⚡ (billing) Automatic usage-based billing (#924)

BREAKING CHANGE: Stripe environment variables simplified. Check out the
new configs to adapt your existing system.

Closes #906





<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
### Summary by CodeRabbit

**New Features:**
- Introduced a usage-based billing system, providing more flexibility
and options for users.
- Integrated with Stripe for a smoother and more secure payment process.
- Enhanced the user interface with improvements to the billing,
workspace, and pricing pages for a more intuitive experience.

**Improvements:**
- Simplified the billing logic, removing additional chats and yearly
billing for a more streamlined user experience.
- Updated email notifications to keep users informed about their usage
and limits.
- Improved pricing and currency formatting for better clarity and
understanding.

**Testing:**
- Updated tests and specifications to ensure the reliability of new
features and improvements.

**Note:** These changes aim to provide a more flexible and user-friendly
billing system, with clearer pricing and improved notifications. Users
should find the new system more intuitive and easier to navigate.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

apps/builder/src/pages/api/stripe/webhook.ts

@@ -46,23 +46,22 @@ const webhookHandler = async (req: NextApiRequest, res: NextApiResponse) => {
           const metadata = session.metadata as unknown as
             | {
                 plan: 'STARTER' | 'PRO'
-                additionalChats: string
                 workspaceId: string
                 userId: string
               }
             | { claimableCustomPlanId: string; userId: string }
           if ('plan' in metadata) {
-            const { workspaceId, plan, additionalChats } = metadata
-            if (!workspaceId || !plan || !additionalChats)
+            const { workspaceId, plan } = metadata
+            if (!workspaceId || !plan)
               return res
                 .status(500)
                 .send({ message: `Couldn't retrieve valid metadata` })
+
             const workspace = await prisma.workspace.update({
               where: { id: workspaceId },
               data: {
                 plan,
                 stripeId: session.customer as string,
-                additionalChatsIndex: parseInt(additionalChats),
                 isQuarantined: false,
               },
               include: {
@@ -84,7 +83,6 @@ const webhookHandler = async (req: NextApiRequest, res: NextApiResponse) => {
                   userId: user.id,
                   data: {
                     plan,
-                    additionalChatsIndex: parseInt(additionalChats),
                   },
                 },
               ])
@@ -119,7 +117,6 @@ const webhookHandler = async (req: NextApiRequest, res: NextApiResponse) => {
                 userId,
                 data: {
                   plan: Plan.CUSTOM,
-                  additionalChatsIndex: 0,
                 },
               },
             ])
@@ -148,7 +145,6 @@ const webhookHandler = async (req: NextApiRequest, res: NextApiResponse) => {
             },
             data: {
               plan: Plan.FREE,
-              additionalChatsIndex: 0,
               customChatsLimit: null,
               customStorageLimit: null,
               customSeatsLimit: null,
@@ -172,7 +168,6 @@ const webhookHandler = async (req: NextApiRequest, res: NextApiResponse) => {
                 userId: user.id,
                 data: {
                   plan: Plan.FREE,
-                  additionalChatsIndex: 0,
                 },
               },
             ])

apps/builder/src/pages/api/workspaces/[workspaceId]/invitations.ts

@@ -8,7 +8,7 @@ import {
 } from '@typebot.io/lib/api'
 import { getAuthenticatedUser } from '@/features/auth/helpers/getAuthenticatedUser'
 import { sendWorkspaceMemberInvitationEmail } from '@typebot.io/emails'
-import { isSeatsLimitReached } from '@typebot.io/lib/pricing'
+import { getSeatsLimit } from '@typebot.io/lib/billing/getSeatsLimit'
 import { env } from '@typebot.io/env'
 
 const handler = async (req: NextApiRequest, res: NextApiResponse) => {
@@ -37,11 +37,8 @@ const handler = async (req: NextApiRequest, res: NextApiResponse) => {
         }),
       ])
     if (
-      isSeatsLimitReached({
-        existingMembersAndInvitationsCount:
-          existingMembersCount + existingInvitationsCount,
-        ...workspace,
-      })
+      getSeatsLimit(workspace) <=
+      existingMembersCount + existingInvitationsCount
     )
       return res.status(400).send('Seats limit reached')
     if (existingUser) {