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Read Live Metrics

Reads the current meter snapshot from the Phantom Studio plugin running in your DAW: loudness, true peak, stereo correlation, band energy, and meter verdicts. This gives your assistant the numbers on your meters at the moment you’re listening, not the numbers from a file analysis.

Warning

Phantom Studio hasn’t shipped yet. The read_live_metrics tool is in the MCP server today, but it reads a snapshot written by the Phantom Studio plugin, and that plugin is still in development. Without it running there is no snapshot to read and the tool returns an error. Join the waitlist if you want to know when it lands. Every other Phantom tool works on audio files and needs nothing extra.

Parameters

Parameter Type Default Description
instance_id string most recent instance Plugin instance ID (the metrics file stem). Omit to read the most recently written snapshot of any running instance.

Example Output

$ read_live_metrics

{ "instance_id": "3f2a-9c11", "age_seconds": 0.4, "stale": false, "instance_count": 2, "snapshot": { "loudness": { "integrated_lufs": -18.2, "short_term_lufs": -15.7, "momentary_lufs": -14.9 }, "true_peak": { "left_dbtp": -3.1, "right_dbtp": -3.4 }, "stereo": { "correlation": 0.74, "width": "wide" }, "band_energy": { "low": -24.1, "low_mid": -19.3, "mid": -18.8, "high_mid": -20.4, "high": -26.9 }, "verdicts": [ "Loudness OK", "Stereo image wide" ] }

What the Numbers Mean

  • instance_id — The plugin instance the snapshot came from. When multiple Phantom Studio instances are running, pass the ID of the instance you care about; when omitted, the most recently written snapshot wins.

  • age_seconds / stale — The plugin publishes a fresh snapshot roughly every half second while it runs and removes its file when the instance closes. A snapshot older than about 10 seconds is flagged stale — usually a crashed host or frozen DAW — and you should treat its numbers with caution.

  • instance_count — How many plugin instances have snapshots available right now.

  • snapshot — The current meter state: loudness (integrated, short-term, momentary LUFS), true peak in dBTP per channel, stereo correlation and width, per-band energy, and meter verdicts. These are the numbers that would be moving on the plugin’s meters while you listen.

Requirements

  • The Phantom Studio plugin must be loaded on a track and playing (or otherwise producing a snapshot).
  • When no snapshot is available, the tool fails with a message explaining that the plugin needs to be running — it doesn’t measure silence by itself.
  • Snapshot files live in PHANTOM_METRICS_DIR when set, otherwise the platform default: ~/Library/PhantomStudio/metrics on macOS, %APPDATA%\PhantomStudio\metrics on Windows, ~/.config/PhantomStudio/metrics on Linux.

Example Prompts

Stereo check while listening

Read the live metrics — is the stereo image collapsing in the chorus?

Loudness on the meters

Read the live loudness while I play this section — is it around -14 LUFS?

Pro tip

Live metrics reflect the moment, file analysis reflects the whole file. Use read_live_metrics while you audition a change, then confirm the result with a file-based analysis once you render.