twelvetake-helix-stadium-mcp 0.1.1

Read and explain Line 6 Helix Stadium (.hsp) presets in plain language — an MCP server.

helix-stadium-mcp

Work with your Line 6 Helix Stadium presets in plain language, without knowing the technical details.

Point your AI assistant at a .hsp preset and ask what it does, or how two snapshots differ. You get a plain-English answer with real values (dB, Hz, ms) instead of raw parameter numbers. It's an MCP server, so it runs in any MCP client (Claude Desktop, Cursor, VS Code, and others).

Example

Ask "what does this preset do?" and point it at a .hsp. You get the whole signal chain back, per path:

# Dual Rectifier Lead
tempo 120.0 BPM | active snapshot #0
Snapshots: 1. Rhythm (blue), 2. Lead (red)
## Path 1
  [amp] Cali Rectifire — on [per-snapshot] · Drive 7.5 | Bass 5.0 | Master 4.0
  [cab] 4x12 Cali V30 — on · HighCut 9.0 kHz | Distance 2.0 "
  [fx]  Minotaur — on [per-snapshot] · Gain 45 % | Level 60 %
  [fx]  Simple Delay — on [per-snapshot] · Mix 18 % | Time 400 ms | Feedback 25 %

Friendly model names, on/off state (and which snapshots switch it), and every parameter in the units you'd read off the hardware.

Because it understands the whole patch, it also walks you through changes: ask how to brighten the lead or get more gain, and it points you to the exact block and parameter to move, which you apply in your editor. Making those edits for you is coming in v0.2 (see the roadmap).

Try asking

• "What does this preset do?"
• "What's different between my Rhythm and Lead snapshots?"
• "What amp and cab is this patch using, and how hard is the drive pushing?"
• "How do I get more gain out of the Lead tone without it getting louder?"
• "Find me a plexi-style amp." / "List every delay model."
• "Is this preset valid?"

What it does

• Reads .hsp presets losslessly (byte-exact round-trip).
• Explains a preset in plain English — the full signal chain of each path with friendly model names, on/off state, per-snapshot & footswitch tags, and parameters in real units (dB, Hz, ms, %).
• Diffs snapshots — exactly what changes between two snapshots (e.g. Rhythm vs Lead), in real units.
• Browses the model catalog (list / describe / search models).
• Validates a preset's structure (and, with the catalog, its model ids and controller sources).

Install & configure

uvx twelvetake-helix-stadium-mcp serve      # or: pipx run twelvetake-helix-stadium-mcp serve

Add it to your MCP client's config. Most use an mcpServers block:

{
  "mcpServers": {
    "helix-stadium": {
      "command": "uvx",
      "args": ["twelvetake-helix-stadium-mcp", "serve"]
    }
  }
}

If the catalog isn't auto-detected, set HELIX_STADIUM_RES to your install's res/ folder (the one containing P35ModelCatalog.json). Check detection with helix-stadium-mcp doctor.

Tools

Tool	What you'd ask it
read_preset	Load a .hsp and get its structure (paths, blocks, snapshots)
explain_preset	The full signal chain in plain English, with real units
diff_snapshots	What changes between two snapshots
list_models · describe_model · search_models	Browse the model catalog
validate_preset	Check a preset's structure
detect_install	Find the Helix Stadium catalog this reads from

Roadmap

Pre-1.0, following semantic versioning — the tool surface can still change between minor versions.

• v0.1 (now) — read, explain & compare presets; browse the model catalog; validate a preset. The assistant understands your patch well enough to talk you through changes you make yourself.
• v0.2 — the assistant makes the changes for you: change parameters, toggle/add/remove/reorder blocks, rename, and manage snapshots, in plain language.
• v0.3 — generate presets from a description, and assemble setlists.
• v1.0 — a stable tool surface.

macOS support is in progress alongside Windows.

Requirements

• Helix Stadium installed (Windows confirmed; macOS support in progress). The server reads the model catalog from your own install at runtime.
• Python 3.10+.

Trademarks

Not affiliated with or endorsed by Line 6 or Yamaha Guitar Group.

All trademarks are the property of their respective owners. "Line 6," "Helix," and "Helix Stadium," along with any amp, cab, or effect model names and other brand or product names that appear (for example through the model catalog or a preset), are used here only to identify compatible gear. This project claims no ownership of any trademark it references.

License

MIT © TwelveTake Studios LLC. See LICENSE.