--- title: Stripe webhooks with Deno slug: stripe-webhooks-with-deno published_at: 2021-12-15 17:00:44 +0000 updated_at: 2023-01-30 22:52:37 +0000 summary: description: Part two of how to handle webhooks using `stripe-node` in a Deno application. We recommend starting with the part one (https://youtu.be/epCHqHEdz8I). In this episode, CJ walks you through handling webhooks using `stripe-node` in a Deno application. ### Presenter CJ Avilla - Developer Advocate at Stripe - https://twitter.com/cjav_dev ### Table of contents 00:00 Introduction 01:00 Configuring your server 03:18 Webhook signing secret 03:47 CryptoProvider 04:43 Testing the endpoint 06:39 Conclusion ### Resources Standing up Deno and installing `stripe-node`: https://youtu.be/epCHqHEdz8I stripe-node: https://github.com/stripe/stripe-node Deno: https://deno.land/ ### Support If you have a question, please feel free to reach out to our support team on Discord at https://stripe.com/go/developer-chat ### Updates Sign up to stay updated with developer news: https://go.stripe.global/dev-digest ### Feedback If you have any feedback about this or other episodes, let us know: https://forms.gle/VjNqzRhotM2snYo88 #Stripe #Payments tags: [stripe, payments, Deno, webhooks, @cjav_dev] views: 716 author: CJ Avilla url: https://www.cjav.dev/videos/stripe-webhooks-with-deno youtube_url: https://www.youtube.com/watch?v=pA1YD4adP9I youtube_id: pA1YD4adP9I embed_url: https://www.youtube.com/embed/pA1YD4adP9I thumbnail_url: https://i.ytimg.com/vi/pA1YD4adP9I/hqdefault.jpg type: video --- # Stripe webhooks with Deno *Published: December 15, 2021* *Views: 716* ## Watch [Watch on YouTube](https://www.youtube.com/watch?v=pA1YD4adP9I) [![Stripe webhooks with Deno](https://i.ytimg.com/vi/pA1YD4adP9I/hqdefault.jpg)](https://www.youtube.com/watch?v=pA1YD4adP9I) ## Description Part two of how to handle webhooks using `stripe-node` in a Deno application. We recommend starting with the part one (https://youtu.be/epCHqHEdz8I). In this episode, CJ walks you through handling webhooks using `stripe-node` in a Deno application. ### Presenter CJ Avilla - Developer Advocate at Stripe - https://twitter.com/cjav_dev ### Table of contents 00:00 Introduction 01:00 Configuring your server 03:18 Webhook signing secret 03:47 CryptoProvider 04:43 Testing the endpoint 06:39 Conclusion ### Resources Standing up Deno and installing `stripe-node`: https://youtu.be/epCHqHEdz8I stripe-node: https://github.com/stripe/stripe-node Deno: https://deno.land/ ### Support If you have a question, please feel free to reach out to our support team on Discord at https://stripe.com/go/developer-chat ### Updates Sign up to stay updated with developer news: https://go.stripe.global/dev-digest ### Feedback If you have any feedback about this or other episodes, let us know: https://forms.gle/VjNqzRhotM2snYo88 #Stripe #Payments ## Transcript in this episode you'll learn how to handle web hooks using stripe node in a dino application [Music] if you haven't already seen our first video about getting started with stripe node and dino head over to the description of this video where we have a link to the getting started where we'll set up a basic dino web server and install stripe node nearly all stripe integrations require web hooks web hook event notifications are sent as post requests to your endpoint and they'll have a header in there called a stripe signature header these signatures are generated based on a hash based message authentication code or hmac code using sha-256 the stripe node client library provides some helper methods for verifying those signatures there's one trick required for verifying webhook signatures with dino because dino doesn't have the same crypto module that the node runtime has all right let's take a look taking a look at the server that we set up in the last episode you'll recall that we are importing stripe from esm and that the crux of the last episode was to pass in this http client so that we can specify fetch we are firing up a server with dino and using this general handler calling serve listener at the bottom let's add a new route to our web server here that will handle requests that come in with a path ending in slash web hook we'll create our new handler and call it handlewebhook and we're going to pass down the request now we'll define an asynchronous handle webhook function that takes in that request and to start with we'll we'll just build a basic webhook handler that will deserialize the payload as json here by calling request.json we'll check to see if the event type is one of customer.created and if so we'll just log a simple message to the console for any other event types we'll just console log the type of the event that came in now we're going to send back the stringified json for the event that we just read in with the status of 200. this is just to kind of like echo back that event type we can fire up our server with dino run dash dash allow net server.js and for experimentation we can send a post request to slash webhook data here is going to include a type of customer.created and we can see that the customer created log message in the console now this is not ideal because any malicious user could send in any data or try to provision access or they could try to trigger fulfillment where we would ship them items and in instead what we want to do is verify the signature that stripe sends us in the header and ensure that this message or this post request came from stripe and only stripe so the way we're going to do that is we're going to start by pulling out that stripe signature from the request header next we need to read the raw body of the request this is important and we don't really want the body to be modified so note that we are using text here and not json then we can use the stripe node helper to construct the event async by calling stripe.webhooks.constructevent async now this takes several arguments first we're going to pass in that raw request body then the signature from the request header then a webhook signing secret now each web hook that you set up whether it's from the stripe dashboard you create one through the api or you create a webhook listener using the stripe cli or the vs code extension you will get a unique web hook signing signature that will start with this wh sec underscore the fourth argument to this method is the tolerance for the time code as an integer we're just going to pass undefined and use the default tolerance and finally we need to pass in a crypto provider passing this crypto provider is the crux of getting signature verification working with striped node for dino now again this signing secret we want to pull this either out of the environment variables or out of some secure storage you may also be wondering where did this crypto provider come from so we can create a new instance of a subtle crypto provider using this stripe node helper so this creates a new crypto provider which uses the subtle crypto interface of the web crypto api instead of node's crypto module next let's wrap our verification in a try catch block and send back a response that is a 400 status code with the error message in the case that we were not able to verify the signature note that stripe will retry failed web hook notifications for up to three days with exponential back off and any status code above 299 including those 300s that are redirects are considered failures all right we'll fire up our server again to start let's try passing that same curl request note that now we get an error message that says we were unable to extract the timestamps and signatures from the header let's get a little bit more sophisticated with our attempt to subvert this signature verification by passing our own header and we'll just try to construct a dummy header that looks roughly like the one that stripe would send now we get back a message that says the key length is zero that's because we didn't actually specify a webhook signing secret so let's stop our server jump into server.js so in order to specify a webhook signing secret we need to have a webhook endpoint created inside of stripe for local testing and debugging the stripe cli is a really powerful tool we can call stripe listen and forward events to a local running server this will create a direct connection between your stripe account and your local running machine so that when events happen on your stripe account they are forwarded to the local machine we can take the webhook signing secret from stripe listen and paste that into server.js so that we now have a webhook signing secret ready to go for verifying signatures another handy tool from the stripe cli is called stripe trigger we can now call stripe trigger and pass in the event type in this case customer.created and that will result in all of the api calls required to fire that event now we can see that our customer was created successfully and those signatures were verified if we again try to send our curl request we now see a new error that says no signatures found matching the expected signature for that payload so as a quick recap we updated our basic dino server and added a web hook handler with signature verification and in the dino runtime we want to use that subtle crypto provider so we created one of those crypto providers and passed that into our construct event async verification function so that we were not using node's crypto module this has been another devbyte a series of short videos showing you how to use stripes apis and tools thanks so much for watching i'm cj avila and i'll see you in the next one --- [Back to all videos](https://www.cjav.dev/videos) --- ## Hey Agent, thanks for visiting! 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