{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://raw.githubusercontent.com/a2e-protocol/a2e-protocol-spec/main/schema/entity-card.schema.json",
  "title": "A2E Protocol",
  "description": "Agent-to-Entity Protocol declaration",
  "type": "object",
  "required": ["a2e", "entity", "mcps"],
  "properties": {
    "a2e": {
      "type": "string",
      "const": "0.1",
      "description": "Protocol version"
    },
    "entity": {
      "type": "object",
      "required": ["domain", "name", "category"],
      "properties": {
        "domain": {
          "type": "string",
          "description": "Primary domain (must match the host serving this file)"
        },
        "name": {
          "type": "string",
          "description": "Human-readable entity name"
        },
        "category": {
          "type": "string",
          "enum": [
            "restaurant",
            "beauty",
            "health",
            "hotel",
            "transport",
            "retail",
            "entertainment",
            "fitness",
            "education",
            "real_estate",
            "services",
            "other"
          ],
          "description": "Primary category"
        },
        "description": {
          "type": "string",
          "maxLength": 500,
          "description": "Brief description (max 500 chars)"
        },
        "location": {
          "type": "object",
          "properties": {
            "address": {
              "type": "string",
              "description": "Street address"
            },
            "city": {
              "type": "string",
              "description": "City"
            },
            "postal_code": {
              "type": "string",
              "description": "Postal/ZIP code"
            },
            "country": {
              "type": "string",
              "pattern": "^[A-Z]{2}$",
              "description": "ISO 3166-1 alpha-2 country code"
            },
            "lat": {
              "type": "number",
              "minimum": -90,
              "maximum": 90,
              "description": "Latitude"
            },
            "lng": {
              "type": "number",
              "minimum": -180,
              "maximum": 180,
              "description": "Longitude"
            }
          }
        },
        "contact": {
          "type": "object",
          "properties": {
            "phone": {
              "type": "string",
              "description": "Phone number (E.164 format recommended)"
            },
            "email": {
              "type": "string",
              "format": "email",
              "description": "Email address"
            }
          }
        }
      }
    },
    "mcps": {
      "type": "array",
      "minItems": 1,
      "description": "List of MCP connections",
      "items": {
        "type": "object",
        "required": ["endpoint", "capabilities"],
        "properties": {
          "endpoint": {
            "type": "string",
            "format": "uri",
            "pattern": "^https://",
            "description": "MCP server URL (must be HTTPS)"
          },
          "capabilities": {
            "type": "array",
            "minItems": 1,
            "items": {
              "type": "string",
              "pattern": "^[a-z_]+$"
            },
            "description": "List of supported capabilities"
          },
          "entity_ref": {
            "type": "string",
            "description": "Entity's ID in the MCP provider's system"
          },
          "auth_required": {
            "type": "boolean",
            "default": false,
            "description": "Whether user OAuth is required to perform actions"
          },
          "priority": {
            "type": "integer",
            "minimum": 1,
            "description": "Preference order when multiple MCPs are available (1 = first choice)"
          }
        }
      }
    }
  }
}