{
  "type": "info",
  "content": {
    "en": "Thanks, {{full-name}}! Based on your income of ${{annual-income}}, you may qualify for assistance."
  }
}

function interpolate(
  template: string,
  formData: Record<string, unknown>
): string {
  return template.replace(/\{\{([^}]+)\}\}/g, (match, fieldId) => {
    const value = formData[fieldId];
    if (value === undefined || value === null) return "";
    return String(value);
  });
}

Welcome back, {{first-name}}!

Households of {{household-size}} people may qualify for up to ${{max-benefit}}.

You entered {{address-line-1}}, {{city}}, {{state}} {{zip}}.