Automating Calendar Sync with N8N and LLMs 🗓️

Okay, so what I have here is a, view of my interaction with an LLM to create a N8N workflow.

in this case I happen to be using codecs.

this is a playback tool.

So if you're on the page that has this video on it, if you scroll down, you can use the playback tool to see, kind of all the detailed steps and expand everything.

a, there's a couple of beginning things where I'm talking about setting up and working on things.

So don't worry about that.

But essentially here I say I existing flow that I'm improving upon.

but contextually it doesn't matter.

So it's upgrading my calendar sync, where I've got two different work calendars, for different types of meetings and I want to get them on my personal calendar so that my personal calendar is blocked off for work meetings and then vice versa when I have, you know, like my kids pre K graduation, that's blocked out on my work calendar and vice versa.

Right.

So it all kind of comes together.

And so I proposed this.

Then I, asked it to plan first.

And so it came up with the plan and frankly didn't read this, but it essentially came through with, you know, take your personal calendar, your work calendar, this is my like to do list calendar and pull it all together and then do things.

I want everything to be private.

So like I don't need my work calendar to know that I have a doctor's appointment.

so when I sync something from my personal calendar to my work calendar, I make sure that the summary is generic and the visibility is private.

But like, it's just, it's blocking out time.

Right?

Like I'm not trying to hide anything, but it's like I don't need the details of one calendar going to the other calendar.

And I think I said let's go.

And so it definitely didn't write this.

It, you know, I clicked the button to implement this plan and it chase that down and did it.

And it had some back and forth.

For example, it was when it created the calendar event in my work calendar, it was saying source calendar id and I had the source calendar of like my email address.

I was like, I don't need my email address to be in my work thing, so let's just genericize it and make it something that doesn't expose domain names.

And so it went on and did that and it's like, hey, Just make it something that's machine readable but not human readable.

And that's, that's fine.

I ran the routine and it had a credentials issue.

The credentials issue was not a credentials issue.

It was a, I was throwing too many events at Google too quickly.

and it called that out.

Right.

It's like it's the right person.

You need to stop doing that.

I ran through and had some backup, had some issues but just kind of just hey, check.

What happened?

Is it working?

No.

Okay.

Make some changes.

I ran a few more tests.

Let's keep checking it and you know, has it back and forth and finally it kind of got to cool.

I've done it 10.

It did.

It decided to do 10 at a time to prevent the rate limiting problem.

did 10 more on the next batch.

There was only seven left.

It finished it and then I ran two more times with empty state and it worked out.

So that was done.

So anyway, This is the entire kind of conversation I had.

it's hard for me to tell you this is 15 minutes.

But that's not, you know, I left in between a lot of these points and didn't necessarily pay attention to it this entire time.

So I'll call out.

The tool that I use is called N8NCLI.

It's a, a third party tool but it basically allows you to, can apply workflows, convert workflows, import them, lint them and format them, test them, all that stuff.

So this is actually outdated.

I need to update my GitHub repo.

But what I've done is I've created a GitHub repo called N8N.

but theoretically this could just be a folder on your computer.

You don't need to put it in GitHub and then workflows.

And then in this case I was checking for a hotel in San Diego for Amex points or something.

but the point is that it created a file that is kept in on your local machine.

And so again I'm showing this to you in GitHub but like if you assume that this, this file existed on my computer, it allows Codex or Claude and I to work on this file locally, changes, make changes and then test it, lint it and ship it to my N8N instance and kind of figure out how to do it.

and so conceptually I have a library full of these different things which is useful because once you set it up, like the fact that this, this thing is like talk to Slack, do some code stuff and then execute it.

Well, it has my Slack account set up and it knows use, it can reference this to understand how I want to interact with something in Slack by looking at other neighboring workflows.

so by just throwing them all in a folder on your computer.

And this, this tool lets you do is just basically pull down all of your workflows locally onto your computer and then or figure out how to iterate on them, change them, create new ones.

by having all of those things locally on your computer, it's, it's help.

so there's install instructions here.

It's, it's again, I'm not even sure I did this.

I'm fairly sure that I just told, I gave in my case Codex this URL and said hey, go set this up and install it.

And I did.

So then this is the workflow it created.

So every hour it comes in and reconciles my events.

it gets my personal events, the two different work calendars I have and then does some.

I think this is like some sort of all it's doing is appending in this step, it's just appending the calendar ID to make sure that it knows which calendar that particular event came from.

and so that's what these things are for.

It then aggregates them all into a single kind of data flow.

So it's got one data set to like figure out what to do with.

And then this is kind of the magic set of it which is that it does a bunch of things again, I didn't write any of this is all Codex pulling it together and it's just kind of setting everything up and getting things ready.

But it's doing a couple things which is that it's like if it created an event called unavailable, which is the, the thing I use to block out something on a different calendar, you don't need to create it as a new one on a different system.

Right.

it's, it's trying to kind of deduplicate itself.

it also blocks out like I think on my personal calendar I have birthdays.

It doesn't worry about birthdays.

If I have all day events, it ignores those.

It's got a couple things that I kind of, I did It a couple times and saw how it was like he was adding random events and it was like, no, no, no, I don't need you to add this offense.

And so Told it to use certain rules to exclude.

it also only does from Monday to Friday, 9 to 5.

Like, there's no reason to add on my work calendar that I'm, you know, my kid has soccer practice Saturday morning.

It's just like, it's not relevant.

Right.

but again, I could read through this code and understand what it does, but like, it doesn't really matter because it wrote the code to filter all the events and push the events that I want and that kind of thing, and then it routes it back in.

This was the complicated part because I have three calendars at play here.

It created a bunch of different routing rules.

but again, that's fine.

This looks, looks complex, but didn't, I didn't write any of it.

And so on, the first work calendar, it, it decides to create, update, or delete things basically back here.

And then it just kind of chases those things down.

And then same thing on the second calendar.

Create, update, or delete things, and it chases those things down.

and these look a little different, which is that they are, they're not Google Calendar events.

But essentially, once you sign in with your Google Calendar credential here, it pulls up and again, I've got to redact it because I cleaned it up, but essentially this is just another Google Calendar, call here.

And so again, I didn't come in here.

know, the way you could have done this was to add, and go in here and search Google Calendar and, and try to figure out how to.

But I, I did not open this interface until my Codex had finished building all of it.

And then I came in here and kind of looked through it and made sure it all made sense.

And look, sometimes you've got to like, it'll.

It gives you this red warning.

It's like, hey, you, you haven't signed in with Google.

You need to, you need to connect the thing.

But that's easy, right?

setting this up and getting the flow right and getting logic right is the hard part.

And I spent very little time doing that because it was able to just kind of iterate through it.

So, anyway, that's the gist of it.

if you have any questions, feel free to reach out and happy to talk more about it.