{
  "openapi": "3.0.3",
  "info": {
    "title": "webCountdown API",
    "version": "1.0.1",
    "description": "A service that redirects the client to a generated webCountdown or count-up page based on the provided target date and time. The resulting countdown page can be shared with friends."
  },
  "servers": [
    {
      "url": "https://www.webcountdown.de"
    }
  ],
  "paths": {
    "/api.php": {
      "get": {
        "summary": "Generate a webCountdown redirect",
        "description": "Redirects the client to a countdown (or count-up) page for the specified date and time. The response is an HTTP redirect to the corresponding countdown page.",
        "parameters": [
          {
            "name": "year",
            "in": "query",
            "required": true,
            "description": "Target year.",
            "schema": {
              "type": "integer",
              "minimum": 1971,
              "maximum": 3000
            }
          },
          {
            "name": "month",
            "in": "query",
            "required": true,
            "description": "Target month.",
            "schema": {
              "type": "integer",
              "minimum": 1,
              "maximum": 12
            }
          },
          {
            "name": "day",
            "in": "query",
            "required": true,
            "description": "Target day.",
            "schema": {
              "type": "integer",
              "minimum": 1,
              "maximum": 31
            }
          },
          {
            "name": "hour",
            "in": "query",
            "required": false,
            "description": "Target hour.",
            "schema": {
              "type": "integer",
              "minimum": 0,
              "maximum": 23,
              "default": 0
            }
          },
          {
            "name": "minute",
            "in": "query",
            "required": false,
            "description": "Target minute.",
            "schema": {
              "type": "integer",
              "minimum": 0,
              "maximum": 59,
              "default": 0
            }
          },
          {
            "name": "second",
            "in": "query",
            "required": false,
            "description": "Target second.",
            "schema": {
              "type": "integer",
              "minimum": 0,
              "maximum": 59,
              "default": 0
            }
          },
          {
            "name": "up",
            "in": "query",
            "required": false,
            "description": "0 = countdown (default), 1 = count-up (continue counting if the date is already in the past).",
            "schema": {
              "type": "integer",
              "enum": [0, 1],
              "default": 0
            }
          }
        ],
        "responses": {
          "302": {
            "description": "Redirect to the generated webCountdown page.",
            "headers": {
              "Location": {
                "description": "URL of the generated countdown.",
                "schema": {
                  "type": "string",
                  "format": "uri"
                }
              }
            },
            "examples": {
              "redirect": {
                "summary": "Example redirect",
                "value": {
                  "Location": "https://www.webcountdown.de/?c=2051222400"
                }
              }
            }
          },
          "400": {
            "description": "Invalid or missing parameters.",
            "content": {
              "text/plain": {
                "schema": {
                  "type": "string"
                },
                "example": "Parameter 'year' is missing or invalid."
              }
            }
          }
        }
      }
    }
  }
}