Templates as parameters

A MostlyRender template is a canvas (width × height, background) plus a stack of named layers. The key idea:

The layer name is the API parameter. To change what a layer shows at render time, send modifications keyed by the layer’s name.

# Modifications

Given a template with a text layer named title, an image layer named photo, and a QR layer named link:

json

{
  "template": "tpl_abc",
  "modifications": {
    "title": "Renders that never go dark",
    "photo": "https://example.com/hero.jpg",
    "link": "https://mostlyrender.com"
  }
}

A string on a text layer sets its text.
A string on an image layer sets its src.
A string on a QR layer sets the encoded value.
An object is merged into the layer, so you can override styling too:

json

{ "modifications": { "title": { "text": "On sale", "color": "#e11d48" } } }

Layers you don’t mention keep their designed defaults. Unknown layer names are ignored.

# Listing templates

bash

curl https://api.mostlyrender.com/v1/templates \
  -H "Authorization: Bearer mr_live_…"

json

{
  "templates": [
    { "id": "tpl_abc", "name": "Launch card", "width": 1200, "height": 630, "engine": "layers" }
  ]
}

Use the id as the template in a render call. Manage templates (create, edit, delete) in the app editor.