{"product_id":"webhook-appointment-availability-check-for-google-calendar","title":"Webhook Appointment Availability Check for Google Calendar","description":"\u003ch3\u003eInstantly check Google Calendar appointment availability via an authenticated Webhook\u003c\/h3\u003e\n\u003cp\u003eThis n8n workflow exposes a secure webhook that verifies a requested time window and returns a structured JSON response showing whether the slot is \u003cstrong\u003eavailable\u003c\/strong\u003e or \u003cstrong\u003ebusy\u003c\/strong\u003e—based on your \u003cstrong\u003eGoogle Calendar\u003c\/strong\u003e free\/busy data.\u003c\/p\u003e\n\n\u003ch3\u003eWhat this workflow does\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReceives a POST webhook\u003c\/strong\u003e with authenticated header auth and a JSON body containing \u003cem\u003estart\u003c\/em\u003e and \u003cem\u003eend\u003c\/em\u003e timestamps.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eValidates input strictly\u003c\/strong\u003e:\n    \u003cul\u003e\n      \u003cli\u003eBoth timestamps must be RFC3339 with seconds and an explicit offset.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cem\u003eStart\u003c\/em\u003e must be in the future.\u003c\/li\u003e\n      \u003cli\u003eThe interval must be positive and \u003cstrong\u003eno longer than 24 hours\u003c\/strong\u003e.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQueries Google Calendar\u003c\/strong\u003e for free\/busy availability for the provided time window.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReturns normalized JSON\u003c\/strong\u003e including:\n    \u003cul\u003e\n      \u003cli\u003e\n\u003ccode\u003estatus\u003c\/code\u003e (available or busy)\u003c\/li\u003e\n      \u003cli\u003e\n\u003ccode\u003eavailable\u003c\/code\u003e (boolean)\u003c\/li\u003e\n      \u003cli\u003eNormalized \u003cstrong\u003eUTC start\u003c\/strong\u003e and \u003cstrong\u003eend\u003c\/strong\u003e\n\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUses clear HTTP outcomes\u003c\/strong\u003e:\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003e200\u003c\/strong\u003e for successful checks\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003e400\u003c\/strong\u003e for validation errors\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003e502\u003c\/strong\u003e if Google Calendar can’t be queried without making an availability claim\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUse cases\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003ePrevent double-booking in an appointment booking SaaS by checking availability before creating an event.\u003c\/li\u003e\n  \u003cli\u003eConfirm whether a proposed meeting time works when a user selects a slot.\u003c\/li\u003e\n  \u003cli\u003eIntegrate n8n into scheduling flows where your app needs a fast \u003cem\u003ewebhook-based\u003c\/em\u003e availability check.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical details\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNodes\/tech stack:\u003c\/strong\u003e \u003ccode\u003ewebhook\u003c\/code\u003e, \u003ccode\u003eif\u003c\/code\u003e, \u003ccode\u003ecode\u003c\/code\u003e, \u003ccode\u003egoogle calendar\u003c\/code\u003e, \u003ccode\u003erespond to webhook\u003c\/code\u003e (plus supporting workflow notes via sticky note).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAuthentication:\u003c\/strong\u003e Header Auth credential (authenticated webhook).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCalendar:\u003c\/strong\u003e Google Calendar OAuth, configurable \u003cstrong\u003ecalendar ID\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOutput:\u003c\/strong\u003e Structured JSON availability result.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"N8N Commerce","offers":[{"title":"Default Title","offer_id":46228895367347,"sku":"N8N-20962","price":37.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0749\/6279\/6723\/files\/sKh0Zw_mUXgvofjDJ_WWY_s9D6MHa5.png?v=1792055801","url":"https:\/\/buyflowscripts.com\/products\/webhook-appointment-availability-check-for-google-calendar","provider":"N8N Commerce","version":"1.0","type":"link"}