{
  "description": "JSON Schema Yosys netlists JSON format",
  "type": "object",
  // an empty object is invalid
  "required": ["modules"],
  "errorMessage": {
    "type": "netlist must be a JSON object",
    "required": "netlist must have a modules property",
  },
  "properties": {
    "modules": {
      "type": "object",
      // there must be at least one module
      "minProperties": 1,
        "errorMessage": {
          "type": "netlist modules must be objects",
          "minProperties": "netlist must have at least one module",
        },
      "additionalProperties": {
        "type": "object",
        "properties": {
          "ports": {
            "type": "object",
            "additionalProperties": {
              "type": "object",
              // all ports must have bits and a direction
              "required": ["direction", "bits"],
              "properties": {
                "direction": {
                  "enum": ["input", "output"]
                },
                "bits": {
                  "type": "array",
                  // bits can be the string "0", "1", "x", or a number.
                  "items": {
                    "oneOf":[{"type":"number"}, {"enum":["0","1","x"]}]
                  }
                }
              }
            }
          },
          "cells": {
            "type": "object",
            "additionalProperties": {
              "type": "object",
              // all cells must have a type and connections
              "required": [
                "type",
                "connections"
              ],
              "properties": {
                "type":{"type":"string"},
                "connections": {
                  "type": "object",
                  "additionalProperties": {
                    "type":"array",
                    "items": {
                      "oneOf":[{"type":"number"}, {"enum":["0","1","x"]}]
                    }
                  }
                },
                // port directions are optional
                "port_directions":{
                  "type": "object",
                  "additionalProperties": {
                    "enum": ["input", "output"]
                  }
                },
                // netlistsvg doesn't use these yet
                "hide_name": {"enum":[0, 1]},
                "parameters": {"type": "object"},
                "attributes": {"type": "object"}
              }
            }
          },
          // not yet used by netlistsvg
          "netnames": {
            "type": "object",
            "additionalProperties": {
              "type": "object",
              "properties": {
                "bits": {
                  "type": "array",
                  // bits can be the string "0", "1", "x", or a number.
                  "items": {
                    "oneOf": [{"type": "number"}, {"enum": ["0", "1", "x"]}]
                  }
                },
                "hide_name": {"enum": [0, 1]},
                "attributes": {"type": "object"}
              }
            }
          },
          "attributes": {
            "type": "object",
            "properties": {
              "top": {"enum": [0, 1, "00000000000000000000000000000000", "00000000000000000000000000000001"]}
            }
          }
        },
        // there must either be ports or cells attribute
        "anyOf": [{"required": ["ports"]},{"required": ["cells"]}]
      }
    }
  }
}