AI/TLDR

Argmax Open-Source SDK (Swift)

WhisperKit, TTSKit and SpeakerKit — on-device speech for Apple Silicon in one Swift package

Audio, Music & VoiceOpen core
Language
Swift
License
MIT

Overview

Argmax Open-Source SDK Swift is a collection of turn-key on-device inference frameworks for Apple Silicon, distributed as one Swift package with three library products. WhisperKit handles speech-to-text with OpenAI Whisper, SpeakerKit does speaker diarization with Pyannote, and TTSKit does text-to-speech with Qwen-TTS.

Everything runs locally on the device rather than calling a hosted API, which is the point: audio never leaves the machine, there is no per-minute billing, and transcription works offline. WhisperKit in particular has become a common way to put Whisper into a macOS or iOS app without shipping a Python runtime alongside it.

You add the package once and pick the products you need — WhisperKit, TTSKit and SpeakerKit individually, or the ArgmaxOSS umbrella product to import all three. Each kit also ships a Swift CLI, WhisperKit adds a local server exposing HTTP endpoints for non-Swift callers, and the transcription and diarization kits can be combined so a transcript carries speaker labels. The project requires macOS 14.0 or later and Xcode 16.0 or later. Argmax also sells a commercial Pro SDK covering real-time transcription with speakers, custom vocabulary, a local server for non-native apps and Android support via a Kotlin SDK; this repository is the open-source subset.

What it does

  • WhisperKit: on-device speech-to-text with OpenAI Whisper, including memory-efficient loading for large files and selectable model sizes
  • SpeakerKit: speaker diarization with Pyannote, combinable with transcription and able to emit RTTM output
  • TTSKit: text-to-speech with Qwen-TTS, custom voices, real-time streaming playback and style instructions on the 1.7B model
  • Distributed as one Swift package with per-kit library products plus an ArgmaxOSS umbrella product
  • A Swift CLI for each kit, and a WhisperKit local server with HTTP endpoints and a generated API specification for non-Swift clients
  • Runs entirely on-device on Apple Silicon — no audio leaves the machine and transcription works offline

Getting started

Add the Swift package to your project and select the kits you need. macOS 14.0+ and Xcode 16.0+ are required. For command-line transcription only, Homebrew is faster.

Add the package in Xcode

File > Add Package Dependencies…, enter the repository URL, choose a version, then select ArgmaxOSS for all kits or pick individual products.

texttext
https://github.com/argmaxinc/argmax-oss-swift

Or declare it in Package.swift

Add the package dependency, then list the products you want as target dependencies.

texttext
dependencies: [
    .package(url: "https://github.com/argmaxinc/argmax-oss-swift.git", from: "0.9.0"),
],

.target(
    name: "YourApp",
    dependencies: [
        // Import everything at once:
        .product(name: "ArgmaxOSS", package: "argmax-oss-swift"),

        // Or pick individual kits:
        // .product(name: "WhisperKit", package: "argmax-oss-swift"),   // speech-to-text
        // .product(name: "TTSKit", package: "argmax-oss-swift"),       // text-to-speech
        // .product(name: "SpeakerKit", package: "argmax-oss-swift"),   // speaker diarization
    ]
),

Transcribe a file with WhisperKit

Initialize the pipeline with default settings and transcribe a local audio file.

texttext
import WhisperKit

// Initialize WhisperKit with default settings
Task {
    let pipe = try? await WhisperKit()
    let results = try? await pipe?.transcribe(audioPath: audioPath)
}

Install the CLI with Homebrew

For transcription from the terminal without building an app.

bashbash
brew install whisperkit-cli

Commands and code are distilled from the project's own documentation — always check the official repo for the latest.

When to use it

  • Ship Whisper transcription inside a macOS or iOS app without a hosted API or a bundled Python runtime
  • Produce a diarized transcript that labels who spoke when, by combining SpeakerKit with WhisperKit
  • Add on-device text-to-speech with custom voices and streaming playback to an Apple-platform app
  • Transcribe audio on a machine with no network access, or where recordings must not leave the device

How Argmax Open-Source SDK (Swift) compares

Argmax Open-Source SDK (Swift) alongside other open-source audio, music & voice tools AI/TLDR tracks, ranked by GitHub stars.

ToolStarsWhat it does
Whisper★ 109kOpenAI's speech recognition model that transcribes and translates audio across many languages.
GPT-SoVITS★ 61.8kAn open-source WebUI that clones a voice from a short audio sample and turns text into speech, with zero-shot and few-shot fine-tuning.
VibeVoice★ 54.3kMicrosoft's text-to-speech model for generating long, expressive multi-speaker audio like podcasts.
Voicebox★ 54.3kLocal-first voice studio that clones a voice from a short sample, generates speech across seven TTS engines and 23 languages, handles system-wide dictation, and speaks for agents over MCP.
whisper.cpp★ 53.7kA dependency-free C/C++ port of Whisper built on ggml, running speech recognition on CPU, Metal, CUDA, Vulkan and NPUs from phones to servers.
Coqui TTS★ 46kA library of text-to-speech models including the multilingual XTTS voice-cloning model.
ChatTTS★ 39.8kChatTTS is an open-source text-to-speech model tuned for dialogue, with multi-speaker support and fine-grained control over laughter, pauses, and prosody.
Argmax Open-Source SDK (Swift)★ 6.4kWhisperKit, TTSKit and SpeakerKit — on-device speech for Apple Silicon in one Swift package