add_to_canvas

Place references (with a steal note), Mobbin screens, notes, color swatches and sections on a board. Direction results go to their direction's section, art above UI.

Plan	Quota	Changes data	Hints
All. Free boards hold 40 items, Pro 300	Item cap per board	Yes

Inputs

Name	Type	Required	Limits	What it does
`canvasId`	string	Yes	1 to 100 characters	The board
`items`	object[]	Yes	1 to 50 per call	What to place, see below
`sectionId`	string	No	1 to 120 characters	Put the items in this section
`thumbs`	boolean	No	default `true`	A small thumbnail of each placed reference in the result (up to 12), so the agent checks what it placed

Item types

`type`	Fields	Notes
`reference`	`referenceId` (required), `note` (1 to 280 characters)	A search result from the tray. The note says what to steal: start it with `steal:`
`screen`	`imageUrl` and `sourceUrl` (required), `app`, `title`, `platform` (`ios` or `web`), `note`, `directionId`	A Mobbin screen from your own Mobbin connector: its `image_url` and `mobbin_url`, passed as returned. `sourceUrl` must be an https page on mobbin.com, `imageUrl` https on mobbin.com. Placed as a UI reference with source mobbin.com, hotlinked, never fetched. `ios` gives a phone shaped tile. Pass the connector’s screen id as `screenId`: adding the same `screenId` again replaces the image of the tile already on the board (Mobbin image links expire after about 30 days; `get_canvas` lists the ones to refresh). See Using Mobbin alongside
`build`	`imageUrl`, `url` and `stitchId` (required), `title`, `note`	A screenshot of your own build, for side by side review: `imageUrl` is an https link to the screenshot, `url` the https link to the build. Placed to the right of its Frankenstein page, the same size, with a Build chip. Image bytes are refused; nothing is stored
`note`	`text` (1 to 2000 characters)	A yellow note. Links are clickable. Caps labels like `WILD:` show as chips
`swatch`	`hex` (`#abc` or `#aabbcc`), `role` (up to 60 characters)	A color swatch, tagged `explore` until a contrast check says otherwise
`section`	`title` (1 to 120 characters), `directionId`	A frame that groups items

Placement rules

A reference found for a direction goes to that direction’s section. If there is none yet, it is created. A screen with a directionId goes there too.
In a direction section, art zone items sit in a labelled Art direction row above the UI references grid. The zone comes with the reference.
A batch that would cross the item cap is refused whole.
Never place results rated bad; they have left the tray anyway.

Example call

{
  "name": "add_to_canvas",
  "arguments": {
    "canvasId": "c3f1a0d2-6b1e-4d8a-9f4b-0a1b2c3d4e5f",
    "sectionId": "sec_cereal",
    "items": [
      { "type": "note", "text": "WILD: giant sparklines everywhere. PATTERN: a loud front panel with a puzzle panel on the side. SIGNATURE: the hero built like a cereal box." },
      { "type": "reference", "referenceId": "ref_3m7k", "note": "steal: the side panel puzzle as the section divider" },
      { "type": "reference", "referenceId": "ref_8k2p", "note": "steal: the oversized product shot cropped by the fold" }
    ]
  }
}

Example output

Added 3 items to "Coffee launch page".
- note it_41 at (120, 96) in section sec_cereal
- image it_42 at (120, 300) in section sec_cereal
- image it_43 at (440, 640) in section sec_cereal
Web link: https://gobanana.fun/c/c3f1a0d2-…

Skipped items are listed with a reason, for example a referenceId that is not in the tray, or a screen whose links are not on mobbin.com.

Messages

Message	Fix
“This canvas has reached the 40 item limit on the free plan. Upgrade: …”	Remove items, new board, or upgrade
“That section was not found on this canvas. Call get_canvas to see section ids.”	Use a current `sectionId`
“items must be a list of 1 to 50 items…”	Check the item shapes above

Next: arrange_canvas.