inventory.facets

A2A invocation

This skill is invoked through A2A's SendMessage operation (SendMessage JSON-RPC method or POST /message:send over HTTP+JSON), not a dedicated REST URL. The same payload travels on either A2A binding — see JSON-RPC binding or REST binding. AAP only defines what goes inside Message.parts[].data.

The inventory.facets skill returns aggregated facet counts and ranges over a dealer's inventory. A buyer agent uses it to discover what a dealer actually carries before composing a search — for example, to learn the set of available makes and models, the year range, or the price ceiling.

Property	Value
Skill id	inventory.facets
Request type	inventory.facets.request
Response type	inventory.facets.response
Anonymous allowed	yes
Consent required	no
ADF compatible	no

Request shape

{
  "type": "inventory.facets.request",
  "filters": {
    "...": "(same shape as inventory.search filters; all optional)"
  }
}

Field	Type	Required	Description
type	const	yes	inventory.facets.request.
filters	object	no	Optional scoping filters. Same shape as the inventory.search filter block; all fields are optional.

When filters is absent, facets are aggregated over the dealer's entire inventory. When it is present, facets are aggregated over only the matching subset (e.g. all condition: ["used"] listings).

Response shape

{
  "type": "inventory.facets.response",
  "data": {
    "makes":           [{ "value": "string", "count": 0 }],
    "models":          [{ "value": "string", "count": 0 }],
    "trims":           [{ "value": "string", "count": 0 }],
    "years":           [{ "value": 0,        "count": 0 }],
    "conditions":      [{ "value": "string", "count": 0 }],
    "transmissions":   [{ "value": "string", "count": 0 }],
    "fuels":           [{ "value": "string", "count": 0 }],
    "drivelines":      [{ "value": "string", "count": 0 }],
    "body_types":      [{ "value": "string", "count": 0 }],
    "exterior_colors": [{ "value": "string", "count": 0 }],
    "interior_colors": [{ "value": "string", "count": 0 }],
    "statuses":        [{ "value": "string", "count": 0 }],
    "price_range":   { "min": 0, "max": 0 },
    "mileage_range": { "min": 0, "max": 0 },
    "year_range":    { "min": 0, "max": 0 }
  }
}

Each *_facet array entry is { value, count } where value is the facet term (string or integer) and count is the number of matching listings. The three *_range fields are { min, max } numeric ranges.

price_range aggregates the FTC-final price field (see Pricing and FTC compliance).

Scoped facets example

Used-only facets:

Request

{
  "type": "inventory.facets.request",
  "filters": { "condition": ["used"] }
}

Response

{
  "type": "inventory.facets.response",
  "data": {
    "makes": [
      { "value": "Honda",  "count": 12 },
      { "value": "Toyota", "count": 27 }
    ],
    "models": [
      { "value": "Civic",   "count": 5 },
      { "value": "Accord",  "count": 4 },
      { "value": "Camry",   "count": 9 },
      { "value": "Corolla", "count": 8 }
    ],
    "conditions": [
      { "value": "used", "count": 39 }
    ],
    "year_range":    { "min": 2015, "max": 2024 },
    "price_range":   { "min": 9990, "max": 38990 },
    "mileage_range": { "min": 8400, "max": 142000 }
  }
}

When to use it

• The buyer agent wants to enumerate the dealer's makes/models before constructing a search.
• The buyer agent needs to surface a price slider or year filter to the user.
• The buyer agent wants a count of the dealer's used inventory before recommending a deeper conversation.

inventory.facets is anonymous and consent-free. The dealer agent SHOULD return the same set of facet keys regardless of filter, omitting only those for which it has no inventory.