@audiolabtools/mcp-server

MCP (Model Context Protocol) server that gives any MCP-capable AI — Claude Desktop, Claude Code, Cursor, and others — eight 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 50 MB) upload over a one-shot signed URL, are analysed, and are then deleted. (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 + dominant band | | analyze_voice | Voice QA: speech/silence ratio, speaking rate, SNR, noise floor, room echo, 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 | | compare_loudness | A/B on two sources (urlA/pathA + urlB/pathB), returns both results |

Example asks to your AI:

• “Analyze the loudness of https://example.com/track.wav” → analyze_loudness with url
• “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 | 60000 | Per-request timeout in milliseconds. |

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 50 MB (host bigger ones at a public URL).
• 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 8 tools + guards; no network

License

MIT © Nathan Renting