# Mmd Device Library

> Create custom MIDI device libraries for MIDI Markdown with aliases, parameters, and documentation. Use when the user wants to create device-specific aliases for hardware (guitar processors, synthesizers, effects units), document MIDI implementations, or build reusable command libraries.

- Skill: `majiayu000/mmd-device-library` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add majiayu000/mmd-device-library`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/mmd-device-library/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Docs & Writing
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/mmd-device-library

---


# Device Library Creation Skill

## Overview

This skill guides you through creating custom device libraries for MIDI Markdown. Device libraries provide high-level aliases for MIDI hardware, making automation code more readable and maintainable.

## What is a Device Library?

A device library is an MMD file containing:
- Device metadata (name, manufacturer, MIDI channel)
- Alias definitions for device-specific commands
- Documentation for each alias
- Optional computed values and conditionals

**Example usage**:
```mmd
@import "devices/my_device.mmd"

[00:00.000]
- my_device_preset 1.5      # Instead of: cc 1.32.0; pc 1.5
```

## Quick Start

### Minimal Device Library

```mmd
---
device: "My Device Name"
manufacturer: "Company Name"
version: 1.0.0
default_channel: 1
---

@alias device_preset pc.{ch}.{preset} "Load preset (0-127)"
```

Save as `devices/my_device.mmd` and import:
```mmd
@import "devices/my_device.mmd"

[00:00.000]
- device_preset 1.42
```

## Step-by-Step Creation

### Step 1: Gather MIDI Implementation

You need:
1. **MIDI Implementation Chart** (from device manual)
2. **CC numbers** for device functions
3. **PC behavior** (how program changes work)
4. **SysEx messages** (if applicable)
5. **Channel assignment** (default MIDI channel)

**Where to find**:
- Device user manual (appendix)
- Manufacturer website (downloads section)
- MIDI implementation PDF/chart

### Step 2: Create Library File

Create `devices/my_device.mmd`:

```mmd
---
device: "Device Name"
manufacturer: "Company"
version: 1.0.0
default_channel: 1
documentation: "https://example.com/midi-docs"
midi_channels: [1]
capabilities:
  - program_change
  - control_change
  - sysex
---

# ==============================================
# Device Name MIDI Library
# ==============================================

# MIDI Implementation Overview:
# - Channel: 1 (default)
# - Program Change: 0-127
# - Control Change: See sections below
# - SysEx: F0 00 01 02 ... F7

# ==============================================
# Section 1: Preset Management
# ==============================================

@alias device_preset pc.{ch}.{preset:0-127} "Load preset (0-127)"

# Add more aliases...
```

### Step 3: Document Your Aliases

Each alias needs a description:

```mmd
@alias device_volume cc.{ch}.7.{value:0-127} "Set master volume (0-127)"
```

**Description guidelines**:
- What it does
- Parameter ranges
- Special notes (if any)

### Step 4: Test the Library

Create test file:
```mmd
---
title: "Device Library Test"
ppq: 480
---

@import "devices/my_device.mmd"

[00:00.000]
- device_preset 1.0
- device_volume 1.100
```

Validate:
```bash
mmdc validate test.mmd
mmdc inspect test.mmd
```

## Alias Patterns

### Simple Aliases

Map device functions to CC or PC:

```mmd
@alias device_function cc.{ch}.{cc_number}.{value} "Description"
```

Examples:
```mmd
@alias amp_gain cc.{ch}.1.{value:0-127} "Amp gain (0-127)"
@alias delay_time cc.{ch}.12.{value:0-127} "Delay time (0-127)"
@alias reverb_mix cc.{ch}.91.{value:0-127} "Reverb mix (0-127)"
```

### Multi-Command Aliases

Combine multiple MIDI commands:

```mmd
@alias device_load {ch}.{bank}.{preset} "Load bank and preset"
  - cc {ch}.32.{bank}      # Bank select LSB
  - cc {ch}.0.0            # Bank select MSB
  - pc {ch}.{preset}       # Program change
@end
```

### Aliases with Defaults

Provide default values for optional parameters:

```mmd
@alias device_volume {ch}.{value=100} "Set volume (default: 100)"
  - cc {ch}.7.{value}
@end

# Usage
- device_volume 1          # Uses default 100
- device_volume 1.75       # Uses 75
```

### Enum Parameters

Named values for parameters:

```mmd
@alias device_routing {ch}.{mode=series:0,parallel:1,a_only:2,b_only:3} "Set routing mode"
  - cc {ch}.85.{mode}
@end

# Usage
- device_routing 1.parallel    # Sends value 1
- device_routing 1.a_only      # Sends value 2
```

### Computed Values

Transform parameters before sending:

```mmd
@alias device_tempo {ch} {bpm:40-300} "Set tempo (40-300 BPM)"
  {midi_val = int((${bpm} - 40) * 127 / 260)}
  - cc {ch}.14.{midi_val}
@end

# BPM 120 → MIDI value 39
```

## Common Device Patterns

### Guitar Processor (Quad Cortex, Helix, Kemper)

```mmd
# Preset loading
@alias cortex_load {ch}.{setlist}.{scene}.{preset} "Load complete preset"
  - cc {ch}.32.{setlist}   # Setlist
  - cc {ch}.0.{scene}      # Scene/group
  - pc {ch}.{preset}       # Preset
@end

# Scene switching
@alias cortex_scene pc.{ch}.{scene:0-7} "Switch scene (A-H = 0-7)"

# Expression pedals
@alias cortex_exp1 cc.{ch}.11.{value:0-127} "Expression pedal 1"
@alias cortex_exp2 cc.{ch}.12.{value:0-127} "Expression pedal 2"

# Stomp switches
@alias cortex_stomp_a cc.{ch}.81.{state:0-127} "Stomp A (0=off, 127=on)"
@alias cortex_stomp_a_on cc.{ch}.81.127 "Stomp A on"
@alias cortex_stomp_a_off cc.{ch}.81.0 "Stomp A off"

# Tap tempo
@alias cortex_tap_tempo cc.{ch}.80.127 "Tap tempo"

# Tuner
@alias cortex_tuner cc.{ch}.68.{state:0-127} "Tuner (0=off, 127=on)"
```

### Multi-FX Unit (Eventide, Strymon)

```mmd
# Preset selection
@alias h90_preset pc.{ch}.{preset:0-127} "Load preset"

# Algorithm selection
@alias h90_algo_a cc.{ch}.82.{algo:0-52} "Algorithm for path A"
@alias h90_algo_b cc.{ch}.83.{algo:0-52} "Algorithm for path B"

# Mix control
@alias h90_mix cc.{ch}.84.{percent:0-100} "A/B mix (0=A, 100=B)"

# Routing
@alias h90_routing cc.{ch}.85.{mode=series:0,parallel:1} "Routing mode"

# Performance controls
@alias h90_bypass cc.{ch}.102.{state=active:127,bypassed:0} "Bypass"
@alias h90_infinity cc.{ch}.90.127 "Infinity (freeze)"
@alias h90_hotswitch cc.{ch}.91.127 "HotSwitch"
```

### Synthesizer

```mmd
# Oscillator controls
@alias synth_osc1_wave cc.{ch}.70.{wave=saw:0,square:32,tri:64,sine:96} "OSC1 waveform"
@alias synth_osc1_detune cc.{ch}.71.{value:0-127} "OSC1 detune"

# Filter controls
@alias synth_filter_cutoff cc.{ch}.74.{value:0-127} "Filter cutoff"
@alias synth_filter_resonance cc.{ch}.71.{value:0-127} "Filter resonance"

# Envelope
@alias synth_env_attack cc.{ch}.73.{value:0-127} "Envelope attack"
@alias synth_env_decay cc.{ch}.75.{value:0-127} "Envelope decay"
@alias synth_env_sustain cc.{ch}.76.{value:0-127} "Envelope sustain"
@alias synth_env_release cc.{ch}.77.{value:0-127} "Envelope release"

# LFO
@alias synth_lfo_rate cc.{ch}.78.{value:0-127} "LFO rate"
@alias synth_lfo_depth cc.{ch}.79.{value:0-127} "LFO depth"
```

## Organization Best Practices

### Section Headers

Organize aliases by function:

```mmd
# ==============================================
# Preset Management
# ==============================================

@alias device_preset ...
@alias device_bank ...

# ==============================================
# Effects Controls
# ==============================================

@alias device_reverb ...
@alias device_delay ...

# ==============================================
# Expression Pedals
# ==============================================

@alias device_exp1 ...
@alias device_exp2 ...
```

### Naming Conventions

**Prefix with device name**:
```mmd
@alias cortex_preset ...   # ✓ Clear
@alias preset ...           # ✗ Too generic
```

**Use descriptive names**:
```mmd
@alias amp_gain ...            # ✓ Descriptive
@alias ag ...                  # ✗ Unclear
```

**Group related functions**:
```mmd
@alias stomp_a_on ...
@alias stomp_a_off ...
@alias stomp_a_toggle ...
```

### Parameter Naming

**Use meaningful names**:
```mmd
{ch}           # Channel
{preset}       # Preset number
{value}        # Generic value
{percent}      # Percentage (0-100)
{state}        # On/off state
{mode}         # Mode selection
```

**Include ranges in descriptions**:
```mmd
@alias device_tempo {ch} {bpm:40-300} "Set tempo (40-300 BPM)"
```

## Advanced Features

### Conditional Aliases

Different behavior based on parameters:

```mmd
@alias smart_load {ch}.{preset}.{device_type} "Device-aware preset load"
  @if {device_type} == "a"
    - cc {ch}.32.0
    - pc {ch}.{preset}
  @elif {device_type} == "b"
    - cc {ch}.71.{preset}
  @end
@end
```

### SysEx Support

Include SysEx messages:

```mmd
@alias device_patch_dump "Request patch dump"
  - sysex F0 00 01 06 02 F7
@end
```

### Macros for Common Sequences

```mmd
@alias scene_change_smooth {ch}.{old_scene}.{new_scene} "Smooth scene transition"
  # Fade out old scene
  - cc {ch}.7.curve(100, 0, ease-in)

  # Switch scene
  [+500ms]
  - pc {ch}.{new_scene}

  # Fade in new scene
  [@]
  - cc {ch}.7.curve(0, 100, ease-out)
@end
```

## Validation and Testing

### Validate Library Structure

```bash
mmdc validate devices/my_device.mmd
```

### Test Each Alias

Create comprehensive test file:

```mmd
---
title: "Device Library Test Suite"
ppq: 480
---

@import "devices/my_device.mmd"

# Test all aliases
[00:00.000]
- device_preset 1.0
- device_volume 1.100
- device_function1 1.50
# ... test each alias

# Test edge cases
[00:10.000]
- device_preset 1.127     # Max value
- device_volume 1.0       # Min value
- device_function1 1.127  # Max value
```

### Verify MIDI Output

```bash
# Inspect generated events
mmdc inspect test.mmd

# Compile and check MIDI
mmdc compile test.mmd -o test.mid

# Play back to verify
mmdc play test.mmd --port 0
```

## Documentation Template

Complete library template:

```mmd
---
device: "Device Full Name"
manufacturer: "Company Name"
version: 1.0.0
default_channel: 1
documentation: "https://example.com/midi-implementation"
midi_channels: [1]
date_created: "2025-01-15"
date_modified: "2025-01-15"
author: "Your Name"
capabilities:
  - program_change
  - control_change
  - sysex
notes: "Additional notes about this device"
---

# ==============================================
# Device Name MIDI Library
# ==============================================

/**
 * MIDI Implementation Summary
 *
 * Channels: 1 (default), supports 1-16
 * Program Change: 0-127 (presets)
 * Control Change: See sections below
 * SysEx: See SysEx section
 *
 * Quick Start:
 *   @import "devices/device_name.mmd"
 *   - device_preset 1.0
 *
 * Documentation: https://example.com/docs
 */

# ==============================================
# Preset Management
# ==============================================

@alias device_preset pc.{ch}.{preset:0-127} "Load preset (0-127)"

@alias device_bank_preset {ch}.{bank:0-7}.{preset:0-127} "Load bank and preset"
  - cc {ch}.32.{bank}
  - pc {ch}.{preset}
@end

# ==============================================
# Effects Controls
# ==============================================

@alias device_reverb cc.{ch}.91.{value:0-127} "Reverb mix (0-127)"
@alias device_delay cc.{ch}.92.{value:0-127} "Delay mix (0-127)"

# ... Add more sections as needed
```

## Real-World Examples

Study existing device libraries:

```bash
# View Quad Cortex implementation
cat devices/quad_cortex.mmd

# View Eventide H90 implementation
cat devices/eventide_h90.mmd

# View Helix implementation
cat devices/helix.mmd
```

These provide patterns for:
- Complex preset loading sequences
- Expression pedal mapping
- Stomp switch control
- Tempo synchronization
- Scene management

## Publishing Your Library

### 1. Test Thoroughly

```bash
# Validate
mmdc validate devices/my_device.mmd

# Test all aliases
mmdc validate test_suite.mmd

# Test with actual device
mmdc play test_suite.mmd --port "Device Name"
```

### 2. Document Usage

Add README or examples:

```mmd
/**
 * Usage Examples
 *
 * Basic preset load:
 *   - device_preset 1.42
 *
 * Bank select:
 *   - device_bank_preset 1.2.5
 *
 * Effects control:
 *   - device_reverb 1.75
 */
```

### 3. Share with Community

- Add to project `devices/` directory
- Create pull request
- Include test files
- Document MIDI implementation source

## Troubleshooting

### Alias Not Working

```bash
# Check import
grep "@import" your_file.mmd

# Verify alias definition
grep "@alias device_name" devices/my_device.mmd

# Test with raw MIDI
- cc 1.XX.YY  # Instead of alias
```

### Parameter Count Mismatch

```mmd
# Check parameter count
@alias name {p1}.{p2} "..."

# Usage must match
- name 1.2      # ✓ Correct
- name 1        # ✗ Missing parameter
```

### Value Out of Range

```mmd
# Add range constraints
@alias func {ch}.{value:0-100} "..."

# Or use computed values
{clamped = min(127, max(0, ${value}))}
```

## Related Skills and Resources

**Skills**:
- **mmd-writing** - MMD syntax reference
- **mmd-debugging** - Troubleshooting aliases
- **mmd-cli** - Testing and validation

**Resources**:
- **devices/** - Existing device libraries (6 examples)
- **examples/04_device_libraries/** - Usage examples
- **docs/user-guide/alias-system.md** - Alias documentation
- **spec.md** - Complete alias syntax reference

## Quick Reference

### Alias Syntax

```mmd
# Simple alias
@alias name command.{param} "Description"

# Multi-command alias
@alias name {p1}.{p2} "Description"
  - command1
  - command2
@end

# With defaults
@alias name {param=default} "Description"

# With enums
@alias name {param=opt1:val1,opt2:val2} "Description"

# With computed values
@alias name {param} "Description"
  {computed = expression}
  - command ${computed}
@end
```

### Testing Workflow

```bash
1. mmdc validate devices/my_device.mmd
2. mmdc validate test_file.mmd
3. mmdc inspect test_file.mmd
4. mmdc play test_file.mmd --port 0
```

For complete device library examples, see the `devices/` directory in the project.