Steno

A fast, private speech-to-text TUI for macOS.

Steno uses Apple's SpeechAnalyzer API (macOS 26) for real-time transcription that runs entirely on-device. No cloud services, no API keys, no rate limits.

Requirements

• macOS 26 (Tahoe) or later
• Apple Silicon (arm64)
• Microphone access

Install

Download (recommended)

Download the latest release from GitHub Releases:

# Download and extract
curl -LO https://github.com/jwulff/steno/releases/latest/download/steno-darwin-arm64.tar.gz
tar xzf steno-darwin-arm64.tar.gz

# Install to ~/.local/bin (make sure it's in your PATH)
mkdir -p ~/.local/bin
mv steno steno-daemon ~/.local/bin/

From source

Requires Swift 6.2+ and Go 1.24+.

git clone https://github.com/jwulff/steno.git
cd steno
make install   # Builds, signs, and installs to ~/.local/bin

Usage

steno            # Launch TUI — auto-starts the daemon
steno --mcp      # Run as MCP stdio server (for Claude Desktop, etc.)

That's it. Running steno automatically starts the daemon in the background if it isn't already running. The daemon survives after you quit the TUI — it keeps recording and persisting transcripts to SQLite.

Controls

Key	Action
Space	Start/stop recording
i	Cycle input devices
a	Toggle system audio capture
Tab	Switch panel focus (topics/transcript)
j/k	Navigate topics
Enter	Expand/collapse topic
Up/Down	Scroll transcript
q	Quit

MCP Server

Steno includes a built-in MCP server for querying your transcript database from AI tools like Claude Desktop.

Add to your MCP client config:

{
  "mcpServers": {
    "steno": {
      "command": "steno",
      "args": ["--mcp"]
    }
  }
}

Available tools: get_overview, list_sessions, get_session, get_transcript, search.

Daemon Management

The daemon runs as a background process. You can also manage it independently:

steno-daemon run         # Run daemon in foreground
steno-daemon status      # Check if daemon is running
steno-daemon install     # Install as launchd service (auto-start on login)
steno-daemon uninstall   # Remove launchd service

How It Works

Steno uses the SpeechAnalyzer API introduced in macOS 26, which provides:

• On-device processing — your audio never leaves your Mac
• Low latency — real-time transcription as you speak
• High accuracy — 55% faster than Whisper Large V3 Turbo in Apple's benchmarks

Architecture

Steno is a two-process system: a Swift daemon handles audio capture and speech recognition, while a Go binary provides the TUI and MCP server.

┌─────────────────┐         Unix socket          ┌──────────────────────┐
│   steno         │◄──── NDJSON commands ────────►│   steno-daemon       │
│   (Go)          │◄──── NDJSON events ──────────►│   (Swift)            │
│                 │                               │                      │
│  - TUI display  │                               │  - Microphone capture│
│  - MCP server   │      SQLite (read-only)       │  - System audio      │
│  - Daemon mgmt  │◄─────────────────────────────►│  - SpeechAnalyzer    │
│  - Level meters │                               │  - Topic extraction  │
└─────────────────┘                               │  - Segment storage   │
                                                  └──────────────────────┘

• steno (Go) — TUI + MCP server + daemon lifecycle management. Connects to the daemon via Unix socket, reads topics from SQLite.
• steno-daemon (Swift) — Captures mic + system audio via ScreenCaptureKit, runs SpeechAnalyzer/SpeechTranscriber, persists segments to SQLite (GRDB), extracts topics via on-device LLMs.

Project Structure

steno/
├── daemon/                    # Swift daemon (steno-daemon)
│   ├── Package.swift
│   ├── Sources/StenoDaemon/
│   │   ├── Audio/             # Mic + system audio capture
│   │   ├── Commands/          # CLI subcommands (run, status, install)
│   │   ├── Dispatch/          # Command dispatcher, event broadcaster
│   │   ├── Engine/            # Recording engine, speech recognizer
│   │   ├── Infrastructure/    # Paths, PID file, signal handling
│   │   ├── Models/            # Domain models
│   │   ├── Permissions/       # TCC permission checks
│   │   ├── Services/          # Summarization, topic extraction
│   │   ├── Socket/            # Unix socket server, NDJSON protocol
│   │   └── Storage/           # SQLite via GRDB
│   └── Tests/StenoDaemonTests/
├── cmd/steno/                 # Go binary (steno)
│   ├── go.mod
│   ├── main.go                # Entry point: --mcp flag dispatches mode
│   └── internal/
│       ├── app/               # Bubbletea TUI model, messages, keybindings
│       ├── daemon/            # Socket client, protocol types, lifecycle manager
│       ├── db/                # SQLite read-only queries (shared by TUI + MCP)
│       ├── mcp/               # MCP tool handlers
│       └── ui/                # Lipgloss styles
└── schema/                    # SQLite schema contract

Development

make build          # Build daemon (release) + steno
make test           # Run all test suites (daemon + steno)
make test-daemon    # Daemon tests only (Swift)
make test-steno     # Steno tests only (Go)
make run-daemon     # Build, sign, and run daemon (debug)
make run-steno      # Build and run TUI
make run-mcp        # Build and run MCP server
make clean          # Remove all build artifacts
make install        # Install to ~/.local/bin (override with PREFIX=)

See CLAUDE.md for development conventions.

License

MIT