HTML Templates & Variables

ZipZign renders document content from HTML using Handlebars for dynamic data injection.

Basic structure

Pass your HTML in the content field:

{
  "content": "<h1>Invoice #{{invoiceNumber}}</h1><p>Dear {{clientName}},</p><p>Amount due: ${{amount}}</p>",
  "variables": {
    "invoiceNumber": "1042",
    "clientName": "Acme Corp",
    "amount": "500.00"
  }
}

Handlebars syntax: {{variableName}}

Supported Handlebars features

<!-- Basic substitution -->
<p>Hello, {{name}}!</p>

<!-- Conditionals -->
{{#if isPremium}}
  <p>Thank you for being a premium member.</p>
{{/if}}

<!-- Loops -->
<ul>
  {{#each items}}
    <li>{{this.description}} — ${{this.price}}</li>
  {{/each}}
</ul>

<!-- Nested objects -->
<p>{{client.firstName}} {{client.lastName}}</p>

Limits

Styling tips

ZipZign renders HTML to PDF using a headless browser. For best results:

• Use inline styles or <style> blocks — external stylesheets won't load
• Use pt or px units; avoid vw/vh
• Prefer @page CSS rules for margins:

<style>
  @page {
    margin: 60px 60px;
  }
  body {
    font-family: Arial, sans-serif;
    font-size: 12pt;
    color: #111;
  }
  h1 { font-size: 20pt; margin-bottom: 16px; }
  table { width: 100%; border-collapse: collapse; }
  td, th { padding: 8px; border: 1px solid #ddd; }
</style>

Full example

{
  "type": "signable",
  "title": "Service Agreement — {{clientName}}",
  "content": "<style>body{font-family:sans-serif;font-size:12pt}</style><h1>Service Agreement</h1><p>This agreement is made between <strong>Acme Corp</strong> and <strong>{{clientName}}</strong> on {{date}}.</p><h2>Scope of Work</h2><ul>{{#each services}}<li>{{this}}</li>{{/each}}</ul><p>Total fee: ${{totalFee}}</p>",
  "variables": {
    "clientName": "Widget Inc",
    "date": "April 15, 2026",
    "services": ["Web design", "SEO audit", "3 months support"],
    "totalFee": "4,500.00"
  },
  "signers": [
    { "name": "Widget Inc Rep", "email": "rep@widgetinc.com" }
  ]
}

Updating content

After creation, you can replace a document's HTML (if it hasn't been signed yet):

curl -X PATCH https://zipzign.com/api/documents/doc_abc123 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "content": "<h1>Updated content</h1>" }'

Updated on: 16/04/2026