One band of a layer_stack — a badge, the layer name, and either a single field/note pane or one pane per column via `cells`. Reads its colour tokens from the CSS custom properties an enclosing layer_stack sets and renders with sane fallback colours standalone. Rarely authored outside layer_stack.layers, but is its own atom type so it can be independently addressed by ComponentId in the A2UI v1.0 ChildList wire format.
| Surface | Note |
|---|---|
| mcp-apps | Inherits layer_stack's blocked IBM Plex faces under the MCP Apps CSP — falls back to the system mono/serif stack. Structure unaffected. |
| Field | Type | |
|---|---|---|
| name | string (required). The layer name, e.g. "Transport". | required |
| badge | string. Small label above the name — defaults to the 1-based position in layer_stack.layers as declared. | optional |
| field | string. The technical/schema fact, rendered monospace. Used when the layer has no `cells`. | optional |
| note | string. The plain-language gloss. Used when the layer has no `cells`. Backtick spans render as inline code. | optional |
| examples | array of strings. Concrete instances at this layer, rendered as a wrapping chip row across the foot of the band, e.g. "stdio", "Streamable HTTP". | optional |
| status | string. 'present' (default), 'absent' or 'partial'. absent renders the pane hollow with a dashed border — the point is that a layer a system does not define stays VISIBLE and reads as a stated absence. Maps onto the palette's cleared / blocked / accent tokens. | optional |
| cells | array. One entry per layer_stack column, index-aligned with it. Each item {field?, note?, status?} — the same three fields, per column. Given cells, the layer's own field/note/status are ignored. | optional |
{
"type": "stack_layer",
"name": "Stack Layer"
}{
"identifier": "urn:air:a2uicatalog.ai:atom:stack_layer",
"displayName": "Stack Layer",
"type": "application/vnd.a2ui.atom+json",
"url": "https://a2uicatalog.ai/atoms/stack_layer",
"capabilities": [
"web",
"google-apps-script-web",
"mcp-apps"
],
"description": "One band of a layer_stack \u2014 a badge, the layer name, and either a single field/note pane or one pane per column via `cells`. Reads its colour tokens from the CSS custom properties an enclosing layer_stack sets and renders with sane fallback colours standalone. Rarely authored outside layer_stack.layers, but is its own atom type so it can be independently addressed by ComponentId in the A2UI v1.0 ChildList wire format.",
"representativeQueries": [
"show a one layer band (badge, name, field/note or per-column cells) \u2014 normally used inside layer_stack",
"one band of a layer_stack \u2014 a badge, the layer name, and either a single field/note pane or one pane",
"render a stack layer"
]
}The renderer is an open-source Google Apps Script web app. Deploy your own instance in 4 commands — you own the URL, no dependency on the demo endpoint.
git clone https://github.com/a2uicatalog/a2ui
cd a2ui/apps-script-surface/gas-wired-renderer
clasp push && clasp deploy