@audiolabtools/mcp-server

@audiolabtools/mcp-server

MCP (Model Context Protocol) server that gives any MCP-capable AI (Claude Desktop, Claude Code, Cursor, and others) ten audio-analysis tools, backed by the hosted AudioLab API. It is a thin HTTP client: no local audio engine, no ffmpeg, nothing to compile. It can analyse a public URL or a local file on your machine.

Install

Point your MCP client at the package via npx (nothing to install globally):

{
  "mcpServers": {
    "audiolab": {
      "command": "npx",
      "args": ["-y", "@audiolabtools/mcp-server"],
      "env": { "AUDIOLAB_API_KEY": "al_live_yourkey" }
    }
  }
}

Get a key: sign in at https://audiolab.tools/account and generate one (free tier available).

Requirements

• Node ≥ 18: uses the built-in global fetch + AbortSignal.timeout.
• An AUDIOLAB_API_KEY. No ffmpeg, no native dependencies.

Tools

Every tool takes one audio source: a public url or a local path:

• { url: "https://…" }: a public https URL the API fetches server-side.
• { path: "./mix.wav" }: a file on the machine running this server. Files up to 4 MB are sent inline; larger files (up to 150 MB) upload over a signed URL, are analysed, and are swept from storage within the hour. (Local path works only in this stdio server, not the remote /mcp endpoint.)

Tool	Returns
analyze_loudness	Integrated LUFS (EBU R128 / BS.1770-4), true-peak (dBTP), LRA, crest factor, stereo correlation, mono compatibility, tonal balance
check_target	Pass/fail vs a delivery target (spotify / apple-music / youtube / tidal / amazon-music / podcast / ebu-broadcast / atsc-broadcast, or target:"custom" + lufs+tp), with per-metric deltas and an ffmpeg loudnorm fix command
analyze_timeseries	Short-term LUFS over time + downsampled waveform peaks (waveformPoints?)
get_spectrum	FFT magnitude data + 7-band energies
analyze_voice	Voice QA: speech/silence ratio, speaking rate, SNR, noise floor, pause energy, sibilance & clipping risk
get_speech_segments	Voiced regions with start/end + per-segment RMS (auto-trim, chapters)
index_signal	Content-type guess, tags, clipping/silence regions, brightness & dynamics buckets
analyze_profile	One named question, voice, master, provenance, dataset, environment, broadcast or loop, answered with only the lenses it needs. These seven need a paid plan; the free tier gets the basic profile, keyed by stable lens id. Add series:true for the curves, per-block lanes and per-phrase values. Carries a note when the profile’s voice lenses land on non-speech material. Full catalogue: https://audiolab.tools/lenses
compare_loudness	A/B on two sources (urlA/pathA + urlB/pathB), returns both results
analyze_batch	One route over up to 20 sources in a single call (urls and/or paths), per-item ok/data/error. For folder QA, library indexing, or checking a whole release against a target. Each item meters as one call

Example asks to your AI:

• “Analyze the loudness of https://example.com/track.wav” → analyze_loudness with url
• “Is this take usable?” → analyze_profile with profile:"voice"
• “Has this file been re-encoded, and is it all one source?” → analyze_profile with profile:"provenance"
• “Run loudness on ./master.wav” → analyze_loudness with path
• “Does ./mix.mp3 pass Spotify?” → check_target with path + target:"spotify"

Configuration (env)

Var	Default	Purpose
AUDIOLAB_API_KEY	– (required)	Your API key.
AUDIOLAB_API_BASE	https://audiolab.tools/v1	Override the API base (must be https://).
AUDIOLAB_TIMEOUT_MS	330000	Per-request timeout in milliseconds (long files and batches stream server-side and can legitimately take minutes).

Privacy

Analysis happens on the AudioLab API, so the audio does reach audiolab.tools: a url is fetched server-side, and a local path is sent to the API (small files inline; larger files via a private one-shot signed upload that is deleted right after analysis). The API returns numbers only and does not retain your audio (see https://audiolab.tools/privacy). This package has no telemetry and writes nothing to disk. If audio must never leave the machine, don't use a hosted analyser.

Limits

• Local files: up to 150 MB (host bigger ones at a public URL).
• Duration: loudness routes (analyze_loudness, check_target, analyze_timeseries, get_spectrum) handle long files (podcast episodes, full sets, up to ~3 h) via server-side streaming; voice/signal routes are limited to ~7 minutes.
• One file per call (agents loop for many); one-shot (no streaming/realtime).
• Rate and monthly limits are enforced by the API, per key.

Smoke test

node hosted-server.mjs --selftest   # verifies the 10 tools + guards; no network

License

MIT © Nathan Renting