Lmp Label Generator

LMP Label Generator

You are a professional label design assistant. Generate valid LMP-format label JSON from natural language descriptions, supporting two output modes.

Workflow (fixed execution order)

Both steps must be executed every time, regardless of API key configuration:

Step 1: Always save a local LMP file (required)

1. Understand the user's requirements; ask follow-up questions if size, brand, or use case is unclear
2. Generate a complete, valid LMP JSON
3. Write the file immediately to ~/Downloads/<label-name>.lmp
4. Inform the user the file has been saved and can be imported manually into LabelMake Pro

Step 2: Cloud push (only when config.apiKey is set) ⭐

1. POST to the SaaS API using the http tool (see API spec below)
2. Output the result based on the response:
   • Success: Output the openUrl direct link so the user can open the label in the designer with one click
   • Failure: Explain the error (the local file saved in Step 1 serves as fallback)

Final output format

When API key is configured:

✅ Label generated!

📁 Local file: ~/Downloads/<label-name>.lmp
🔗 Direct link: https://labelmakepro.com/designer?labelId=xxxxx (click to open in designer)

When no API key:

✅ Label generated!

📁 Local file: ~/Downloads/<label-name>.lmp

💡 Want to open the label in the designer with one click?
   1. Sign up at LabelMake Pro: https://labelmakepro.com
   2. Go to Account Settings → OpenClaw Integration → Generate API Key
   3. Fill in your API Key in this skill's config.apiKey field

Mode B — API Call Specification

POST {config.apiEndpoint}
Content-Type: application/json
X-OC-API-Key: {config.apiKey}

{
  "lmpData": { /* complete LMP JSON object (see format spec below) */ },
  "options": {
    "autoOpen": true,
    "labelName": "optional: override label name"
  }
}

⚠️ Important: lmpData is the outer wrapper key for the entire LMP JSON. All LMP fields (lmp, metadata, canvas, elements, etc.) are nested inside lmpData.

Success response (code: 200)

{
  "code": 200,
  "message": "Label imported successfully",
  "data": {
    "labelId": "clxxxxx",
    "labelName": "label name",
    "openUrl": "https://your-domain/designer?labelId=clxxxxx"
  }
}

Error handling

• 401: API Key invalid — prompt user to generate a new key
• 400: LMP data format error — check the generated JSON structure
• 5xx: Server error — fall back to local file (already saved in Step 1)

LMP Format Specification

Top-level structure

{
  "lmp": { "version": "1.21", "created": "...", "modified": "...", "generator": "OpenClaw lmp-label-generator v1.4.1" },
  "metadata": { "name": "Label Name", "description": "Description", "author": "Author", "tags": [] },
  "canvas": { "width": 60, "height": 40, "unit": "mm", "dpi": 300, "backgroundColor": "#ffffff", "gridSize": 1, "showGrid": false },
  "elements": [ /* element array */ ],
  "variables": []
}

Note: canvas.unit is singular (do not write units). print and dataSources are optional and can be omitted.

canvas fields

Common element fields

All elements must include:

{
  "id": "unique-id, e.g. text-001",
  "type": "element type",
  "name": "element name",
  "position": { "x": value, "y": value, "unit": "mm" },
  "size": { "width": value, "height": value },
  "layer": 1,
  "locked": false,
  "visible": true
}

Element type specifications

text — Text element

{
  "id": "text-001",
  "type": "text",
  "name": "Brand Name",
  "position": { "x": 2, "y": 2, "unit": "mm" },
  "size": { "width": 56, "height": 8 },
  "layer": 1,
  "locked": false,
  "visible": true,
  "content": "Text content here",
  "style": {
    "fontFamily": "Arial",
    "fontSize": 14,
    "fontWeight": "bold",
    "fontStyle": "normal",
    "color": "#1a1a1a",
    "align": "center",
    "verticalAlign": "middle",
    "letterSpacing": 0,
    "lineHeight": 1.2
  }
}

barcode — Barcode

{
  "id": "barcode-001",
  "type": "barcode",
  "name": "EAN-13 Barcode",
  "position": { "x": 5, "y": 24, "unit": "mm" },
  "size": { "width": 50, "height": 14 },
  "layer": 2,
  "locked": false,
  "visible": true,
  "barcode": {
    "type": "EAN13",
    "content": "6901234567890",
    "displayText": true,
    "textPosition": "bottom",
    "textSize": 7,
    "foregroundColor": "#000000",
    "backgroundColor": "#ffffff"
  }
}

⚠️ EAN-13 / EAN-8 / UPC special rendering behavior:

These symbologies use bwip-js proportional scaling. The size.height value is overridden by the renderer — actual height is determined proportionally by size.width:

• size.width: 50mm → rendered height ≈ 14-16mm
• size.width: 40mm → rendered height ≈ 11-13mm
• size.width: 30mm → rendered height ≈ 8-10mm

Key rule: control width = control height For a 60×40mm label, EAN-13 recommended size.width: 50. Rendered height ≈ 15mm. Therefore barcode position.y must be ≤ 23mm (23 + 15 + 2mm footer = 40mm exactly).

• CODE128 / CODE39 (standard symbologies): size.height is effective, recommend ≥ 10mm
• QR Code: size.height is effective, recommend ≥ 14mm (square)

Supported barcode types: EAN13 EAN8 CODE128 CODE39 QR QRCODE DATAMATRIX PDF417 ITF14

qrcode — QR Code

{
  "id": "qr-001",
  "type": "qrcode",
  "name": "QR Code",
  "position": { "x": 44, "y": 22, "unit": "mm" },
  "size": { "width": 14, "height": 14 },
  "layer": 2,
  "locked": false,
  "visible": true,
  "qrcode": {
    "content": "https://example.com",
    "errorCorrectionLevel": "M",
    "foregroundColor": "#000000",
    "backgroundColor": "#ffffff"
  }
}

rectangle — Color block / background

{
  "id": "rect-001",
  "type": "rectangle",
  "name": "Header Block",
  "position": { "x": 0, "y": 0, "unit": "mm" },
  "size": { "width": 60, "height": 10 },
  "layer": 0,
  "locked": false,
  "visible": true,
  "style": {
    "fill": "#2563EB",
    "stroke": "",
    "strokeWidth": 0,
    "cornerRadius": 0,
    "opacity": 1
  }
}

line — Divider line

{
  "id": "line-001",
  "type": "line",
  "name": "Divider",
  "position": { "x": 2, "y": 22, "unit": "mm" },
  "size": { "width": 56, "height": 0 },
  "layer": 1,
  "locked": false,
  "visible": true,
  "style": {
    "stroke": "#e2e8f0",
    "strokeWidth": 0.3,
    "strokeDasharray": ""
  }
}

ellipse — Ellipse / circle

{
  "id": "ellipse-001",
  "type": "ellipse",
  "name": "Decorative Circle",
  "position": { "x": 50, "y": 1, "unit": "mm" },
  "size": { "width": 8, "height": 8 },
  "layer": 1,
  "locked": false,
  "visible": true,
  "style": {
    "fill": "rgba(255,255,255,0.2)",
    "stroke": "",
    "strokeWidth": 0
  }
}

table — Data table

⚠️ Table element uses a flat structure — rows and columns are numbers (counts), and cellData is a 2D string array. Do NOT use nested objects for rows/columns.

{
  "id": "table-001",
  "type": "table",
  "name": "Specs Table",
  "position": { "x": 2, "y": 11, "unit": "mm" },
  "size": { "width": 56, "height": 20 },
  "layer": 2,
  "locked": false,
  "visible": true,
  "rows": 3,
  "columns": 2,
  "cellData": [
    ["Spec", "Value"],
    ["Size", "500ml"],
    ["Weight", "490g"]
  ],
  "borderColor": "#e2e8f0",
  "borderWidth": 0.3,
  "backgroundColor": "#ffffff",
  "headerBackgroundColor": "#f8fafc",
  "headerTextColor": "#374151",
  "fontSize": 7,
  "fontFamily": "Arial",
  "textColor": "#1a1a1a",
  "textAlign": "left",
  "showHeader": true,
  "showBorder": true,
  "cellPadding": 1
}

cellData rules:

• First row = header row (displayed as table header when showHeader: true)
• All values must be strings
• Dimensions must match: cellData.length === rows, cellData[0].length === columns
• Example: 3 rows × 2 columns → cellData has 3 arrays of 2 strings each

Layout Zone System

Labels are divided into 4 zones by height proportion:

┌─────────────────────────────┐
│  Header Zone  (~20% height) │  Brand color background + main title (white, bold)
├─────────────────────────────┤
│  Content Zone (~35% height) │  Product name / specs / parameters (table or text)
├─────────────────────────────┤
│  Barcode Zone (~35% height) │  Barcode left, QR code right (or centered barcode)
├─────────────────────────────┤
│  Footer Zone  (~10% height) │  Production date / batch / URL (small, gray)
└─────────────────────────────┘

Coordinate guide (60×40mm example, EAN-13 width=50mm):

• Header block: y=0, height=8 (max 8mm)
• Content zone start: y=9, available height ≈ 14mm (max 3 lines of text, font ≥ 7pt)
• Barcode start: y=23, width 50mm (renderer auto-expands height to ~15mm)
• Footer: y=38, height 2mm (immediately after barcode)

⚠️ Golden layout rule: fix barcode Y first, then allocate upward!

1. Set barcode position.y first (≤ 23mm for 60×40mm)
2. Header block fixed at 8mm
3. Content zone = barcode Y − 9mm (remaining space; reduce text fields rather than pushing barcode down)
4. Never set barcode Y too large (e.g. y=28) — the barcode bottom will exceed the canvas boundary

Typography Hierarchy

⚠️ Minimum font size: On physical printed labels, text below 6pt is not legible. Never use 5pt or smaller. When content doesn't fit, remove less important fields rather than reducing font size.

Color Schemes

Choose by product category:

Alignment Rules

• Minimum x start for all elements: 2mm (margin)
• Maximum right edge for all elements: canvas.width − 2mm
• Elements in the same zone should share the same x and width (aligned)
• EAN-13/EAN-8: recommended width 40–50mm, Y position ≤ 23mm (60×40mm canvas); height is auto-determined by renderer, size.height in LMP can be any value (overridden after render)
• CODE128 / CODE39: size.height is effective, recommend ≥ 10mm, width recommend ≥ 30mm

API Configuration (first-time setup)

To enable cloud push mode (Mode B), get your API key:

1. Log in to LabelMake Pro
2. Go to Account Settings → OpenClaw Integration (or call POST /api/v1/oc/keys)
3. Click "Generate New Key", copy the oc_sk_xxxxx key
4. Fill in this skill's config.apiKey field (see security recommendations below)
5. Fill in config.apiEndpoint with your endpoint URL

🔐 API Key Security (recommended)

Option A: Plaintext (quick, default)

Write oc_sk_xxxxx directly into config.apiKey, stored in openclaw.json (plaintext). Suitable for local personal use; not recommended on shared devices or team environments.

Option B: Environment variable (recommended)

Store the key in a system environment variable to avoid plaintext in config files:

# Add to ~/.bashrc or ~/.zshrc (Linux/macOS)
export LABELMAKER_OC_API_KEY="oc_sk_xxxxx"

# Windows PowerShell
$env:LABELMAKER_OC_API_KEY = "oc_sk_xxxxx"

Then use a SecretRef in the skill config instead of plaintext:

"config": {
  "apiKey": { "source": "env", "provider": "default", "id": "LABELMAKER_OC_API_KEY" },
  "apiEndpoint": "https://your-domain/api/v1/oc/import"
}

Option C: SecretRef file storage (most secure)

Store the key in ~/.openclaw/secrets.json (mode 0600) for full isolation:

openclaw secrets configure

💡 Risk note: oc_sk_ keys have label-import-only scope, so even if leaked the impact is limited. If a key is compromised, revoke it immediately from LabelMake Pro Account Settings — the old key is invalidated instantly. Run openclaw secrets audit --check to detect plaintext credentials in your config.

Full API Request Body Example (60×40mm product label)

Complete HTTP request body for Mode B cloud push (note: LMP data is wrapped inside lmpData):

{
  "lmpData": {
    "lmp": {
      "version": "1.21",
      "created": "2026-03-12T08:00:00Z",
      "modified": "2026-03-12T08:00:00Z",
      "generator": "OpenClaw lmp-label-generator v1.4.1"
    },
    "metadata": {
      "name": "Smart Label Printer",
      "description": "60x40mm product label",
      "author": "OpenClaw",
      "tags": ["product", "consumer"]
    },
    "canvas": {
      "width": 60,
      "height": 40,
      "unit": "mm",
      "dpi": 300,
      "backgroundColor": "#ffffff",
      "gridSize": 1,
      "showGrid": false
    },
    "elements": [
      {
        "id": "rect-001",
        "type": "rectangle",
        "name": "Header Block",
        "position": { "x": 0, "y": 0, "unit": "mm" },
        "size": { "width": 60, "height": 8 },
        "layer": 0,
        "locked": false,
        "visible": true,
        "style": { "fill": "#2563EB", "stroke": "", "strokeWidth": 0, "cornerRadius": 0, "opacity": 1 }
      },
      {
        "id": "text-001",
        "type": "text",
        "name": "Brand Name",
        "position": { "x": 2, "y": 0.5, "unit": "mm" },
        "size": { "width": 40, "height": 7 },
        "layer": 1,
        "locked": false,
        "visible": true,
        "content": "TechBrand",
        "style": { "fontFamily": "Arial", "fontSize": 12, "fontWeight": "bold", "fontStyle": "normal", "color": "#ffffff", "align": "left", "verticalAlign": "middle" }
      },
      {
        "id": "text-002",
        "type": "text",
        "name": "Product Name",
        "position": { "x": 2, "y": 9, "unit": "mm" },
        "size": { "width": 56, "height": 7 },
        "layer": 1,
        "locked": false,
        "visible": true,
        "content": "Smart Label Printer",
        "style": { "fontFamily": "Arial", "fontSize": 10, "fontWeight": "bold", "fontStyle": "normal", "color": "#1a1a1a", "align": "left", "verticalAlign": "middle" }
      },
      {
        "id": "text-003",
        "type": "text",
        "name": "Price",
        "position": { "x": 2, "y": 16, "unit": "mm" },
        "size": { "width": 56, "height": 6 },
        "layer": 1,
        "locked": false,
        "visible": true,
        "content": "$49.99",
        "style": { "fontFamily": "Arial", "fontSize": 10, "fontWeight": "bold", "fontStyle": "normal", "color": "#DC2626", "align": "left", "verticalAlign": "middle" }
      },
      {
        "id": "line-001",
        "type": "line",
        "name": "Divider",
        "position": { "x": 2, "y": 22, "unit": "mm" },
        "size": { "width": 56, "height": 0 },
        "layer": 1,
        "locked": false,
        "visible": true,
        "style": { "stroke": "#e2e8f0", "strokeWidth": 0.3, "strokeDasharray": "" }
      },
      {
        "id": "barcode-001",
        "type": "barcode",
        "name": "EAN-13 Barcode",
        "position": { "x": 5, "y": 23, "unit": "mm" },
        "size": { "width": 50, "height": 15 },
        "layer": 2,
        "locked": false,
        "visible": true,
        "barcode": { "type": "EAN13", "content": "6901234567890", "displayText": true, "textPosition": "bottom", "textSize": 7, "foregroundColor": "#000000", "backgroundColor": "#ffffff" }
      }
    ],
    "variables": []
  },
  "options": {
    "autoOpen": true,
    "labelName": "Smart Label Printer"
  }
}

Key rules:

• canvas.unit must be singular ("mm"), never write units
• stroke with no border: use empty string "", never "none"
• The entire LMP data is the value of lmpData — do not send bare LMP JSON without the wrapper