{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://schemas.api.aws/cloudformation/template.json",
  "title": "AWS CloudFormation Template",
  "description": "Represents the structure of an AWS CloudFormation template. A template is a JSON or YAML formatted text file that describes the AWS infrastructure and resources to provision. Templates can be used to create and update CloudFormation stacks.",
  "type": "object",
  "required": [
    "Resources"
  ],
  "properties": {
    "AWSTemplateFormatVersion": {
      "type": "string",
      "description": "The AWS CloudFormation template version that the template conforms to. The only valid value is 2010-09-09.",
      "const": "2010-09-09"
    },
    "Description": {
      "type": "string",
      "description": "A text string that describes the template.",
      "maxLength": 1024
    },
    "Metadata": {
      "type": "object",
      "description": "Objects that provide additional information about the template. Can include template-specific metadata such as AWS::CloudFormation::Interface.",
      "additionalProperties": true
    },
    "Parameters": {
      "type": "object",
      "description": "Values to pass to your template at runtime when you create or update a stack. Parameters enable you to customize stack creation.",
      "additionalProperties": {
        "$ref": "#/$defs/ParameterDefinition"
      }
    },
    "Rules": {
      "type": "object",
      "description": "Validates a parameter or a combination of parameters passed to a template during stack creation or update.",
      "additionalProperties": {
        "$ref": "#/$defs/Rule"
      }
    },
    "Mappings": {
      "type": "object",
      "description": "A mapping of keys and associated values that you can use to specify conditional parameter values. Similar to a lookup table.",
      "additionalProperties": {
        "type": "object",
        "additionalProperties": {
          "type": "object",
          "additionalProperties": true
        }
      }
    },
    "Conditions": {
      "type": "object",
      "description": "Conditions that control whether certain resources are created or whether certain resource properties are assigned a value during stack creation or update.",
      "additionalProperties": true
    },
    "Transform": {
      "description": "For serverless applications, specifies the version of the AWS SAM to use. You can also use AWS::Include transforms to work with template snippets stored separately.",
      "oneOf": [
        {
          "type": "string"
        },
        {
          "type": "array",
          "items": {
            "type": "string"
          }
        }
      ]
    },
    "Resources": {
      "type": "object",
      "description": "Specifies the stack resources and their properties, such as an Amazon EC2 instance or an Amazon S3 bucket. You must declare each resource separately.",
      "minProperties": 1,
      "additionalProperties": {
        "$ref": "#/$defs/Resource"
      }
    },
    "Outputs": {
      "type": "object",
      "description": "Describes the values that are returned whenever you view your stack's properties. Output values can be used for cross-stack references.",
      "additionalProperties": {
        "$ref": "#/$defs/OutputDefinition"
      },
      "maxProperties": 200
    }
  },
  "$defs": {
    "ParameterDefinition": {
      "type": "object",
      "description": "A template parameter declaration.",
      "required": [
        "Type"
      ],
      "properties": {
        "Type": {
          "type": "string",
          "description": "The data type for the parameter.",
          "enum": [
            "String",
            "Number",
            "List<Number>",
            "CommaDelimitedList",
            "AWS::SSM::Parameter::Type",
            "AWS::SSM::Parameter::Value<String>",
            "AWS::SSM::Parameter::Value<List<String>>",
            "AWS::SSM::Parameter::Value<CommaDelimitedList>",
            "AWS::EC2::AvailabilityZone::Name",
            "AWS::EC2::Image::Id",
            "AWS::EC2::Instance::Id",
            "AWS::EC2::KeyPair::KeyName",
            "AWS::EC2::SecurityGroup::GroupName",
            "AWS::EC2::SecurityGroup::Id",
            "AWS::EC2::Subnet::Id",
            "AWS::EC2::Volume::Id",
            "AWS::EC2::VPC::Id",
            "AWS::Route53::HostedZone::Id",
            "List<AWS::EC2::AvailabilityZone::Name>",
            "List<AWS::EC2::Image::Id>",
            "List<AWS::EC2::Instance::Id>",
            "List<AWS::EC2::SecurityGroup::GroupName>",
            "List<AWS::EC2::SecurityGroup::Id>",
            "List<AWS::EC2::Subnet::Id>",
            "List<AWS::EC2::Volume::Id>",
            "List<AWS::EC2::VPC::Id>",
            "List<AWS::Route53::HostedZone::Id>"
          ]
        },
        "Default": {
          "description": "A value of the appropriate type for the template to use if no value is specified."
        },
        "NoEcho": {
          "type": "boolean",
          "description": "Whether to mask the parameter value to prevent it from being displayed.",
          "default": false
        },
        "AllowedValues": {
          "type": "array",
          "description": "An array containing the list of values allowed for the parameter."
        },
        "AllowedPattern": {
          "type": "string",
          "description": "A regular expression that represents the patterns to allow for String types."
        },
        "MaxLength": {
          "type": "integer",
          "description": "Maximum number of characters for String types."
        },
        "MinLength": {
          "type": "integer",
          "description": "Minimum number of characters for String types."
        },
        "MaxValue": {
          "type": "number",
          "description": "Maximum numeric value for Number types."
        },
        "MinValue": {
          "type": "number",
          "description": "Minimum numeric value for Number types."
        },
        "Description": {
          "type": "string",
          "description": "A string that describes the parameter.",
          "maxLength": 4000
        },
        "ConstraintDescription": {
          "type": "string",
          "description": "A string that explains a constraint when the constraint is violated."
        }
      }
    },
    "Rule": {
      "type": "object",
      "description": "A rule that validates parameter values.",
      "properties": {
        "RuleCondition": {
          "description": "Determines when a rule takes effect."
        },
        "Assertions": {
          "type": "array",
          "description": "The assertions for the rule.",
          "items": {
            "type": "object",
            "required": [
              "Assert",
              "AssertDescription"
            ],
            "properties": {
              "Assert": {
                "description": "The assertion condition."
              },
              "AssertDescription": {
                "type": "string",
                "description": "The assertion description."
              }
            }
          }
        }
      }
    },
    "Resource": {
      "type": "object",
      "description": "A resource declaration in the template.",
      "required": [
        "Type"
      ],
      "properties": {
        "Type": {
          "type": "string",
          "description": "The resource type (e.g. AWS::EC2::Instance).",
          "pattern": "^[A-Za-z0-9]{2,64}::[A-Za-z0-9]{2,64}::[A-Za-z0-9]{2,64}$|^Custom::.+$"
        },
        "Properties": {
          "type": "object",
          "description": "Resource-specific properties.",
          "additionalProperties": true
        },
        "DependsOn": {
          "description": "Specifies that the creation of a specific resource follows another.",
          "oneOf": [
            {
              "type": "string"
            },
            {
              "type": "array",
              "items": {
                "type": "string"
              }
            }
          ]
        },
        "Condition": {
          "type": "string",
          "description": "Associates a condition with the resource so that it is created only when the condition is true."
        },
        "DeletionPolicy": {
          "type": "string",
          "description": "Determines what happens to the resource when the stack is deleted.",
          "enum": [
            "Delete",
            "Retain",
            "Snapshot",
            "RetainExceptOnCreate"
          ]
        },
        "UpdatePolicy": {
          "type": "object",
          "description": "Specifies how CloudFormation handles updates to specific resources.",
          "additionalProperties": true
        },
        "UpdateReplacePolicy": {
          "type": "string",
          "description": "Determines what happens to the resource when it is replaced during a stack update.",
          "enum": [
            "Delete",
            "Retain",
            "Snapshot"
          ]
        },
        "CreationPolicy": {
          "type": "object",
          "description": "Prevents a resource's status from reaching CREATE_COMPLETE until CloudFormation receives a specified number of success signals.",
          "additionalProperties": true
        },
        "Metadata": {
          "type": "object",
          "description": "Metadata to associate with the resource.",
          "additionalProperties": true
        }
      }
    },
    "OutputDefinition": {
      "type": "object",
      "description": "An output declaration in the template.",
      "required": [
        "Value"
      ],
      "properties": {
        "Description": {
          "type": "string",
          "description": "A description of the output value.",
          "maxLength": 1024
        },
        "Value": {
          "description": "The value of the property returned by the aws cloudformation describe-stacks command."
        },
        "Export": {
          "type": "object",
          "description": "The name of the resource output to be exported for cross-stack reference.",
          "properties": {
            "Name": {
              "description": "The export name."
            }
          },
          "required": [
            "Name"
          ]
        },
        "Condition": {
          "type": "string",
          "description": "Associates a condition with the output."
        }
      }
    }
  }
}