{
  "name": "Check appointment availability in Google Calendar",
  "nodes": [
    {
      "name": "Setup Instructions",
      "type": "n8n-nodes-base.stickyNote",
      "typeVersion": 1,
      "position": [
        0,
        -1160
      ],
      "parameters": {
        "content": "## Check appointment availability in Google Calendar\n\nCheck a proposed appointment interval through an authenticated webhook. This workflow validates the requested times, reads Google Calendar availability, and returns a structured available or busy result. It suits booking forms, voice assistants, chat assistants, and internal scheduling tools that already have a proposed start and end time.\n\n### Setup\n1. Import the workflow and leave it inactive while configuring it.\n2. In Receive Request, create a Header Auth credential with your chosen header name and secret value. Set a unique webhook path. Keep the secret in credentials and in your calling application, never in the workflow JSON.\n3. In Check Calendar, connect your Google Calendar OAuth credential and replace YOUR_CALENDAR_ID with a calendar that credential can access. Start with a dedicated test calendar.\n4. Send Content-Type: application/json and the configured authentication header. The request body needs start and end, such as {\"start\":\"2030-01-15T14:00:00-06:00\",\"end\":\"2030-01-15T14:30:00-06:00\"}. Replace these example dates with a future interval you intend to test.\n5. Test one free interval and one busy interval. Test invalid times and a provider permission failure. Verify that a provider failure never returns an available result.\n6. Activate only after these checks, then use the production webhook URL shown by n8n.\n\nHTTP 200 returns status available or busy, a boolean available, and the normalized UTC start and end. HTTP 400 returns invalid_request and validation errors. HTTP 502 returns unavailable without claiming that the interval is free. This is a snapshot for one interval. It neither generates a slot catalogue nor holds or creates an appointment. Calendar state can change after the check. Successful, error, and manual execution saving are disabled in the export; review your instance logging and retention before using real requests. Prepared by Benian Technologies: https://benian.ai/integrations/n8n-automation",
        "width": 1280,
        "height": 780
      },
      "id": "template-node-1"
    },
    {
      "name": "Receive Request",
      "type": "n8n-nodes-base.webhook",
      "typeVersion": 2,
      "position": [
        0,
        0
      ],
      "parameters": {
        "httpMethod": "POST",
        "path": "template-calendar-availability",
        "authentication": "headerAuth",
        "responseMode": "responseNode",
        "options": {}
      },
      "webhookId": "template-calendar-availability-entry",
      "id": "template-node-2"
    },
    {
      "name": "Validate Request",
      "type": "n8n-nodes-base.code",
      "typeVersion": 2,
      "position": [
        240,
        0
      ],
      "parameters": {
        "jsCode": "const b = $input.first().json.body || {};\nconst errors = [];\nconst parseInstant = value => {\n  if (typeof value !== 'string') return null;\n  const match = value.match(/^(\\d{4})-(\\d{2})-(\\d{2})T(\\d{2}):(\\d{2}):(\\d{2})(?:\\.(\\d{1,3}))?(Z|[+-]\\d{2}:\\d{2})$/);\n  if (!match) return null;\n  const [year,month,day,hour,minute,second] = match.slice(1,7).map(Number);\n  const leapYear = year%4===0 && (year%100!==0 || year%400===0);\n  const days = [31,leapYear ? 29 : 28,31,30,31,30,31,31,30,31,30,31];\n  if (month<1 || month>12 || day<1 || day>days[month-1] || hour>23 || minute>59 || second>59) return null;\n  const offset = match[8];\n  if (offset!=='Z' && (Number(offset.slice(1,3))>23 || Number(offset.slice(4,6))>59)) return null;\n  const parsed = new Date(value);\n  return Number.isFinite(parsed.getTime()) ? parsed : null;\n};\nconst start = parseInstant(b.start);\nconst end = parseInstant(b.end);\nif (!start || !end) errors.push('start and end must be real RFC3339 dates with seconds and an explicit offset');\nelse {\n  if (start <= new Date()) errors.push('start must be in the future');\n  if (end <= start || end-start > 24*60*60*1000) errors.push('The interval must be positive and at most one day');\n}\n\nreturn [{ json: { valid: errors.length===0, errors, request: { start: errors.length ? null : start.toISOString(), end: errors.length ? null : end.toISOString(),  } } }];"
      },
      "id": "template-node-3"
    },
    {
      "name": "Request Is Valid",
      "type": "n8n-nodes-base.if",
      "typeVersion": 2.2,
      "position": [
        480,
        0
      ],
      "parameters": {
        "conditions": {
          "options": {
            "caseSensitive": true,
            "leftValue": "",
            "typeValidation": "strict",
            "version": 2
          },
          "conditions": [
            {
              "id": "condition-valid",
              "leftValue": "={{ $json.valid }}",
              "rightValue": true,
              "operator": {
                "type": "boolean",
                "operation": "true",
                "singleValue": true
              }
            }
          ],
          "combinator": "and"
        },
        "options": {}
      },
      "id": "template-node-4"
    },
    {
      "name": "Check Calendar",
      "type": "n8n-nodes-base.googleCalendar",
      "typeVersion": 1.3,
      "position": [
        720,
        0
      ],
      "parameters": {
        "resource": "calendar",
        "operation": "availability",
        "calendar": {
          "__rl": true,
          "value": "YOUR_CALENDAR_ID",
          "mode": "id"
        },
        "timeMin": "={{ $('Validate Request').first().json.request.start }}",
        "timeMax": "={{ $('Validate Request').first().json.request.end }}",
        "options": {
          "outputFormat": "availability"
        }
      },
      "onError": "continueErrorOutput",
      "id": "template-node-5"
    },
    {
      "name": "Format Availability",
      "type": "n8n-nodes-base.code",
      "typeVersion": 2,
      "position": [
        960,
        0
      ],
      "parameters": {
        "jsCode": "if (typeof $json.available !== 'boolean') throw new Error('No availability result');\nconst interval = $('Validate Request').first().json.request;\nreturn [{ json: { status: $json.available ? 'available' : 'busy', available: $json.available, start: interval.start, end: interval.end } }];"
      },
      "id": "template-node-6",
      "onError": "continueErrorOutput"
    },
    {
      "name": "Return Availability",
      "type": "n8n-nodes-base.respondToWebhook",
      "typeVersion": 1.4,
      "position": [
        1200,
        0
      ],
      "parameters": {
        "respondWith": "json",
        "responseBody": "={{ $json }}",
        "options": {
          "responseCode": 200
        }
      },
      "id": "template-node-7"
    },
    {
      "name": "Return Invalid",
      "type": "n8n-nodes-base.respondToWebhook",
      "typeVersion": 1.4,
      "position": [
        720,
        260
      ],
      "parameters": {
        "respondWith": "json",
        "responseBody": "={{ { status: 'invalid_request', errors: $json.errors } }}",
        "options": {
          "responseCode": 400
        }
      },
      "id": "template-node-8"
    },
    {
      "name": "Return Provider Error",
      "type": "n8n-nodes-base.respondToWebhook",
      "typeVersion": 1.4,
      "position": [
        960,
        260
      ],
      "parameters": {
        "respondWith": "json",
        "responseBody": "={{ { status: 'unavailable', message: 'The calendar could not be checked. No availability claim was made.' } }}",
        "options": {
          "responseCode": 502
        }
      },
      "id": "template-node-9"
    },
    {
      "parameters": {
        "content": "## Validate the interval\n\nSend start and end in the JSON body. Use complete timestamps with seconds and Z or a numeric UTC offset. Start must be in the future; duration must be greater than zero and at most 24 hours. Invalid requests stop before Google Calendar.",
        "width": 600,
        "height": 240
      },
      "id": "public-guide-calendar-availability-1",
      "name": "Validate the interval",
      "type": "n8n-nodes-base.stickyNote",
      "typeVersion": 1,
      "position": [
        0,
        -320
      ]
    },
    {
      "parameters": {
        "content": "## Configure the calendar\n\nSelect a Google Calendar OAuth credential and replace YOUR_CALENDAR_ID. Use a dedicated test calendar first. This node reads availability only; it does not reserve or create an event.",
        "width": 600,
        "height": 240
      },
      "id": "public-guide-calendar-availability-2",
      "name": "Configure the calendar",
      "type": "n8n-nodes-base.stickyNote",
      "typeVersion": 1,
      "position": [
        680,
        -320
      ]
    },
    {
      "parameters": {
        "content": "## Interpret the response\n\n200: available or busy with a boolean result.\n400: invalid_request.\n502: unavailable, with no availability claim.\n\nA free result is a snapshot. Recheck before booking and account for concurrent calendar changes.",
        "width": 600,
        "height": 260
      },
      "id": "public-guide-calendar-availability-3",
      "name": "Interpret the response",
      "type": "n8n-nodes-base.stickyNote",
      "typeVersion": 1,
      "position": [
        680,
        500
      ]
    }
  ],
  "connections": {
    "Receive Request": {
      "main": [
        [
          {
            "node": "Validate Request",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Validate Request": {
      "main": [
        [
          {
            "node": "Request Is Valid",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Request Is Valid": {
      "main": [
        [
          {
            "node": "Check Calendar",
            "type": "main",
            "index": 0
          }
        ],
        [
          {
            "node": "Return Invalid",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Check Calendar": {
      "main": [
        [
          {
            "node": "Format Availability",
            "type": "main",
            "index": 0
          }
        ],
        [
          {
            "node": "Return Provider Error",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Format Availability": {
      "main": [
        [
          {
            "node": "Return Availability",
            "type": "main",
            "index": 0
          }
        ],
        [
          {
            "node": "Return Provider Error",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "settings": {
    "executionOrder": "v1",
    "timezone": "UTC",
    "saveDataSuccessExecution": "none",
    "saveDataErrorExecution": "none",
    "saveManualExecutions": false
  },
  "active": false
}