OSGKeyboard

Hold a key, speak, release — AI-polished text appears at your cursor in any app. An open-source, custom-keyboard-based voice input tool for iOS 18+, inspired by Typeless and OpenLess.

中文 README

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What is it?

OSGKeyboard is a free, open alternative to commercial voice-input tools. It runs as a Custom Keyboard Extension on iOS, so you can use it in any app — Messages, Notes, Mail, ChatGPT, Claude, Cursor, you name it.

1. Press and hold the mic key
2. Speak naturally
3. Release — the AI polishes your words into clean text and inserts it at the cursor

The audio stays on-device (transcribed by Apple's on-device SpeechAnalyzer on iOS 26+, or SFSpeechRecognizer on iOS 18/19). Only the polished transcript is sent to your chosen cloud LLM. No audio ever leaves your phone.

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Features

• 🎙 Push-to-talk with a Typeless-style circular mic button
• 🧠 On-device ASR (iOS 26 SpeechAnalyzer + DictationTranscriber; iOS 18 SFSpeechRecognizer fallback)
• ✍️ AI polishing — adds structure, punctuation, fixes grammar, optionally produces lists
• 🔌 Bring-your-own API — works with any OpenAI-compatible endpoint (OpenAI, DeepSeek, Qwen DashScope, your own self-hosted server, …)
• 🔒 Privacy first — audio never leaves your device; transcripts only sent to the LLM you choose
• 🎨 Native SwiftUI — dark theme, frosted glass, ~2000 lines of Swift
• 🪶 Zero dependencies — no SwiftPM packages, no CocoaPods, no Carthage

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Quick start

Requirements

• macOS with Xcode 16+ (Xcode 26 recommended)
• iPhone running iOS 18.0+ (iOS 26+ for the best on-device ASR)
• XcodeGen: brew install xcodegen
• An OpenAI-compatible API key (e.g. from OpenAI, DeepSeek, or Qwen DashScope)

Build & run

git clone https://github.com/<OWNER>/OSGKeyboard.git
cd OSGKeyboard
xcodegen generate          # produces OSGKeyboard.xcodeproj
open OSGKeyboard.xcodeproj # or build via CLI:
xcodebuild -project OSGKeyboard.xcodeproj -scheme OSGKeyboard \
  -destination 'generic/platform=iOS Simulator' build

Enable the keyboard in iOS

1. Run the app on your device or simulator.
2. Follow the 3-step onboarding: enable the keyboard in iOS Settings, then allow Full Access (required for the mic and LLM calls), then paste your API key.
3. In any text field, tap 🌐 to switch to OSGKeyboard.
4. Press and hold the mic, speak, release. ✨

"Allow Full Access" is required. Without it, iOS blocks the keyboard from using the microphone and from making network requests. We never log, store, or transmit your keystrokes — see PrivacyInfo.xcprivacy.

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Architecture

OSGKeyboard/
├── OSGKeyboard/                 # Main iOS app (settings, onboarding)
│   ├── Views/                   # SwiftUI screens
│   ├── OSGKeyboardApp.swift     # @main entry
│   ├── PrivacyInfo.xcprivacy    # Required privacy manifest
│   └── OSGKeyboard.entitlements # App Group declaration
├── OSGKeyboardExt/              # Custom Keyboard Extension
│   ├── KeyboardViewController.swift   # Principal class
│   ├── Services/
│   │   ├── AudioCaptureService.swift  # AVAudioEngine → 16 kHz PCM
│   │   ├── ASRService.swift           # iOS 26 + iOS 18 ASR
│   │   └── PolishingService.swift     # LLM call with timeout
│   └── Views/                   # RecordButton, Waveform, KeyboardRootView
├── OSGKeyboardShared/           # Framework shared by app + extension
│   ├── Models/                  # ProviderConfig, LLMRequest, LLMProvider
│   ├── Services/                # LLMClient (OpenAI-compatible)
│   └── Constants/               # AppGroup identifier
├── OSGKeyboardTests/            # XCTest unit tests
├── project.yml                  # XcodeGen project definition
└── .github/workflows/ci.yml     # Lint + build CI

Data flow

[Long-press mic] → AudioCaptureService → AudioBufferSnapshot (16 kHz mono)
                                          ↓
                                  ASRService.transcribe()
                                          ↓
                                ASREvent.final(rawTranscript)
                                          ↓
                              PolishingService.polish()
                                          ↓
                            LLMClient (OpenAI-compatible)
                                          ↓
                          textDocumentProxy.insertText(polished)

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Adding a new LLM provider

Open OSGKeyboardShared/Models/LLMProvider.swift and append a new LLMProvider to the presets array. The default OpenAICompatibleClient handles any endpoint that speaks the POST /chat/completions protocol.

LLMProvider(
    id: "groq",
    name: "Groq",
    defaultBaseURL: "https://api.groq.com/openai/v1",
    defaultModel: "llama-3.1-70b-versatile",
    apiKeyURL: URL(string: "https://console.groq.com/keys")
)

That's it. No other code changes required.

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Limitations

• iOS sandboxes keyboard extensions: ~60 MB memory cap, Full Access required.
• The keyboard does not work in password fields or some WKWebView textareas (iOS limitation).
• iOS 18 uses SFSpeechRecognizer instead of SpeechAnalyzer; on iOS 26, SpeechAnalyzer is significantly faster and supports more locales.

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License

MIT — use it, fork it, ship it. No warranty.

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Acknowledgements

• Inspired by Typeless and the desktop open-source OpenLess
• Built with XcodeGen
• Powered by Apple's SpeechAnalyzer and SFSpeechRecognizer

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Note: replace <OWNER> in badges and the git clone URL with your GitHub username.