Templates: the view language

A template is a small tree of native views bound to a JSON object: a tool's structuredContent (or data of an {ok, data} result), the overview object, or { args, preview } for a confirmation card. Display only: a template can never send data, run code or load anything but allowlisted images. Organization file: templates/<id>.json { "id", "schema": "streamline.template/1", "root": node }. Personal file: templates: { "<id>": { "root": node } }.

Contents

• Nodes
• Paths
• Interpolation and formatters
• when
• Button actions
• Limits
• Spoken summary
• Patterns (list, money, status, confirm card, overview)
• Checking a template against a real result

Nodes

Every node has type; any node may have when and padding (0–24 pt).

Paths

$ the root object; @ the current list element; .key, ["key with spaces"], [0]; [*] only at the end of a list's items. No filters, slices or recursion. An unresolved path is null, never an error. Outside the bound object: user.name, user.firstName, user.store, tenant.shortName, chat.<key>, context.<key> (forms), now.

Interpolation and formatters

"{{ path | formatter:arg | … }}"; text outside holes is literal; arguments are numbers or 'single-quoted'.

Any other formatter name is a check error.

when

"when": "$.offer" (truthy: not null, false, 0, "" or []), or { "path": "$.status", "eq": "pending" } with eq, ne, in (array), gt, lt; { "not": when }, { "all": [when…] }, { "any": [when…] }. That is all.

Button actions

A literal openURL/download URL (no {{ }}) to a host that isn't allowed fails the check (link.host); one filled from a result is checked at the tap.

Limits

Depth ≤ 12; ≤ 200 nodes after list expansion; ≤ 50 items per list. A template that breaks a limit or fails to parse renders as a plain card with the tool's text; it never blanks a stream.

Spoken summary

"speech": { "summary": "Customer card: {{ $.name }}." } beside root (≤ 200 characters, interpolation and formatters only) is what Speak replies says for the card; without it the card is "A card is on screen: <activity>". Never on a template a sealed view uses (speech.sealed): sealed data is never spoken.

Patterns

A search result list with a fast-path button

{ "type": "list", "items": "$.results[*]", "max": 5, "more": "and {{ count }} more", "dividers": true, "item":
  { "type": "row", "spacing": 10, "children": [
    { "type": "image", "url": "{{ @.photo }}", "aspect": "1:1", "width": 56, "corner": 8 },
    { "type": "stack", "spacing": 2, "children": [
      { "type": "text", "text": "{{ @.title }}", "style": "body", "weight": "medium", "lines": 2 },
      { "type": "text", "text": "{{ @.sku }} · {{ @.onHand }} at this store", "style": "caption", "color": "secondary" },
      { "type": "money", "value": "@.tagPrice", "style": "callout" } ] },
    { "type": "button", "label": "Add", "style": "secondary",
      "action": { "tool": "cart_add_item", "args": { "cartId": "{{ chat.cartId }}", "sku": "{{ @.sku }}" }, "fallback": "Add {{ @.sku }}" } } ] } }

Money with a struck tag price, and a status badge

{ "type": "row", "distribute": "spaceBetween", "children": [
  { "type": "stack", "align": "trailing", "spacing": 1, "children": [
    { "type": "money", "value": "$.price" },
    { "type": "money", "value": "$.tagPrice", "style": "caption", "strike": true, "when": { "path": "$.discounted", "eq": true } } ] },
  { "type": "badge", "text": "{{ $.status | title }}",
    "toneMap": { "path": "$.status", "map": { "approved": "positive", "pending": "warning", "declined": "negative" }, "default": "neutral" } } ] }

A confirmation card (root is { "args": <the call's arguments>, "preview": <the preview tool's result> })

{ "id": "confirm.sale", "schema": "streamline.template/1", "root": { "type": "stack", "spacing": 8, "padding": 14, "children": [
  { "type": "text", "text": "Submit this sale?", "style": "headline" },
  { "type": "keyValue", "rows": [
    { "label": "Customer", "value": "{{ $.preview.customer.name }}" },
    { "label": "Items", "value": "{{ $.preview.items | count }}" },
    { "label": "Total", "value": "{{ $.preview.total | money }}" } ] },
  { "type": "text", "when": { "path": "$.preview.balance", "gt": 0 }, "text": "Balance due {{ $.preview.balance | money }}", "style": "callout", "color": "warning" } ] } }

An overview and its compact strip: one stack with the job's headline facts, a list of lines, a keyValue of totals and a status badge; the compact template is a single row with distribute: spaceBetween.

Checking a template against a real result

Bind against a real structuredContent (from the server, with fake data), not a guess at its shape. Check every path exists in the result, every formatter is in the table, every when path is right, and buttons' tools are direct. configcheck --render <template> <fixture.json> (when available) prints the resolved tree as text.