We built Phantom because we were tired of the round-trip.
Hear something off in a stem. Open a spectrum analyzer. Check the reading. Open the reference track. Compare manually. Back to the mix. Repeat. The analysis work wasn’t hard. It was just slow, and it lived in a different window than the thinking.
Claude could already hold a whole session in its head: track notes, revision history, what the reference sounds like, what the client asked for. But it couldn’t measure anything. No way to look at a file and tell you the integrated loudness, or where the masking was happening between the kick and the bass, or whether your stereo image was going to collapse in mono.
So we built the measurement layer. Phantom is an MCP server that connects Claude to professional audio analysis tools. The kind that give you actual numbers.
What it does
17 tools covering the full analysis side of a session: spectrum, loudness, dynamics, stereo field, phase relationships, problem detection, frequency masking between stems, reference comparison, target matching, stem separation, full diagnostic runs.
Hand it a stem and ask what’s wrong. Compare your master to a reference track. Check whether your kick and bass are fighting each other before committing to the arrangement. The full diagnostic is where it gets useful fast: instead of manually checking six things, you run phantom analyze and Claude tells you what needs attention and why. You still make the call. Phantom just makes sure you’re not missing something.
Skills
Five domain expert modes: mix engineer, effects engineer, mastering engineer, audio diagnostician, and session architect. Each one shifts how Claude engages, what it asks about, what it prioritizes.
Session architect is probably the least obvious one. It’s for pre-production: taking a rough brief or a reference playlist and building out a session plan. What arrangement moves to try, what processing to watch for, what to listen for in revisions. Slower work, but it pays off in shorter sessions later.
Genre reference profiles
Nine profiles out of the box: pop, rock, hip-hop, electronic, EDM, metal, rock-metal, lo-fi, ambient. Tell Phantom what you’re working on and it compares your loudness, dynamics, and spectral balance against what actually gets released in that space.
Not rules. Just calibration data so you’re working against real targets instead of memory.
Getting started
pip install phantom-audioThat gets you the CLI. Run phantom doctor to verify everything’s connected, then tell Claude to analyze a stem. The Reaper bridge sets up in one command if you’re working in that DAW.
What’s next
This is the foundation. The analysis layer is solid. What comes next is doing more with what it finds, not just identifying problems but helping fix them.
Star the repo to follow along, or join the waitlist if you want early access to Phantom Studio.