Audiolab

@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 measure a public URL or a local file on your machine, but the measuring always happens on the hosted API: the file is read here and uploaded there (see Privacy).

Install

Point your MCP client at the package via npx (nothing to install globally). No account needed for a first score:

{

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

Without a key you are on the keyless trial: 20 calls a month and 3 a minute per IP address, for single analyses of a URL or a local file up to 4 MB. Batches and larger files need a key. A free key gives 1,000 calls and 2 GB a month, no card: sign in at https://audiolab.tools/account, generate one, and add it:

"env": { "AUDIOLAB_API_KEY": "al_live_yourkey" }

Requirements

• Node ≥ 18: uses the built-in global fetch + AbortSignal.timeout.
• Optionally an AUDIOLAB_API_KEY (see Install). 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.)*

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"
• *“Which of these recordings were upsampled?”* → analyze_batch with endpoint:"signallab/index" and bandLimit:true
• *“Run loudness on ./master.wav”* → analyze_loudness with path
• *“Does ./mix.mp3 pass Spotify?”* → check_target with path + target:"spotify"

Configuration (env)

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 read here and uploaded to the API (small files in the request body; larger files via a private one-shot signed upload into EU storage). The API returns numbers only and does not keep your audio: a direct request is decoded and discarded inside the request, and a signed upload is swept from storage within the hour (see https://audiolab.tools/privacy). This package has no telemetry and writes nothing to disk. There is no offline mode, and the engine is not published as an installable package. If audio must never leave the machine, don't use a hosted analyser; the in-browser labs on the website measure on-device, but they are for people, not for agents.

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 (per IP address on the keyless trial).

Smoke test

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

License

MIT © Nathan Renting