |
| 95 | ### 3. lipo simulator slices |
| 96 | |
| 97 | ```bash |
| 98 | # iOS simulator fat lib |
| 99 | lipo -create \ |
| 100 | target/x86_64-apple-ios/release/libonde.a \ |
| 101 | target/aarch64-apple-ios-sim/release/libonde.a \ |
| 102 | -output /tmp/libonde-ios-sim.a |
| 103 | |
| 104 | # tvOS simulator fat lib |
| 105 | lipo -create \ |
| 106 | target/x86_64-apple-tvos/release/libonde.a \ |
| 107 | target/aarch64-apple-tvos-sim/release/libonde.a \ |
| 108 | -output /tmp/libonde-tvos-sim.a |
| 109 | |
| 110 | # macOS universal fat lib |
| 111 | lipo -create \ |
| 112 | target/aarch64-apple-darwin/release/libonde.a \ |
| 113 | target/x86_64-apple-darwin/release/libonde.a \ |
| 114 | -output /tmp/libonde-macos.a |
| 115 | ``` |
| 116 | |
| 117 | ### 4. Generate Swift bindings |
| 118 | |
| 119 | ```bash |
| 120 | mkdir -p sdk/Onde/Sources/Onde |
| 121 | |
| 122 | $BINDGEN generate \ |
| 123 | --library target/aarch64-apple-ios/release/libonde.a \ |
| 124 | --language swift \ |
| 125 | --out-dir sdk/Onde/Sources/Onde \ |
| 126 | --config uniffi.toml |
| 127 | ``` |
| 128 | |
| 129 | This produces `onde.swift` and `ondeFFI.h` (+ `ondeFFI.modulemap`). |
| 130 | |
| 131 | ### 5. Create the `.xcframework` |
| 132 | |
| 133 | Each slice needs a headers directory alongside its `.a`: |
| 134 | |
| 135 | ```bash |
| 136 | HEADERS=sdk/Onde/Sources/Onde # contains ondeFFI.h + ondeFFI.modulemap |
| 137 | |
| 138 | xcodebuild -create-xcframework \ |
| 139 | -library target/aarch64-apple-ios/release/libonde.a -headers $HEADERS \ |
| 140 | -library /tmp/libonde-ios-sim.a -headers $HEADERS \ |
| 141 | -library target/aarch64-apple-tvos/release/libonde.a -headers $HEADERS \ |
| 142 | -library /tmp/libonde-tvos-sim.a -headers $HEADERS \ |
| 143 | -library /tmp/libonde-macos.a -headers $HEADERS \ |
| 144 | -output sdk/Onde/OndeFramework.xcframework |
| 145 | ``` |
| 146 | |
| 147 | ### 6. Zip and compute checksum |
| 148 | |
| 149 | ```bash |
| 150 | cd sdk/Onde |
| 151 | zip -r OndeFramework.xcframework.zip OndeFramework.xcframework |
| 152 | CHECKSUM=$(shasum -a 256 OndeFramework.xcframework.zip | cut -d ' ' -f1) |
| 153 | echo $CHECKSUM |
| 154 | ``` |
| 155 | |
| 156 | ### 7. Publish (two-repo strategy) |
| 157 | |
| 158 | 1. Upload `OndeFramework.xcframework.zip` as a GitHub Release asset on the |
| 159 | Rust source repo. |
| 160 | 2. In the `ondeinference/onde-kit` Swift-only repo, update `Package.swift`: |
| 161 | - `url:` → the GitHub Release asset download URL |
| 162 | - `checksum:` → the SHA-256 from step 6 |
| 163 | 3. Commit, tag the version (`0.1.0`, etc.), and push to `onde-kit`. |
| 164 | 4. Swift Package Index indexes `onde-kit` on every new tag. |
| 165 | |
| 166 | --- |
| 167 | |
| 168 | ## `Package.swift` (published form) |
| 169 | |
| 170 | ```swift |
| 171 | // swift-tools-version:5.5 |
| 172 | import PackageDescription |
| 173 | |
| 174 | let package = Package( |
| 175 | name: "Onde", |
| 176 | platforms: [ |
| 177 | .iOS(.v14), |
| 178 | .macOS(.v12), |
| 179 | .tvOS(.v13), |
| 180 | ], |
| 181 | products: [ |
| 182 | .library(name: "Onde", targets: ["Onde"]) |
| 183 | ], |
| 184 | targets: [ |
| 185 | .binaryTarget( |
| 186 | name: "OndeFramework", |
| 187 | url: "https://github.com/ondeinference/onde-kit/releases/download/0.1.0/OndeFramework.xcframework.zip", |
| 188 | checksum: "<sha256>" |
| 189 | ), |
| 190 | .target( |
| 191 | name: "Onde", |
| 192 | dependencies: [.target(name: "OndeFramework")] |
| 193 | ), |
| 194 | ] |
| 195 | ) |
| 196 | ``` |
| 197 | |
| 198 | --- |
| 199 | |
| 200 | ## UniFFI type map (Rust → Swift) |
| 201 | |
| 202 | | Rust type | UniFFI derive | Swift type | |
| 203 | |---|---|---| |
| 204 | | `ChatRole` | `uniffi::Enum` | `enum ChatRole` | |
| 205 | | `ChatMessage` | `uniffi::Record` | `struct ChatMessage` | |
| 206 | | `SamplingConfig` | `uniffi::Record` | `struct SamplingConfig` | |
| 207 | | `GgufModelConfig` | `uniffi::Record` | `struct GgufModelConfig` | |
| 208 | | `InferenceResult` | `uniffi::Record` | `struct InferenceResult` | |
| 209 | | `StreamChunk` | `uniffi::Record` | `struct StreamChunk` | |
| 210 | | `EngineStatus` | `uniffi::Enum` | `enum EngineStatus` | |
| 211 | | `EngineInfo` | `uniffi::Record` | `struct EngineInfo` | |
| 212 | | `InferenceError` | `uniffi::Error` | `enum OndeError : Error` | |
| 213 | | `OndeChatEngine` | `uniffi::Object` | `class OndeChatEngine` | |
| 214 | | `StreamChunkListener` | `callback_interface` | `protocol StreamChunkListener` | |
| 215 | |
| 216 | **UniFFI compatibility rules:** |
| 217 | - Use `u64`/`u32` instead of `usize` (UniFFI does not support `usize`). |
| 218 | - Streaming is exposed as a **free function** (`streamChatMessage`) not an |
| 219 | Object method — UniFFI 0.31 does not support `callback_interface` in Object |
| 220 | method parameters. |
| 221 | - Use concrete `String` parameters in `OndeChatEngine` methods — `impl Into<String>` |
| 222 | does not cross the FFI boundary. |
| 223 | |
| 224 | --- |
| 225 | |
| 226 | ## Swift API quick reference |
| 227 | |
| 228 | ```swift |
| 229 | import Onde |
| 230 | |
| 231 | // Engine lifecycle |
| 232 | let engine = OndeChatEngine() |
| 233 | try await engine.loadDefaultModel(systemPrompt: "You are helpful.", sampling: nil) |
| 234 | try await engine.loadGgufModel(config: qwen251_5bConfig(), systemPrompt: nil, sampling: nil) |
| 235 | await engine.unloadModel() |
| 236 | let loaded: Bool = await engine.isLoaded() |
| 237 | let info: EngineInfo = await engine.info() |
| 238 | |
| 239 | // Chat |
| 240 | let result: InferenceResult = try await engine.sendMessage(message: "Hello!") |
| 241 | let oneShot: InferenceResult = try await engine.generate(messages: [...], sampling: nil) |
| 242 | |
| 243 | // History |
| 244 | let history: [ChatMessage] = await engine.history() |
| 245 | let removed: UInt64 = await engine.clearHistory() |
| 246 | await engine.pushHistory(message: userMessage(content: "...")) |
| 247 | |
| 248 | // Streaming (free function, callback-based) |
| 249 | try await streamChatMessage(engine: engine, message: "Tell me a story.", listener: myHandler) |
| 250 | |
| 251 | // Config free functions |
| 252 | defaultModelConfig() // platform-appropriate default |
| 253 | qwen251_5bConfig() // ~941 MB, iOS/tvOS/Android |
| 254 | qwen253bConfig() // ~1.93 GB, macOS/desktop |
| 255 | |
| 256 | // Sampling presets |
| 257 | defaultSamplingConfig() // temp=0.7, top_p=0.95, max=512 |
| 258 | deterministicSamplingConfig() // temp=0.0 |
| 259 | mobileSamplingConfig() // temp=0.7, max=128 |
| 260 | |
| 261 | // Message constructors |
| 262 | systemMessage(content:) |
| 263 | userMessage(content:) |
| 264 | assistantMessage(content:) |
| 265 | ``` |
| 266 | |
| 267 | --- |
| 268 | |
| 269 | ## App Group Shared Container & Cache Convention |
| 270 | |
| 271 | All Onde-powered apps use the App Group `group.com.ondeinference.apps` to share |
| 272 | downloaded models. The cache layout inside the shared container is: |
| 273 | |
| 274 | ``` |
| 275 | <group container>/ |
| 276 | ├── models/ ← HF_HOME |
| 277 | │ └── hub/ ← HF_HUB_CACHE (GGUF files live here) |
| 278 | └── tmp/ ← TMPDIR (iOS sandbox restricts system TMPDIR) |
| 279 | ``` |
| 280 | |
| 281 | **Important:** The subdirectory is `models/`, NOT `huggingface/`. This was |
| 282 | chosen to be user-friendly when browsing the container in Finder/Files. All |
| 283 | SDKs (Rust, Swift, Dart) and all app types (Tauri, Flutter, native) must use |
| 284 | the same path or models won't be shared. |
| 285 | |
| 286 | ### Swift setup (called once at app launch) |
| 287 | |
| 288 | ```swift |
| 289 | import Foundation |
| 290 | |
| 291 | func setupInferenceEnvironment() { |
| 292 | guard let container = FileManager.default.containerURL( |
| 293 | forSecurityApplicationGroupIdentifier: "group.com.ondeinference.apps" |
| 294 | ) else { |
| 295 | // Fall back to app-private Application Support if App Group is unavailable. |
| 296 | let appSupport = FileManager.default |
| 297 | .urls(for: .applicationSupportDirectory, in: .userDomainMask)[0] |
| 298 | setupHfCache(at: appSupport) |
| 299 | return |
| 300 | } |
| 301 | setupHfCache(at: container) |
| 302 | } |
| 303 | |
| 304 | private func setupHfCache(at base: URL) { |
| 305 | let hfHome = base.appendingPathComponent("models") |
| 306 | let hfHub = hfHome.appendingPathComponent("hub") |
| 307 | try? FileManager.default.createDirectory(at: hfHub, withIntermediateDirectories: true) |
| 308 | |
| 309 | setenv("HF_HOME", hfHome.path, 1) |
| 310 | setenv("HF_HUB_CACHE", hfHub.path, 1) |
| 311 | |
| 312 | let tmp = base.appendingPathComponent("tmp") |
| 313 | try? FileManager.default.createDirectory(at: tmp, withIntermediateDirectories: true) |
| 314 | setenv("TMPDIR", tmp.path, 1) |
| 315 | } |
| 316 | ``` |
| 317 | |
| 318 | ### Entitlements required |
| 319 | |
| 320 | Both iOS and macOS targets need the App Group entitlement: |
| 321 | |
| 322 | ```xml |
| 323 | <key>com.apple.security.application-groups</key> |
| 324 | <array> |
| 325 | <string>group.com.ondeinference.apps</string> |
| 326 | </array> |
| 327 | ``` |
| 328 | |
| 329 | The App Group must also be registered in the Apple Developer Portal under |
| 330 | **Identifiers → App Groups** before Xcode can provision it. |
| 331 | |
| 332 | --- |
| 333 | |
| 334 | ## Local development (Xcode) |
| 335 | |
| 336 | Use the **local path** form during development — the remote binary form is only |
| 337 | needed for distribution: |
| 338 | |
| 339 | ```swift |
| 340 | // Package.swift (local dev only — never commit to onde-kit) |
| 341 | .binaryTarget(name: "OndeFramework", path: "./OndeFramework.xcframework") |
| 342 | ``` |
| 343 | |
| 344 | In Xcode: **File → Add Package Dependencies → Add Local** → select `sdk/Onde/`. |
| 345 | |
| 346 | --- |
| 347 | |
| 348 | ## Common pitfalls |
| 349 | |
| 350 | | Pitfall | Fix | |
| 351 | |---|---| |
| 352 | | Local `path:` in published `Package.swift` | Always `url:` + `checksum:` in `onde-swift` | |
| 353 | | Stale checksum after rebuild | Always recompute `shasum -a 256` — never hardcode | |
| 354 | | Missing simulator slice | lipo `x86_64` + `aarch64-sim` before passing to `xcodebuild` | |
| 355 | | UniFFI version drift | Keep `uniffi = "=0.31.0"` in both `Cargo.toml` and `uniffi-bindgen/Cargo.toml` | |
| 356 | | tvOS build with stable toolchain | tvOS targets are tier-3; always use `cargo +nightly -Z build-std` | |
| 357 | | Empty `Sources/` in `onde-swift` | Copy the generated `onde.swift` (and header) into the repo on every release | |
| 358 | | `___chkstk_darwin` linker error | Ensure `tvos_chkstk.s` exists at crate root; `build.rs` compiles it automatically | |
| 359 | | Missing Metal toolchain (Xcode 26+) | Run `xcodebuild -downloadComponent MetalToolchain`, then `cargo clean -p mistralrs-quant` | |
| 360 | | Cache path mismatch (`huggingface/` vs `models/`) | All SDKs MUST use `<container>/models/hub/` — using `huggingface/hub/` means models are not shared across apps | |
| 361 | | App Group not working | Register `group.com.ondeinference.apps` in Apple Developer Portal → Identifiers → App Groups; enable App Groups capability on the App ID; add entitlement to the target | |
| 362 | | `CODE_SIGN_IDENTITY = "-"` blocks App Groups | Remove ad-hoc signing from project-level build settings; App Groups require a real development certificate | |
| 363 | | Android NDK `LD` on PATH breaks Xcode | Never `export LD=$TOOLCHAIN/bin/ld` globally — it hijacks Xcode's linker. Use Cargo's `.cargo/config.toml` for Android linker config | |