schema.json

{
  "type": "object",
  "properties": {
    "Version": {
      "type": "string"
    },
    "Statement": {
      "type": "array",
      "items": {
        "$ref": "#/definitions/Statement"
      }
    }
  },
  "required": ["Version", "Statement"],
  "definitions": {
    "Condition": {
      "type": "object"
    },
    "Statement": {
      "type": "object",
      "allOf": [{
        "required": ["Effect"]
      }, {
        "not": {
          "anyOf": [{
            "required": ["Action", "NotAction"]
          }, {
            "required": ["Resource", "NotResource"]
          }, {
            "required": ["Principal", "NotPrincipal"]
          }]
        }
      }],

      "properties": {
        "Effect": {
          "type": "string",
          "enum": ["Allow", "Deny"]
        },
        "Sid": {
          "type": "string"
        },
        "Action": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "Resource": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "Principal": {
          "type": "object",
          "properties": {
            "AWS": {
              "type": "array",
              "items": {
                "type": "string"
              }
            },
            "Service": {
              "type": "array",
              "items": {
                "type": "string"
              }
            }
          }
        },
        "Condition": {
          "$ref": "#/definitions/Condition"
        }
      }
    }
  }
}