Dynamic Content

Beyond simple substitution, the template engine can generate scenes from arrays and show or hide content with flags — the building blocks of data-driven videos (product feeds, listings, leaderboards, reports).

iterate — one scene per array item

Set iterate on a scene to the name of an array variable. The scene is rendered once per item, in order:

{
  "variables": {
    "products": [
      {
        "title": "Aurora Sneakers",
        "price": "$129",
        "photo": "https://…/aurora.jpg"
      },
      {
        "title": "Nimbus Backpack",
        "price": "$89",
        "photo": "https://…/nimbus.jpg"
      },
      { "title": "Vega Watch", "price": "$249", "photo": "https://…/vega.jpg" }
    ]
  },
  "scenes": [
    {
      "id": "product",
      "iterate": "products",
      "duration": 3,
      "transition": "slideleft",
      "visuals": [
        { "type": "IMAGE", "src": "{{item.photo}}", "resize": "cover" },
        { "type": "TEXT", "text": "{{item.title}} — {{item.price}}" }
      ]
    }
  ]
}

Inside an iterated scene:

• {{item}} is the current array element (rename it with "iterateAs": "product" → {{product.title}}).
• {{index}} is the zero-based position.
• Generated scenes get ids product-0, product-1, … and the scene's transition automatically chains clone → clone, with the last clone keeping the original transition target.

Limits: up to 50 items per iterated scene and 100 scenes after expansion by default (plan-dependent — validation errors report your active limits).

condition — show or hide

condition prunes a scene (or an element) when falsy. It takes a boolean flag — a literal, a boolean variable, or a {{flag}} placeholder that resolves to one (by design there is no expression language):

{
  "variables": { "showOutro": false, "hasDiscount": true },
  "scenes": [
    {
      "id": "main",
      "visuals": [
        { "type": "TEXT", "text": "20% OFF", "condition": "{{hasDiscount}}" }
      ]
    },
    { "id": "outro", "condition": "{{showOutro}}", "visuals": [] }
  ]
}

iterate and condition combine: the condition is evaluated per item, so "condition": "{{item.featured}}" renders only the featured products.

Validation & debugging

• iterate referencing a non-array (or undefined) variable is a field-level validation error.
• Pruned scenes/elements are counted in the render's resolution stats.
• The editor's Variables panel previews iteration (first item) and condition results live on the stage, and flags undeclared variables before you save.

Put it together: bulk personalized videos

iterate builds the inside of one video from data; bulk rendering renders many videos from many variable sets. A product-feed pipeline typically uses both: one template, iterate for the per-video product list, bulk items for per-customer or per-category variants.