{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://fleet.forgesdlc.com/schemas/fleet-app-ui-v1.schema.json",
  "title": "Forge Fleet App UI spec v1",
  "description": "Declarative admin UI tree consumed by forge-fleet-app-ui.js.",
  "type": "object",
  "additionalProperties": false,
  "required": ["protocol_version", "widgets"],
  "properties": {
    "protocol_version": { "type": "integer", "const": 1 },
    "title": { "type": "string" },
    "poll_ms": { "type": "integer", "minimum": 1000, "maximum": 300000 },
    "widgets": {
      "type": "array",
      "items": { "$ref": "#/$defs/widget" }
    }
  },
  "$defs": {
    "widget": {
      "type": "object",
      "required": ["kind"],
      "properties": {
        "kind": {
          "type": "string",
          "enum": [
            "section",
            "heading",
            "prose",
            "kpi_row",
            "data_table",
            "action_button",
            "action_row",
            "alert",
            "alert_list",
            "diagnostic_panel",
            "health_card",
            "chart",
            "docs_link",
            "toggle",
            "status_badge",
            "event_feed",
            "link_button",
            "surface_wall"
          ]
        },
        "title": { "type": "string" },
        "collapsed": { "type": "boolean" },
        "text": { "type": "string" },
        "level": { "type": "integer", "minimum": 2, "maximum": 4 },
        "variant": { "type": "string", "enum": ["info", "warning", "danger", "success"] },
        "binding": { "type": "string", "minLength": 1 },
        "action": { "type": "string", "minLength": 1 },
        "label": { "type": "string" },
        "body": { "type": "object" },
        "buttons": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["action", "label"],
            "properties": {
              "action": { "type": "string" },
              "label": { "type": "string" },
              "body": { "type": "object" },
              "variant": { "type": "string", "enum": ["primary", "ghost"] }
            }
          }
        },
        "variants": {
          "type": "object",
          "additionalProperties": { "type": "string" }
        },
        "columns": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["key", "label"],
            "properties": {
              "key": { "type": "string" },
              "label": { "type": "string" },
              "format": { "type": "string", "enum": ["badge", "link", "row_action"] },
              "action": { "type": "string" },
              "body_keys": {
                "type": "array",
                "items": { "type": "string" }
              },
              "action_label": { "type": "string" },
              "variants": {
                "type": "object",
                "additionalProperties": { "type": "string" }
              }
            }
          }
        },
        "items": {
          "type": "array",
          "items": {
            "type": "object",
            "properties": {
              "label": { "type": "string" },
              "binding": { "type": "string" },
              "format": { "type": "string" }
            }
          }
        },
        "chart_kind": { "type": "string" },
        "href": { "type": "string" },
        "widgets": {
          "type": "array",
          "items": { "$ref": "#/$defs/widget" }
        }
      }
    }
  }
}