<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/elements/1.1/">
  <channel>
    <title>DEV Community: Gabriel Rodewald</title>
    <description>The latest articles on DEV Community by Gabriel Rodewald (@gabriel_rodewald).</description>
    <link>https://dev.to/gabriel_rodewald</link>
    <image>
      <url>https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3937975%2Fb48d4240-588d-4349-8c12-9ce311b45793.gif</url>
      <title>DEV Community: Gabriel Rodewald</title>
      <link>https://dev.to/gabriel_rodewald</link>
    </image>
    <atom:link rel="self" type="application/rss+xml" href="https://dev.to/feed/gabriel_rodewald"/>
    <language>en</language>
    <item>
      <title>Stripe vs Paddle vs Lemon Squeezy: Wiring All Three Behind One Protocol</title>
      <dc:creator>Gabriel Rodewald</dc:creator>
      <pubDate>Mon, 18 May 2026 15:19:53 +0000</pubDate>
      <link>https://dev.to/gabriel_rodewald/stripe-vs-paddle-vs-lemon-squeezy-what-wiring-all-three-behind-one-protocol-51cm</link>
      <guid>https://dev.to/gabriel_rodewald/stripe-vs-paddle-vs-lemon-squeezy-what-wiring-all-three-behind-one-protocol-51cm</guid>
      <description>&lt;div class="table-wrapper-paragraph"&gt;&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Stripe&lt;/th&gt;
&lt;th&gt;Paddle&lt;/th&gt;
&lt;th&gt;Lemon Squeezy&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;Direct processor. Fastest to set up. You handle your own VAT and sales tax. Fits US-focused SaaS, or any product that already has tax infrastructure in place.&lt;/td&gt;
&lt;td&gt;Merchant of Record for higher volumes. Provides invoicing, revenue reports, and enterprise billing flows. Fits B2B SaaS or companies that need formal financial tooling and VAT handled at scale.&lt;/td&gt;
&lt;td&gt;Merchant of Record. Handles global tax on your behalf. Fits indie developers selling digital products internationally, where compliance matters more than optimizing fees.&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;&lt;/div&gt;

&lt;p&gt;I wired all three into the same codebase. Here is what you find out only by doing it.&lt;/p&gt;

&lt;p&gt;Different billing providers have header names and verification methods. That's about the thing you can count on, but what about the rest? Let's take a look:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Stripe's webhook signature comes in the &lt;code&gt;Stripe-Signature&lt;/code&gt; header.&lt;/li&gt;
&lt;li&gt;Paddle's webhook signature comes in the &lt;code&gt;Paddle-Signature&lt;/code&gt; header. It looks like this: &lt;code&gt;ts=1704067200;h1=abc123def456&lt;/code&gt;.&lt;/li&gt;
&lt;li&gt;Lemon Squeezy's webhook signature comes in the &lt;code&gt;X-Signature&lt;/code&gt; header.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;When you connect one billing provider you just learn its API, but when you connect three providers behind the same interface you really learn what billing is all about. You see what it looks like under all the software development kits (SDKs) and provider documentation.&lt;/p&gt;

&lt;h2&gt;
  
  
  The problem with integrating each provider
&lt;/h2&gt;

&lt;p&gt;Most billing code is written using a providers SDK. It works fine until your business needs to switch providers or you want to run your tests without hitting a live API.&lt;/p&gt;

&lt;p&gt;That's when you realize that your checkout logic, webhook handlers and subscription queries are all mixed up with Stripe's details. If you want to switch providers you have to rewrite the application layer.&lt;/p&gt;

&lt;p&gt;A better approach would be to figure out what billing really means before deciding which provider to use.&lt;/p&gt;

&lt;h2&gt;
  
  
  The six-method protocol
&lt;/h2&gt;

&lt;p&gt;In Python, a &lt;code&gt;Protocol&lt;/code&gt; defines a contract through structural subtyping. Any class implementing the right methods satisfies it, without inheritance.&lt;/p&gt;

&lt;p&gt;For billing, six methods cover the full lifecycle:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="k"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;BillingProvider&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;Protocol&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;list_plans&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;list&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;PlanResponse&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt; &lt;span class="bp"&gt;...&lt;/span&gt;

    &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;create_checkout&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;organization_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;plan_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="n"&gt;success_url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;cancel_url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;

    &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;CheckoutResponse&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;...&lt;/span&gt;
    &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;create_portal_session&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;organization_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;return_url&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;PortalResponse&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;...&lt;/span&gt;

    &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;get_subscription&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;organization_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;SubscriptionResponse&lt;/span&gt; &lt;span class="o"&gt;|&lt;/span&gt; &lt;span class="bp"&gt;None&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;...&lt;/span&gt;

    &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;cancel_subscription&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;organization_id&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="n"&gt;SubscriptionResponse&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;...&lt;/span&gt;

    &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;handle_webhook&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;payload&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;bytes&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;signature&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="bp"&gt;...&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The domain layer relies on the protocol. We have three adapters that use this protocol. Our application does not directly use Stripe, Paddle or Lemon Squeezy. It only uses a BillingProvider.&lt;/p&gt;

&lt;h2&gt;
  
  
  What implementing three adapters reveals
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Webhook verification
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;Stripe&lt;/strong&gt; delegates to its SDK:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;event&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;stripe&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;Webhook&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;construct_event&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;payload&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;signature&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;config&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;webhook_secret&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Paddle&lt;/strong&gt; uses a custom header format: &lt;code&gt;ts=1704067200;h1=abc123&lt;/code&gt;. You split it, extract timestamp and hash, then verify manually:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;parts&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;dict&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;part&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;split&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;=&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;part&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;signature&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;split&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;;&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
&lt;span class="n"&gt;ts&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;parts&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;ts&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;""&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="n"&gt;h1&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;parts&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;h1&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;""&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

&lt;span class="n"&gt;expected&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;hmac&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;new&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;secret&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;encode&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;ts&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="s"&gt;:&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;payload&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;decode&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;encode&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="n"&gt;hashlib&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;sha256&lt;/span&gt;
&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;hexdigest&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;hmac&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;compare_digest&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;expected&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;h1&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="k"&gt;raise&lt;/span&gt; &lt;span class="nc"&gt;ValueError&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Invalid Paddle webhook signature&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Lemon Squeezy&lt;/strong&gt; uses a direct HMAC-SHA256 over the raw payload:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;expected&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;hmac&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;new&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;secret&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;encode&lt;/span&gt;&lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="n"&gt;payload&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;hashlib&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;sha256&lt;/span&gt;
&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;hexdigest&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;

&lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="ow"&gt;not&lt;/span&gt; &lt;span class="n"&gt;hmac&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;compare_digest&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;expected&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;signature&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="k"&gt;raise&lt;/span&gt; &lt;span class="nc"&gt;ValueError&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Invalid Lemon Squeezy webhook signature&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Here is the rule for all three: you have to check the bytes before you do any JSON parsing. The signature is for the payload. If you parse the JSON first and then check it does not work because the JSON can change the bytes without you noticing.&lt;/p&gt;

&lt;h3&gt;
  
  
  Event types
&lt;/h3&gt;

&lt;p&gt;After you have checked the payload you still need to know what is going on. Each provider names event types differently.&lt;/p&gt;

&lt;div class="table-wrapper-paragraph"&gt;&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;What happened&lt;/th&gt;
&lt;th&gt;Stripe&lt;/th&gt;
&lt;th&gt;Paddle&lt;/th&gt;
&lt;th&gt;Lemon Squeezy&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;Payment succeeded&lt;/td&gt;
&lt;td&gt;&lt;code&gt;checkout.session.completed&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;transaction.completed&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;order_created&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Subscription created&lt;/td&gt;
&lt;td&gt;&lt;code&gt;customer.subscription.created&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;subscription.created&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;subscription_created&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Subscription cancelled&lt;/td&gt;
&lt;td&gt;&lt;code&gt;customer.subscription.deleted&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;subscription.canceled&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;subscription_cancelled&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;Payment failed&lt;/td&gt;
&lt;td&gt;&lt;code&gt;invoice.payment_failed&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;transaction.payment_failed&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;subscription_payment_failed&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;&lt;/div&gt;

&lt;p&gt;Notice that Lemon Squeezy uses &lt;code&gt;subscription_cancelled&lt;/code&gt; with two &lt;code&gt;l's&lt;/code&gt; (the L letter), while Paddle uses &lt;code&gt;subscription.canceled&lt;/code&gt; with only one l. A silly change that can make you debug code for hours.&lt;/p&gt;

&lt;h3&gt;
  
  
  Checkout URL location
&lt;/h3&gt;

&lt;p&gt;You've created the checkout. Now you need the URL to redirect the user. Each provider puts it somewhere different.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Stripe&lt;/strong&gt;: &lt;code&gt;session.url&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Paddle&lt;/strong&gt; nests it inside a &lt;code&gt;checkout&lt;/code&gt; object, but not reliably:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;url&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;checkout&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{}).&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;url&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="ow"&gt;or&lt;/span&gt; &lt;span class="n"&gt;result&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;url&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;""&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Lemon Squeezy&lt;/strong&gt; uses JSON:API format, so everything lives under &lt;code&gt;data.attributes&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;url&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;data&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;data&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;attributes&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;url&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Portal sessions
&lt;/h3&gt;

&lt;p&gt;The portal page is where customers can upgrade or downgrade or cancel. This page works differently depending on who is providing it.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Stripe&lt;/strong&gt; requires creating a session before returning a URL:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;session&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;stripe_client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;billing_portal&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;sessions&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;create_async&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="n"&gt;customer&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;customer_id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="n"&gt;return_url&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;return_url&lt;/span&gt;
&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nc"&gt;PortalResponse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;url&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;session&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;url&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Paddle&lt;/strong&gt; returns the portal URL directly on the customer object. No session creation:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;customer&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;_get_customer&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;organization_id&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nc"&gt;PortalResponse&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;url&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;customer&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;portal_url&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Lemon Squeezy&lt;/strong&gt; stores it nested under &lt;code&gt;customer.urls&lt;/code&gt;:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;portal_url&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;customer_data&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;attributes&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;urls&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;customer_portal&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Status values
&lt;/h3&gt;

&lt;p&gt;Subscription statuses look the same until they don't:&lt;/p&gt;

&lt;div class="table-wrapper-paragraph"&gt;&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Stripe&lt;/th&gt;
&lt;th&gt;Paddle&lt;/th&gt;
&lt;th&gt;Lemon Squeezy&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;&lt;code&gt;active&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;active&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;active&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;&lt;code&gt;trialing&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;trialing&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;on_trial&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;&lt;code&gt;past_due&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;past_due&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;past_due&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;&lt;code&gt;canceled&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;canceled&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;cancelled&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;---&lt;/td&gt;
&lt;td&gt;&lt;code&gt;paused&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;&lt;code&gt;paused&lt;/code&gt;&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;&lt;code&gt;incomplete&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;---&lt;/td&gt;
&lt;td&gt;---&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;&lt;/div&gt;

&lt;p&gt;&lt;code&gt;trialing&lt;/code&gt; versus &lt;code&gt;on_trial&lt;/code&gt;. &lt;code&gt;canceled&lt;/code&gt; versus &lt;code&gt;cancelled&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;These won't cause an error. They can cause your query for trials to return zero rows on two out of three providers, and you will spend an afternoon figuring out why. &lt;/p&gt;

&lt;p&gt;Normalize at the adapter boundary - what enters the database should come from your vocabulary, and should not be copied from provider documents.&lt;/p&gt;

&lt;h3&gt;
  
  
  Plan feature metadata
&lt;/h3&gt;

&lt;p&gt;Each provider has a different convention for storing the feature list shown on a pricing page.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Stripe&lt;/strong&gt; uses &lt;code&gt;marketing_features&lt;/code&gt; on the product, falling back to product metadata:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;features&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;f&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;product&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;marketing_features&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; \
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;product&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;marketing_features&lt;/span&gt; \
    &lt;span class="k"&gt;else&lt;/span&gt; &lt;span class="n"&gt;product&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;metadata&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;features&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;""&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;split&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;,&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Paddle&lt;/strong&gt; uses &lt;code&gt;custom_data&lt;/code&gt;, falling back to description lines:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="n"&gt;features&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;product&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;custom_data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;features&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;[])&lt;/span&gt; \
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;product&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;custom_data&lt;/span&gt; \
    &lt;span class="k"&gt;else&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;line&lt;/span&gt; &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;product&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;description&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;split&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\n&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;line&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;strip&lt;/span&gt;&lt;span class="p"&gt;()]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Lemon Squeezy&lt;/strong&gt; parses variant description lines directly.&lt;/p&gt;

&lt;p&gt;None of these options are wrong. They show three ways to think about where information about features is stored. The adapter keeps this hidden from the rest of the application.&lt;/p&gt;

&lt;h2&gt;
  
  
  What the abstraction makes visible
&lt;/h2&gt;

&lt;p&gt;When we look at three adapters one thing becomes clear: the differences are not about the business logic.&lt;/p&gt;

&lt;p&gt;The core ideas common for all three providers are the same:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;how to define a &lt;code&gt;subscription&lt;/code&gt;
&lt;/li&gt;
&lt;li&gt;when it starts&lt;/li&gt;
&lt;li&gt;when it ends&lt;/li&gt;
&lt;li&gt;is it active or cancelled&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The differences are about how we connect to them: the names of headers, the structure of URLs, the words we use for events, the strings we use for status.&lt;/p&gt;

&lt;h3&gt;
  
  
  Why hexagonal architecture
&lt;/h3&gt;

&lt;p&gt;The hexagonal architecture draws a line between these two concerns. The main part of the application does not know what a &lt;code&gt;Stripe-Signature&lt;/code&gt; is. The main part of the application knows what a &lt;code&gt;SubscriptionResponse&lt;/code&gt; is.&lt;/p&gt;

&lt;p&gt;This has an effect on testing. With the protocol as the boundary each adapter can be tested alone using made payloads and real HMAC signatures. We do not need API accounts and we do not need to mock providers that might not behave like they do in production. All 110 tests across the domain, providers, configs, router, webhook and repository layers can run offline.&lt;/p&gt;

&lt;h2&gt;
  
  
  Choosing between the three
&lt;/h2&gt;

&lt;p&gt;Once the architecture is in place choosing a provider is a business decision. The technical differences are real and quite limited.&lt;/p&gt;

&lt;p&gt;Stripe has the mature software development kit and the best documentation. It also has the complex rules to follow when selling outside the US.&lt;/p&gt;

&lt;p&gt;Paddle and Lemon Squeezy are both services that handle payments and taxes for us, send VAT and sales tax on our behalf. If we are selling to customers in the EU and do not want to register for tax in countries this matters even more.&lt;/p&gt;

&lt;p&gt;Lemon Squeezy has the simplest way of working. JSON:API is a bit wordy but consistent. The webhook verification is the simplest of the three to do correctly.&lt;/p&gt;

&lt;p&gt;Paddle has the flexible pricing models. We can charge based on usage, seats or custom plans. The &lt;code&gt;ts=...;h1=...&lt;/code&gt; Signature format is the trickiest to get right and the easiest to get wrong without noticing.&lt;/p&gt;

&lt;h2&gt;
  
  
  If you take one thing from each section
&lt;/h2&gt;

&lt;p&gt;First write down the six protocol methods as ideas before you look at the Stripe documentation. This one step helps you understand what billing means in your code without getting confused with what Stripe calls things. If you think about Stripe early it can mess up your understanding of what billing means.&lt;/p&gt;

&lt;p&gt;Make status strings and event types consistent at the adapter boundary. The webhook handler should not see things like &lt;code&gt;on_trial&lt;/code&gt; or &lt;code&gt;subscription_cancelled&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;When you check signatures use the bytes, not a re-serialized dictionary. If you convert JSON back and forth it can quietly change the bytes. That can cause a really bad kind of bug if someone tampers with the payload.&lt;/p&gt;

&lt;p&gt;Do not pretend to check webhook signature verification in tests. Instead create a HMAC and use the real verification function. The Paddle format has cases that a pretend version will not catch, like what happens when the &lt;code&gt;ts&lt;/code&gt; key is there but empty.&lt;/p&gt;

&lt;p&gt;These patterns took me a while to get right. If you'd rather skip that, &lt;a href="https://softwarelabs.gumroad.com/l/billing-foundation" rel="noopener noreferrer"&gt;Billing Foundation&lt;/a&gt; is a paid starter kit that ships all three adapters already wired behind this Protocol, with 110 tests, a FastAPI backend, Next.js 16, PostgreSQL, Redis, Docker Compose, and an interactive (12-section) step-by-step tutorial runs in any browser.&lt;/p&gt;

&lt;p&gt;You can start with a billing layer that you know works instead of debugging special cases like &lt;code&gt;ts=...;h1=...&lt;/code&gt;.&lt;/p&gt;

&lt;h2&gt;
  
  
  What's your experience ?
&lt;/h2&gt;

&lt;p&gt;If you're running billing in production: which provider, and what's the edge case you hit that the documentation didn't mention?&lt;/p&gt;

</description>
      <category>python</category>
      <category>webdev</category>
      <category>programming</category>
      <category>stripe</category>
    </item>
  </channel>
</rss>
