Update README for 1.3.0

Document the warm whisper-server, live mic-level HUD, and custom
dictionary; add them to the feature list and Settings; note the
loopback-only server and the one-time model load at startup.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -3,6 +3,7 @@ macos/build/
 macos/WhisperDictate.app/Contents/MacOS/
 macos/WhisperDictate.app/Contents/Frameworks/
 macos/WhisperDictate.app/Contents/_CodeSignature/
+macos/WhisperDictate.app/Contents/CodeResources
 WhisperDictate
 *.o
 *.dSYM/

README.md

@@ -12,17 +12,26 @@ A simple menu bar app for voice dictation using OpenAI Whisper (local, offline).
 
 ## macOS
 
+### What's new in 1.3.0
+
+- ⚡ **Warm transcription server** — the Whisper model stays loaded in a background `whisper-server`, so each dictation is a fast local call (~0.5s) instead of reloading the 1.5–1.6 GB model on every utterance
+- 📊 **Live mic-level HUD** while recording, which warns ("No audio input?") if the microphone stays silent
+- 📖 **Custom dictionary** — an editable *Heard → Replacement* table that fixes names/jargon in the transcript and also biases recognition
+
 ### Features
 
 - 🎤 Global hotkey (⌃⌥D) to start/stop recording
+- ⚡ Fast transcription via a warm whisper-server (model stays loaded — no per-dictation reload), with automatic fallback to `whisper-cli`
+- 📊 Live mic-level meter while recording, with a "no audio input" warning
+- 📖 Custom dictionary (heard → replacement) that also biases recognition
 - 🔒 Fully offline - uses local Whisper model
-- ⚡ Automatic paste into any focused app
+- ⌨️ Automatic paste into any focused app
 - 📋 Clipboard preservation - your copied content is restored after paste
 - ⚙️ Settings window with model selection dropdown
 - 📥 Built-in model downloader with progress indicator
 - 🚀 Launch at login support
 - 🔊 Sound feedback (optional)
-- 📦 Self-contained - whisper-cli bundled in app
+- 📦 Self-contained - whisper-cli and whisper-server bundled in the app
 
 ### Requirements
 
@@ -75,6 +84,7 @@ make install
 Click the menu bar icon → Settings to configure:
 - **Language**: Auto-detect or 31 supported languages
 - **Model**: Select from installed models or download new ones
+- **Dictionary**: Add *Heard → Replacement* pairs to fix names/jargon (use `\n` for a newline); the replacement terms also improve recognition
 - **Sound feedback**: Toggle audio feedback on/off
 - **Launch at login**: Start automatically when you log in
 
@@ -93,6 +103,8 @@ Download models directly from the app or manually:
 
 Models are stored in `~/.whisper-models/`
 
+> With the warm server (1.3.0+), the selected model loads once at startup (a few seconds); after that each dictation skips the reload, so the speeds above are roughly the per-dictation transcription time.
+
 ### Audio Feedback
 
 - 🔔 **Tink** - Recording started
@@ -114,6 +126,7 @@ Grant these in System Settings → Privacy & Security:
 ## Security
 
 - All processing is done locally - no data leaves your device
+- The bundled `whisper-server` is bound to `127.0.0.1` (loopback only) and is never exposed on the network
 - Audio files are stored in private temp directory and deleted after transcription
 - Clipboard is cleared after paste (transcript doesn't remain accessible)
 - Original clipboard content is preserved and restored after paste

macos/Makefile

@@ -2,7 +2,7 @@
 
 APP_NAME = WhisperDictate
 APP_BUNDLE = $(APP_NAME).app
-VERSION = 1.2.0
+VERSION = 1.3.0
 
 # Directories
 SRC_DIR = src

macos/WhisperDictate.app/Contents/Info.plist

@@ -2,35 +2,40 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
-    <key>CFBundleDevelopmentRegion</key>
-    <string>en</string>
-    <key>CFBundleExecutable</key>
-    <string>WhisperDictate</string>
-    <key>CFBundleIconFile</key>
-    <string>AppIcon</string>
-    <key>CFBundleIdentifier</key>
-    <string>com.whisperdictate.app</string>
-    <key>CFBundleInfoDictionaryVersion</key>
-    <string>6.0</string>
-    <key>CFBundleName</key>
-    <string>WhisperDictate</string>
-    <key>CFBundleDisplayName</key>
-    <string>WhisperDictate</string>
-    <key>CFBundlePackageType</key>
-    <string>APPL</string>
-    <key>CFBundleShortVersionString</key>
-    <string>1.0.0</string>
-    <key>CFBundleVersion</key>
-    <string>1</string>
-    <key>LSMinimumSystemVersion</key>
-    <string>13.0</string>
-    <key>LSUIElement</key>
-    <true/>
-    <key>NSHighResolutionCapable</key>
-    <true/>
-    <key>NSMicrophoneUsageDescription</key>
-    <string>WhisperDictate needs microphone access to record your voice for transcription.</string>
-    <key>NSAppleEventsUsageDescription</key>
-    <string>WhisperDictate needs accessibility access to paste transcribed text.</string>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleDisplayName</key>
+	<string>WhisperDictate</string>
+	<key>CFBundleExecutable</key>
+	<string>WhisperDictate</string>
+	<key>CFBundleIconFile</key>
+	<string>AppIcon</string>
+	<key>CFBundleIdentifier</key>
+	<string>com.whisperdictate.app</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>WhisperDictate</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.3.0</string>
+	<key>CFBundleVersion</key>
+	<string>3</string>
+	<key>LSMinimumSystemVersion</key>
+	<string>13.0</string>
+	<key>LSUIElement</key>
+	<true/>
+	<key>NSAppTransportSecurity</key>
+	<dict>
+		<key>NSAllowsLocalNetworking</key>
+		<true/>
+	</dict>
+	<key>NSAppleEventsUsageDescription</key>
+	<string>WhisperDictate needs accessibility access to paste transcribed text.</string>
+	<key>NSHighResolutionCapable</key>
+	<true/>
+	<key>NSMicrophoneUsageDescription</key>
+	<string>WhisperDictate needs microphone access to record your voice for transcription.</string>
 </dict>
 </plist>

macos/WhisperDictate.entitlements

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<!-- Not sandboxed: WhisperDictate uses global Accessibility / synthetic
+	     keystrokes and spawns a bundled CLI, which the App Sandbox forbids.
+	     Distributed via Developer ID, not the Mac App Store. -->
+	<key>com.apple.security.app-sandbox</key>
+	<false/>
+	<!-- The app bundles whisper-cli + ggml/whisper dylibs in the app. Disabling
+	     library validation lets the process tree load them without tripping the
+	     hardened runtime's same-Team-ID check. -->
+	<key>com.apple.security.cs.disable-library-validation</key>
+	<true/>
+	<!-- Hardened-runtime resource-access entitlement. REQUIRED for microphone
+	     access under the hardened runtime: without it tccd refuses to even
+	     prompt and denies kTCCServiceMicrophone outright, so the app records
+	     silence (and whisper hallucinates on the empty audio). Must be present
+	     on any Developer ID / notarized build. -->
+	<key>com.apple.security.device.audio-input</key>
+	<true/>
+	<!-- whisper.cpp's Metal/ggml backend generates code at runtime; the
+	     hardened runtime needs allow-jit so the bundled whisper-cli/dylibs
+	     don't get killed for JIT. -->
+	<key>com.apple.security.cs.allow-jit</key>
+	<true/>
+</dict>
+</plist>

macos/bundle-whisper.sh

@@ -25,6 +25,17 @@ mkdir -p "$FRAMEWORKS_DIR"
 cp "$WHISPER_CLI_REAL" "$MACOS_DIR/whisper-cli"
 chmod +x "$MACOS_DIR/whisper-cli"
 
+# Copy whisper-server (warm, preloaded-model HTTP backend) from the same bin dir
+WHISPER_BIN_DIR=$(dirname "$WHISPER_CLI_REAL")
+WHISPER_SERVER_REAL="$WHISPER_BIN_DIR/whisper-server"
+if [ -f "$WHISPER_SERVER_REAL" ]; then
+    cp "$WHISPER_SERVER_REAL" "$MACOS_DIR/whisper-server"
+    chmod +x "$MACOS_DIR/whisper-server"
+    echo "Copied: whisper-server"
+else
+    echo "Warning: whisper-server not found at $WHISPER_SERVER_REAL"
+fi
+
 # List of dylibs to copy
 DYLIBS=(
     "libwhisper.1.dylib"
@@ -49,9 +60,12 @@ for dylib in "${DYLIBS[@]}"; do
     fi
 done
 
-# Fix dylib paths in whisper-cli
-for dylib in "${DYLIBS[@]}"; do
-    install_name_tool -change "@rpath/$dylib" "@executable_path/../Frameworks/$dylib" "$MACOS_DIR/whisper-cli" 2>/dev/null || true
+# Fix dylib paths in the bundled executables (whisper-cli + whisper-server)
+for exe in whisper-cli whisper-server; do
+    [ -f "$MACOS_DIR/$exe" ] || continue
+    for dylib in "${DYLIBS[@]}"; do
+        install_name_tool -change "@rpath/$dylib" "@executable_path/../Frameworks/$dylib" "$MACOS_DIR/$exe" 2>/dev/null || true
+    done
 done
 
 # Fix dylib paths in each dylib (they reference each other)
@@ -67,8 +81,10 @@ for dylib in "${DYLIBS[@]}"; do
     fi
 done
 
-# Sign everything
-codesign --force --sign - "$MACOS_DIR/whisper-cli" 2>/dev/null || true
+# Sign everything (ad-hoc; the release flow re-signs with Developer ID afterward)
+for exe in whisper-cli whisper-server; do
+    [ -f "$MACOS_DIR/$exe" ] && codesign --force --sign - "$MACOS_DIR/$exe" 2>/dev/null || true
+done
 for dylib in "${DYLIBS[@]}"; do
     codesign --force --sign - "$FRAMEWORKS_DIR/$dylib" 2>/dev/null || true
 done

macos/src/main.swift

@@ -3,12 +3,14 @@ import AVFoundation
 import Carbon.HIToolbox
 import ServiceManagement
 import ApplicationServices
+import Darwin
 
 // MARK: - User Defaults Keys
 struct Defaults {
     static let language = "whisperLanguage"
     static let modelPath = "whisperModelPath"
     static let playSounds = "playSounds"
+    static let replacements = "customReplacements"
 }
 
 // MARK: - Whisper Models
@@ -150,12 +152,250 @@ struct SupportedLanguages {
     }
 }
 
+// MARK: - Whisper Server (warm, preloaded-model backend)
+// Keeps a whisper-server child process alive with the model already loaded, so
+// each dictation is a fast local HTTP call (~0.5s) instead of a multi-second
+// model + Metal reload on every utterance (what plain whisper-cli does).
+final class WhisperServer {
+    private let serverPath: String
+    private let modelPath: String
+    private let threads: Int
+    private var process: Process?
+    private var stopping = false
+    private(set) var port: Int = 0
+    private(set) var isReady = false
+
+    init(serverPath: String, modelPath: String, threads: Int) {
+        self.serverPath = serverPath
+        self.modelPath = modelPath
+        self.threads = threads
+    }
+
+    func start(onReady: @escaping (Bool) -> Void) {
+        port = WhisperServer.findFreePort()
+        let task = Process()
+        task.executableURL = URL(fileURLWithPath: serverPath)
+        task.arguments = [
+            "-m", modelPath,
+            "--host", "127.0.0.1",
+            "--port", String(port),
+            "-t", String(threads),
+            "-nt",   // no timestamps -> plain text response
+            "-sns",  // suppress non-speech tokens -> fewer hallucinations
+        ]
+        task.standardOutput = FileHandle.nullDevice
+        task.standardError = FileHandle.nullDevice
+        task.terminationHandler = { [weak self] _ in self?.isReady = false }
+        do {
+            try task.run()
+            process = task
+        } catch {
+            NSLog("WhisperServer: failed to launch: \(error)")
+            onReady(false)
+            return
+        }
+        // Model load can take ~10s (incl. Metal init); poll the port off-thread.
+        DispatchQueue.global(qos: .userInitiated).async { [weak self] in
+            guard let self = self else { return }
+            let deadline = Date().addingTimeInterval(120)
+            while Date() < deadline {
+                if self.stopping || !(self.process?.isRunning ?? false) { break }
+                if WhisperServer.canConnect(port: self.port) {
+                    self.isReady = true
+                    onReady(true)
+                    return
+                }
+                Thread.sleep(forTimeInterval: 0.3)
+            }
+            onReady(false)
+        }
+    }
+
+    func stop() {
+        stopping = true
+        isReady = false
+        process?.terminationHandler = nil
+        process?.terminate()
+        process = nil
+    }
+
+    // Synchronous transcription via the warm server. Call OFF the main thread.
+    func transcribe(wavPath: String, language: String, prompt: String?) -> String? {
+        guard isReady,
+              let url = URL(string: "http://127.0.0.1:\(port)/inference"),
+              let wavData = try? Data(contentsOf: URL(fileURLWithPath: wavPath)) else { return nil }
+
+        let boundary = "----WhisperDictate\(UInt32.random(in: 0 ... .max))"
+        var req = URLRequest(url: url)
+        req.httpMethod = "POST"
+        req.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
+        req.timeoutInterval = 120
+
+        var body = Data()
+        let nl = "\r\n"
+        func raw(_ s: String) { body.append(s.data(using: .utf8)!) }
+        // audio file part
+        raw("--\(boundary)\(nl)")
+        raw("Content-Disposition: form-data; name=\"file\"; filename=\"audio.wav\"\(nl)")
+        raw("Content-Type: audio/wav\(nl)\(nl)")
+        body.append(wavData)
+        raw(nl)
+        // text fields
+        func field(_ name: String, _ value: String) {
+            raw("--\(boundary)\(nl)")
+            raw("Content-Disposition: form-data; name=\"\(name)\"\(nl)\(nl)")
+            raw("\(value)\(nl)")
+        }
+        field("response_format", "json")
+        field("temperature", "0")
+        if language.lowercased() != SupportedLanguages.autoDetect { field("language", language.lowercased()) }
+        if let prompt = prompt, !prompt.isEmpty { field("prompt", prompt) }
+        raw("--\(boundary)--\(nl)")
+        req.httpBody = body
+
+        let sem = DispatchSemaphore(value: 0)
+        var result: String?
+        URLSession.shared.dataTask(with: req) { data, _, error in
+            defer { sem.signal() }
+            if let error = error { NSLog("WhisperServer: request error: \(error)"); return }
+            guard let data = data,
+                  let obj = try? JSONSerialization.jsonObject(with: data) as? [String: Any],
+                  let text = obj["text"] as? String else { return }
+            result = text.trimmingCharacters(in: .whitespacesAndNewlines)
+        }.resume()
+        sem.wait()
+        return result
+    }
+
+    // MARK: socket helpers (find a free loopback port + readiness probe)
+    static func findFreePort() -> Int {
+        let fd = socket(AF_INET, SOCK_STREAM, 0)
+        if fd < 0 { return 8123 }
+        defer { close(fd) }
+        var addr = sockaddr_in()
+        addr.sin_family = sa_family_t(AF_INET)
+        addr.sin_addr.s_addr = inet_addr("127.0.0.1")
+        addr.sin_port = 0
+        let bound = withUnsafePointer(to: &addr) {
+            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
+                Darwin.bind(fd, $0, socklen_t(MemoryLayout<sockaddr_in>.size))
+            }
+        }
+        guard bound == 0 else { return 8123 }
+        var len = socklen_t(MemoryLayout<sockaddr_in>.size)
+        _ = withUnsafeMutablePointer(to: &addr) {
+            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
+                getsockname(fd, $0, &len)
+            }
+        }
+        return Int(UInt16(bigEndian: addr.sin_port))
+    }
+
+    static func canConnect(port: Int) -> Bool {
+        let fd = socket(AF_INET, SOCK_STREAM, 0)
+        if fd < 0 { return false }
+        defer { close(fd) }
+        var addr = sockaddr_in()
+        addr.sin_family = sa_family_t(AF_INET)
+        addr.sin_port = in_port_t(UInt16(port)).bigEndian
+        addr.sin_addr.s_addr = inet_addr("127.0.0.1")
+        let r = withUnsafePointer(to: &addr) {
+            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
+                Darwin.connect(fd, $0, socklen_t(MemoryLayout<sockaddr_in>.size))
+            }
+        }
+        return r == 0
+    }
+}
+
+// MARK: - Recording HUD (live mic level + silence warning)
+// A small floating, non-interactive panel shown while recording. Doubles as a
+// diagnostic: if the input stays silent it flags "no input" — exactly the
+// failure that silently produced empty recordings + whisper hallucinations.
+final class MeterView: NSView {
+    private var level: CGFloat = 0
+    private var silent = false
+
+    func set(level: CGFloat, silent: Bool) {
+        self.level = max(0, min(1, level))
+        self.silent = silent
+        needsDisplay = true
+    }
+    func reset() { level = 0; silent = false; needsDisplay = true }
+
+    override func draw(_ dirtyRect: NSRect) {
+        let bg = NSBezierPath(roundedRect: bounds, xRadius: 12, yRadius: 12)
+        NSColor(calibratedWhite: 0.10, alpha: 0.93).setFill()
+        bg.fill()
+
+        let label = silent ? "🎤 No audio input?" : "🎤 Recording…"
+        label.draw(at: NSPoint(x: 16, y: bounds.height - 26), withAttributes: [
+            .font: NSFont.systemFont(ofSize: 12, weight: .medium),
+            .foregroundColor: silent ? NSColor.systemRed : NSColor.white
+        ])
+
+        let segs = 20
+        let margin: CGFloat = 16, gap: CGFloat = 3, segH: CGFloat = 14, y: CGFloat = 14
+        let segW = (bounds.width - margin * 2 - gap * CGFloat(segs - 1)) / CGFloat(segs)
+        let lit = Int((level * CGFloat(segs)).rounded())
+        for i in 0..<segs {
+            let rect = NSRect(x: margin + CGFloat(i) * (segW + gap), y: y, width: segW, height: segH)
+            let path = NSBezierPath(roundedRect: rect, xRadius: 2, yRadius: 2)
+            if i < lit {
+                let frac = CGFloat(i) / CGFloat(segs)
+                (silent ? NSColor.systemRed
+                        : frac > 0.85 ? .systemRed
+                        : frac > 0.6 ? .systemYellow : .systemGreen).setFill()
+            } else {
+                NSColor(calibratedWhite: 1, alpha: 0.12).setFill()
+            }
+            path.fill()
+        }
+    }
+}
+
+final class RecordingHUD {
+    private var window: NSWindow?
+    private let meter = MeterView(frame: NSRect(x: 0, y: 0, width: 260, height: 72))
+
+    func show() {
+        if window == nil {
+            let w = NSPanel(contentRect: NSRect(x: 0, y: 0, width: 260, height: 72),
+                            styleMask: [.borderless, .nonactivatingPanel],
+                            backing: .buffered, defer: false)
+            w.isOpaque = false
+            w.backgroundColor = .clear
+            w.hasShadow = true
+            w.level = .statusBar
+            w.ignoresMouseEvents = true
+            w.isFloatingPanel = true
+            w.collectionBehavior = [.canJoinAllSpaces, .stationary, .fullScreenAuxiliary, .ignoresCycle]
+            w.contentView = meter
+            window = w
+        }
+        if let screen = NSScreen.main, let window = window {
+            let vf = screen.visibleFrame
+            window.setFrameOrigin(NSPoint(x: vf.midX - window.frame.width / 2, y: vf.minY + 120))
+        }
+        meter.reset()
+        window?.orderFrontRegardless()
+    }
+
+    func update(level: CGFloat, silent: Bool) { meter.set(level: level, silent: silent) }
+    func hide() { window?.orderOut(nil) }
+}
+
 // MARK: - App Delegate
-class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
+class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate, NSTableViewDataSource, NSTableViewDelegate, NSTextFieldDelegate, NSWindowDelegate {
     var statusItem: NSStatusItem!
     var audioRecorder: AVAudioRecorder?
     var isRecording = false
     var settingsWindowController: NSWindowController?
+    var whisperServer: WhisperServer?
+    let recordingHUD = RecordingHUD()
+    var meterTimer: Timer?
+    var silenceStart: Date?
+    weak var dictTable: NSTableView?
 
     // Use private temp directory with unique filename
     var audioFilePath: String {
@@ -178,19 +418,51 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
         set { UserDefaults.standard.set(newValue, forKey: Defaults.playSounds) }
     }
 
+    // Custom dictionary: ordered list of ["from": recognised, "to": replacement].
+    var replacements: [[String: String]] {
+        get { (UserDefaults.standard.array(forKey: Defaults.replacements) as? [[String: String]]) ?? [] }
+        set { UserDefaults.standard.set(newValue, forKey: Defaults.replacements) }
+    }
+
+    // Whisper initial prompt built from the desired ("to") terms, to bias
+    // recognition toward the user's names/jargon. Returns nil if empty.
+    func customPrompt() -> String? {
+        let terms = replacements.compactMap { $0["to"] }
+            .map { $0.replacingOccurrences(of: "\\n", with: " ") }
+            .map { $0.trimmingCharacters(in: .whitespaces) }
+            .filter { !$0.isEmpty }
+        return terms.isEmpty ? nil : terms.joined(separator: ", ")
+    }
+
+    // Apply the dictionary find/replace pairs to a transcript. "\n" in a
+    // replacement becomes a real newline (e.g. spoken-command → line break).
+    func applyReplacements(_ text: String) -> String {
+        var result = text
+        for pair in replacements {
+            guard let from = pair["from"], !from.isEmpty else { continue }
+            let to = (pair["to"] ?? "").replacingOccurrences(of: "\\n", with: "\n")
+            result = result.replacingOccurrences(of: from, with: to, options: [.caseInsensitive])
+        }
+        return result
+    }
+
     func applicationDidFinishLaunching(_ notification: Notification) {
         setupStatusItem()
         registerHotkey()
         requestMicrophonePermission()
-        checkAccessibilityPermission()
 
-        // First-run: check if model exists, if not show setup wizard
+        // Start warming the model server BEFORE the (blocking) accessibility
+        // prompt, so the multi-second model load overlaps with the user
+        // granting permissions instead of running after it.
         if !hasAnyModel() {
             showFirstRunWizard()
         } else {
             checkModelExists()
+            startWhisperServer()
         }
 
+        checkAccessibilityPermission()
+
         NSLog("WhisperDictate started. Press ⌃⌥D to toggle recording.")
     }
 
@@ -287,6 +559,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
             updateStatus("Ready - \(model.name)")
             if playSounds { NSSound(named: "Glass")?.play() }
             NSLog("Model downloaded: \(model.name)")
+            startWhisperServer()
         } catch {
             statusItem.button?.title = "🎤"
             updateStatus("⚠️ Save failed")
@@ -310,6 +583,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
     }
 
     func applicationWillTerminate(_ notification: Notification) {
+        whisperServer?.stop()
         cleanupAudioFile()
     }
 
@@ -350,17 +624,18 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
 
     func createSettingsWindow() -> NSWindow {
         let window = NSWindow(
-            contentRect: NSRect(x: 0, y: 0, width: 450, height: 280),
+            contentRect: NSRect(x: 0, y: 0, width: 450, height: 540),
             styleMask: [.titled, .closable],
             backing: .buffered,
             defer: false
         )
         window.title = "WhisperDictate Settings"
         window.center()
+        window.delegate = self
 
         let contentView = NSView(frame: window.contentView!.bounds)
 
-        var y: CGFloat = 230
+        var y: CGFloat = 498
         let labelWidth: CGFloat = 120
         let controlX: CGFloat = 140
         let controlWidth: CGFloat = 280
@@ -453,6 +728,44 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
         loginCheck.state = isLaunchAtLoginEnabled() ? .on : .off
         contentView.addSubview(loginCheck)
 
+        // Custom dictionary (recognised -> replacement)
+        let dictLabel = NSTextField(labelWithString: "Dictionary (heard → replacement):")
+        dictLabel.frame = NSRect(x: 20, y: 304, width: 300, height: 20)
+        contentView.addSubview(dictLabel)
+
+        let scroll = NSScrollView(frame: NSRect(x: 20, y: 104, width: 410, height: 192))
+        scroll.hasVerticalScroller = true
+        scroll.borderType = .bezelBorder
+        let table = NSTableView(frame: scroll.bounds)
+        table.usesAlternatingRowBackgroundColors = true
+        table.rowHeight = 22
+        let colFrom = NSTableColumn(identifier: NSUserInterfaceItemIdentifier("from"))
+        colFrom.title = "Heard"; colFrom.width = 195; colFrom.isEditable = true
+        let colTo = NSTableColumn(identifier: NSUserInterfaceItemIdentifier("to"))
+        colTo.title = "Replacement"; colTo.width = 195
+        table.addTableColumn(colFrom)
+        table.addTableColumn(colTo)
+        table.dataSource = self
+        table.delegate = self
+        scroll.documentView = table
+        contentView.addSubview(scroll)
+        dictTable = table
+
+        let addBtn = NSButton(title: "+", target: self, action: #selector(addReplacement))
+        addBtn.frame = NSRect(x: 20, y: 70, width: 34, height: 26)
+        addBtn.bezelStyle = .rounded
+        contentView.addSubview(addBtn)
+        let delBtn = NSButton(title: "–", target: self, action: #selector(removeReplacement))
+        delBtn.frame = NSRect(x: 56, y: 70, width: 34, height: 26)
+        delBtn.bezelStyle = .rounded
+        contentView.addSubview(delBtn)
+
+        let dictHint = NSTextField(labelWithString: "The Replacement column also improves recognition. \\n = newline.")
+        dictHint.frame = NSRect(x: 100, y: 74, width: 330, height: 18)
+        dictHint.font = NSFont.systemFont(ofSize: 10)
+        dictHint.textColor = .tertiaryLabelColor
+        contentView.addSubview(dictHint)
+
         // Models directory hint
         let hintLabel = NSTextField(labelWithString: "Models stored in: ~/.whisper-models/")
         hintLabel.frame = NSRect(x: 20, y: 15, width: 410, height: 20)
@@ -487,6 +800,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
             let path = installedModels[index].path
             modelPath = path
             checkModelExists()
+            startWhisperServer()
             NSLog("Model changed to: \(path)")
         }
     }
@@ -549,6 +863,72 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
         setLaunchAtLogin(sender.state == .on)
     }
 
+    // MARK: - Custom dictionary table (view-based, editable text fields)
+    func numberOfRows(in tableView: NSTableView) -> Int { replacements.count }
+
+    func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? {
+        guard let column = tableColumn, row < replacements.count else { return nil }
+        let id = column.identifier
+        let field: NSTextField
+        if let reused = tableView.makeView(withIdentifier: id, owner: self) as? NSTextField {
+            field = reused
+        } else {
+            field = NSTextField()
+            field.identifier = id
+            field.isBordered = false
+            field.drawsBackground = false
+            field.isEditable = true
+            field.isSelectable = true
+            field.font = NSFont.systemFont(ofSize: 12)
+            field.lineBreakMode = .byTruncatingTail
+            field.delegate = self
+            field.placeholderString = id.rawValue == "from" ? "heard word" : "replacement (\\n = newline)"
+        }
+        field.stringValue = replacements[row][id.rawValue] ?? ""
+        return field
+    }
+
+    // Commit an edited cell back into the model (fires on Enter, Tab, focus loss).
+    func controlTextDidEndEditing(_ obj: Notification) {
+        guard let field = obj.object as? NSTextField, let table = dictTable else { return }
+        let row = table.row(for: field), col = table.column(for: field)
+        guard row >= 0, row < replacements.count, col >= 0, col < table.tableColumns.count else { return }
+        let id = table.tableColumns[col].identifier.rawValue
+        var rows = replacements
+        rows[row][id] = field.stringValue
+        replacements = rows
+    }
+
+    @objc func addReplacement() {
+        pruneEmptyReplacements()
+        var rows = replacements
+        rows.append(["from": "", "to": ""])
+        replacements = rows
+        dictTable?.reloadData()
+        dictTable?.editColumn(0, row: rows.count - 1, with: nil, select: true)
+    }
+
+    @objc func removeReplacement() {
+        guard let table = dictTable, table.selectedRow >= 0, table.selectedRow < replacements.count else { return }
+        var rows = replacements
+        rows.remove(at: table.selectedRow)
+        replacements = rows
+        table.reloadData()
+    }
+
+    // Drop rows where both columns are blank so empty rows aren't persisted.
+    func pruneEmptyReplacements() {
+        let cleaned = replacements.filter {
+            !(($0["from"] ?? "").trimmingCharacters(in: .whitespaces).isEmpty
+              && ($0["to"] ?? "").trimmingCharacters(in: .whitespaces).isEmpty)
+        }
+        if cleaned.count != replacements.count { replacements = cleaned }
+    }
+
+    func windowWillClose(_ notification: Notification) {
+        pruneEmptyReplacements()
+    }
+
     // MARK: - Launch at Login
     func isLaunchAtLoginEnabled() -> Bool {
         if #available(macOS 13.0, *) {
@@ -698,21 +1078,58 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
 
         do {
             audioRecorder = try AVAudioRecorder(url: audioURL, settings: settings)
+            audioRecorder?.isMeteringEnabled = true
             audioRecorder?.record()
             isRecording = true
             statusItem.button?.title = "🔴"
             updateStatus("Recording...")
             if playSounds { NSSound(named: "Tink")?.play() }
             NSLog("Recording started")
+            startMeter()
         } catch {
             NSLog("Recording failed: \(error)")
             if playSounds { NSSound(named: "Basso")?.play() }
         }
     }
 
+    // MARK: - Live mic meter (HUD)
+    func startMeter() {
+        silenceStart = nil
+        recordingHUD.show()
+        meterTimer?.invalidate()
+        meterTimer = Timer.scheduledTimer(withTimeInterval: 0.05, repeats: true) { [weak self] _ in
+            self?.updateMeter()
+        }
+    }
+
+    func stopMeter() {
+        meterTimer?.invalidate()
+        meterTimer = nil
+        silenceStart = nil
+        recordingHUD.hide()
+    }
+
+    func updateMeter() {
+        guard isRecording, let recorder = audioRecorder else { return }
+        recorder.updateMeters()
+        let avg = recorder.averagePower(forChannel: 0)   // dBFS, ~-160...0
+        let peak = recorder.peakPower(forChannel: 0)
+        let level = max(0, min(1, CGFloat((avg + 50) / 50)))
+
+        // Flag "no input" if the peak stays at silence for over ~1.2s.
+        if peak < -50 {
+            if silenceStart == nil { silenceStart = Date() }
+        } else {
+            silenceStart = nil
+        }
+        let silent = silenceStart.map { Date().timeIntervalSince($0) > 1.2 } ?? false
+        recordingHUD.update(level: level, silent: silent)
+    }
+
     func stopRecordingAndTranscribe() {
         audioRecorder?.stop()
         isRecording = false
+        stopMeter()
         statusItem.button?.title = "⏳"
         updateStatus("Transcribing...")
         if playSounds { NSSound(named: "Pop")?.play() }
@@ -749,9 +1166,57 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
         return nil
     }
 
+    func findWhisperServer() -> String? {
+        if let bundlePath = Bundle.main.executablePath {
+            let bundled = (bundlePath as NSString).deletingLastPathComponent + "/whisper-server"
+            if FileManager.default.isExecutableFile(atPath: bundled) { return bundled }
+        }
+        let paths = [
+            "/opt/homebrew/bin/whisper-server",
+            "/usr/local/bin/whisper-server",
+            "/opt/local/bin/whisper-server",
+            NSHomeDirectory() + "/bin/whisper-server"
+        ]
+        for path in paths where FileManager.default.isExecutableFile(atPath: path) { return path }
+        return nil
+    }
+
+    // (Re)start the warm whisper-server for the current model. Falls back to
+    // per-call whisper-cli if the server binary is missing or fails to come up.
+    func startWhisperServer() {
+        whisperServer?.stop()
+        whisperServer = nil
+
+        guard let serverPath = findWhisperServer() else {
+            NSLog("whisper-server not found — using per-call whisper-cli")
+            return
+        }
+        guard isValidModelPath(modelPath).valid else { return }
+
+        statusItem.button?.title = "⏳"
+        updateStatus("Loading model…")
+
+        let threads = min(8, max(2, ProcessInfo.processInfo.activeProcessorCount - 2))
+        let server = WhisperServer(serverPath: serverPath, modelPath: modelPath, threads: threads)
+        whisperServer = server
+        server.start { [weak self] ok in
+            DispatchQueue.main.async {
+                guard let self = self, self.whisperServer === server else { return }
+                self.statusItem.button?.title = "🎤"
+                if ok {
+                    self.updateStatus("Ready")
+                    NSLog("whisper-server ready on port \(server.port)")
+                } else {
+                    self.updateStatus("Ready (CLI fallback)")
+                    self.whisperServer = nil
+                    NSLog("whisper-server failed to start — falling back to whisper-cli")
+                }
+            }
+        }
+    }
+
     // MARK: - Transcription
     func transcribe() {
-        // Validate inputs before execution
         let modelValidation = isValidModelPath(modelPath)
         guard modelValidation.valid else {
             DispatchQueue.main.async {
@@ -771,6 +1236,34 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
             return
         }
 
+        // Prefer the warm server (~0.5s); fall back to a per-call whisper-cli spawn.
+        let prompt = customPrompt()
+        let result: String?
+        if let server = whisperServer, server.isReady {
+            result = server.transcribe(wavPath: audioFilePath, language: language, prompt: prompt)
+        } else {
+            result = transcribeWithCLI(prompt: prompt)
+        }
+
+        self.cleanupAudioFile()
+
+        let finalText = result.map { applyReplacements($0) }
+
+        DispatchQueue.main.async {
+            if let finalText = finalText, !finalText.isEmpty {
+                self.pasteText(finalText)
+            } else {
+                self.statusItem.button?.title = "🎤"
+                self.updateStatus("Ready")
+                if self.playSounds { NSSound(named: "Basso")?.play() }
+                NSLog("No speech recognized")
+            }
+        }
+    }
+
+    // Per-call transcription via whisper-cli (reloads the model every time).
+    // Fallback for when the warm server is unavailable.
+    func transcribeWithCLI(prompt: String? = nil) -> String? {
         guard let whisperPath = findWhisperCLI() else {
             DispatchQueue.main.async {
                 self.statusItem.button?.title = "🎤"
@@ -778,17 +1271,16 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
                 if self.playSounds { NSSound(named: "Basso")?.play() }
                 NSLog("whisper-cli not found in PATH")
             }
-            return
+            return nil
         }
 
         let task = Process()
         task.executableURL = URL(fileURLWithPath: whisperPath)
-
-        // Build arguments - skip language flag for auto-detect
         var args = ["-m", modelPath]
         if language.lowercased() != SupportedLanguages.autoDetect {
             args += ["-l", language.lowercased()]
         }
+        if let prompt = prompt, !prompt.isEmpty { args += ["--prompt", prompt] }
         args += ["-f", audioFilePath]
         task.arguments = args
 
@@ -799,45 +1291,18 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate {
         do {
             try task.run()
             task.waitUntilExit()
-
             let data = pipe.fileHandleForReading.readDataToEndOfFile()
             let output = String(data: data, encoding: .utf8) ?? ""
-
-            let lines = output.components(separatedBy: "\n")
             var result = ""
-            for line in lines {
-                if line.hasPrefix("[") {
-                    if let range = line.range(of: "]") {
-                        let text = String(line[range.upperBound...]).trimmingCharacters(in: .whitespaces)
-                        result += text + " "
-                    }
-                }
-            }
-            result = result.trimmingCharacters(in: .whitespaces)
-
-            // Cleanup audio file after transcription
-            self.cleanupAudioFile()
-
-            DispatchQueue.main.async {
-                if !result.isEmpty {
-                    self.pasteText(result)
-                } else {
-                    self.statusItem.button?.title = "🎤"
-                    self.updateStatus("Ready")
-                    if self.playSounds { NSSound(named: "Basso")?.play() }
-                    NSLog("No speech recognized")
+            for line in output.components(separatedBy: "\n") where line.hasPrefix("[") {
+                if let range = line.range(of: "]") {
+                    result += String(line[range.upperBound...]).trimmingCharacters(in: .whitespaces) + " "
                 }
             }
+            return result.trimmingCharacters(in: .whitespaces)
         } catch {
-            // Cleanup even on error
-            self.cleanupAudioFile()
-
-            DispatchQueue.main.async {
-                self.statusItem.button?.title = "🎤"
-                self.updateStatus("Error")
-                if self.playSounds { NSSound(named: "Basso")?.play() }
-                NSLog("Transcription failed: \(error)")
-            }
+            NSLog("Transcription failed: \(error)")
+            return nil
         }
     }