{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "description": "IPython Notebook v3.0 JSON schema.",
    "type": "object",
    "additionalProperties": false,
    "required": ["metadata", "nbformat_minor", "nbformat", "worksheets"],
    "properties": {
        "metadata": {
            "description": "Notebook root-level metadata.",
            "type": "object",
            "additionalProperties": true,
            "properties": {
                "kernel_info": {
                    "description": "Kernel information.",
                    "type": "object",
                    "required": ["name", "language"],
                    "properties": {
                        "name": {
                            "description": "Name of the kernel specification.",
                            "type": "string"
                        },
                        "language": {
                            "description": "The programming language which this kernel runs.",
                            "type": "string"
                        },
                        "codemirror_mode": {
                            "description": "The codemirror mode to use for code in this language.",
                            "type": "string"
                        }
                    }
                },
                "signature": {
                    "description": "Hash of the notebook.",
                    "type": "string"
                }
            }
        },
        "nbformat_minor": {
            "description": "Notebook format (minor number). Incremented for backward compatible changes to the notebook format.",
            "type": "integer",
            "minimum": 0
        },
        "nbformat": {
            "description": "Notebook format (major number). Incremented between backwards incompatible changes to the notebook format.",
            "type": "integer",
            "minimum": 3,
            "maximum": 3
        },
        "orig_nbformat": {
            "description": "Original notebook format (major number) before converting the notebook between versions.",
            "type": "integer",
            "minimum": 1
        },
        "worksheets" : {
            "description": "Array of worksheets",
            "type": "array",
            "items": {"$ref": "#/definitions/worksheet"}
        }
    },

    "definitions": {
        "worksheet": {
            "additionalProperties": false,
            "required" : ["cells"],
            "properties":{
                "cells": {
                    "description": "Array of cells of the current notebook.",
                    "type": "array",
                    "items": {
                        "type": "object",
                        "oneOf": [
                            {"$ref": "#/definitions/raw_cell"},
                            {"$ref": "#/definitions/markdown_cell"},
                            {"$ref": "#/definitions/heading_cell"},
                            {"$ref": "#/definitions/code_cell"}
                        ]
                    }
                },
                "metadata": {
                    "type": "object",
                    "description": "metadata of the current worksheet"
                }
            }
        },
        "raw_cell": {
            "description": "Notebook raw nbconvert cell.",
            "type": "object",
            "additionalProperties": false,
            "required": ["cell_type", "source"],
            "properties": {
                "cell_type": {
                    "description": "String identifying the type of cell.",
                    "enum": ["raw"]
                },
                "metadata": {
                    "description": "Cell-level metadata.",
                    "type": "object",
                    "additionalProperties": true,
                    "properties": {
                        "format": {
                            "description": "Raw cell metadata format for nbconvert.",
                            "type": "string"
                        },
                        "name": {"$ref": "#/definitions/misc/metadata_name"},
                        "tags": {"$ref": "#/definitions/misc/metadata_tags"}
                    }
                },
                "source": {"$ref": "#/definitions/misc/source"}
            }
        },

        "markdown_cell": {
            "description": "Notebook markdown cell.",
            "type": "object",
            "additionalProperties": false,
            "required": ["cell_type", "source"],
            "properties": {
                "cell_type": {
                    "description": "String identifying the type of cell.",
                    "enum": ["markdown", "html"]
                },
                "metadata": {
                    "description": "Cell-level metadata.",
                    "type": "object",
                    "properties": {
                        "name": {"$ref": "#/definitions/misc/metadata_name"},
                        "tags": {"$ref": "#/definitions/misc/metadata_tags"}
                    },
                    "additionalProperties": true
                },
                "source": {"$ref": "#/definitions/misc/source"}
            }
        },

        "heading_cell": {
            "description": "Notebook heading cell.",
            "type": "object",
            "additionalProperties": false,
            "required": ["cell_type", "source", "level"],
            "properties": {
                "cell_type": {
                    "description": "String identifying the type of cell.",
                    "enum": ["heading"]
                },
                "metadata": {
                    "description": "Cell-level metadata.",
                    "type": "object",
                    "additionalProperties": true
                },
                "source": {"$ref": "#/definitions/misc/source"},
                "level": {
                    "description": "Level of heading cells.",
                    "type": "integer",
                    "minimum": 1
                }
            }
        },

        "code_cell": {
            "description": "Notebook code cell.",
            "type": "object",
            "additionalProperties": false,
            "required": ["cell_type", "input", "outputs", "language"],
            "properties": {
                "cell_type": {
                    "description": "String identifying the type of cell.",
                    "enum": ["code"]
                },
                "language": {
                    "description": "The cell's language (always Python)",
                    "type": "string"
                },
                "collapsed": {
                    "description": "Whether the cell is collapsed/expanded.",
                    "type": "boolean"
                },
                "metadata": {
                    "description": "Cell-level metadata.",
                    "type": "object",
                    "additionalProperties": true
                },
                "input": {"$ref": "#/definitions/misc/source"},
                "outputs": {
                    "description": "Execution, display, or stream outputs.",
                    "type": "array",
                    "items": {"$ref": "#/definitions/output"}
                },
                "prompt_number": {
                    "description": "The code cell's prompt number. Will be null if the cell has not been run.",
                    "type": ["integer", "null"],
                    "minimum": 0
                }
            }
        },
        "output": {
            "type": "object",
            "oneOf": [
                {"$ref": "#/definitions/pyout"},
                {"$ref": "#/definitions/display_data"},
                {"$ref": "#/definitions/stream"},
                {"$ref": "#/definitions/pyerr"}
            ]
        },
        "pyout": {
            "description": "Result of executing a code cell.",
            "type": "object",
            "additionalProperties": false,
            "required": ["output_type", "prompt_number"],
            "properties": {
                "output_type": {
                    "description": "Type of cell output.",
                    "enum": ["pyout"]
                },
                "prompt_number": {
                    "description": "A result's prompt number.",
                    "type": ["integer"],
                    "minimum": 0
                },
                "text": {"$ref": "#/definitions/misc/multiline_string"},
                "latex": {"$ref": "#/definitions/misc/multiline_string"},
                "png": {"$ref": "#/definitions/misc/multiline_string"},
                "jpeg": {"$ref": "#/definitions/misc/multiline_string"},
                "svg": {"$ref": "#/definitions/misc/multiline_string"},
                "html": {"$ref": "#/definitions/misc/multiline_string"},
                "javascript": {"$ref": "#/definitions/misc/multiline_string"},
                "json": {"$ref": "#/definitions/misc/multiline_string"},
                "pdf": {"$ref": "#/definitions/misc/multiline_string"},
                "metadata": {"$ref": "#/definitions/misc/output_metadata"}
            },
            "patternProperties": {
                "^[a-zA-Z0-9]+/[a-zA-Z0-9\\-\\+\\.]+$": {
                    "description": "mimetype output (e.g. text/plain), represented as either an array of strings or a string.",
                    "$ref": "#/definitions/misc/multiline_string"
                }
            }
        },

        "display_data": {
            "description": "Data displayed as a result of code cell execution.",
            "type": "object",
            "additionalProperties": false,
            "required": ["output_type"],
            "properties": {
                "output_type": {
                    "description": "Type of cell output.",
                    "enum": ["display_data"]
                },
                "text": {"$ref": "#/definitions/misc/multiline_string"},
                "latex": {"$ref": "#/definitions/misc/multiline_string"},
                "png": {"$ref": "#/definitions/misc/multiline_string"},
                "jpeg": {"$ref": "#/definitions/misc/multiline_string"},
                "svg": {"$ref": "#/definitions/misc/multiline_string"},
                "html": {"$ref": "#/definitions/misc/multiline_string"},
                "javascript": {"$ref": "#/definitions/misc/multiline_string"},
                "json": {"$ref": "#/definitions/misc/multiline_string"},
                "pdf": {"$ref": "#/definitions/misc/multiline_string"},
                "metadata": {"$ref": "#/definitions/misc/output_metadata"}
            },
            "patternProperties": {
                "[a-zA-Z0-9]+/[a-zA-Z0-9\\-\\+\\.]+$": {
                    "description": "mimetype output (e.g. text/plain), represented as either an array of strings or a string.",
                    "$ref": "#/definitions/misc/multiline_string"
                }
            }
        },

        "stream": {
            "description": "Stream output from a code cell.",
            "type": "object",
            "additionalProperties": false,
            "required": ["output_type", "stream", "text"],
            "properties": {
                "output_type": {
                    "description": "Type of cell output.",
                    "enum": ["stream"]
                },
                "stream": {
                    "description": "The stream type/destination.",
                    "type": "string"
                },
                "text": {
                    "description": "The stream's text output, represented as an array of strings.",
                    "$ref": "#/definitions/misc/multiline_string"
                }
            }
        },

        "pyerr": {
            "description": "Output of an error that occurred during code cell execution.",
            "type": "object",
            "additionalProperties": false,
            "required": ["output_type", "ename", "evalue", "traceback"],
            "properties": {
                "output_type": {
                    "description": "Type of cell output.",
                    "enum": ["pyerr"]
                },
                "ename": {
                    "description": "The name of the error.",
                    "type": "string"
                },
                "evalue": {
                    "description": "The value, or message, of the error.",
                    "type": "string"
                },
                "traceback": {
                    "description": "The error's traceback, represented as an array of strings.",
                    "type": "array",
                    "items": {"type": "string"}
                }
            }
        },

        "misc": {
            "metadata_name": {
                "description": "The cell's name. If present, must be a non-empty string.",
                "type": "string",
                "pattern": "^.+$"
            },
            "metadata_tags": {
                "description": "The cell's tags. Tags must be unique, and must not contain commas.",
                "type": "array",
                "uniqueItems": true,
                "items": {
                    "type": "string",
                    "pattern": "^[^,]+$"
                }
            },
            "source": {
                "description": "Contents of the cell, represented as an array of lines.",
                "$ref": "#/definitions/misc/multiline_string"
            },
            "prompt_number": {
                "description": "The code cell's prompt number. Will be null if the cell has not been run.",
                "type": ["integer", "null"],
                "minimum": 0
            },
            "mimetype": {
                "patternProperties": {
                    "^[a-zA-Z0-9\\-\\+]+/[a-zA-Z0-9\\-\\+]+": {
                        "description": "The cell's mimetype output (e.g. text/plain), represented as either an array of strings or a string.",
                        "$ref": "#/definitions/misc/multiline_string"
                    }
                }
            },
            "output_metadata": {
                "description": "Cell output metadata.",
                "type": "object",
                "additionalProperties": true
            },
            "multiline_string": {
                "oneOf" : [
                    {"type": "string"},
                    {
                        "type": "array",
                        "items": {"type": "string"}
                    }
                ]
            }
        }
    }
}