How to book appointments in Google Calendar with n8n

TFU AI cannot book into Google Calendar by itself yet. n8n can do it for you. Your agent asks n8n for open times and offers them. When the caller picks one, n8n books it in Google Calendar. Google Calendar stays your only diary.

Does the sub-account use GoHighLevel? Then connect Google Calendar inside GoHighLevel, and book into that GoHighLevel calendar instead.

How it works

You add one workflow to n8n and two workflows to your agent.

Agent workflow	What n8n does
Find a time	Reads your busy times in Google Calendar. Sends back up to six open times.
Book the time	Checks that the time is still open. Creates the event, or sends back new times.

n8n only offers times inside your opening hours. It refuses any other time, even if the agent asks for one.

Before you start

An n8n account. n8n Cloud connects Google with one button.
The Google account whose calendar gets the bookings.
A TFU Live agent.

Step 1: Add the workflow to n8n

Copy the workflow

Open The n8n workflow below and copy the JSON.

Paste it into n8n

In n8n, create a new workflow. Click the empty canvas and paste. If n8n asks whether you are pasting from an AI tool, click Skip.You can also save the JSON as a file. Then open the … menu at the top and choose Import, then From file.

The n8n workflow

{
  "name": "TFU AI: Google Calendar booking",
  "nodes": [
    {
      "id": "20aa38b9-0d53-4ed4-9e03-0ba7a3a04a7e",
      "name": "Webhook",
      "type": "n8n-nodes-base.webhook",
      "typeVersion": 2.1,
      "position": [
        0,
        0
      ],
      "webhookId": "d99aa4e0-1d4c-4484-b607-fe0915a893ff",
      "parameters": {
        "httpMethod": "POST",
        "path": "tfu-calendar",
        "authentication": "headerAuth",
        "responseMode": "responseNode",
        "options": {}
      }
    },
    {
      "id": "d2c42663-fae4-41cd-9f94-d3c462d9292d",
      "name": "Read busy times",
      "type": "n8n-nodes-base.googleCalendar",
      "typeVersion": 1.3,
      "position": [
        220,
        0
      ],
      "alwaysOutputData": true,
      "parameters": {
        "resource": "calendar",
        "operation": "availability",
        "calendar": {
          "__rl": true,
          "mode": "list",
          "value": "primary",
          "cachedResultName": "primary"
        },
        "timeMin": "={{ $now }}",
        "timeMax": "={{ $now.plus({ days: 15 }) }}",
        "options": {
          "outputFormat": "bookedSlots"
        }
      }
    },
    {
      "id": "bc54eea3-3edd-4332-bdab-e355ce43501c",
      "name": "Find open times",
      "type": "n8n-nodes-base.code",
      "typeVersion": 2,
      "position": [
        440,
        0
      ],
      "parameters": {
        "jsCode": "// Your settings. Change these to match your business.\nconst TIMEZONE = 'America/Chicago';\nconst OPEN_HOURS = {\n  mon: ['09:00', '17:00'],\n  tue: ['09:00', '17:00'],\n  wed: ['09:00', '17:00'],\n  thu: ['09:00', '17:00'],\n  fri: ['09:00', '17:00'],\n};\nconst APPOINTMENT_MINUTES = 30;\nconst NOTICE_MINUTES = 120;\nconst DAYS_AHEAD = 14; // Up to 14. Read busy times reads 15 days.\nconst TIMES_PER_DAY = 3;\nconst MAX_TIMES = 6;\n\n// You do not need to change anything below this line.\nconst body = $('Webhook').first().json.body || {};\nconst fields = body.fields || {};\nconst contact = body.contact || {};\nconst busy = $input.all()\n  .map(item => item.json)\n  .filter(slot => slot.start && slot.end)\n  .map(slot => [DateTime.fromISO(slot.start).toMillis(), DateTime.fromISO(slot.end).toMillis()]);\n\nconst now = DateTime.now().setZone(TIMEZONE);\nconst earliest = now.plus({ minutes: NOTICE_MINUTES });\nconst lastDay = now.startOf('day').plus({ days: Math.min(DAYS_AHEAD, 14) });\nconst DAY_NAMES = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun'];\n\n// Every open time from today to the last day.\nconst open = [];\nfor (let day = now.startOf('day'); day < lastDay; day = day.plus({ days: 1 })) {\n  const hours = OPEN_HOURS[DAY_NAMES[day.weekday - 1]];\n  if (!hours) continue;\n  const [openAt, closeAt] = hours.map(time => {\n    const [hour, minute] = time.split(':').map(Number);\n    return day.set({ hour, minute });\n  });\n  for (let start = openAt; start.plus({ minutes: APPOINTMENT_MINUTES }) <= closeAt; start = start.plus({ minutes: APPOINTMENT_MINUTES })) {\n    const end = start.plus({ minutes: APPOINTMENT_MINUTES });\n    const taken = busy.some(([from, to]) => from < end.toMillis() && to > start.toMillis());\n    if (start >= earliest && !taken) open.push(start);\n  }\n}\n\nconst label = time => time.toFormat(\"cccc d LLLL 'at' h:mm a\");\nconst code = time => time.toFormat(\"yyyy-LL-dd'T'HH:mm\");\n\n// The times to offer: from the day the caller asked for, a few per day.\nfunction offer() {\n  const asked = /^\\d{4}-\\d{2}-\\d{2}$/.test(fields.day || '') ? DateTime.fromISO(fields.day, { zone: TIMEZONE }) : now;\n  const perDay = {};\n  const times = [];\n  for (const time of open) {\n    if (time < asked.startOf('day') || times.length >= MAX_TIMES) continue;\n    const day = time.toISODate();\n    perDay[day] = (perDay[day] || 0) + 1;\n    if (perDay[day] <= TIMES_PER_DAY) times.push(`${label(time)} (code ${code(time)})`);\n  }\n  return { times: times.join('\\n') || 'none', count: times.length };\n}\n\nif (fields.action === 'book') {\n  const wanted = DateTime.fromISO(String(fields.start || ''), { zone: TIMEZONE });\n  const time = wanted.isValid ? open.find(slot => slot.toMillis() === wanted.toMillis()) : undefined;\n  if (time) {\n    const name = [contact.firstName, contact.lastName].filter(Boolean).join(' ') || 'New lead';\n    return [{ json: {\n      book: true,\n      event: {\n        start: time.toISO(),\n        end: time.plus({ minutes: APPOINTMENT_MINUTES }).toISO(),\n        summary: `Call with ${name}`,\n        description: [`Phone: ${contact.phone || 'not given'}`, `Email: ${contact.email || 'not given'}`, 'Booked by your TFU AI agent.'].join('\\n'),\n      },\n      answer: { booked: 'yes', when: label(time), times: 'none', count: 0 },\n    } }];\n  }\n  return [{ json: { book: false, answer: { booked: 'no', when: 'none', ...offer() } } }];\n}\n\nreturn [{ json: { book: false, answer: { booked: 'no', when: 'none', ...offer() } } }];\n"
      }
    },
    {
      "id": "bc0a614c-7030-4bfb-a7ca-05df2c59e5c4",
      "name": "Book it?",
      "type": "n8n-nodes-base.if",
      "typeVersion": 2.2,
      "position": [
        660,
        0
      ],
      "parameters": {
        "conditions": {
          "options": {
            "caseSensitive": true,
            "leftValue": "",
            "typeValidation": "strict",
            "version": 2
          },
          "conditions": [
            {
              "id": "9bc3c1e1-4633-4204-ba0c-6ad4ccbeb42b",
              "leftValue": "={{ $json.book }}",
              "rightValue": "",
              "operator": {
                "type": "boolean",
                "operation": "true",
                "singleValue": true
              }
            }
          ],
          "combinator": "and"
        },
        "options": {}
      }
    },
    {
      "id": "3e123159-27bc-466f-b915-c48c1a513bc8",
      "name": "Create event",
      "type": "n8n-nodes-base.googleCalendar",
      "typeVersion": 1.3,
      "position": [
        880,
        -100
      ],
      "parameters": {
        "calendar": {
          "__rl": true,
          "mode": "list",
          "value": "primary",
          "cachedResultName": "primary"
        },
        "start": "={{ $json.event.start }}",
        "end": "={{ $json.event.end }}",
        "useDefaultReminders": true,
        "additionalFields": {
          "summary": "={{ $json.event.summary }}",
          "description": "={{ $json.event.description }}"
        }
      }
    },
    {
      "id": "131b1647-8dfe-43f9-9408-5523a793c84a",
      "name": "Reply to TFU AI",
      "type": "n8n-nodes-base.respondToWebhook",
      "typeVersion": 1.4,
      "position": [
        1100,
        0
      ],
      "parameters": {
        "respondWith": "json",
        "responseBody": "={{ $('Find open times').first().json.answer }}",
        "options": {}
      }
    }
  ],
  "connections": {
    "Webhook": {
      "main": [
        [
          {
            "node": "Read busy times",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Read busy times": {
      "main": [
        [
          {
            "node": "Find open times",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Find open times": {
      "main": [
        [
          {
            "node": "Book it?",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Book it?": {
      "main": [
        [
          {
            "node": "Create event",
            "type": "main",
            "index": 0
          }
        ],
        [
          {
            "node": "Reply to TFU AI",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Create event": {
      "main": [
        [
          {
            "node": "Reply to TFU AI",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "settings": {
    "executionOrder": "v1"
  }
}

Step 2: Connect Google Calendar

Open Read busy times. Under Credential, create a new credential. Click Sign in with Google, choose the account and click Allow.

Choose the calendar

Under Calendar, keep primary or choose another calendar.

Do the same in Create event

Open Create event. Choose the same credential and the same calendar.

Read busy times with the Google Calendar credential, the primary calendar and the Booked Slots output.

Self-hosted n8n has no one-click Google sign-in. Create your own Google client first, as in n8n’s Google guide. If that Google app stays in testing mode, the sign-in ends after seven days. Then sign in again.

Step 3: Protect the webhook

Anyone with the webhook address could book into your calendar. A secret header stops that. n8n refuses a request without it.

Open the Webhook node

Authentication is already Header Auth. Under Credential for Header Auth, create a new credential.

Set the secret

Enter X-Webhook-Secret as the Name. Enter a long random string as the Value. Keep a copy for Step 6, then click Save.

The Header Auth credential, with X-Webhook-Secret as the name and a hidden value.

Step 4: Set your opening hours

Open Find open times. Change the settings at the top of the code. Do not change anything below the line that says so.

Setting	What it does	Default
`TIMEZONE`	Your business time zone, such as `America/Chicago`. The agent offers times in it.	`America/Chicago`
`OPEN_HOURS`	When you open and close each day, in 24-hour time. Leave a day out to close it.	Monday to Friday, `09:00` to `17:00`
`APPOINTMENT_MINUTES`	How long an appointment lasts. Times start this far apart.	`30`
`NOTICE_MINUTES`	How soon the first time can be.	`120`
`DAYS_AHEAD`	How many days ahead to look. Up to `14`.	`14`
`TIMES_PER_DAY`	The most times offered on one day.	`3`
`MAX_TIMES`	The most times the agent gets.	`6`

The Find open times code, with the settings at the top.

Step 5: Publish and copy the address

Publish

Click Publish at the top right, then Publish again.

Copy the Production URL

Open Webhook. Under Webhook URLs, click Production URL and copy it. The Test URL works only while n8n listens for a test event.

The Webhook node, with the Production URL shown and Header Auth chosen.

Step 6: Add Find a time to your agent

Open the agent and click Configure myself. On Brain, click Actions. Click Add a workflow, then Start blank.

Name it

Enter Find a time as the Workflow name. Under When to run it, enter The lead wants to book a call, or asks when we are free. Also run it again when they ask about a different day. Click Done.

The Find a time workflow, with its name and when to run it.

Ask for a day

Click + after the workflow, then Collect information.

Setting	Value
What to collect	`Preferred day`
How the AI asks	`Ask which day suits them. If they have no preference, leave this empty.`
Save to	Only for this call, not saved
Data type	Date
Required	Off

Collect information set to Preferred day, a date, not required.

Call n8n

Click + after it, then Webhook with response.

Setting	Value
Endpoint URL	The Production URL from Step 5
Method	`POST`
Timeout (ms)	`10000`
Fields	`action` from Fixed text `find`. Then `day` from Collected answer Preferred day.
Headers	`X-Webhook-Secret`, with the value from Step 3. Secret turns on by itself.
Use from the response	Name `times`, path `times`. Name `count`, path `count`.

Webhook with response with the n8n address, the action and day fields, the secret header and the times and count values.

Tell the agent what to say

On Success, add Steer the agent with this guidance:

The open times are below, one per line. Offer two of them, on different days if you can. Say only the day and the time, never the code. Never offer a time that is not on this list. If the list says none, say there are no open times in the next two weeks and offer a call back from the team. When the caller picks a time, run Book the time with the code of that time.
{{response.times}}

On Failed, add another Steer the agent:

You could not check the calendar. Say sorry, you cannot see the diary right now. Offer a call back from the team to book. Never say a time is free.

The finished Find a time workflow: Collect information, Webhook with response, then Steer the agent on Success and on Failed.

Step 7: Add Book the time to your agent

Click Add a workflow, then Start blank again.

Name it

Enter Book the time as the Workflow name. Under When to run it, enter The lead picked one of the times that Find a time gave you and said yes to it.

Get the chosen time

Add Collect information. Enter Time code under What to collect. Under How the AI asks, enter Use the code of the time the caller picked, from Find a time. Never ask the caller for a code. Keep Text and Required.

Call n8n

Add Webhook with response. Use the same address, method, timeout and header as in Step 6.

Setting	Value
Fields	`action` from Fixed text `book`. Then `start` from Collected answer Time code.
Use from the response	`booked`, `when` and `times`, each with the same path.

Webhook with response with the action and start fields, the secret header and the booked, when and times values.

Check the answer

On Success, add Condition. Choose booked as the Field, equals as the Comparison and yes as the Value. Name the route Booked, and name Otherwise Not booked.

The Condition: booked equals yes on the Booked route, and Not booked when no route matches.

Tell the agent what to say

Add Steer the agent on each route.On Booked:

The appointment is booked for {{response.when}}. Tell the caller the day and time, and say the team will call them then. Do not run Book the time again.

On Not booked:

That time was just taken, so nothing was booked. Say sorry and offer two of these new times instead. Say only the day and the time, never the code. When the caller picks one, run Book the time again with its code.
{{response.times}}

On Failed:

You could not confirm the booking. Do not say it is booked. Say sorry, the diary did not respond, and offer a call back from the team to book.

Save

Click Save changes.

The finished Book the time workflow: Collect information, Webhook with response, a Condition with Booked and Not booked, and Steer the agent on each path.

Step 8: Test it with a real call

The agent test in the builder never calls n8n. Both workflows take the Failed path there, and the agent says it cannot see the diary. Test with the campaign instead.

Start a campaign test in your browser

Click Test, choose Web, then click Run next to Campaign. Enter a name and a phone number, then click Start campaign session. This is a real call in your browser, so the booking is real too.

The Run a test menu with Web chosen, and Run next to Campaign.

Book a time

Ask for a call, ask for a day and pick a time. The conversation shows each workflow as it runs.

A test call: the caller asks for Wednesday, Find a time runs, the agent offers two times, Book the time runs, and the agent confirms the booking.

Check n8n and Google Calendar

In n8n, open Executions. A booking shows every step in green. The event is in Google Calendar, with the lead’s phone and email.

An n8n execution where every step ran, through Create event to Reply to TFU AI.

What this setup does not do

It does not cancel or move a booking. Do that in Google Calendar.
The event has no guests, so Google sends no invite.
Two callers who book the same time in the same second can both get it. This is rare. Move one of them in Google Calendar.

Troubleshooting

The agent says it cannot see the diary

Open Executions in n8n. If nothing ran, check three things. The workflow is published. TFU AI uses the Production URL. The secret is the same in TFU AI and in n8n. If a run failed, open it to see the step that stopped. n8n must answer within 10 seconds.

The agent offers times when you are busy

Read busy times reads one calendar. Choose the calendar you book into, and choose the same one in Create event.

The times are a few hours off

Set TIMEZONE in Find open times, then publish again. Google Calendar may show the event in your own time zone. The time is still right.

You moved n8n to a new address

Enter the secret again in both Webhook with response steps. TFU AI keeps a secret only for the address it was saved with.

Next steps

Workflows: every step you can add.
Test your agent: the other ways to test.
TFU Live authoring: build agents over the API.
How-to guides: more step-by-step guides.

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How to book appointments in Google Calendar with n8n

How it works

Before you start

Step 1: Add the workflow to n8n

Step 2: Connect Google Calendar

Step 3: Protect the webhook

Step 4: Set your opening hours

Step 5: Publish and copy the address

Step 6: Add Find a time to your agent

Step 7: Add Book the time to your agent

Step 8: Test it with a real call

What this setup does not do

Troubleshooting

Next steps