[feature] voice-typing keyboard: dictate into any app

[YJack0000]

What

A dictation keyboard for Parley: tap the mic in any text field and speak; the words land in the field. The phone's version of the desktop's voice_typing.rs.

The constraint

A keyboard extension cannot open the microphone (iOS forbids it since iOS 8, Full Access included). So the keyboard doesn't record — it bounces to the container app, the app records, and the transcript is handed back. Same pattern every dictation keyboard on the App Store uses.

Recording reuses the existing pipeline: AudioCapture (16 kHz mono) → SttRelayClient (hosted relay, billed under feature: "dictation", no API key on the phone). New parts are the keyboard, the App Group hand-off, and the in-app dictation session.

Flow

1. Keyboard mic tap — mints a session, captures the host app's bundle id (best-effort), writes the uplink, opens parley://dictate via SwiftUI openURL (the responder-chain openURL: walk was disabled for keyboards in iOS 18; openURL is the path that still works, walk kept as older-system fallback).
2. App records — onOpenURL → DictationCoordinator starts mic + relay, mirrors the growing transcript into the downlink, posts a Darwin note per update.
3. Return to host app — see below.
4. Keyboard inserts — on the Darwin note (and every viewWillAppear, in case it was suspended through the notification) it inserts whatever is new past its insertedCount high-water mark, so a killed-and-relaunched keyboard never double-inserts.

App Group channel (DictationChannel, in ParleyKit)

Two single-writer mailboxes (dictation-down.json app→keyboard, dictation-up.json keyboard→app) plus two Darwin notifications. The files are the source of truth; the notes are pure "go re-read" signals — which is what makes the hand-off robust to the keyboard being suspended/killed while the app is foregrounded.

The "jump back to the previous app" problem

Typeless's auto-return was never a public API. Apple closed it in iOS 26.4 — the private host-bundle-id getters return nil and the private launch lands on the Home Screen. Wispr Flow's own docs confirm they switched to a manual swipe on 26.4.

Decision (obfuscation + version gate):

• iOS < 26.4 — auto-return via the private LSApplicationWorkspace launch. Every private symbol is assembled from string fragments at runtime and reached through responds(to:)/perform, so no literal private symbol sits in the binary (verified: strings finds none of _hostBundleID, LSApplicationWorkspace, openApplicationWithBundleID) and a missing getter is a nil, never a crash.
• iOS 26.4+ — no private call attempted; the dictation screen teaches the swipe-right gesture with a first-run guide and keeps recording alive in the background (UIBackgroundModes: audio).

Action Button / Control Center

StartDictationIntent (AudioRecordingIntent, iOS 18+) starts dictation without leaving the current app at all — the lowest-friction trigger, sidestepping the auto-return problem entirely.

App Review

• 4.4.1 — the keyboard always shows a minimal key row (globe/space/return/delete), functional without Full Access; dictation itself needs Full Access and says so with a jump to Settings.
• 2.5.1 — the auto-return path is private and version-gated to where it works; everything else (openURL, App Group, insertText, App Intents) is public.
• Memory — the keyboard process holds no audio, no model, no transcript history, staying under the jetsam limit.

Verification

• xcodebuild app + keyboard extension → BUILD SUCCEEDED (iPhone 17 Pro sim).
• ParleyKit: 19 tests pass.
• Bundle integration: ParleyKeyboard.appex embedded, extension point com.apple.keyboard-service, RequestsOpenAccess true, App Group entitlement on both targets.
• Obfuscation confirmed at the binary level (no literal private symbols).

Not verified here (needs manual device QA)

The full keyboard round trip (switch keyboard → jump → return → text insertion) needs a signed-in account, the keyboard enabled in system Settings, and a host app; auto-return only fires on iOS < 26.4. Logic/build/integration are verified; the live path needs a device pass.

Before a real App Store build

Register in the Apple Developer portal, or archive signing will fail:

• App Group group.com.pathors.parley.ios (on both App IDs)
• Keyboard bundle id com.pathors.parley.ios.keyboard

Design doc: docs/design/ios-voice-keyboard.md. Bumps iOS build to 5.

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud