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The Template Playground lets you create legal agreement templates using three core components: a Concerto data model, TemplateMark template, and JSON data.

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Understanding the three editors

The playground consists of three main editors that work together:
  • Concerto Model: Defines the data structure for your template
  • TemplateMark: The template markup that generates your agreement
  • JSON Data: Sample data used to populate the template

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Create a template from scratch

1

Start with a blank template

Click Load Sample in the Concerto Model editor header and select blank from the dropdown.
2

Define your data model

Write your Concerto model in the top editor. The model defines the structure of data your template will use.
namespace [email protected]

import [email protected] from https://models.accordproject.org/accordproject/contract.cto

@template
concept TemplateModel extends Contract {
  o String seller
  o String buyer
  o Double amount
}
3

Write your template

In the TemplateMark editor, use the data fields defined in your model. Access properties using double curly braces:
# Purchase Agreement

This agreement is between {{seller}} (the "Seller") and {{buyer}} (the "Buyer").

The purchase amount is ${{amount}}.
4

Add sample data

In the JSON Data editor, provide values that match your Concerto model:
{
  "$class": "[email protected]",
  "seller": "ABC Company",
  "buyer": "John Smith",
  "amount": 5000
}
5

Preview the result

The Preview panel on the right automatically updates to show the merged result of your template and data.

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Use formatting toolbar

The TemplateMark editor includes a toolbar with formatting shortcuts:
  • Heading buttons: Insert H1, H2, or H3 headings
  • Bold: Make text bold
  • Italic: Italicize text
  • Lists: Create ordered or unordered lists
  • Link: Insert a hyperlink
  • Image: Embed an image

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Collapse and expand editors

You can collapse editors you’re not actively using to focus on specific parts:
  • Click the chevron icon (▼ or ►) in the Concerto Model or JSON Data editor headers
  • Collapsed editors show only their header
  • Click the chevron again to expand
The TemplateMark editor cannot be collapsed as it’s the primary editing area.

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Format JSON data

If your JSON data becomes messy or unformatted:
  1. Locate the format icon in the JSON Data editor header
  2. Click it to automatically format and indent your JSON

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Working with complex data

For nested data structures, use clause tags to create scope: 
{{#clause address}}
  Street: {{street}}
  City: {{city}}
{{/clause}}
For lists, use olist (ordered) or ulist (unordered): 
{{#olist items}}
  Item: {{name}} - Price: ${{price}}
{{/olist}}

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View errors and problems

If there are issues with your template, model, or data:
  1. The Problem Panel appears at the bottom of the editors
  2. Review error messages with line numbers
  3. Click an error to jump to the relevant location
The playground validates your template in real-time. If the preview doesn’t update, check the Problem Panel for errors.

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Next steps

Using samples

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