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Advanced settings control voice activity detection (VAD), query routing behavior, and logging. These settings are typically edited directly in config.toml.

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Voice Activity Detection (VAD)

Klaus uses WebRTC VAD with multi-stage filtering to detect when you’re speaking and reject background noise.

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VAD Sensitivity

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vad_sensitivity
integer
default:"3"
WebRTC VAD sensitivity level for noise filtering.Valid range: 0 to 3
  • 0 = Least aggressive (accepts more background noise)
  • 1 = Low sensitivity
  • 2 = Medium sensitivity
  • 3 = Most aggressive noise filtering (default, recommended)
Higher values reduce false triggers from background noise but may miss quiet speech.
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vad_silence_timeout
float
default:"1.5"
Seconds of silence before voice activation finalizes your question.Typical range: 1.0 to 3.0 seconds
  • Lower values finalize faster but may cut off slow speakers
  • Higher values wait longer for you to continue speaking

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VAD Quality Gates

These settings filter out low-quality audio before it reaches STT:
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vad_min_duration
float
default:"0.5"
Minimum utterance duration in seconds.Audio shorter than this is rejected as noise. Helps filter out brief background sounds.
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vad_min_voiced_ratio
float
default:"0.28"
Minimum ratio of voiced frames to total frames.Range: 0.0 to 1.0An utterance must have at least this fraction of frames classified as “voiced” by WebRTC VAD. Helps reject sustained background hum or fan noise.
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vad_min_voiced_frames
integer
default:"8"
Minimum number of voiced 30ms frames in an utterance.Utterances with fewer voiced frames are rejected. Works with vad_min_voiced_ratio to filter noise.
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vad_min_rms_dbfs
float
default:"-45.0"
Minimum RMS loudness in dBFS (decibels relative to full scale).Typical range: -60.0 to -30.0
  • -60.0 = Very quiet (accepts almost everything)
  • -45.0 = Moderate loudness gate (default)
  • -30.0 = Loud (requires clear, loud speech)
Higher (less negative) values are stricter. This is a secondary gate that runs after WebRTC VAD checks.
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vad_min_voiced_run_frames
integer
default:"6"
Minimum length of the longest contiguous run of voiced frames.The utterance must contain at least one contiguous sequence of voiced frames of this length. Helps reject choppy noise that WebRTC VAD might accept.

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VAD Configuration Example

config.toml
# Stricter VAD for noisy environments
vad_sensitivity = 3
vad_silence_timeout = 2.0
vad_min_duration = 0.8
vad_min_voiced_ratio = 0.35
vad_min_voiced_frames = 10
vad_min_rms_dbfs = -40.0
vad_min_voiced_run_frames = 8
If Klaus triggers on background noise, increase vad_sensitivity, vad_min_rms_dbfs, and vad_min_voiced_ratio. If Klaus misses quiet speech, decrease these values.

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Query Router

Klaus uses an intelligent query router to classify questions and decide what context (image, history, memory, notes) to include.
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enable_query_router
boolean
default:"true"
Enable intelligent query routing.
  • true: Router classifies each question and optimizes context (default, recommended)
  • false: All questions get full context (slower, more expensive, may reduce quality)

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Router Model

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router_model
string
default:"claude-haiku-4-5"
Claude model used for ambiguous intent classification.The router uses local heuristics for most questions. Only uncertain classifications invoke this model.Options: Any Anthropic Claude model, e.g.:
  • claude-haiku-4-5 (default, fast and cheap)
  • claude-sonnet-4-6 (more accurate, slower, more expensive)

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Router Timeouts

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router_timeout_ms
integer
default:"350"
LLM router call timeout in milliseconds.If the router model doesn’t respond within this time, Klaus falls back to the default route.Typical range: 200 to 1000 ms
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router_max_tokens
integer
default:"80"
Maximum output tokens for LLM router classification.The router only needs a brief classification response. Keep this low to reduce latency and cost.

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Router Confidence Thresholds

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router_local_confidence_threshold
float
default:"0.78"
Minimum confidence for local heuristic routing to skip LLM call.Range: 0.0 to 1.0If local heuristics produce a confidence score above this threshold, the LLM router is not invoked.
  • Higher values → more LLM router calls (slower, more accurate)
  • Lower values → more local routing (faster, cheaper)
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router_local_margin_threshold
float
default:"0.18"
Minimum margin between top two local route scores to skip LLM call.Range: 0.0 to 1.0If the difference between the top two route scores is below this threshold (i.e., too close to call), the LLM router is invoked.
  • Higher values → more LLM router calls (slower, more accurate)
  • Lower values → more local routing (faster, cheaper)
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router_llm_confidence_threshold
float
default:"0.60"
Minimum confidence for LLM router classification.Range: 0.0 to 1.0If the LLM router’s confidence is below this threshold, Klaus falls back to a default route.

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Router Configuration Example

config.toml
# More aggressive local routing (faster, cheaper)
enable_query_router = true
router_model = "claude-haiku-4-5"
router_timeout_ms = 300
router_max_tokens = 80
router_local_confidence_threshold = 0.70
router_local_margin_threshold = 0.25
router_llm_confidence_threshold = 0.65
Query routing reduces latency and API costs by only sending relevant context. Most turns are classified by fast local heuristics; uncertain turns get a lightweight LLM call.

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User Background

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user_background
string
default:""
Optional free-text description of your background and expertise.Klaus injects this into the system prompt so it can tailor explanations to your level.Example:
user_background = "I'm a second-year physics PhD student focusing on quantum information theory."
Set this in the setup wizard or Settings dialog. Klaus will adjust its explanations based on your background.

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Obsidian Integration

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obsidian_vault_path
string
default:""
Path to your Obsidian vault folder for the notes feature.When set, you can ask Klaus to save notes directly to your vault.Example:
obsidian_vault_path = "/Users/yourname/Documents/ObsidianVault"
You can also use the environment variable OBSIDIAN_VAULT_PATH.
If obsidian_vault_path is empty, the notes feature is disabled. Configure this in the Settings dialog under the “Profile” tab.

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Logging

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log_level
string
default:"INFO"
Logging verbosity level.Options:
  • DEBUG: Very verbose, shows all internal operations
  • INFO: Normal verbosity, shows key operations (default)
  • WARNING: Only warnings and errors
  • ERROR: Only errors
Logs are printed to the console where Klaus was launched.

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Example: Enable Debug Logging

config.toml
log_level = "DEBUG"
DEBUG mode is very verbose and may log sensitive information. Only use for troubleshooting.

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Microphone Device

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mic_index
integer
default:"-1"
Index of the microphone device to use.Default: -1 (system default microphone)If you have multiple microphones:
  • -1 = Use system default
  • 0 = First microphone
  • 1 = Second microphone, etc.
Use Klaus’s Settings dialog to select the correct microphone. The index will be saved automatically.

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Setup Wizard

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setup_complete
boolean
default:"false"
Flag indicating whether the first-run setup wizard has been completed.Do not edit this manually. It’s set automatically by the setup wizard.To re-run the setup wizard:
  1. Close Klaus
  2. Edit config.toml and set setup_complete = false
  3. Restart Klaus

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Example: Complete Advanced Configuration

config.toml
# Advanced VAD tuning for noisy office environment
vad_sensitivity = 3
vad_silence_timeout = 2.0
vad_min_duration = 0.7
vad_min_voiced_ratio = 0.32
vad_min_voiced_frames = 10
vad_min_rms_dbfs = -42.0
vad_min_voiced_run_frames = 7

# Query router optimization for speed
enable_query_router = true
router_model = "claude-haiku-4-5"
router_timeout_ms = 300
router_max_tokens = 60
router_local_confidence_threshold = 0.75
router_local_margin_threshold = 0.20
router_llm_confidence_threshold = 0.65

# User profile and notes
user_background = "Undergraduate physics student with strong math background"
obsidian_vault_path = "/Users/student/Documents/StudyNotes"

# Debug logging
log_level = "DEBUG"

# Non-default microphone
mic_index = 1

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Performance Tuning

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For Noisy Environments

# Stricter VAD to reduce false triggers
vad_sensitivity = 3
vad_min_rms_dbfs = -40.0
vad_min_voiced_ratio = 0.35

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For Quiet/Soft Speakers

# More lenient VAD to catch quiet speech
vad_sensitivity = 2
vad_min_rms_dbfs = -50.0
vad_min_voiced_ratio = 0.25

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For Faster Response Times

# Shorter silence timeout
vad_silence_timeout = 1.0

# More aggressive local routing
router_local_confidence_threshold = 0.70
router_timeout_ms = 250

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For Cost Optimization

# Maximize local routing to reduce LLM calls
router_local_confidence_threshold = 0.65
router_local_margin_threshold = 0.30
router_timeout_ms = 200

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Troubleshooting

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VAD Triggers on Background Noise

  • Increase vad_sensitivity to 3
  • Increase vad_min_rms_dbfs (e.g., from -45.0 to -40.0)
  • Increase vad_min_voiced_ratio (e.g., from 0.28 to 0.35)

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VAD Misses Quiet Speech

  • Decrease vad_sensitivity to 2 or 1
  • Decrease vad_min_rms_dbfs (e.g., from -45.0 to -50.0)
  • Decrease vad_min_voiced_ratio (e.g., from 0.28 to 0.20)

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Router Too Slow

  • Decrease router_timeout_ms (e.g., to 250 ms)
  • Increase router_local_confidence_threshold to avoid LLM calls
  • Increase router_local_margin_threshold to make local routing more decisive

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Notes Feature Not Working

  • Verify obsidian_vault_path is set correctly
  • Check that the path exists and Klaus has write permissions
  • Ensure the path doesn’t have a trailing slash

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