diff --git a/.env.example b/.env.example
deleted file mode 100644
index 8e5445f..0000000
--- a/.env.example
+++ /dev/null
@@ -1,232 +0,0 @@
-# Copy this file to .env and fill in your values.
-
-# ── Bolt server (required) ──────────────────────────────────────────────────
-# The same server URL + key desk_client/bolt_desk.py and the Android app use.
-# DESK_API_KEY is the master key from the server's own .env, or a per-user
-# key minted via the api_key_generate desk marker (see the main repo's
-# CLAUDE.md "Per-user API keys" section).
-BOLT_SERVER_URL=http://your-server:5002
-DESK_API_KEY=
-
-# Unique per machine/install so sessions don't collide. Defaults to
-# "pet-<hostname>" if unset.
-#DESK_SESSION_ID=pet-my-desktop
-
-# ── Wake word ────────────────────────────────────────────────────────────────
-# openWakeWord model trained for "thunderbolt" — thunderbolt.onnx ships in
-# the project root next to this file. Point WAKE_MODEL_FILE at a different
-# .onnx model to change the phrase (same convention as desk_client's
-# WAKE_MODEL_FILE / bolt.onnx in the main repo).
-#WAKE_MODEL_FILE=thunderbolt.onnx
-#WAKE_WORD_THRESHOLD=0.5
-#WAKE_CHECK_INTERVAL_SECONDS=1.2
-
-# ── STT / TTS (server-hosted — same /desk/stt and /desk/tts the Android app
-# uses) ──────────────────────────────────────────────────────────────────────
-# No Deepgram or ElevenLabs account needed here: both go through
-# BOLT_SERVER_URL/DESK_API_KEY above, the same as the rest of this file.
-# ELEVENLABS_VOICE_ID just tells the server which voice to request — omit it
-# to fall back to offline pyttsx3 TTS instead (STT still works either way).
-ELEVENLABS_VOICE_ID=
-#TTS_SAMPLE_RATE=16000
-
-# Ask Bolt to use a different voice (or another language) and the server
-# picks one from the ElevenLabs voice library and tags the reply with it.
-# It only tags one reply, and it can't remember the id afterwards — so the
-# pet keeps using that voice until a new one is picked or you choose "Use
-# default voice" in the tray. VOICE_STICKY=false makes each pick last for
-# exactly the one reply it came with instead.
-#VOICE_STICKY=true
-
-# ── Multi-voice dialogue (ElevenLabs Text to Dialogue) ──────────────────────
-# The one feature the server has no endpoint for, so this is the only place
-# in the whole app that still needs a local ElevenLabs API key — everything
-# else (the normal reply voice, transcription) goes through the server above.
-# Lets Bolt play a short scene in several voices with delivery tags the v3
-# model acts on ("[cheerfully] Hello", "[whispering] He is lying"), driven by
-# the server through a relayed `dialoguectl` command. Name the cast here —
-# "self" always means whatever voice the pet is currently using.
-ELEVENLABS_API_KEY=
-#DIALOGUE=true
-#DIALOGUE_MODEL_ID=eleven_v3
-#DIALOGUE_VOICES=narrator:9BWtsMINqrJLrRacOk9x,villain:IKne3meq5aSn9XLyUdCD
-
-# ── Self-restart (optional) ─────────────────────────────────────────────────
-# `petctl self_restart <why>` lets Bolt reload the pet after editing its own
-# code, so he can check the change live. The code is import-checked first, the
-# restart waits for the current turn to finish, and the reason is carried
-# across so the new process reports back. The guard refuses more than
-# SELF_RESTART_MAX restarts within SELF_RESTART_WINDOW_SECONDS.
-#SELF_RESTART=true
-#SELF_RESTART_MAX=5
-#SELF_RESTART_WINDOW_SECONDS=900
-
-# ── Audio devices (optional — leave blank for the system default) ──────────
-#MIC_DEVICE=
-#SPEAKER_DEVICE=
-
-# ── VAD tuning (optional) ───────────────────────────────────────────────────
-#VAD_RMS_THRESHOLD=300
-#VAD_SILENCE_END_SEC=1.2
-#VAD_MAX_UTTERANCE_SECONDS=15
-#VAD_MIN_UTTERANCE_SECONDS=0.4
-#VAD_GRACE_SECONDS=4            # how long to wait for you to start talking
-
-# ── Follow-up listening (optional) ──────────────────────────────────────────
-# When a reply ends on a question, the pet keeps listening for your answer
-# instead of dropping back to idle and making you say the wake word again.
-# FOLLOW_UP_MAX_TURNS caps how many question-and-answer rounds can chain
-# without you re-triggering it (0 = no cap) — a stop on runaway loops if the
-# server ends every reply with "?" and the mic keeps feeding it noise.
-#FOLLOW_UP_LISTEN=true
-#FOLLOW_UP_MAX_TURNS=3
-#FOLLOW_UP_GRACE_SECONDS=7      # longer than VAD_GRACE_SECONDS: you were asked something
-
-# ── Pet window (optional) ───────────────────────────────────────────────────
-#PET_SIZE=160
-#PET_START_X=
-#PET_START_Y=
-#PET_ALWAYS_ON_TOP=true
-#IDLE_ANIMATION_FPS=6
-
-# ── Wandering (optional) — the pet strolls to a random spot while idle ───────
-#PET_WANDER=true
-#PET_WANDER_INTERVAL_SECONDS=45   # average pause between strolls (randomized 0.5x-1.5x)
-#PET_WANDER_SPEED=90              # pixels per second
-#PET_WANDER_MAX_DISTANCE=600      # cap on a single stroll's length
-#PET_WANDER_MARGIN=20             # keep this far off the screen edges
-
-# ── Mouse behaviour (optional) ──────────────────────────────────────────────
-# Shaped input = the square window's transparent corners stop eating clicks.
-# Click-through = the pet ignores the mouse entirely (control it from the tray).
-#PET_SHAPED_INPUT=true
-#PET_CLICK_THROUGH=false
-#PET_EDGE_SNAP=true
-#PET_SNAP_MARGIN=48
-# Start where you last dragged it. A position on a monitor that's no longer
-# connected is ignored, so unplugging a screen can't hide the pet off-desktop.
-#PET_REMEMBER_POSITION=true
-
-# ── Barge-in (optional) — interrupt the pet mid-sentence ────────────────────
-# BARGE_IN_MODE decides what counts as an interruption:
-#   wake   — only the wake word cuts playback (default). Background noise,
-#            coughs and the TV can't stop it mid-sentence.
-#   energy — any sustained noise above BARGE_IN_RMS_THRESHOLD does. Faster to
-#            trigger, but interrupts on anything loud. That threshold defaults
-#            to 4x VAD_RMS_THRESHOLD because the mic also hears the pet's own
-#            voice out of the speakers; raise it if playback self-interrupts.
-#BARGE_IN=true
-#BARGE_IN_MODE=wake
-#BARGE_IN_RMS_THRESHOLD=1200   # energy mode only
-#BARGE_IN_FRAMES=4             # energy mode only
-# Wake mode only. Blank tracks the live WAKE_WORD_THRESHOLD (tray tuner);
-# set a number to make interrupting harder than waking the pet from idle,
-# e.g. if Bolt's own voice occasionally trips the model.
-#BARGE_IN_WAKE_THRESHOLD=0.6
-
-# ── Auto-update (optional) ──────────────────────────────────────────────────
-# Watches the Gitea releases page for a tag newer than bolt_pet.__version__,
-# then `git checkout`s it and restarts — only ever between turns, never
-# mid-conversation. Requires the install to be a git clone; a working tree
-# with local changes is skipped (never stashed), and any failure after the
-# checkout rolls back to the ref that was live before.
-#AUTO_UPDATE=true
-#UPDATE_REPO_API=https://git.themajesticnetwork.com/api/v1/repos/TheMajesticNetwork/Bolt-Pet
-#UPDATE_CHECK_INTERVAL_SECONDS=3600
-#UPDATE_GIT_REMOTE=origin
-#UPDATE_INSTALL_DEPS=true
-# Only needed if the repo is private (a Gitea token with read:repository).
-#UPDATE_TOKEN=
-
-# ── Streaming TTS (optional) — starts talking on the first chunk ────────────
-#TTS_STREAMING=true
-
-# ── Latency: streaming the reply and the transcript ─────────────────────────
-# STREAMING_REPLIES speaks each sentence as the server generates it, instead of
-# waiting out the whole model call before the first word. STT_STREAMING sends
-# mic frames to the server's /desk/stt relay as you talk, so the transcript is
-# ready the moment you stop, instead of uploading the whole clip afterward.
-# Both fall back to the old path automatically if anything goes wrong.
-# VAD_SILENCE_END_SEC is the other half: it is dead air on every single turn,
-# so 0.8-1.0 feels markedly snappier than the 1.2 default.
-#STREAMING_REPLIES=true
-#STT_STREAMING=true
-
-# ── Screen context (optional) ───────────────────────────────────────────────
-# Sends the focused window's title along with what you said, so "what's this
-# error?" has a referent. Text only — no screenshots leave the machine.
-#SCREEN_CONTEXT=true
-
-# ── Monitors (optional) ─────────────────────────────────────────────────────
-# Tacks a one-line summary of your screen layout onto each utterance (how
-# many, their sizes, which one the pet is standing on) so Bolt can decide to
-# `petctl jump 2` without asking what you've got plugged in. Costs nothing —
-# the list comes from the UI, nothing is probed per turn.
-#MONITOR_CONTEXT=true
-
-# ── Screen text / OCR (optional) ────────────────────────────────────────────
-# Lets Bolt read what's actually on a monitor with `petctl read [n|here|all]`
-# and use it in his reply. Pull-only — nothing is captured unless he asks,
-# and every read is logged.
-#
-# Needs the extras from requirements.txt plus an OCR engine:
-#     pip install mss pytesseract && sudo apt install tesseract-ocr
-#   or, without sudo:
-#     pip install mss rapidocr-onnxruntime
-# mss captures on X11/Windows/macOS but NOT Wayland.
-#
-# This sends the text of a whole screen to the server when used. That's not a
-# new capability — the shell relay could already screenshot and OCR — but it's
-# a far easier one to reach for. SCREEN_TEXT=false removes it entirely.
-#SCREEN_TEXT=true
-#SCREEN_TEXT_MAX_CHARS=4000
-
-# ── Quiet hours / do-not-disturb (optional) ────────────────────────────────
-# Comma-separated HH:MM-HH:MM ranges; wrapping past midnight is fine. While
-# napping the pet dims, stops wandering and makes no proactive noise — the
-# wake word and click-to-talk still work.
-#QUIET_HOURS=23:00-08:00
-#DND_ON_FULLSCREEN=true
-
-# ── Desktop notification bridge (optional, Linux/D-Bus) ────────────────────
-# Forwards matching desktop notifications to the server so Bolt can react to
-# them. Off by default: each forwarded notification is a converse() round
-# trip. NOTIFICATION_FILTER is a regex over "<app>: <summary> <body>".
-#NOTIFICATION_BRIDGE=false
-#NOTIFICATION_FILTER=build|deploy|calendar
-#NOTIFICATION_MIN_INTERVAL_SECONDS=60
-
-# ── Push-to-talk (optional) ─────────────────────────────────────────────────
-# Global hotkey; needs pynput and a session that allows global key hooks
-# (most Wayland sessions don't). Leave blank to disable.
-#PUSH_TO_TALK_HOTKEY=ctrl+alt+space
-
-# ── Wake-word tuning (optional) ─────────────────────────────────────────────
-# Scores within this margin below the threshold show up as "near misses" in
-# the tray's wake-word tuner.
-#WAKE_NEAR_MISS_MARGIN=0.2
-#WAKE_NEAR_MISS_LIMIT=40
-
-# ── sudo password prompts (optional) ────────────────────────────────────────
-# The pet has no terminal, so a server-relayed `sudo` would block forever on
-# a tty nobody is watching. With this on, bare `sudo` becomes `sudo -A` and
-# the password is collected in a desktop dialog you have to answer — a real
-# askpass binary if one is installed, otherwise a generated zenity/kdialog
-# wrapper in ~/.cache/bolt-pet/askpass.sh.
-# Set it to false if you'd rather Bolt never be able to ask for root: sudo
-# commands then just fail. Read the dialogs — that box is the only thing
-# between "Bolt decided to run sudo" and it running.
-#SUDO_ASKPASS_PROMPT=true
-#SUDO_ASKPASS_HELPER=            # blank = auto-detect
-#SUDO_COMMAND_TIMEOUT_SECONDS=180  # long enough for a human to answer
-
-# ── File delivery (optional) ────────────────────────────────────────────────
-# The server's deliver_files tool ("send me that report") queues workspace
-# files on this session; the pet fetches and saves them automatically.
-#RECEIVE_FILES=true
-#DELIVERED_FILES_DIR=~/Downloads/Bolt
-
-# ── Misc (optional) ──────────────────────────────────────────────────────────
-#COMMAND_TIMEOUT_SECONDS=30
-#HEARTBEAT_INTERVAL_SECONDS=60
-#HISTORY_LIMIT=100
diff --git a/bolt_pet/audio/mic.py b/bolt_pet/audio/mic.py
index e3a6a3c..c8e2502 100644
--- a/bolt_pet/audio/mic.py
+++ b/bolt_pet/audio/mic.py
@@ -126,6 +126,27 @@ def record_utterance(
     return pcm
 
 
+def list_input_devices() -> list[dict]:
+    """Every input-capable device sounddevice can see, as
+    {"index", "name", "hostapi"}.
+
+    On Windows in particular, the *same* physical (or virtual) device is
+    normally listed once per host API — MME, DirectSound, WASAPI, WDM-KS —
+    all sharing (or near enough sharing) one name. That makes the name alone
+    an unreliable, often ambiguous way to pick a device (sounddevice matches
+    a string device as a substring and refuses to guess between ties), so the
+    tray's mic picker saves the numeric index instead, which this list exists
+    to let it show alongside a human-readable label."""
+    import sounddevice as sd
+
+    devices = []
+    for index, info in enumerate(sd.query_devices()):
+        if info.get("max_input_channels", 0) > 0:
+            hostapi = sd.query_hostapis(info["hostapi"])["name"]
+            devices.append({"index": index, "name": info["name"], "hostapi": hostapi})
+    return devices
+
+
 def open_input_stream():
     """Real sounddevice input stream, imported lazily so pure-logic tests
     (record_utterance with a fake stream) don't need PortAudio installed."""
diff --git a/bolt_pet/config.py b/bolt_pet/config.py
index 1c63585..57aaabc 100644
--- a/bolt_pet/config.py
+++ b/bolt_pet/config.py
@@ -9,6 +9,7 @@ from __future__ import annotations
 
 import os
 import platform
+import re
 from pathlib import Path
 
 HERE = Path(__file__).resolve().parent.parent  # project root (one above bolt_pet/)
@@ -29,6 +30,26 @@ def _load_env() -> None:
 _load_env()
 
 
+def set_env_value(key: str, value: str) -> None:
+    """Write *key=value* into .env, in place — replacing (or uncommenting)
+    an existing line for it, appending a new one otherwise. Used by the tray's
+    microphone picker so a device pick survives a restart without hand-editing
+    the file. Settings read once at import time (like MIC_DEVICE) still need
+    that restart to take effect; this only updates the file and os.environ."""
+    env_path = HERE / ".env"
+    lines = env_path.read_text(encoding="utf-8").splitlines() if env_path.exists() else []
+    pattern = re.compile(rf"^\s*#?\s*{re.escape(key)}\s*=")
+    new_line = f"{key}={value}"
+    for i, line in enumerate(lines):
+        if pattern.match(line):
+            lines[i] = new_line
+            break
+    else:
+        lines.append(new_line)
+    env_path.write_text("\n".join(lines) + "\n", encoding="utf-8")
+    os.environ[key] = value
+
+
 def _node_name() -> str:
     try:
         return platform.node() or "desktop"
@@ -115,7 +136,22 @@ DIALOGUE_VOICES = os.environ.get("DIALOGUE_VOICES", "")
 
 # ── mic / VAD (same tuning knobs as bolt_desk.py) ───────────────────────────
 
-MIC_DEVICE = os.environ.get("MIC_DEVICE", "") or None  # sounddevice name/index
+def _mic_device(raw: str):
+    """sounddevice treats an int index and a string name very differently: a
+    string is matched as a (fragile, often ambiguous) substring against every
+    device name, while an int is used as-is. .env only ever gives us a
+    string, so a numeric one — what the tray's mic picker saves, since the
+    same physical device usually shows up once per host API (MME,
+    DirectSound, WASAPI, ...) under the same name — has to be cast back to
+    int here, or it goes through the substring path and matches nothing (or
+    everything) instead."""
+    raw = raw.strip()
+    if not raw:
+        return None
+    return int(raw) if raw.lstrip("-").isdigit() else raw
+
+
+MIC_DEVICE = _mic_device(os.environ.get("MIC_DEVICE", ""))
 SPEAKER_DEVICE = os.environ.get("SPEAKER_DEVICE", "") or None
 
 RMS_THRESHOLD = int(os.environ.get("VAD_RMS_THRESHOLD", "300"))
diff --git a/bolt_pet/ui/app.py b/bolt_pet/ui/app.py
index 7725858..954393f 100644
--- a/bolt_pet/ui/app.py
+++ b/bolt_pet/ui/app.py
@@ -11,13 +11,14 @@ from __future__ import annotations
 import sys
 
 from PySide6.QtCore import QThread
-from PySide6.QtWidgets import QApplication
+from PySide6.QtWidgets import QApplication, QMessageBox
 
 from .. import config, updater
 from ..controller import PetController
 from ..hotkey import GlobalHotkey
 from ..state import PetState
 from .history_window import HistoryWindow
+from .mic_picker import MicPickerDialog
 from .pet_window import PetWindow
 from .tray import PetTray
 from .wake_tuner import WakeTunerWindow
@@ -57,6 +58,19 @@ def run() -> int:
     window.publish_monitors()
     window.copied.connect(lambda text: _log(f"Copied to clipboard: {text[:60]}"))
 
+    # The updater has already moved the checkout by the time this fires; all
+    # that's left is to let Qt tear down cleanly (so the mic and the tray
+    # icon are released) and then exec the new code. Doing the exec after
+    # app.exec() returns, rather than from the controller thread, is what
+    # guarantees the audio device is free before the new process opens it.
+    # Defined early so the mic picker (below) can trigger the same restart
+    # a self-update or self-restart does.
+    pending_restart = {"tag": None}
+
+    def _handle_restart(tag: str) -> None:
+        pending_restart["tag"] = tag
+        app.quit()
+
     history_window = HistoryWindow(controller.history)
     tuner_window = WakeTunerWindow(
         get_threshold=controller.wake_threshold,
@@ -65,6 +79,23 @@ def run() -> int:
         on_reset=controller.reset_wake_stats,
     )
 
+    def _save_mic_device(value) -> None:
+        config.set_env_value("MIC_DEVICE", str(value) if value is not None else "")
+        _log(f"Microphone set to device #{value}." if value is not None else
+             "Microphone set to system default.")
+        answer = QMessageBox.question(
+            None, "Restart Bolt?",
+            "Restart now so Bolt starts listening on the new microphone?",
+            QMessageBox.Yes | QMessageBox.No,
+        )
+        if answer == QMessageBox.Yes:
+            _handle_restart("microphone change")
+
+    mic_picker = MicPickerDialog(
+        get_current=lambda: config.MIC_DEVICE,
+        on_save=_save_mic_device,
+    )
+
     def _set_nap(napping: bool) -> None:
         # Clicking the tray item pins the state; the schedule takes over again
         # only after a restart or a `petctl nap off`.
@@ -82,6 +113,7 @@ def run() -> int:
         on_set_nap=_set_nap,
         on_show_history=history_window.show_refreshed,
         on_show_wake_tuner=tuner_window.show_refreshed,
+        on_show_mic_picker=mic_picker.show_refreshed,
         on_reset_voice=controller.reset_voice,
     )
 
@@ -104,17 +136,6 @@ def run() -> int:
     elif hotkey.running:
         _log(f"Push-to-talk: {config.PUSH_TO_TALK_HOTKEY}")
 
-    # The updater has already moved the checkout by the time this fires; all
-    # that's left is to let Qt tear down cleanly (so the mic and the tray
-    # icon are released) and then exec the new code. Doing the exec after
-    # app.exec() returns, rather than from the controller thread, is what
-    # guarantees the audio device is free before the new process opens it.
-    pending_restart = {"tag": None}
-
-    def _handle_restart(tag: str) -> None:
-        pending_restart["tag"] = tag
-        app.quit()
-
     controller.restart_requested.connect(_handle_restart)
 
     def _shutdown() -> None:
diff --git a/bolt_pet/ui/mic_picker.py b/bolt_pet/ui/mic_picker.py
new file mode 100644
index 0000000..a1547fd
--- /dev/null
+++ b/bolt_pet/ui/mic_picker.py
@@ -0,0 +1,98 @@
+"""Microphone picker — MIC_DEVICE in .env is a device index most people have
+no way to look up short of running a script. This dialog lists whatever
+sounddevice can actually see, lets you click one, and writes its index back
+to .env so it survives a restart.
+
+The index, not the name, is what gets saved: the same device is commonly
+listed once per host API (MME, DirectSound, WASAPI, WDM-KS, ...) under the
+same or a near-identical name, which makes a bare name an ambiguous pick that
+sounddevice will flatly refuse to resolve (see audio/mic.list_input_devices).
+The index is exact.
+
+The mic is only ever opened once, at startup (see controller.run()), so a
+pick made here still needs a restart before Bolt actually uses it — this
+dialog just makes finding and saving the right device painless, and offers
+to do the restart for you.
+"""
+
+from __future__ import annotations
+
+from typing import Callable, Optional
+
+from PySide6.QtCore import Qt
+from PySide6.QtWidgets import (
+    QDialog, QDialogButtonBox, QHBoxLayout, QLabel, QListWidget,
+    QListWidgetItem, QPushButton, QVBoxLayout,
+)
+
+from ..audio.mic import list_input_devices
+
+_DEFAULT_LABEL = "System default"
+
+
+class MicPickerDialog(QDialog):
+    def __init__(
+        self,
+        get_current: Callable[[], Optional[int]],
+        on_save: Callable[[Optional[int]], None],
+    ):
+        super().__init__()
+        self._get_current = get_current
+        self._on_save = on_save
+
+        self.setWindowTitle("Bolt — select microphone")
+        self.resize(440, 320)
+
+        self._list = QListWidget()
+        refresh_button = QPushButton("Refresh")
+        refresh_button.clicked.connect(self.refresh)
+
+        top = QHBoxLayout()
+        top.addWidget(QLabel("Pick the microphone Bolt should listen on:"))
+        top.addStretch(1)
+        top.addWidget(refresh_button)
+
+        buttons = QDialogButtonBox(QDialogButtonBox.Save | QDialogButtonBox.Cancel)
+        buttons.accepted.connect(self._save)
+        buttons.rejected.connect(self.reject)
+
+        layout = QVBoxLayout(self)
+        layout.addLayout(top)
+        layout.addWidget(self._list)
+        layout.addWidget(buttons)
+
+    def refresh(self) -> None:
+        self._list.clear()
+        default_item = QListWidgetItem(_DEFAULT_LABEL)
+        default_item.setData(Qt.UserRole, None)
+        self._list.addItem(default_item)
+
+        current = self._get_current()
+        selected = default_item
+        try:
+            devices = list_input_devices()
+        except Exception as exc:
+            self._list.addItem(f"Could not list devices: {exc}")
+            devices = []
+
+        for device in devices:
+            item = QListWidgetItem(
+                f"{device['name']}  [{device['hostapi']}]  (#{device['index']})"
+            )
+            item.setData(Qt.UserRole, device["index"])
+            self._list.addItem(item)
+            if current == device["index"]:
+                selected = item
+        self._list.setCurrentItem(selected)
+
+    def _save(self) -> None:
+        item = self._list.currentItem()
+        value = item.data(Qt.UserRole) if item is not None else None
+        self._on_save(value)
+        self.accept()
+
+    def show_refreshed(self) -> None:
+        self.refresh()
+        self.show()
+        self.raise_()
+        self.activateWindow()
diff --git a/bolt_pet/ui/tray.py b/bolt_pet/ui/tray.py
index e2d2867..113686c 100644
--- a/bolt_pet/ui/tray.py
+++ b/bolt_pet/ui/tray.py
@@ -47,6 +47,7 @@ class PetTray(QSystemTrayIcon):
         on_set_nap: Optional[Callable[[bool], None]] = None,
         on_show_history: Optional[Callable[[], None]] = None,
         on_show_wake_tuner: Optional[Callable[[], None]] = None,
+        on_show_mic_picker: Optional[Callable[[], None]] = None,
         on_reset_voice: Optional[Callable[[], None]] = None,
         parent=None,
     ):
@@ -104,6 +105,11 @@ class PetTray(QSystemTrayIcon):
             tuner_action.triggered.connect(on_show_wake_tuner)
             menu.addAction(tuner_action)
 
+        if on_show_mic_picker is not None:
+            mic_action = QAction("Select microphone…", menu)
+            mic_action.triggered.connect(on_show_mic_picker)
+            menu.addAction(mic_action)
+
         # Only ever enabled while a server-picked voice (speak_as) is in use —
         # it's the way back from "talk like a pirate", which nothing else
         # undoes short of a restart.
diff --git a/tests/test_config.py b/tests/test_config.py
new file mode 100644
index 0000000..5dd3106
--- /dev/null
+++ b/tests/test_config.py
@@ -0,0 +1,62 @@
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from bolt_pet import config
+
+
+def test_set_env_value_uncomments_existing_line(tmp_path, monkeypatch):
+    (tmp_path / ".env").write_text("#MIC_DEVICE=\nOTHER=1\n", encoding="utf-8")
+    monkeypatch.setattr(config, "HERE", tmp_path)
+
+    config.set_env_value("MIC_DEVICE", "USB Mic")
+
+    lines = (tmp_path / ".env").read_text(encoding="utf-8").splitlines()
+    assert lines == ["MIC_DEVICE=USB Mic", "OTHER=1"]
+    assert config.os.environ["MIC_DEVICE"] == "USB Mic"
+
+
+def test_set_env_value_overwrites_existing_uncommented_line(tmp_path, monkeypatch):
+    (tmp_path / ".env").write_text("MIC_DEVICE=Old Mic\n", encoding="utf-8")
+    monkeypatch.setattr(config, "HERE", tmp_path)
+
+    config.set_env_value("MIC_DEVICE", "New Mic")
+
+    lines = (tmp_path / ".env").read_text(encoding="utf-8").splitlines()
+    assert lines == ["MIC_DEVICE=New Mic"]
+
+
+def test_set_env_value_appends_when_key_is_missing(tmp_path, monkeypatch):
+    (tmp_path / ".env").write_text("OTHER=1\n", encoding="utf-8")
+    monkeypatch.setattr(config, "HERE", tmp_path)
+
+    config.set_env_value("MIC_DEVICE", "New Mic")
+
+    lines = (tmp_path / ".env").read_text(encoding="utf-8").splitlines()
+    assert lines == ["OTHER=1", "MIC_DEVICE=New Mic"]
+
+
+def test_set_env_value_creates_file_if_missing(tmp_path, monkeypatch):
+    monkeypatch.setattr(config, "HERE", tmp_path)
+
+    config.set_env_value("MIC_DEVICE", "New Mic")
+
+    assert (tmp_path / ".env").read_text(encoding="utf-8") == "MIC_DEVICE=New Mic\n"
+
+
+def test_mic_device_parses_a_numeric_index_as_int():
+    # sounddevice only takes an int index as-is; a string (even "1") goes
+    # through substring matching against every device name instead, which is
+    # not what a saved index means — see the tray's mic picker.
+    assert config._mic_device("1") == 1
+    assert isinstance(config._mic_device("1"), int)
+
+
+def test_mic_device_keeps_a_name_as_a_string():
+    assert config._mic_device("USB Mic") == "USB Mic"
+
+
+def test_mic_device_blank_is_none():
+    assert config._mic_device("") is None
+    assert config._mic_device("   ") is None
diff --git a/tests/test_mic.py b/tests/test_mic.py
index f20a9de..6f67a5a 100644
--- a/tests/test_mic.py
+++ b/tests/test_mic.py
@@ -100,6 +100,32 @@ def test_returns_none_when_should_continue_stops_before_speech():
     assert result is None
 
 
+def test_list_input_devices_filters_to_input_capable(monkeypatch):
+    fake_devices = [
+        {"name": "Speakers", "max_input_channels": 0, "hostapi": 0},
+        {"name": "USB Mic", "max_input_channels": 2, "hostapi": 0},
+        {"name": "Line In", "max_input_channels": 1, "hostapi": 1},
+    ]
+    fake_hostapis = [{"name": "MME"}, {"name": "WASAPI"}]
+
+    class _FakeSoundDevice:
+        @staticmethod
+        def query_devices():
+            return fake_devices
+
+        @staticmethod
+        def query_hostapis(index):
+            return fake_hostapis[index]
+
+    monkeypatch.setitem(sys.modules, "sounddevice", _FakeSoundDevice())
+
+    devices = mic.list_input_devices()
+    assert devices == [
+        {"index": 1, "name": "USB Mic", "hostapi": "MME"},
+        {"index": 2, "name": "Line In", "hostapi": "WASAPI"},
+    ]
+
+
 def test_pcm_to_wav_bytes_round_trips_via_wave_module():
     import wave
     import io