{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Step",
  "description": "One recorded user action — discriminated union by `op`.",
  "oneOf": [
    {
      "description": "Fields shared by every step variant (flattened in JSON).",
      "type": "object",
      "required": [
        "id",
        "op",
        "page",
        "to"
      ],
      "properties": {
        "effect": {
          "anyOf": [
            {
              "$ref": "#/definitions/StepEffect"
            },
            {
              "type": "null"
            }
          ]
        },
        "id": {
          "type": "integer",
          "format": "uint32",
          "minimum": 0.0
        },
        "op": {
          "type": "string",
          "enum": [
            "navigate"
          ]
        },
        "page": {
          "description": "Reference into `pages[]`.",
          "type": "string"
        },
        "to": {
          "type": "string"
        }
      }
    },
    {
      "description": "Fields shared by every step variant (flattened in JSON).",
      "type": "object",
      "required": [
        "id",
        "op",
        "page",
        "target"
      ],
      "properties": {
        "effect": {
          "anyOf": [
            {
              "$ref": "#/definitions/StepEffect"
            },
            {
              "type": "null"
            }
          ]
        },
        "id": {
          "type": "integer",
          "format": "uint32",
          "minimum": 0.0
        },
        "op": {
          "type": "string",
          "enum": [
            "click"
          ]
        },
        "page": {
          "description": "Reference into `pages[]`.",
          "type": "string"
        },
        "target": {
          "$ref": "#/definitions/TargetDescriptor"
        }
      }
    },
    {
      "description": "Fields shared by every step variant (flattened in JSON).",
      "type": "object",
      "required": [
        "id",
        "op",
        "page",
        "target",
        "value"
      ],
      "properties": {
        "effect": {
          "anyOf": [
            {
              "$ref": "#/definitions/StepEffect"
            },
            {
              "type": "null"
            }
          ]
        },
        "id": {
          "type": "integer",
          "format": "uint32",
          "minimum": 0.0
        },
        "op": {
          "type": "string",
          "enum": [
            "fill"
          ]
        },
        "page": {
          "description": "Reference into `pages[]`.",
          "type": "string"
        },
        "redacted": {
          "type": [
            "boolean",
            "null"
          ]
        },
        "target": {
          "$ref": "#/definitions/TargetDescriptor"
        },
        "value": {
          "type": "string"
        }
      }
    },
    {
      "description": "Fields shared by every step variant (flattened in JSON).",
      "type": "object",
      "required": [
        "id",
        "op",
        "page",
        "selection",
        "target"
      ],
      "properties": {
        "effect": {
          "anyOf": [
            {
              "$ref": "#/definitions/StepEffect"
            },
            {
              "type": "null"
            }
          ]
        },
        "id": {
          "type": "integer",
          "format": "uint32",
          "minimum": 0.0
        },
        "op": {
          "type": "string",
          "enum": [
            "select"
          ]
        },
        "page": {
          "description": "Reference into `pages[]`.",
          "type": "string"
        },
        "selection": {
          "type": "array",
          "items": {
            "$ref": "#/definitions/SelectedOption"
          }
        },
        "target": {
          "$ref": "#/definitions/TargetDescriptor"
        }
      }
    },
    {
      "description": "Fields shared by every step variant (flattened in JSON).",
      "type": "object",
      "required": [
        "id",
        "key",
        "op",
        "page"
      ],
      "properties": {
        "effect": {
          "anyOf": [
            {
              "$ref": "#/definitions/StepEffect"
            },
            {
              "type": "null"
            }
          ]
        },
        "id": {
          "type": "integer",
          "format": "uint32",
          "minimum": 0.0
        },
        "key": {
          "type": "string"
        },
        "modifiers": {
          "type": [
            "array",
            "null"
          ],
          "items": {
            "$ref": "#/definitions/KeyModifier"
          }
        },
        "op": {
          "type": "string",
          "enum": [
            "press"
          ]
        },
        "page": {
          "description": "Reference into `pages[]`.",
          "type": "string"
        },
        "target": {
          "anyOf": [
            {
              "$ref": "#/definitions/TargetDescriptor"
            },
            {
              "type": "null"
            }
          ]
        }
      }
    }
  ],
  "definitions": {
    "KeyModifier": {
      "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
      "type": "string",
      "enum": [
        "alt",
        "ctrl",
        "meta",
        "shift"
      ]
    },
    "SelectedOption": {
      "description": "One selected option (`select` op).",
      "type": "object",
      "required": [
        "value"
      ],
      "properties": {
        "label": {
          "type": [
            "string",
            "null"
          ]
        },
        "value": {
          "type": "string"
        }
      }
    },
    "StepEffect": {
      "description": "Observed navigation after a step (objective fact only).",
      "type": "object",
      "required": [
        "navigated_to"
      ],
      "properties": {
        "navigated_to": {
          "description": "Reference into `pages[]` for the destination page.",
          "type": "string"
        }
      }
    },
    "TargetDescriptor": {
      "description": "Stable semantic handle for an interacted element.\n\n`name` and `nearby_label` are **untrusted page text**.",
      "type": "object",
      "required": [
        "tag"
      ],
      "properties": {
        "name": {
          "type": [
            "string",
            "null"
          ]
        },
        "name_attr": {
          "type": [
            "string",
            "null"
          ]
        },
        "nearby_label": {
          "type": [
            "string",
            "null"
          ]
        },
        "placeholder": {
          "type": [
            "string",
            "null"
          ]
        },
        "role": {
          "type": [
            "string",
            "null"
          ]
        },
        "tag": {
          "type": "string"
        }
      }
    }
  }
}