JSON Schema for Pipx Metadata v0.2.0, draft 00; see https://github.com/pipxproject/pipx/pull/660. The regex for package version is [not trivial](https://regex101.com/r/BbPqar/1), and is copied verbatim from [Pep 440](https://www.python.org/dev/peps/pep-0440/#appendix-b-parsing-version-strings-with-regular-expressions).

pipx-metadata_v0.2.0_draft00.json

{
  "$schema": "https://json-schema.org/draft/2019-09/schema",
  "$id": "https://pipxproject.github.io/pipx/schema/pipx-metadata_v0.2.0_draft00.json",
  "$defs": {
    "package_name": {
      "type": "string",
      "pattern": "^[A-Za-z][0-9A-Za-z_-]*$"
    },
    "python_version": {
      "type": "string",
      "pattern": "Python [23]\\.[0-9]+\\.[0-9]+"
    },
    "package_version": {
      "type": "string",
      "pattern": "^([1-9][0-9]*!)?(0|[1-9][0-9]*)(\\.(0|[1-9][0-9]*))*((a|b|rc)(0|[1-9][0-9]*))?(\\.post(0|[1-9][0-9]*))?(\\.dev(0|[1-9][0-9]*))?$"
    },
    "app_name": {
      "type": "string",
      "pattern": "^[A-Za-z][0-9A-Za-z_-]*$"
    },
    "app_path": {
      "type": "object",
      "properties": {
        "__Path__": {
          "type": "string"
        },
        "__type__": {
          "type": "string",
          "enum": ["Path"]
        }
      }
    },
    "package": {
      "type": "object",
      "properties": {
        "package": {
          "$ref": "#/$defs/package_name"
        },
        "package_version": {
          "type": "string"
        },
        "package_or_url": {
          "type": "string"
        },
        "suffix": {
          "type": "string"
        },
        "include_apps": {
          "type": "boolean"
        },
        "include_dependencies": {
          "type": "boolean"
        },
        "pip_args": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "apps": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "apps_of_dependencies": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "app_paths": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/app_path"
          }
        },
        "app_paths_of_dependencies": {
          "type": "object",
          "additionalProperties": {
            "$ref": "#/$defs/app_path"
          },
          "propertyNames": {
            "$ref": "#/$defs"
          }
        }
      }
    }
  },
  "type": "object",
  "properties": {
    "pipx_metadata_version": {
      "type": "string"
    },
    "python_version": {
      "$ref": "#/$defs/python_version"
    },
    "venv_args": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "main_package": {
      "$ref": "#/$defs/package"
    },
    "injected_packages": {
      "type": "object",
      "additionalProperties": {
        "type": "#/$defs/package"
      },
      "propertyNames": {
        "$ref": "#/$defs/package_name"
      }
    }
  }
}