--- title: Stripe Checkout clientRefrenceId slug: stripe-checkout-clientrefrenceid published_at: 2021-01-06 17:00:36 +0000 updated_at: 2026-03-04 20:14:36 +0000 summary: description: tags: [] views: 340 author: CJ Avilla url: https://www.cjav.dev/videos/stripe-checkout-clientrefrenceid youtube_url: https://www.youtube.com/watch?v=kslu9SKNtaw youtube_id: kslu9SKNtaw embed_url: https://www.youtube.com/embed/kslu9SKNtaw thumbnail_url: https://i.ytimg.com/vi/kslu9SKNtaw/hqdefault.jpg type: video --- # Stripe Checkout clientRefrenceId *Published: January 06, 2021* *Views: 340* ## Watch [Watch on YouTube](https://www.youtube.com/watch?v=kslu9SKNtaw) [![Stripe Checkout clientRefrenceId](https://i.ytimg.com/vi/kslu9SKNtaw/hqdefault.jpg)](https://www.youtube.com/watch?v=kslu9SKNtaw) ## Description ## Transcript hey folks uh i've had a couple questions recently uh around checkout and how to use the client reference id in particular and how that flows from the client uh through stripe and through the web hook handler back to your web hook a couple questions about just like setting up the webhook handler in general and those have been in php so today i wanted to just like do a super quick video where we're going to set up a php backend and a very simple client to show how to pass that client reference id in checkout through to your webhook handler so let's jump into some code here i'm going to make the client a directory for a client and a directory for a server and i'm just going to start with very basic client index.html that will be blank and server server.php which will also be blank okay let's use a little bit of tmx with the screen here and the first things i'm going to do is i'm going to install with composer i'm going to install the stripe php library and also slim 3.2 which is going to be our web framework and then i'm going to use dot end php.n from v lucas as uh to manage my environment variables so as that's installing i'll come over here and open up my client um here okay it's blank html file um actually let's make this start with demo okay and then i'm really just gonna follow the guide here for checkout so we'll start with recurring payments and we're going to start a subscription and yeah so this is how it's going to work step one is going to be we're going to have some plans and products which we've already created our dashboard the plan is called starter so i'm kind of just going to gloss over this step one you can go check it out in your dashboard you can go create products and plans so our plan has the id starter we're gonna use that so jumping into step two here it says create a checkout session on your server so we could optionally create this session on our server i'm actually going to do this on the client the question was more about setting this up on the client so i'm going to use the client only integration here for recurring payments going down here to creating that um wow recurring payments here okay so this is how this works so we want to redirect to checkout when a button is clicked so we're going to add a button here um it's going to have an id checkout button and we're going to say checkout i'm just going to say checkout okay and then instead of having a sku we're gonna use a plan we're gonna use starter okay and this is gonna pass forward the customer email address now the question here was how do i pass a client reference id from the front end and receive that in my web hook handler on the back end so the client reference id is something you can pass here this could be a string this could be some value it could be you know like the id of the user in your database or something so here we're going to say like my test ref id okay so we're looking for this coming back in our web hook handler all right so let's grab reference to this checkout button check out button and when it's clicked we want to actually do this redirect to checkout stuff okay and then if there for some reason there's an error we'll console log the error um uh or the result here all right so now we should have at least a button that we can click and it's gonna redirect to checkout but we don't actually have a server yet that we can use so let's go to our server all right so this was the front end stuff we're mostly done with that we'll go to the back end okay we're going to use dot n to manage our environment variables and we're going to use a slim app um okay and what we want to say here is uh the very first thing we want to do is just like make sure that we can get the client html page i'm going to actually kill that and okay so to start up the server i'm going to say php dash s local host 4242 server.php that's actually roughly the right thing for some reason um using index.php works a little better uh okay so now we have local let's let's go check this out and see if it's working um let me show you the browser okay so in the browser we have a checkout button and when we click on the checkout button we should be redirected to the checkout page and we're not so let's see if there's any errors the way that we can look and see if there's errors in the client is we right click and say inspect element or inspect okay this opens the chrome console i mean i'm using google chrome here and if there is an error we'll see the error there we can click on it and it says stripe is not defined okay stripe is not defined so this is the first step in debugging is like look and see what the errors are so we click on this nothing's happening it's because stripe is not defined so we need to go back into our code for the client and make sure that stripe is defined so here we are using stripe redirect to checkout but we're not actually using we haven't included stripe.js yet so we'll include that refresh the page clear clear our errors refresh click on checkout stripe is still not defined so i included stripe.js but didn't actually fire it up okay so now we have included it and initialized it refresh the page and okay sorry browser back to the browser okay refresh click on checkout and now we're being redirected to the the checkout page here put in some test card details and hit submit and now the checkout is processing and we're redirecting back to our page or to the success url that we used on the client so that that is looking good now we need to figure out how to handle this client reference id coming back to our system so this is going to be done by using a web hook so we want to pull up the web hook strike web hook setup and we're using php today and let's see so yeah so this code here if you just copy and paste this code it gets us pretty close in a slim app it looks a little differently because we need to create our own url here and we're going to send back like message okay and that did not paste well okay this is missing a close bracket all right so this is just the code that we copy and pasted from the stripe web hook handler so let's go through this line by line and talk about what each thing does by default slim map has some methods that help us get the body and construct an event from the body so we're not going to actually use this file get contents because we are using slim's post request handler so we'll remove that we'll call the payload just request.body request.getbody and we're going to construct the event from that okay so now if the event is constructed successfully that means that we were able to parse the post request that came from stripe to this webhook endpoint and we're saying handle the handle the response with the 400 and then exit so in that case we actually want to with json error and then i believe this is 400 here okay and we're going to handle the event type so depending on the event type there are already methods that are implemented here that are being made they're they were like in the documentation but they're not actually implemented for you so it's expected that you would write your own handle payment intent success succeeded method uh so here we're actually just going to comment these out um in fact we're going to delete all this because we only want to handle checkout.session.compleated and in the case that checkout session completed happened what we're really interested in is looking at the event so we want to just like console log that event or log it to the the um to the server log here okay and then if for some reason it did not fail event not handled okay all right so i think this is roughly what we're looking at doing now with the stripe cli we can test this out so we can say stripe listen forward to stripe listen forward to localhost webhook what did we call it webhooks or webhook called it webhook okay so now we're forwarding events to the web hook strike listen web hook all right and this is going to be our web hook secret that we're gonna we could use for web hook like uh verifying the authenticity of our web hook if you want more information about like how to set up web hook handlers we did that in another episode but this is really just to show you how the web hook um event is passed through so i have two of those all right so here we can do stripe trigger checkout.set it's going to create a bunch of resources for us and trigger a checkout session completed event and you'll see here that our server is now handling these different events including this checkout session completed event so this was one of the many events that we're handling okay and if we look in our server lat our server log here you'll see that we did print out one event and the event id is here and if we scroll all the way down to the bottom we see that the type of the event was a checkout session completed event we should uh where did that go type where is the type ah yes here check out session completed okay so uh that is just one way to test is using stripe listen and stripe trigger so the listener forwards the web hook events that are being sent by stripe to our system and it lets us forward those to our local development machine and then stripe trigger lets us trigger those events without actually having to go through the checkout so let's look at um let's look at this in a little bit more depth and or like a little bit more completely so from the front end um i can show you what this looks like so if we're yeah we've got our server going here let's move back to the browser and i'll show you this from scratch so localhost 4242 when we click the checkout button we will be redirected to the stripe hosted checkout page we fill in our information and remember sorry let's let's let's uh let's take a step back so in the sources for creating our redirect to checkout right so when we click this button we're using stripes redirect to checkout function and we're passing this client reference id of my test reference id okay so if i put a break point there i can click on the line number and that adds a break point so when i click checkout it breaks on that line and then i can use these tools over here to like step over a line or into a line i'm going to step over the line and i can kind of like walk through the function as it's happening but i know that right here we're going to redirect to another page so i'm just going to click play and we are looking for again this client reference id to be passed back to us in the webhook handler so we're going to click play here and fill out our details click subscribe we're subscribing to some monthly starter plan and then if we look back at our server log okay this is where we're going to be waiting to receive a web hook event for a checkout session completed and it looks like we did so now if we if we scroll up within this event data we should see the client reference id and we do so here is my test ref id this is the client reference id that came from the front end okay so this is how the client reference id is passed from the back end to the front end now um let's keep that going so a couple of questions um all right if you were to uh instead of commenting out or if you were to use like handled checkout let's see in the docs right we have this um recurring payments starting a subscription we say handle the web hook completed event how do we show you how to do this after the payment maybe we should have okay so here we have an example of how to complete um or how to set up the webhook handler right and here in the webhook handler code we say fulfill the purchase and we have this handle checkout session so let's say that we copied this content directly from here right and so we know that our code is making it into i'm sorry you weren't looking at the browser so in the in the after payment after the payment section of the checkout docs there's a section here for setting up the webhook handler and down in the webhook handler we say break out the session from the event data and then fulfill the purchase by passing the session to this handle checkout session function but it turns out this handle checkout session function is not defined so if we just copied that and pasted it here instead of actually like implementing that handle checkout session function i want i want to show you what happens okay so if we were to just copy and paste it directly from copy paste the the web hook handler directly from the documentation this is what would happen we would when we complete our checkout it's going to throw a 500 error because that function is not defined that handle checkout function is just a it's like a placeholder it's expected that you as the developer would fill that in with the logic that takes the client reference id and does something with it okay so here we're completing the processing and then we'll go back over to the code and we do see that this through a 500 response right so that 500 response if we were to log into our dashboard we would be able to see that in our dashboard too and let me just show you that here so pull up the browser okay so if we go to our events or our web hooks and we pulled up the uh the webhook event for checkout session completed you'll see that it's failing but also let's see okay sorry go back to the events filter it by the type of checkout.session.com okay checkout session was completed it's failing to this one because i don't have ngrok set up anymore but the one that we really care about is the one that's going to stripe cli because that's what we're testing with and you'll see that it's responding with a 500 internal server error and that lines up with what we're seeing in our server logs right so like in the server log here we are like crashing and this is a big long nasty error from line 36 which is telling us here that there is no function defined for message call to undefined function handle checkout session so it's attempting to call handle checkout session which was in our documentation but is really just a placeholder sorry so here here in server logs this is where we're looking message call to undefined function handle checkout session right there at the top of uh of that function so the problem here is that in the documentation we give you a call to this handle checkout session function but this function is something that you have to define yourself to pull out the client reference id if that's what you're using and you and like actually use that to fulfill the purchase so here instead you might either like go down and define a function that does this or alternatively you might just say like let's debug like uh we're just going to print out to the console session and i believe this is going to be client reference id okay note that this is only in the case of the checkout session completed event type if you have another event type that you're handling here maybe like charge dot succeeded the charge that succeeded event doesn't contain the client reference id the way that we know that is based on the type of event so here the type of event is a charge succeeded and the base of that type is charge so the data that's going to be included in the charge succeeded event is the charge data here in the check and checkout session completed event the data that's included is going to be a checkout session so if we go over to the api reference back in the browser here so we pull up the api reference for [Music] checkout session sorry here pull up checkout session okay so the session object is what's coming back when when a checkout.session.com event happens the data that's coming back is a checkout session completed is a session object and the session object has a client reference id this was the id that we used when we passed it from the client forward we are not passing the client reference id as part of a charge because a charge object is what's included the charge object is what's included in charge that's exceeded and the charge object does not have a client reference id so because the charge object doesn't have a client reference id if we're listening for charge that succeeded that's not going to have the id that we're looking for okay so it's really important that we're picking the right event type here and listening to checkout session completed and handling the fulfillment of that purchase with checkout session completed because that's where we're going to have the client reference id all right so now that we have refreshed this what we're looking for now is to see in the server log that that client reference id is output so if we go back yeah so this is the checkout session completed event we're expecting this client reference id to be logged to the server log when the checkout session completes i'm just going to go back to the flow again on the browser and let you watch the server log here so i clicked checkout and then i'm going through the whole process of paying okay clicking subscribe and now we're going to see some events come through okay undefined property of stripe charge client reference id that's because we attempted to access client reference id on the charge but it wasn't there so now uh we printed null and now we're printing out um my ref id this is this first error is because in that case statement we didn't put any content for the charge that succeeded but we are indeed printing out my test ref id which is the client reference id from the checkout client so hopefully this was helpful um yeah again uh passing the client reference id through a couple of keys one the method that's defined in the docs um or that is called in the docs it's invoked handle checkout session is not actually defined anywhere so you would have to define and implement that method yourself or you can just kind of like delete it and replace the content of that webhook handler with your own logic for for dealing with the client reference id the other thing is that the client reference id is only available on the checkout session object it's not on the charge succeeded it's not on any other object so you will want to make sure that you're listening for the checkout session completed event type cool all right that's it for today --- [Back to all videos](https://www.cjav.dev/videos) --- ## Hey Agent, thanks for visiting! 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