# T3 Mobile Terminal Native Module

This local Expo module owns the native terminal surface for the mobile app.

The JavaScript contract is intentionally small:

- input from the native surface is emitted as `{ data: string }`
- resize from the native surface is emitted as `{ cols: number, rows: number }`
- remote PTY output is delivered by the existing `WsRpcClient.terminal` RPC stream

The iOS implementation uses the vendored `GhosttyKit.xcframework` built from the Ghostty custom-I/O
fork, with T3's iOS 16 compatibility patch applied. `T3TerminalView` owns a `libghostty` surface and
uses that callback I/O model:

1. initialize libghostty once for the process
2. create one Ghostty app and surface per native view
3. feed remote output into the surface with `ghostty_surface_feed_data`
4. send user input back to JS with the write callback
5. emit Ghostty's measured terminal size through `onResize`

Android implements the same view contract with upstream `libghostty-vt` for terminal state, parsing,
reflow, and scrollback. An Android Canvas view renders compact snapshots produced by the JNI bridge,
so the React Native screen and RPC code stay platform-neutral.

Vendored Ghostty revision and license details are in `THIRD_PARTY_NOTICES.md`.

## Rebuilding GhosttyKit

The checked-in `GhosttyKit.xcframework` is built from the Ghostty custom-I/O fork (https://github.com/Yash-Singh1/ghostty/tree/custom-io).
Set the directory to the cloned repository checked out on the `custom-io` branch to `GHOSTTY_SOURCE_DIR`.

```bash
apps/mobile/modules/t3-terminal/scripts/build-libghostty-ios16.sh
```

The script builds Ghostty with Zig 0.15.2, strips the iOS archives, and replaces only the
`ios-arm64` and `ios-arm64-simulator` slices. Xcode's Metal toolchain must be installed; if `metal`
fails, run `xcodebuild -downloadComponent MetalToolchain`.

## Rebuilding libghostty-vt for Android

The checked-in Android shared libraries and headers are pinned to the revision recorded in
`native/libghostty-vt/VERSION` at the repository root. Set `ANDROID_NDK_HOME` and run:

```bash
apps/mobile/modules/t3-terminal/scripts/build-libghostty-android.sh
```

The script downloads Zig 0.15.2 when needed, checks out the pinned upstream Ghostty revision, and
rebuilds all four Android ABIs with 16 KB page-size support.