Template System

Any .it file with {{placeholders}} is a template. Feed it data, get a document.

template.it  +  data.json  →  merge  →  document  →  render  →  output

Variable syntax

Variables use double curly braces: {{variableName}}.

Syntax	Resolution	Example
{{name}}	data.name	"Acme Corp"
{{company.name}}	data.company.name	Dot notation for nested objects
{{items.0.description}}	data.items[0].description	Array index access
{{date}}	System: current date	Auto-generated
{{year}}	System: current year	Auto-generated
{{timestamp}}	System: ISO timestamp	Auto-generated
{{agent}}	doc.metadata.agent	From document metadata
{{page}}	Runtime — page number	Left for print renderer
{{pages}}	Runtime — total pages	Left for print renderer

Missing variables

When a variable has no matching data, the block gets an unresolved: 1 property. No crash, no silent removal — the {{variable}} text remains visible, and the block is flagged.

Security

• Path depth capped at 20 levels
• __proto__, constructor, prototype keys are blocked
• Path length capped at 200 characters

Writing a template

title: {{document_type}} for {{client_name}}
summary: {{description}}
meta: | type: template | domain: {{domain}}

section: Parties
contact: {{client_name}} | role: Client | email: {{client_email}}
contact: {{provider_name}} | role: Provider | email: {{provider_email}}

section: Terms
This {{document_type}} is effective as of {{effective_date}}.
{{terms}}

section: Deliverables
| Description | Due Date | Amount | each: deliverables |
| {{deliverable.description}} | {{deliverable.due}} | {{deliverable.amount}} |

section: Total
metric: Total Value | value: {{total}} | unit: {{currency}}

each: dynamic table rows

Add each: arrayName as the last column header to repeat rows for each item in an array.

| Item | Qty | Price | each: items |
| {{item.description}} | {{item.qty}} | {{item.price}} |

How each: works

1. The merge engine reads the array from data.items
2. The template row (first row after header) is expanded once per array element
3. The loop variable is auto-singularized: items → item, entries → entry, categories → category
4. The each: column is stripped from the output — it's a directive, not a column

Explicit naming

If auto-singularization doesn't produce the right name:

| Description | Amount | each: line_items as line |
| {{line.description}} | {{line.amount}} |

Zero items

If the array is empty, zero data rows are rendered. The table header always appears.

Conditional & computed fields — the mini-language

Beyond {{}} substitution, two property values carry a tiny, eval-free expression language (field-logic.ts) for dynamic form/intake documents. Both run on a hand-written recursive-descent parser — never eval/Function.

show-if: / when: — one comparison

show-if: (on an x-form: input field) and when: (on a require: line) hold exactly one comparison:

key <op> value

• Operators: = == != > < >= <= (= is loose for ==).
• The compare is numeric when both sides parse as numbers (thousands separators stripped), otherwise string.
• There is no && / || / ! and no grouping — a single comparison only. (For several conditions, use several require: lines.)
• The key resolves against the document's own values (other fields, plus metric: labels/keys and meta: properties). An unresolvable condition defaults to true/active, so a field or required approval is never silently dropped.

x-form: input | label: VAT number | key: vat | show-if: country == SA
require: finance | when: amount > 100000

A show-if: field only renders — and only counts toward form completeness — while its condition holds. A require: whose when: does not hold is inactive (see require: →).

compute: — arithmetic

compute: (on an x-form: input field) derives a value from other fields so the recipient never types it. It holds arithmetic over field keys and numbers:

• Operators: + - * / with ( ) grouping.
• Identifiers resolve from other field values (commas stripped); a non-numeric or missing operand evaluates to 0.

x-form: input | label: Quantity   | key: qty    | type: number
x-form: input | label: Unit price | key: price  | type: number
x-form: input | label: Total      | key: total  | type: number | compute: qty * price

The operator set is additive-only after the format freeze — operators may be added, never removed or redefined.

Data format

Data is a JSON object:

{
  "client_name": "GlobalTech Industries",
  "client_email": "contracts@globaltech.co",
  "provider_name": "Acme Corp",
  "provider_email": "legal@acme.co",
  "document_type": "Service Agreement",
  "description": "Annual IT support contract",
  "domain": "legal",
  "effective_date": "2026-04-01",
  "terms": "Payment within 30 days of invoice.",
  "deliverables": [
    {
      "description": "Cloud migration",
      "due": "2026-06-01",
      "amount": "$50,000"
    },
    {
      "description": "Security audit",
      "due": "2026-08-01",
      "amount": "$25,000"
    },
    { "description": "Training", "due": "2026-09-01", "amount": "$10,000" }
  ],
  "total": "85000",
  "currency": "USD"
}

Merge API

CLI

# Merge to JSON
dotit template.it --data data.json

# Merge and render HTML
dotit template.it --data data.json --html

# Merge and render with theme
dotit template.it --data data.json --html --theme corporate

# Merge to print HTML
dotit template.it --data data.json --print

# Merge to PDF (requires puppeteer)
dotit template.it --data data.json --pdf

JavaScript

import {
  parseIntentText,
  mergeData,
  parseAndMerge,
  renderHTML,
  renderPrint,
} from "@dotit/core";

const doc = parseIntentText(templateSource);
const merged = mergeData(doc, data);

// Or one-step:
const merged2 = parseAndMerge(templateSource, data);

// For finished documents, render unresolved fields as empty instead of {{markers}}:
const issued = parseAndMerge(templateSource, data, { missing: "blank" });

// Render
const html = renderHTML(merged);
const printHtml = renderPrint(merged, { theme: "corporate" });

Notes

• mergeData is a pure function — it never mutates the input document
• Merge order: each: table rows are expanded first, then all {{}} are resolved
• Variables work in content, properties, table cells, and inline nodes
• Metadata title: and summary: are also resolved

Template library

A template is just a .it file, so you can keep your own in version control and merge them with parseAndMerge from any service. The repository also ships a seed library of 77 example templates organized into eight domains:

Domain	Examples
business	Proposals, reports, plans (largest set)
organization	Contracts, NDAs, policies, compliance docs
reports	Quarterly, financial, and status reports
agent	Workflow and task-plan definitions
editorial	Articles and long-form writing
personal	Personal documents and letters
book	Long-form / multi-chapter documents
developer	Technical specs, runbooks, RFCs

:::note Experimental The browsable IntentText Hub web app is experimental and not part of the supported v4 release surface. The seed templates above are plain .it files you can copy and merge with @dotit/core directly — no Hub required. :::