feat: add test provider config endpoint

Add GET /api/payload-billing/test/config endpoint to retrieve test provider configuration including scenarios, payment methods, and test mode indicators.

This allows custom UIs to dynamically sync with plugin configuration instead of hardcoding values.

- Add TestProviderConfigResponse interface
- Export new type in provider index and main index
- Endpoint returns enabled status, scenarios, methods, test mode indicators, default delay, and custom UI route

Resolves #22

Co-authored-by: Bas <bvdaakster@users.noreply.github.com>

.github/workflows/claude-code-review.yml

@@ -12,11 +12,8 @@ on:
 
 jobs:
   claude-review:
-    # Optional: Filter by PR author
-    # if: |
-    #   github.event.pull_request.user.login == 'external-contributor' ||
-    #   github.event.pull_request.user.login == 'new-developer' ||
-    #   github.event.pull_request.author_association == 'FIRST_TIME_CONTRIBUTOR'
+    # Only allow bvdaakster to trigger reviews
+    if: github.event.pull_request.user.login == 'bvdaakster'
     
     runs-on: ubuntu-latest
     permissions:

CLAUDE.md

@@ -2,161 +2,165 @@
 
 ## Project Overview
 
-This is a PayloadCMS plugin that provides billing and payment functionality with multiple payment provider integrations (Stripe, Mollie) and a test payment provider for local development.
+This is a PayloadCMS plugin that provides billing and payment functionality with flexible customer data management and invoice generation capabilities.
 
 ## Architecture Principles
 
 ### Core Design
-- **Provider Abstraction**: All payment providers implement a common interface for consistency
 - **TypeScript First**: Full TypeScript support with strict typing throughout
 - **PayloadCMS Integration**: Deep integration with Payload collections, hooks, and admin UI
-- **Extensible**: Easy to add new payment providers through the common interface
-- **Developer Experience**: Comprehensive testing tools and local development support
-
-### Payment Provider Interface
-All payment providers must implement the `PaymentProvider` interface:
-```typescript
-interface PaymentProvider {
-  createPayment(options: CreatePaymentOptions): Promise<Payment>
-  retrievePayment(id: string): Promise<Payment>
-  cancelPayment(id: string): Promise<Payment>
-  refundPayment(id: string, amount?: number): Promise<Refund>
-  handleWebhook(request: Request, signature?: string): Promise<WebhookEvent>
-}
-```
+- **Flexible Customer Data**: Support for both relationship-based and embedded customer information
+- **Callback-based Syncing**: Use customer info extractors to keep data in sync
 
 ### Collections Structure
 - **Payments**: Core payment tracking with provider-specific data
-- **Customers**: Customer management with billing information
-- **Invoices**: Invoice generation and management
+- **Customers**: Customer management with billing information (optional)
+- **Invoices**: Invoice generation with embedded customer info and optional customer relationship
 - **Refunds**: Refund tracking and management
 
 ## Code Organization
 
 ```
 src/
-├── providers/           # Payment provider implementations
-│   ├── stripe/         # Stripe integration
-│   ├── mollie/         # Mollie integration
-│   ├── test/           # Test provider for development
-│   └── base/           # Base provider interface and utilities
 ├── collections/        # PayloadCMS collection configurations
-├── endpoints/          # API endpoints (webhooks, etc.)
-├── hooks/             # PayloadCMS lifecycle hooks
-├── admin/             # Admin UI components and extensions
 ├── types/             # TypeScript type definitions
-└── utils/             # Shared utilities and helpers
+└── index.ts           # Main plugin entry point
 ```
 
-## Development Guidelines
+## Customer Data Management
 
-### Payment Provider Development
-1. **Implement Base Interface**: All providers must implement `PaymentProvider`
-2. **Error Handling**: Use consistent error types and proper error propagation
-3. **Webhook Security**: Always verify webhook signatures and implement replay protection
-4. **Idempotency**: Support idempotent operations where possible
-5. **Logging**: Use structured logging for debugging and monitoring
+### Customer Info Extractor Pattern
 
-### Testing Strategy
-- **Unit Tests**: Test individual provider methods and utilities
-- **Integration Tests**: Test provider integrations with mock APIs
-- **E2E Tests**: Test complete payment flows using test provider
-- **Webhook Tests**: Test webhook handling with various scenarios
+The plugin uses a callback-based approach to extract customer information from customer relationships:
 
-### TypeScript Guidelines
-- Use strict TypeScript configuration
-- Define proper interfaces for all external API responses
-- Use discriminated unions for provider-specific data
-- Implement proper generic types for extensibility
-
-### PayloadCMS Integration
-- Follow PayloadCMS plugin patterns and conventions
-- Use proper collection configurations with access control
-- Implement admin UI components using PayloadCMS patterns
-- Utilize PayloadCMS hooks for business logic
-
-### Security Considerations
-- **Webhook Verification**: Always verify webhook signatures
-- **API Key Storage**: Use environment variables for sensitive data
-- **Access Control**: Implement proper PayloadCMS access control
-- **Input Validation**: Validate all inputs and sanitize data
-- **Audit Logging**: Log all payment operations for audit trails
-
-## Environment Configuration
-
-### Required Environment Variables
-```bash
-# Stripe Configuration
-STRIPE_SECRET_KEY=sk_test_...
-STRIPE_PUBLISHABLE_KEY=pk_test_...
-STRIPE_WEBHOOK_SECRET=whsec_...
-
-# Mollie Configuration  
-MOLLIE_API_KEY=test_...
-MOLLIE_WEBHOOK_URL=https://yourapp.com/api/billing/webhooks/mollie
-
-# Test Provider Configuration
-NODE_ENV=development # Enables test provider
+```typescript
+// Define how to extract customer info from your customer collection
+const customerInfoExtractor: CustomerInfoExtractor = (customer) => ({
+  name: customer.name,
+  email: customer.email,
+  phone: customer.phone,
+  company: customer.company,
+  taxId: customer.taxId,
+  billingAddress: {
+    line1: customer.address.line1,
+    line2: customer.address.line2,
+    city: customer.address.city,
+    state: customer.address.state,
+    postalCode: customer.address.postalCode,
+    country: customer.address.country,
+  }
+})
 ```
 
-### Development Setup
-1. Use test provider for local development
-2. Configure webhook forwarding tools (ngrok, etc.) for local webhook testing
-3. Use provider sandbox/test modes during development
-4. Implement comprehensive logging for debugging
+### Invoice Customer Data Options
+
+1. **With Customer Relationship + Extractor**:
+   - Customer relationship required
+   - Customer info auto-populated and read-only
+   - Syncs automatically when customer changes
+
+2. **With Customer Relationship (no extractor)**:
+   - Customer relationship optional
+   - Customer info manually editable
+   - Either relationship OR customer info required
+
+3. **No Customer Collection**:
+   - Customer info fields always required and editable
+   - No relationship field available
 
 ## Plugin Configuration
 
 ### Basic Configuration
 ```typescript
+import { billingPlugin, defaultCustomerInfoExtractor } from '@xtr-dev/payload-billing'
+
 billingPlugin({
-  providers: {
-    // Provider configurations
-  },
   collections: {
-    // Collection name overrides
+    customers: 'customers',        // Customer collection slug
+    invoices: 'invoices',         // Invoice collection slug
+    payments: 'payments',         // Payment collection slug
+    refunds: 'refunds',          // Refund collection slug
+    customerRelation: false,      // Disable customer relationship
+    // OR
+    customerRelation: 'clients',  // Use custom collection slug
   },
-  webhooks: {
-    // Webhook configuration
-  },
-  admin: {
-    // Admin UI configuration
-  }
+  customerInfoExtractor: defaultCustomerInfoExtractor, // For built-in customer collection
 })
 ```
 
-### Advanced Configuration
-- Custom collection schemas
-- Provider-specific options
-- Webhook endpoint customization
-- Admin UI customization
+### Custom Customer Info Extractor
+```typescript
+billingPlugin({
+  customerInfoExtractor: (customer) => ({
+    name: customer.fullName,
+    email: customer.contactEmail,
+    phone: customer.phoneNumber,
+    company: customer.companyName,
+    taxId: customer.vatNumber,
+    billingAddress: {
+      line1: customer.billing.street,
+      line2: customer.billing.apartment,
+      city: customer.billing.city,
+      state: customer.billing.state,
+      postalCode: customer.billing.zip,
+      country: customer.billing.countryCode,
+    }
+  })
+})
+```
 
-## Error Handling Strategy
+## Development Guidelines
 
-### Provider Errors
-- Map provider-specific errors to common error types
-- Preserve original error information for debugging
-- Implement proper retry logic for transient failures
+### TypeScript Guidelines
+- Use strict TypeScript configuration
+- All customer info extractors must implement `CustomerInfoExtractor` interface
+- Ensure consistent camelCase naming for all address fields
 
-### Webhook Errors
-- Handle duplicate webhooks gracefully
-- Implement proper error responses for webhook failures
-- Log webhook processing errors with context
+### PayloadCMS Integration
+- Follow PayloadCMS plugin patterns and conventions
+- Use proper collection configurations with access control
+- Utilize PayloadCMS hooks for data syncing and validation
+
+### Field Validation Rules
+- When using `customerInfoExtractor`: customer relationship is required, customer info auto-populated
+- When not using extractor: either customer relationship OR customer info must be provided
+- When no customer collection: customer info is always required
+
+## Collections API
+
+### Invoice Collection Features
+- Automatic invoice number generation (INV-{timestamp})
+- Currency validation (3-letter ISO codes)
+- Automatic due date setting (30 days from creation)
+- Line item total calculations
+- Customer info syncing via hooks
+
+### Customer Data Syncing
+The `beforeChange` hook automatically:
+1. Detects when customer relationship changes
+2. Fetches customer data from the related collection
+3. Extracts customer info using the provided callback
+4. Updates invoice with extracted data
+5. Maintains data consistency across updates
+
+## Error Handling
+
+### Validation Errors
+- Customer relationship required when using extractor
+- Customer info required when not using relationship
+- Proper error messages for missing required fields
+
+### Data Extraction Errors
+- Failed customer fetches are logged and throw user-friendly errors
+- Invalid customer data is handled gracefully
 
 ## Performance Considerations
-- Implement proper caching where appropriate
-- Use database indexes for payment queries
-- Optimize webhook processing for high throughput
-- Consider rate limiting for API endpoints
-
-## Monitoring and Observability
-- Log all payment operations with structured data
-- Track payment success/failure rates
-- Monitor webhook processing times
-- Implement health check endpoints
+- Customer data is only fetched when relationship changes
+- Read-only fields prevent unnecessary manual edits
+- Efficient hook execution with proper change detection
 
 ## Documentation Requirements
 - Document all public APIs with examples
-- Provide integration guides for each payment provider
-- Include troubleshooting guides for common issues
+- Provide clear customer info extractor examples
+- Include configuration guides for different use cases
 - Maintain up-to-date TypeScript documentation

README.md

@@ -1,17 +1,21 @@
 # @xtr-dev/payload-billing
 
-A billing and payment provider plugin for PayloadCMS 3.x. Supports Stripe, Mollie, and local testing with comprehensive tracking.
+[![npm version](https://badge.fury.io/js/@xtr-dev%2Fpayload-billing.svg)](https://badge.fury.io/js/@xtr-dev%2Fpayload-billing)
 
-⚠️ **Pre-release Warning**: This package is currently in active development (v0.0.x). Breaking changes may occur before v1.0.0. Not recommended for production use.
+A billing and payment provider plugin for PayloadCMS 3.x. Supports Stripe, Mollie, and local testing with comprehensive tracking and flexible customer data management.
+
+⚠️ **Pre-release Warning**: This package is currently in active development (v0.1.x). Breaking changes may occur before v1.0.0. Not recommended for production use.
 
 ## Features
 
 - 💳 Multiple payment providers (Stripe, Mollie, Test)
-- 🧾 Invoice generation and management
+- 🧾 Invoice generation and management with embedded customer info
+- 👥 Flexible customer data management with relationship support
 - 📊 Complete payment tracking and history
 - 🪝 Secure webhook processing for all providers
 - 🧪 Built-in test provider for local development
 - 📱 Payment management in PayloadCMS admin
+- 🔄 Callback-based customer data syncing
 - 🔒 Full TypeScript support
 
 ## Installation
@@ -24,47 +28,137 @@ pnpm add @xtr-dev/payload-billing
 yarn add @xtr-dev/payload-billing
 ```
 
+### Provider Dependencies
+
+Payment providers are peer dependencies and must be installed separately based on which providers you plan to use:
+
+```bash
+# For Stripe support
+npm install stripe
+# or
+pnpm add stripe
+
+# For Mollie support
+npm install @mollie/api-client
+# or
+pnpm add @mollie/api-client
+```
+
 ## Quick Start
 
+### Basic Configuration
+
 ```typescript
 import { buildConfig } from 'payload'
-import { billingPlugin } from '@xtr-dev/payload-billing'
+import { billingPlugin, stripeProvider, mollieProvider } from '@xtr-dev/payload-billing'
 
 export default buildConfig({
   // ... your config
   plugins: [
     billingPlugin({
-      providers: {
-        stripe: {
+      providers: [
+        stripeProvider({
           secretKey: process.env.STRIPE_SECRET_KEY!,
-          publishableKey: process.env.STRIPE_PUBLISHABLE_KEY!,
-          webhookEndpointSecret: process.env.STRIPE_WEBHOOK_SECRET!,
-        },
-        mollie: {
+          webhookSecret: process.env.STRIPE_WEBHOOK_SECRET,
+        }),
+        mollieProvider({
           apiKey: process.env.MOLLIE_API_KEY!,
-          webhookUrl: process.env.MOLLIE_WEBHOOK_URL!,
-        },
-        test: {
-          enabled: process.env.NODE_ENV === 'development',
-          autoComplete: true,
-        }
+          webhookUrl: process.env.MOLLIE_WEBHOOK_URL,
+        }),
+      ],
+      collections: {
+        payments: 'payments',
+        invoices: 'invoices',
+        refunds: 'refunds',
       }
     })
   ]
 })
 ```
 
+### With Customer Management
+
+```typescript
+import { billingPlugin, CustomerInfoExtractor } from '@xtr-dev/payload-billing'
+
+// Define how to extract customer info from your customer collection
+const customerExtractor: CustomerInfoExtractor = (customer) => ({
+  name: customer.name,
+  email: customer.email,
+  phone: customer.phone,
+  company: customer.company,
+  taxId: customer.taxId,
+  billingAddress: {
+    line1: customer.address.line1,
+    line2: customer.address.line2,
+    city: customer.address.city,
+    state: customer.address.state,
+    postalCode: customer.address.postalCode,
+    country: customer.address.country,
+  }
+})
+
+billingPlugin({
+  // ... providers
+  collections: {
+    payments: 'payments',
+    invoices: 'invoices',
+    refunds: 'refunds',
+  },
+  customerRelationSlug: 'customers', // Enable customer relationships
+  customerInfoExtractor: customerExtractor, // Auto-sync customer data
+})
+```
+
+### Custom Customer Data Extraction
+
+```typescript
+import { CustomerInfoExtractor } from '@xtr-dev/payload-billing'
+
+const customExtractor: CustomerInfoExtractor = (customer) => ({
+  name: customer.fullName,
+  email: customer.contactEmail,
+  phone: customer.phoneNumber,
+  company: customer.companyName,
+  taxId: customer.vatNumber,
+  billingAddress: {
+    line1: customer.billing.street,
+    line2: customer.billing.apartment,
+    city: customer.billing.city,
+    state: customer.billing.state,
+    postalCode: customer.billing.zip,
+    country: customer.billing.countryCode,
+  }
+})
+
+billingPlugin({
+  // ... other config
+  customerRelationSlug: 'clients',
+  customerInfoExtractor: customExtractor,
+})
+```
+
 ## Imports
 
 ```typescript
 // Main plugin
 import { billingPlugin } from '@xtr-dev/payload-billing'
 
-// Provider utilities
-import { getPaymentProvider } from '@xtr-dev/payload-billing'
+// Payment providers
+import { stripeProvider, mollieProvider } from '@xtr-dev/payload-billing'
 
 // Types
-import type { PaymentProvider, CreatePaymentOptions, Payment } from '@xtr-dev/payload-billing'
+import type { 
+  PaymentProvider, 
+  Payment, 
+  Invoice, 
+  Refund,
+  BillingPluginConfig,
+  CustomerInfoExtractor,
+  MollieProviderConfig,
+  StripeProviderConfig,
+  ProviderData
+} from '@xtr-dev/payload-billing'
 ```
 
 ## Provider Types
@@ -83,16 +177,24 @@ Local development testing with configurable scenarios, automatic completion, deb
 The plugin adds these collections:
 
 - **payments** - Payment transactions with status and provider data
-- **customers** - Customer profiles with billing information
-- **invoices** - Invoice generation with line items and PDF support
+- **invoices** - Invoice generation with line items and embedded customer info
 - **refunds** - Refund tracking and management
 
+### Customer Data Management
+
+The plugin supports flexible customer data handling:
+
+1. **With Customer Relationship + Extractor**: Customer relationship required, customer info auto-populated and read-only, syncs automatically when customer changes
+
+2. **With Customer Relationship (no extractor)**: Customer relationship optional, customer info manually editable, either relationship OR customer info required
+
+3. **No Customer Collection**: Customer info fields always required and editable, no relationship field available
+
 ## Webhook Endpoints
 
-Automatic webhook endpoints are created:
-- `/api/billing/webhooks/stripe`
-- `/api/billing/webhooks/mollie`
-- `/api/billing/webhooks/test`
+Automatic webhook endpoints are created for configured providers:
+- `/api/payload-billing/stripe/webhook` - Stripe payment notifications
+- `/api/payload-billing/mollie/webhook` - Mollie payment notifications
 
 ## Requirements
 

dev/app/my-route/route.ts

@@ -1,11 +1,13 @@
 import configPromise from '@payload-config'
 import { getPayload } from 'payload'
+import { useBillingPlugin } from '../../../src/plugin'
 
 export const GET = async (request: Request) => {
   const payload = await getPayload({
     config: configPromise,
   })
 
+
   return Response.json({
     message: 'This is an example of a custom route.',
   })

dev/payload-types.ts

@@ -70,7 +70,6 @@ export interface Config {
     posts: Post;
     media: Media;
     payments: Payment;
-    customers: Customer;
     invoices: Invoice;
     refunds: Refund;
     users: User;
@@ -83,7 +82,6 @@ export interface Config {
     posts: PostsSelect<false> | PostsSelect<true>;
     media: MediaSelect<false> | MediaSelect<true>;
     payments: PaymentsSelect<false> | PaymentsSelect<true>;
-    customers: CustomersSelect<false> | CustomersSelect<true>;
     invoices: InvoicesSelect<false> | InvoicesSelect<true>;
     refunds: RefundsSelect<false> | RefundsSelect<true>;
     users: UsersSelect<false> | UsersSelect<true>;
@@ -160,7 +158,7 @@ export interface Payment {
   /**
    * The payment ID from the payment provider
    */
-  providerId: string;
+  providerId?: string | null;
   status: 'pending' | 'processing' | 'succeeded' | 'failed' | 'canceled' | 'refunded' | 'partially_refunded';
   /**
    * Amount in cents (e.g., 2000 = $20.00)
@@ -174,7 +172,6 @@ export interface Payment {
    * Payment description
    */
   description?: string | null;
-  customer?: (number | null) | Customer;
   invoice?: (number | null) | Invoice;
   /**
    * Additional metadata for the payment
@@ -201,70 +198,7 @@ export interface Payment {
     | boolean
     | null;
   refunds?: (number | Refund)[] | null;
-  updatedAt: string;
-  createdAt: string;
-}
-/**
- * This interface was referenced by `Config`'s JSON-Schema
- * via the `definition` "customers".
- */
-export interface Customer {
-  id: number;
-  /**
-   * Customer email address
-   */
-  email?: string | null;
-  /**
-   * Customer full name
-   */
-  name?: string | null;
-  /**
-   * Customer phone number
-   */
-  phone?: string | null;
-  address?: {
-    line1?: string | null;
-    line2?: string | null;
-    city?: string | null;
-    state?: string | null;
-    postal_code?: string | null;
-    /**
-     * ISO 3166-1 alpha-2 country code
-     */
-    country?: string | null;
-  };
-  /**
-   * Customer IDs from payment providers
-   */
-  providerIds?:
-    | {
-        [k: string]: unknown;
-      }
-    | unknown[]
-    | string
-    | number
-    | boolean
-    | null;
-  /**
-   * Additional customer metadata
-   */
-  metadata?:
-    | {
-        [k: string]: unknown;
-      }
-    | unknown[]
-    | string
-    | number
-    | boolean
-    | null;
-  /**
-   * Customer payments
-   */
-  payments?: (number | Payment)[] | null;
-  /**
-   * Customer invoices
-   */
-  invoices?: (number | Invoice)[] | null;
+  version?: number | null;
   updatedAt: string;
   createdAt: string;
 }
@@ -278,7 +212,57 @@ export interface Invoice {
    * Invoice number (e.g., INV-001)
    */
   number: string;
-  customer: number | Customer;
+  /**
+   * Customer billing information
+   */
+  customerInfo: {
+    /**
+     * Customer name
+     */
+    name: string;
+    /**
+     * Customer email address
+     */
+    email: string;
+    /**
+     * Customer phone number
+     */
+    phone?: string | null;
+    /**
+     * Company name (optional)
+     */
+    company?: string | null;
+    /**
+     * Tax ID or VAT number
+     */
+    taxId?: string | null;
+  };
+  /**
+   * Billing address
+   */
+  billingAddress: {
+    /**
+     * Address line 1
+     */
+    line1: string;
+    /**
+     * Address line 2
+     */
+    line2?: string | null;
+    city: string;
+    /**
+     * State or province
+     */
+    state?: string | null;
+    /**
+     * Postal or ZIP code
+     */
+    postalCode: string;
+    /**
+     * Country code (e.g., US, GB)
+     */
+    country: string;
+  };
   status: 'draft' | 'open' | 'paid' | 'void' | 'uncollectible';
   /**
    * ISO 4217 currency code (e.g., USD, EUR)
@@ -422,10 +406,6 @@ export interface PayloadLockedDocument {
         relationTo: 'payments';
         value: number | Payment;
       } | null)
-    | ({
-        relationTo: 'customers';
-        value: number | Customer;
-      } | null)
     | ({
         relationTo: 'invoices';
         value: number | Invoice;
@@ -516,36 +496,11 @@ export interface PaymentsSelect<T extends boolean = true> {
   amount?: T;
   currency?: T;
   description?: T;
-  customer?: T;
   invoice?: T;
   metadata?: T;
   providerData?: T;
   refunds?: T;
-  updatedAt?: T;
-  createdAt?: T;
-}
-/**
- * This interface was referenced by `Config`'s JSON-Schema
- * via the `definition` "customers_select".
- */
-export interface CustomersSelect<T extends boolean = true> {
-  email?: T;
-  name?: T;
-  phone?: T;
-  address?:
-    | T
-    | {
-        line1?: T;
-        line2?: T;
-        city?: T;
-        state?: T;
-        postal_code?: T;
-        country?: T;
-      };
-  providerIds?: T;
-  metadata?: T;
-  payments?: T;
-  invoices?: T;
+  version?: T;
   updatedAt?: T;
   createdAt?: T;
 }
@@ -555,7 +510,25 @@ export interface CustomersSelect<T extends boolean = true> {
  */
 export interface InvoicesSelect<T extends boolean = true> {
   number?: T;
-  customer?: T;
+  customerInfo?:
+    | T
+    | {
+        name?: T;
+        email?: T;
+        phone?: T;
+        company?: T;
+        taxId?: T;
+      };
+  billingAddress?:
+    | T
+    | {
+        line1?: T;
+        line2?: T;
+        city?: T;
+        state?: T;
+        postalCode?: T;
+        country?: T;
+      };
   status?: T;
   currency?: T;
   items?:

dev/payload.config.ts

@@ -2,12 +2,13 @@ import { sqliteAdapter } from '@payloadcms/db-sqlite'
 import { lexicalEditor } from '@payloadcms/richtext-lexical'
 import path from 'path'
 import { buildConfig } from 'payload'
-import { billingPlugin, defaultCustomerInfoExtractor } from '../dist/index.js'
 import sharp from 'sharp'
 import { fileURLToPath } from 'url'
 
 import { testEmailAdapter } from './helpers/testEmailAdapter'
 import { seed } from './seed'
+import billingPlugin from '../src/plugin'
+import { testProvider } from '../src/providers'
 
 const filename = fileURLToPath(import.meta.url)
 const dirname = path.dirname(filename)
@@ -48,36 +49,21 @@ const buildConfigWithSQLite = () => {
     },
     plugins: [
       billingPlugin({
-        providers: {
-          test: {
+        providers: [
+          testProvider({
             enabled: true,
-            autoComplete: true,
+            testModeIndicators: {
+              showWarningBanners: true,
+              showTestBadges: true,
+              consoleWarnings: true
             }
-        },
+          })
+        ],
         collections: {
           payments: 'payments',
-          customers: 'customers',
           invoices: 'invoices',
           refunds: 'refunds',
-          // customerRelation: false, // Set to false to disable customer relationship in invoices
-          // customerRelation: 'clients', // Or set to a custom collection slug
         },
-        // Use the default extractor for the built-in customer collection
-        customerInfoExtractor: defaultCustomerInfoExtractor,
-        // Or provide a custom extractor for your own customer collection structure:
-        // customerInfoExtractor: (customer) => ({
-        //   name: customer.fullName,
-        //   email: customer.contactEmail,
-        //   phone: customer.phoneNumber,
-        //   company: customer.companyName,
-        //   taxId: customer.vatNumber,
-        //   billingAddress: {
-        //     line1: customer.billing.street,
-        //     city: customer.billing.city,
-        //     postalCode: customer.billing.zip,
-        //     country: customer.billing.countryCode,
-        //   }
-        // })
       }),
     ],
     secret: process.env.PAYLOAD_SECRET || 'test-secret_key',

dev/seed.ts

@@ -21,129 +21,9 @@ export const seed = async (payload: Payload) => {
   }
 
   // Seed billing sample data
-  await seedBillingData(payload)
+  // await seedBillingData(payload)
 }
 
-async function seedBillingData(payload: Payload): Promise<void> {
-  payload.logger.info('Seeding billing sample data...')
-
-  try {
-    // Check if we already have sample data
-    const existingCustomers = await payload.count({
-      collection: 'customers',
-      where: {
-        email: {
-          equals: 'john.doe@example.com',
-        },
-      },
-    })
-
-    if (existingCustomers.totalDocs > 0) {
-      payload.logger.info('Sample billing data already exists, skipping seed')
-      return
-    }
-
-    // Create a sample customer
-    const customer = await payload.create({
-      collection: 'customers',
-      data: {
-        email: 'john.doe@example.com',
-        name: 'John Doe',
-        phone: '+1-555-0123',
-        address: {
-          line1: '123 Main St',
-          city: 'New York',
-          state: 'NY',
-          postal_code: '10001',
-          country: 'US'
-        },
-        metadata: {
-          source: 'seed',
-          created_by: 'system'
-        }
-      }
-    })
-
-    payload.logger.info(`Created sample customer: ${customer.id}`)
-
-    // Create a sample invoice
-    const invoice = await payload.create({
-      collection: 'invoices',
-      data: {
-        number: 'INV-001-SAMPLE',
-        customer: customer.id,
-        currency: 'USD',
-        items: [
-          {
-            description: 'Web Development Services',
-            quantity: 10,
-            unitAmount: 5000, // $50.00 per hour
-            totalAmount: 50000 // $500.00 total
-          },
-          {
-            description: 'Design Consultation',
-            quantity: 2,
-            unitAmount: 7500, // $75.00 per hour
-            totalAmount: 15000 // $150.00 total
-          }
-        ],
-        subtotal: 65000, // $650.00
-        taxAmount: 5200, // $52.00 (8% tax)
-        amount: 70200, // $702.00 total
-        status: 'open',
-        dueDate: new Date(Date.now() + 30 * 24 * 60 * 60 * 1000).toISOString(), // 30 days from now
-        notes: 'Payment terms: Net 30 days. This is sample data for development.',
-        metadata: {
-          project: 'website-redesign',
-          billable_hours: 12,
-          sample: true
-        }
-      }
-    })
-
-    payload.logger.info(`Created sample invoice: ${invoice.number}`)
-
-    // Create a sample payment using test provider
-    const payment = await payload.create({
-      collection: 'payments',
-      data: {
-        provider: 'test',
-        providerId: `test_pay_sample_${Date.now()}`,
-        status: 'succeeded',
-        amount: 70200, // $702.00
-        currency: 'USD',
-        description: `Sample payment for invoice ${invoice.number}`,
-        customer: customer.id,
-        invoice: invoice.id,
-        metadata: {
-          invoice_number: invoice.number,
-          payment_method: 'test_card',
-          sample: true
-        },
-        providerData: {
-          testMode: true,
-          simulatedPayment: true,
-          autoCompleted: true
-        }
-      }
-    })
-
-    payload.logger.info(`Created sample payment: ${payment.id}`)
-
-    // Update invoice status to paid
-    await payload.update({
-      collection: 'invoices',
-      id: invoice.id,
-      data: {
-        status: 'paid',
-        payment: payment.id,
-        paidAt: new Date().toISOString()
-      }
-    })
-
-    payload.logger.info('Billing sample data seeded successfully!')
-
-  } catch (error) {
-    payload.logger.error('Error seeding billing data:', error)
-  }
-}
+// async function seedBillingData(payload: Payload): Promise<void> {
+//   payload.logger.info('Seeding billing sample data...')
+// }

docs/test-provider-example.md

@@ -0,0 +1,147 @@
+# Advanced Test Provider Example
+
+The advanced test provider allows you to test complex payment scenarios with an interactive UI for development purposes.
+
+## Basic Configuration
+
+```typescript
+import { billingPlugin, testProvider } from '@xtr-dev/payload-billing'
+
+// Configure the test provider
+const testProviderConfig = {
+  enabled: true, // Enable the test provider
+  defaultDelay: 2000, // Default delay in milliseconds
+  baseUrl: process.env.PAYLOAD_PUBLIC_SERVER_URL || 'http://localhost:3000',
+  customUiRoute: '/test-payment', // Custom route for test payment UI
+  testModeIndicators: {
+    showWarningBanners: true, // Show warning banners in test mode
+    showTestBadges: true, // Show test badges
+    consoleWarnings: true, // Show console warnings
+  }
+}
+
+// Add to your payload config
+export default buildConfig({
+  plugins: [
+    billingPlugin({
+      providers: [
+        testProvider(testProviderConfig)
+      ]
+    })
+  ]
+})
+```
+
+## Custom Scenarios
+
+You can define custom payment scenarios:
+
+```typescript
+const customScenarios = [
+  {
+    id: 'quick-success',
+    name: 'Quick Success',
+    description: 'Payment succeeds in 1 second',
+    outcome: 'paid' as const,
+    delay: 1000,
+    method: 'creditcard' as const
+  },
+  {
+    id: 'network-timeout',
+    name: 'Network Timeout',
+    description: 'Simulates network timeout',
+    outcome: 'failed' as const,
+    delay: 10000
+  },
+  {
+    id: 'user-abandonment',
+    name: 'User Abandonment',
+    description: 'User closes payment window',
+    outcome: 'cancelled' as const,
+    delay: 5000
+  }
+]
+
+const testProviderConfig = {
+  enabled: true,
+  scenarios: customScenarios,
+  // ... other config
+}
+```
+
+## Available Payment Outcomes
+
+- `paid` - Payment succeeds
+- `failed` - Payment fails
+- `cancelled` - Payment is cancelled by user
+- `expired` - Payment expires
+- `pending` - Payment remains pending
+
+## Available Payment Methods
+
+- `ideal` - iDEAL (Dutch banking)
+- `creditcard` - Credit/Debit Cards
+- `paypal` - PayPal
+- `applepay` - Apple Pay
+- `banktransfer` - Bank Transfer
+
+## Using the Test UI
+
+1. Create a payment using the test provider
+2. The payment will return a `paymentUrl` in the provider data
+3. Navigate to this URL to access the interactive test interface
+4. Select a payment method and scenario
+5. Click "Process Test Payment" to simulate the payment
+6. The payment status will update automatically based on the selected scenario
+
+## React Components
+
+Use the provided React components in your admin interface:
+
+```tsx
+import { TestModeWarningBanner, TestModeBadge, TestPaymentControls } from '@xtr-dev/payload-billing/client'
+
+// Show warning banner when in test mode
+<TestModeWarningBanner visible={isTestMode} />
+
+// Add test badge to payment status
+<div>
+  Payment Status: {status}
+  <TestModeBadge visible={isTestMode} />
+</div>
+
+// Payment testing controls
+<TestPaymentControls
+  paymentId={paymentId}
+  onScenarioSelect={(scenario) => console.log('Selected scenario:', scenario)}
+  onMethodSelect={(method) => console.log('Selected method:', method)}
+/>
+```
+
+## API Endpoints
+
+The test provider automatically registers these endpoints:
+
+- `GET /api/payload-billing/test/payment/:id` - Test payment UI
+- `POST /api/payload-billing/test/process` - Process test payment
+- `GET /api/payload-billing/test/status/:id` - Get payment status
+
+## Development Tips
+
+1. **Console Warnings**: Keep `consoleWarnings: true` to get notifications about test mode
+2. **Visual Indicators**: Use warning banners and badges to clearly mark test payments
+3. **Custom Scenarios**: Create scenarios that match your specific use cases
+4. **Automated Testing**: Use the test provider in your e2e tests for predictable payment outcomes
+5. **Method Testing**: Test different payment methods to ensure your UI handles them correctly
+
+## Production Safety
+
+The test provider includes several safety mechanisms:
+
+- Must be explicitly enabled with `enabled: true`
+- Clearly marked with test indicators
+- Console warnings when active
+- Separate endpoint namespace (`/payload-billing/test/`)
+- No real payment processing
+
+**Important**: Never use the test provider in production environments!

eslint.config.js

@@ -44,6 +44,7 @@ export default [
       'perfectionist/sort-switch-case': 'off',
       'perfectionist/sort-union-types': 'off',
       'perfectionist/sort-variable-declarations': 'off',
+      'perfectionist/sort-intersection-types': 'off',
     },
   },
   {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@xtr-dev/payload-billing",
-  "version": "0.1.2",
+  "version": "0.1.8",
   "description": "PayloadCMS plugin for billing and payment provider integrations with tracking and local testing",
   "license": "MIT",
   "type": "module",
@@ -70,6 +70,7 @@
   "devDependencies": {
     "@changesets/cli": "^2.27.1",
     "@eslint/eslintrc": "^3.2.0",
+    "@mollie/api-client": "^3.7.0",
     "@payloadcms/db-mongodb": "3.37.0",
     "@payloadcms/db-postgres": "3.37.0",
     "@payloadcms/db-sqlite": "3.37.0",
@@ -99,16 +100,17 @@
     "rimraf": "3.0.2",
     "sharp": "0.34.2",
     "sort-package-json": "^2.10.0",
+    "stripe": "^18.5.0",
     "typescript": "5.7.3",
     "vite-tsconfig-paths": "^5.1.4",
     "vitest": "^3.1.2"
   },
   "peerDependencies": {
-    "payload": "^3.37.0"
+    "@mollie/api-client": "^3.7.0 || ^4.0.0",
+    "payload": "^3.37.0",
+    "stripe": "^18.5.0"
   },
   "dependencies": {
-    "stripe": "^14.15.0",
-    "@mollie/api-client": "^3.7.0",
     "zod": "^3.22.4"
   },
   "engines": {

pnpm-lock.yaml

@@ -8,12 +8,6 @@ importers:
 
   .:
     dependencies:
-      '@mollie/api-client':
-        specifier: ^3.7.0
-        version: 3.7.0
-      stripe:
-        specifier: ^14.15.0
-        version: 14.25.0
       zod:
         specifier: ^3.22.4
         version: 3.25.76
@@ -24,6 +18,9 @@ importers:
       '@eslint/eslintrc':
         specifier: ^3.2.0
         version: 3.3.1
+      '@mollie/api-client':
+        specifier: ^3.7.0
+        version: 3.7.0
       '@payloadcms/db-mongodb':
         specifier: 3.37.0
         version: 3.37.0(payload@3.37.0(graphql@16.11.0)(typescript@5.7.3))
@@ -111,6 +108,9 @@ importers:
       sort-package-json:
         specifier: ^2.10.0
         version: 2.15.1
+      stripe:
+        specifier: ^18.5.0
+        version: 18.5.0(@types/node@22.18.1)
       typescript:
         specifier: 5.7.3
         version: 5.7.3
@@ -5165,9 +5165,14 @@ packages:
   strip-literal@3.0.0:
     resolution: {integrity: sha512-TcccoMhJOM3OebGhSBEmp3UZ2SfDMZUEBdRA/9ynfLi8yYajyWX3JiXArcJt4Umh4vISpspkQIY8ZZoCqjbviA==}
 
-  stripe@14.25.0:
-    resolution: {integrity: sha512-wQS3GNMofCXwH8TSje8E1SE8zr6ODiGtHQgPtO95p9Mb4FhKC9jvXR2NUTpZ9ZINlckJcFidCmaTFV4P6vsb9g==}
+  stripe@18.5.0:
+    resolution: {integrity: sha512-Hp+wFiEQtCB0LlNgcFh5uVyKznpDjzyUZ+CNVEf+I3fhlYvh7rZruIg+jOwzJRCpy0ZTPMjlzm7J2/M2N6d+DA==}
     engines: {node: '>=12.*'}
+    peerDependencies:
+      '@types/node': '>=12.x.x'
+    peerDependenciesMeta:
+      '@types/node':
+        optional: true
 
   strtok3@10.3.4:
     resolution: {integrity: sha512-KIy5nylvC5le1OdaaoCJ07L+8iQzJHGH6pWDuzS+d07Cu7n1MZ2x26P8ZKIWfbK02+XIL8Mp4RkWeqdUCrDMfg==}
@@ -8875,7 +8880,7 @@ snapshots:
       eslint: 9.35.0
       eslint-import-resolver-node: 0.3.9
       eslint-import-resolver-typescript: 3.10.1(eslint-plugin-import-x@4.4.2(eslint@9.35.0)(typescript@5.7.3))(eslint-plugin-import@2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint@9.35.0))(eslint@9.35.0)
-      eslint-plugin-import: 2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint-import-resolver-typescript@3.10.1)(eslint@9.35.0)
+      eslint-plugin-import: 2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint-import-resolver-typescript@3.10.1(eslint-plugin-import-x@4.4.2(eslint@9.35.0)(typescript@5.7.3))(eslint-plugin-import@2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint@9.35.0))(eslint@9.35.0))(eslint@9.35.0)
       eslint-plugin-jsx-a11y: 6.10.2(eslint@9.35.0)
       eslint-plugin-react: 7.37.5(eslint@9.35.0)
       eslint-plugin-react-hooks: 5.2.0(eslint@9.35.0)
@@ -8909,7 +8914,7 @@ snapshots:
       tinyglobby: 0.2.15
       unrs-resolver: 1.11.1
     optionalDependencies:
-      eslint-plugin-import: 2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint-import-resolver-typescript@3.10.1)(eslint@9.35.0)
+      eslint-plugin-import: 2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint-import-resolver-typescript@3.10.1(eslint-plugin-import-x@4.4.2(eslint@9.35.0)(typescript@5.7.3))(eslint-plugin-import@2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint@9.35.0))(eslint@9.35.0))(eslint@9.35.0)
       eslint-plugin-import-x: 4.4.2(eslint@9.35.0)(typescript@5.7.3)
     transitivePeerDependencies:
       - supports-color
@@ -8960,7 +8965,7 @@ snapshots:
       - typescript
     optional: true
 
-  eslint-plugin-import@2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint-import-resolver-typescript@3.10.1)(eslint@9.35.0):
+  eslint-plugin-import@2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint-import-resolver-typescript@3.10.1(eslint-plugin-import-x@4.4.2(eslint@9.35.0)(typescript@5.7.3))(eslint-plugin-import@2.32.0(@typescript-eslint/parser@8.43.0(eslint@9.35.0)(typescript@5.7.3))(eslint@9.35.0))(eslint@9.35.0))(eslint@9.35.0):
     dependencies:
       '@rtsao/scc': 1.1.0
       array-includes: 3.1.9
@@ -11434,10 +11439,11 @@ snapshots:
     dependencies:
       js-tokens: 9.0.1
 
-  stripe@14.25.0:
+  stripe@18.5.0(@types/node@22.18.1):
     dependencies:
-      '@types/node': 22.18.1
       qs: 6.14.0
+    optionalDependencies:
+      '@types/node': 22.18.1
 
   strtok3@10.3.4:
     dependencies:

src/collections/customers.ts

@@ -1,149 +0,0 @@
-import type { CollectionConfig } from 'payload'
-
-import type { 
-  AccessArgs,
-  CollectionAfterChangeHook,
-  CollectionBeforeChangeHook,
-  CustomerData,
-  CustomerDocument
-} from '../types/payload'
-
-export function createCustomersCollection(slug: string = 'customers'): CollectionConfig {
-  return {
-    slug,
-    access: {
-      create: ({ req: { user } }: AccessArgs) => !!user,
-      delete: ({ req: { user } }: AccessArgs) => !!user,
-      read: ({ req: { user } }: AccessArgs) => !!user,
-      update: ({ req: { user } }: AccessArgs) => !!user,
-    },
-    admin: {
-      defaultColumns: ['email', 'name', 'createdAt'],
-      group: 'Billing',
-      useAsTitle: 'email',
-    },
-    fields: [
-      {
-        name: 'email',
-        type: 'email',
-        admin: {
-          description: 'Customer email address',
-        },
-        index: true,
-        unique: true,
-      },
-      {
-        name: 'name',
-        type: 'text',
-        admin: {
-          description: 'Customer full name',
-        },
-      },
-      {
-        name: 'phone',
-        type: 'text',
-        admin: {
-          description: 'Customer phone number',
-        },
-      },
-      {
-        name: 'address',
-        type: 'group',
-        fields: [
-          {
-            name: 'line1',
-            type: 'text',
-            label: 'Address Line 1',
-          },
-          {
-            name: 'line2',
-            type: 'text',
-            label: 'Address Line 2',
-          },
-          {
-            name: 'city',
-            type: 'text',
-            label: 'City',
-          },
-          {
-            name: 'state',
-            type: 'text',
-            label: 'State/Province',
-          },
-          {
-            name: 'postalCode',
-            type: 'text',
-            label: 'Postal Code',
-          },
-          {
-            name: 'country',
-            type: 'text',
-            admin: {
-              description: 'ISO 3166-1 alpha-2 country code',
-            },
-            label: 'Country',
-            maxLength: 2,
-          },
-        ],
-      },
-      {
-        name: 'providerIds',
-        type: 'json',
-        admin: {
-          description: 'Customer IDs from payment providers',
-          readOnly: true,
-        },
-      },
-      {
-        name: 'metadata',
-        type: 'json',
-        admin: {
-          description: 'Additional customer metadata',
-        },
-      },
-      {
-        name: 'payments',
-        type: 'relationship',
-        admin: {
-          description: 'Customer payments',
-          readOnly: true,
-        },
-        hasMany: true,
-        relationTo: 'payments',
-      },
-      {
-        name: 'invoices',
-        type: 'relationship',
-        admin: {
-          description: 'Customer invoices',
-          readOnly: true,
-        },
-        hasMany: true,
-        relationTo: 'invoices',
-      },
-    ],
-    hooks: {
-      afterChange: [
-        ({ doc, operation, req }: CollectionAfterChangeHook<CustomerDocument>) => {
-          if (operation === 'create') {
-            req.payload.logger.info(`Customer created: ${doc.id} (${doc.email})`)
-          }
-        },
-      ],
-      beforeChange: [
-        ({ data, operation }: CollectionBeforeChangeHook<CustomerData>) => {
-          if (operation === 'create' || operation === 'update') {
-            // Normalize country code
-            if (data.address?.country) {
-              data.address.country = data.address.country.toUpperCase()
-              if (!/^[A-Z]{2}$/.test(data.address.country)) {
-                throw new Error('Country must be a 2-letter ISO code')
-              }
-            }
-          }
-        },
-      ],
-    },
-    timestamps: true,
-  }
-}

src/collections/hooks.ts

@@ -0,0 +1,11 @@
+import type { Payment } from '../plugin/types/index'
+import type { Payload } from 'payload'
+import { useBillingPlugin } from '../plugin/index'
+
+export const initProviderPayment = (payload: Payload, payment: Partial<Payment>) => {
+  const billing = useBillingPlugin(payload)
+  if (!payment.provider || !billing.providerConfig[payment.provider]) {
+    throw new Error(`Provider ${payment.provider} not found.`)
+  }
+  return billing.providerConfig[payment.provider].initPayment(payload, payment)
+}

src/collections/invoices.ts

@@ -1,35 +1,19 @@
-import type { CollectionConfig } from 'payload'
-
-import type {
+import {
   AccessArgs,
   CollectionAfterChangeHook,
   CollectionBeforeChangeHook,
   CollectionBeforeValidateHook,
-  InvoiceData,
-  InvoiceDocument,
-  InvoiceItemData
-} from '../types/payload'
-import type { CustomerInfoExtractor } from '../types'
+  CollectionConfig, Field,
+} from 'payload'
+import type { BillingPluginConfig} from '../plugin/config';
+import { defaults } from '../plugin/config'
+import { extractSlug } from '../plugin/utils'
+import type { Invoice } from '../plugin/types/invoices'
 
-export function createInvoicesCollection(
-  slug: string = 'invoices',
-  customerCollectionSlug?: string,
-  customerInfoExtractor?: CustomerInfoExtractor
-): CollectionConfig {
-  return {
-    slug,
-    access: {
-      create: ({ req: { user } }: AccessArgs) => !!user,
-      delete: ({ req: { user } }: AccessArgs) => !!user,
-      read: ({ req: { user } }: AccessArgs) => !!user,
-      update: ({ req: { user } }: AccessArgs) => !!user,
-    },
-    admin: {
-      defaultColumns: ['number', 'customerInfo.name', 'status', 'amount', 'currency', 'dueDate'],
-      group: 'Billing',
-      useAsTitle: 'number',
-    },
-    fields: [
+export function createInvoicesCollection(pluginConfig: BillingPluginConfig): CollectionConfig {
+  const {customerRelationSlug, customerInfoExtractor} = pluginConfig
+  const overrides = typeof pluginConfig.collections?.invoices === 'object' ? pluginConfig.collections?.invoices : {}
+  let fields: Field[] = [
     {
       name: 'number',
       type: 'text',
@@ -41,14 +25,14 @@ export function createInvoicesCollection(
       unique: true,
     },
     // Optional customer relationship
-      ...(customerCollectionSlug ? [{
+    ...(customerRelationSlug ? [{
       name: 'customer',
       type: 'relationship' as const,
       admin: {
         position: 'sidebar' as const,
         description: 'Link to customer record (optional)',
       },
-        relationTo: customerCollectionSlug as any,
+      relationTo: extractSlug(customerRelationSlug),
       required: false,
     }] : []),
     // Basic customer info fields (embedded)
@@ -56,10 +40,10 @@ export function createInvoicesCollection(
       name: 'customerInfo',
       type: 'group',
       admin: {
-          description: customerCollectionSlug && customerInfoExtractor
+        description: customerRelationSlug && customerInfoExtractor
           ? 'Customer billing information (auto-populated from customer relationship)'
           : 'Customer billing information',
-          readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+        readOnly: !!(customerRelationSlug && customerInfoExtractor),
       },
       fields: [
         {
@@ -67,25 +51,25 @@ export function createInvoicesCollection(
           type: 'text',
           admin: {
             description: 'Customer name',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
-            required: !customerCollectionSlug || !customerInfoExtractor,
+          required: !customerRelationSlug || !customerInfoExtractor,
         },
         {
           name: 'email',
           type: 'email',
           admin: {
             description: 'Customer email address',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
-            required: !customerCollectionSlug || !customerInfoExtractor,
+          required: !customerRelationSlug || !customerInfoExtractor,
         },
         {
           name: 'phone',
           type: 'text',
           admin: {
             description: 'Customer phone number',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
         },
         {
@@ -93,7 +77,7 @@ export function createInvoicesCollection(
           type: 'text',
           admin: {
             description: 'Company name (optional)',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
         },
         {
@@ -101,7 +85,7 @@ export function createInvoicesCollection(
           type: 'text',
           admin: {
             description: 'Tax ID or VAT number',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
         },
       ],
@@ -110,10 +94,10 @@ export function createInvoicesCollection(
       name: 'billingAddress',
       type: 'group',
       admin: {
-          description: customerCollectionSlug && customerInfoExtractor
+        description: customerRelationSlug && customerInfoExtractor
           ? 'Billing address (auto-populated from customer relationship)'
           : 'Billing address',
-          readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+        readOnly: !!(customerRelationSlug && customerInfoExtractor),
       },
       fields: [
         {
@@ -121,32 +105,32 @@ export function createInvoicesCollection(
           type: 'text',
           admin: {
             description: 'Address line 1',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
-            required: !customerCollectionSlug || !customerInfoExtractor,
+          required: !customerRelationSlug || !customerInfoExtractor,
         },
         {
           name: 'line2',
           type: 'text',
           admin: {
             description: 'Address line 2',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
         },
         {
           name: 'city',
           type: 'text',
           admin: {
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
-            required: !customerCollectionSlug || !customerInfoExtractor,
+          required: !customerRelationSlug || !customerInfoExtractor,
         },
         {
           name: 'state',
           type: 'text',
           admin: {
             description: 'State or province',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
         },
         {
@@ -154,19 +138,19 @@ export function createInvoicesCollection(
           type: 'text',
           admin: {
             description: 'Postal or ZIP code',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
-            required: !customerCollectionSlug || !customerInfoExtractor,
+          required: !customerRelationSlug || !customerInfoExtractor,
         },
         {
           name: 'country',
           type: 'text',
           admin: {
             description: 'Country code (e.g., US, GB)',
-              readOnly: customerCollectionSlug && customerInfoExtractor ? true : false,
+            readOnly: !!(customerRelationSlug && customerInfoExtractor),
           },
           maxLength: 2,
-            required: !customerCollectionSlug || !customerInfoExtractor,
+          required: !customerRelationSlug || !customerInfoExtractor,
         },
       ],
     },
@@ -281,7 +265,7 @@ export function createInvoicesCollection(
       name: 'paidAt',
       type: 'date',
       admin: {
-          condition: (data: InvoiceData) => data.status === 'paid',
+        condition: (data) => data.status === 'paid',
         readOnly: true,
       },
     },
@@ -289,10 +273,10 @@ export function createInvoicesCollection(
       name: 'payment',
       type: 'relationship',
       admin: {
-          condition: (data: InvoiceData) => data.status === 'paid',
+        condition: (data) => data.status === 'paid',
         position: 'sidebar',
       },
-        relationTo: 'payments',
+      relationTo: extractSlug(pluginConfig.collections?.payments || defaults.paymentsCollection),
     },
     {
       name: 'notes',
@@ -308,19 +292,36 @@ export function createInvoicesCollection(
         description: 'Additional invoice metadata',
       },
     },
-    ],
+  ]
+  if (overrides?.fields) {
+    fields = overrides.fields({defaultFields: fields})
+  }
+  return {
+    slug: extractSlug(pluginConfig.collections?.invoices || defaults.invoicesCollection),
+    access: {
+      create: ({ req: { user } }: AccessArgs) => !!user,
+      delete: ({ req: { user } }: AccessArgs) => !!user,
+      read: ({ req: { user } }: AccessArgs) => !!user,
+      update: ({ req: { user } }: AccessArgs) => !!user,
+    },
+    admin: {
+      defaultColumns: ['number', 'customerInfo.name', 'status', 'amount', 'currency', 'dueDate'],
+      group: 'Billing',
+      useAsTitle: 'number',
+    },
+    fields,
     hooks: {
       afterChange: [
-        ({ doc, operation, req }: CollectionAfterChangeHook<InvoiceDocument>) => {
+        ({ doc, operation, req }) => {
           if (operation === 'create') {
             req.payload.logger.info(`Invoice created: ${doc.number}`)
           }
         },
-      ],
+      ] satisfies CollectionAfterChangeHook<Invoice>[],
       beforeChange: [
-        async ({ data, operation, req, originalDoc }: CollectionBeforeChangeHook<InvoiceData>) => {
+        async ({ data, operation, req, originalDoc }) => {
           // Sync customer info from relationship if extractor is provided
-          if (customerCollectionSlug && customerInfoExtractor && data.customer) {
+          if (customerRelationSlug && customerInfoExtractor && data.customer) {
             // Check if customer changed or this is a new invoice
             const customerChanged = operation === 'create' ||
               (originalDoc && originalDoc.customer !== data.customer)
@@ -329,8 +330,8 @@ export function createInvoicesCollection(
               try {
                 // Fetch the customer data
                 const customer = await req.payload.findByID({
-                  collection: customerCollectionSlug,
-                  id: data.customer,
+                  collection: customerRelationSlug as never,
+                  id: data.customer as never,
                 })
 
                 // Extract customer info using the provided callback
@@ -383,37 +384,37 @@ export function createInvoicesCollection(
             data.paidAt = new Date().toISOString()
           }
         },
-      ],
+      ] satisfies CollectionBeforeChangeHook<Invoice>[],
       beforeValidate: [
-        ({ data }: CollectionBeforeValidateHook<InvoiceData>) => {
+        ({ data }) => {
           if (!data) return
 
           // If using extractor, customer relationship is required
-          if (customerCollectionSlug && customerInfoExtractor && !data.customer) {
+          if (customerRelationSlug && customerInfoExtractor && !data.customer) {
             throw new Error('Please select a customer')
           }
 
           // If not using extractor but have customer collection, either relationship or info is required
-          if (customerCollectionSlug && !customerInfoExtractor &&
+          if (customerRelationSlug && !customerInfoExtractor &&
               !data.customer && (!data.customerInfo?.name || !data.customerInfo?.email)) {
             throw new Error('Either select a customer or provide customer information')
           }
 
           // If no customer collection, ensure customer info is provided
-          if (!customerCollectionSlug && (!data.customerInfo?.name || !data.customerInfo?.email)) {
+          if (!customerRelationSlug && (!data.customerInfo?.name || !data.customerInfo?.email)) {
             throw new Error('Customer name and email are required')
           }
 
           if (data && data.items && Array.isArray(data.items)) {
             // Calculate totals for each line item
-            data.items = data.items.map((item: InvoiceItemData) => ({
+            data.items = data.items.map((item) => ({
               ...item,
               totalAmount: (item.quantity || 0) * (item.unitAmount || 0),
             }))
 
             // Calculate subtotal
             data.subtotal = data.items.reduce(
-              (sum: number, item: InvoiceItemData) => sum + (item.totalAmount || 0),
+              (sum: number, item) => sum + (item.totalAmount || 0),
               0
             )
 
@@ -421,7 +422,7 @@ export function createInvoicesCollection(
             data.amount = (data.subtotal || 0) + (data.taxAmount || 0)
           }
         },
-      ],
+      ] satisfies CollectionBeforeValidateHook<Invoice>[],
     },
     timestamps: true,
   }

src/collections/payments.ts

@@ -1,28 +1,13 @@
-import type { CollectionConfig } from 'payload'
+import type { AccessArgs, CollectionBeforeChangeHook, CollectionConfig, Field } from 'payload'
+import type { BillingPluginConfig} from '../plugin/config';
+import { defaults } from '../plugin/config'
+import { extractSlug } from '../plugin/utils'
+import type { Payment } from '../plugin/types/payments'
+import { initProviderPayment } from './hooks'
 
-import type { 
-  AccessArgs,
-  CollectionAfterChangeHook,
-  CollectionBeforeChangeHook,
-  PaymentData,
-  PaymentDocument
-} from '../types/payload'
-
-export function createPaymentsCollection(slug: string = 'payments'): CollectionConfig {
-  return {
-    slug,
-    access: {
-      create: ({ req: { user } }: AccessArgs) => !!user,
-      delete: ({ req: { user } }: AccessArgs) => !!user,
-      read: ({ req: { user } }: AccessArgs) => !!user,
-      update: ({ req: { user } }: AccessArgs) => !!user,
-    },
-    admin: {
-      defaultColumns: ['id', 'provider', 'status', 'amount', 'currency', 'createdAt'],
-      group: 'Billing',
-      useAsTitle: 'id',
-    },
-    fields: [
+export function createPaymentsCollection(pluginConfig: BillingPluginConfig): CollectionConfig {
+  const overrides = typeof pluginConfig.collections?.payments === 'object' ? pluginConfig.collections?.payments : {}
+  let fields: Field[] = [
     {
       name: 'provider',
       type: 'select',
@@ -43,8 +28,8 @@ export function createPaymentsCollection(slug: string = 'payments'): CollectionC
         description: 'The payment ID from the payment provider',
       },
       label: 'Provider Payment ID',
-        required: true,
       unique: true,
+      index: true, // Ensure this field is indexed for webhook lookups
     },
     {
       name: 'status',
@@ -88,21 +73,13 @@ export function createPaymentsCollection(slug: string = 'payments'): CollectionC
         description: 'Payment description',
       },
     },
-      {
-        name: 'customer',
-        type: 'relationship',
-        admin: {
-          position: 'sidebar',
-        },
-        relationTo: 'customers',
-      },
     {
       name: 'invoice',
       type: 'relationship',
       admin: {
         position: 'sidebar',
       },
-        relationTo: 'invoices',
+      relationTo: extractSlug(pluginConfig.collections?.invoices || defaults.invoicesCollection),
     },
     {
       name: 'metadata',
@@ -127,19 +104,39 @@ export function createPaymentsCollection(slug: string = 'payments'): CollectionC
         readOnly: true,
       },
       hasMany: true,
-        relationTo: 'refunds',
+      relationTo: extractSlug(pluginConfig.collections?.refunds || defaults.refundsCollection),
     },
-    ],
-    hooks: {
-      afterChange: [
-        ({ doc, operation, req }: CollectionAfterChangeHook<PaymentDocument>) => {
-          if (operation === 'create') {
-            req.payload.logger.info(`Payment created: ${doc.id} (${doc.provider})`)
+    {
+      name: 'version',
+      type: 'number',
+      defaultValue: 1,
+      admin: {
+        hidden: true, // Hide from admin UI to prevent manual tampering
+      },
+      index: true, // Index for optimistic locking performance
+    },
+  ]
+  if (overrides?.fields) {
+    fields = overrides?.fields({defaultFields: fields})
   }
+  return {
+    slug: extractSlug(pluginConfig.collections?.payments || defaults.paymentsCollection),
+    access: overrides?.access || {
+      create: ({ req: { user } }: AccessArgs) => !!user,
+      delete: ({ req: { user } }: AccessArgs) => !!user,
+      read: ({ req: { user } }: AccessArgs) => !!user,
+      update: ({ req: { user } }: AccessArgs) => !!user,
     },
-      ],
+    admin: {
+      defaultColumns: ['id', 'provider', 'status', 'amount', 'currency', 'createdAt'],
+      group: 'Billing',
+      useAsTitle: 'id',
+      ...overrides?.admin
+    },
+    fields,
+    hooks: {
       beforeChange: [
-        ({ data, operation }: CollectionBeforeChangeHook<PaymentData>) => {
+        async ({ data, operation, req, originalDoc }) => {
           if (operation === 'create') {
             // Validate amount format
             if (data.amount && !Number.isInteger(data.amount)) {
@@ -153,9 +150,20 @@ export function createPaymentsCollection(slug: string = 'payments'): CollectionC
                 throw new Error('Currency must be a 3-letter ISO code')
               }
             }
+
+            await initProviderPayment(req.payload, data)
+          }
+
+          // Auto-increment version for manual updates (not webhook updates)
+          // Webhook updates handle their own versioning in updatePaymentStatus
+          if (operation === 'update' && !data.version) {
+            // If version is not being explicitly set (i.e., manual admin update),
+            // increment it automatically
+            const currentVersion = (originalDoc as Payment)?.version || 1
+            data.version = currentVersion + 1
           }
         },
-      ],
+      ] satisfies CollectionBeforeChangeHook<Payment>[],
     },
     timestamps: true,
   }

src/collections/refunds.ts

@@ -1,16 +1,12 @@
-import type { CollectionConfig } from 'payload'
+import type { AccessArgs, CollectionConfig } from 'payload'
+import { BillingPluginConfig, defaults } from '../plugin/config'
+import { extractSlug } from '../plugin/utils'
+import { Payment } from '../plugin/types/index'
 
-import type {
-  AccessArgs,
-  CollectionAfterChangeHook,
-  CollectionBeforeChangeHook,
-  RefundData,
-  RefundDocument
-} from '../types/payload'
-
-export function createRefundsCollection(slug: string = 'refunds'): CollectionConfig {
+export function createRefundsCollection(pluginConfig: BillingPluginConfig): CollectionConfig {
+  // TODO: finish collection overrides
   return {
-    slug,
+    slug: extractSlug(pluginConfig.collections?.refunds || defaults.refundsCollection),
     access: {
       create: ({ req: { user } }: AccessArgs) => !!user,
       delete: ({ req: { user } }: AccessArgs) => !!user,
@@ -39,7 +35,7 @@ export function createRefundsCollection(slug: string = 'refunds'): CollectionCon
         admin: {
           position: 'sidebar',
         },
-        relationTo: 'payments',
+        relationTo: extractSlug(pluginConfig.collections?.payments || defaults.paymentsCollection),
         required: true,
       },
       {
@@ -113,7 +109,7 @@ export function createRefundsCollection(slug: string = 'refunds'): CollectionCon
     ],
     hooks: {
       afterChange: [
-        async ({ doc, operation, req }: CollectionAfterChangeHook<RefundDocument>) => {
+        async ({ doc, operation, req }) => {
           if (operation === 'create') {
             req.payload.logger.info(`Refund created: ${doc.id} for payment: ${doc.payment}`)
 
@@ -121,15 +117,15 @@ export function createRefundsCollection(slug: string = 'refunds'): CollectionCon
             try {
               const payment = await req.payload.findByID({
                 id: typeof doc.payment === 'string' ? doc.payment : doc.payment.id,
-                collection: 'payments',
-              })
+                collection: extractSlug(pluginConfig.collections?.payments || defaults.paymentsCollection),
+              }) as Payment
 
               const refundIds = Array.isArray(payment.refunds) ? payment.refunds : []
               await req.payload.update({
                 id: typeof doc.payment === 'string' ? doc.payment : doc.payment.id,
-                collection: 'payments',
+                collection: extractSlug(pluginConfig.collections?.payments || defaults.paymentsCollection),
                 data: {
-                  refunds: [...refundIds, doc.id as any],
+                  refunds: [...refundIds, doc.id],
                 },
               })
             } catch (error) {
@@ -139,7 +135,7 @@ export function createRefundsCollection(slug: string = 'refunds'): CollectionCon
         },
       ],
       beforeChange: [
-        ({ data, operation }: CollectionBeforeChangeHook<RefundData>) => {
+        ({ data, operation }) => {
           if (operation === 'create') {
             // Validate amount format
             if (data.amount && !Number.isInteger(data.amount)) {

src/exports/client.tsx

@@ -60,9 +60,130 @@ export const PaymentStatusBadge: React.FC<{ status: string }> = ({ status }) =>
   )
 }
 
+// Test mode indicator components
+export const TestModeWarningBanner: React.FC<{ visible?: boolean }> = ({ visible = true }) => {
+  if (!visible) return null
+
+  return (
+    <div style={{
+      background: 'linear-gradient(90deg, #ff6b6b, #ffa726)',
+      color: 'white',
+      padding: '12px 20px',
+      textAlign: 'center',
+      fontWeight: 600,
+      fontSize: '14px',
+      marginBottom: '20px',
+      borderRadius: '4px'
+    }}>
+      🧪 TEST MODE - Payment system is running in test mode for development
+    </div>
+  )
+}
+
+export const TestModeBadge: React.FC<{ visible?: boolean }> = ({ visible = true }) => {
+  if (!visible) return null
+
+  return (
+    <span style={{
+      display: 'inline-block',
+      background: '#6c757d',
+      color: 'white',
+      padding: '4px 8px',
+      borderRadius: '4px',
+      fontSize: '12px',
+      fontWeight: 600,
+      textTransform: 'uppercase',
+      marginLeft: '8px'
+    }}>
+      Test
+    </span>
+  )
+}
+
+export const TestPaymentControls: React.FC<{
+  paymentId?: string
+  onScenarioSelect?: (scenario: string) => void
+  onMethodSelect?: (method: string) => void
+}> = ({ paymentId, onScenarioSelect, onMethodSelect }) => {
+  const [selectedScenario, setSelectedScenario] = React.useState('')
+  const [selectedMethod, setSelectedMethod] = React.useState('')
+
+  const scenarios = [
+    { id: 'instant-success', name: 'Instant Success', description: 'Payment succeeds immediately' },
+    { id: 'delayed-success', name: 'Delayed Success', description: 'Payment succeeds after delay' },
+    { id: 'cancelled-payment', name: 'Cancelled Payment', description: 'User cancels payment' },
+    { id: 'declined-payment', name: 'Declined Payment', description: 'Payment declined' },
+    { id: 'expired-payment', name: 'Expired Payment', description: 'Payment expires' },
+    { id: 'pending-payment', name: 'Pending Payment', description: 'Payment stays pending' }
+  ]
+
+  const methods = [
+    { id: 'ideal', name: 'iDEAL', icon: '🏦' },
+    { id: 'creditcard', name: 'Credit Card', icon: '💳' },
+    { id: 'paypal', name: 'PayPal', icon: '🅿️' },
+    { id: 'applepay', name: 'Apple Pay', icon: '🍎' },
+    { id: 'banktransfer', name: 'Bank Transfer', icon: '🏛️' }
+  ]
+
+  return (
+    <div style={{ border: '1px solid #e9ecef', borderRadius: '8px', padding: '16px', margin: '16px 0' }}>
+      <h4 style={{ marginBottom: '12px', color: '#2c3e50' }}>🧪 Test Payment Controls</h4>
+
+      <div style={{ marginBottom: '16px' }}>
+        <label style={{ display: 'block', marginBottom: '8px', fontWeight: '600' }}>Payment Method:</label>
+        <select
+          value={selectedMethod}
+          onChange={(e) => {
+            setSelectedMethod(e.target.value)
+            onMethodSelect?.(e.target.value)
+          }}
+          style={{ width: '100%', padding: '8px', borderRadius: '4px', border: '1px solid #ccc' }}
+        >
+          <option value="">Select payment method...</option>
+          {methods.map(method => (
+            <option key={method.id} value={method.id}>
+              {method.icon} {method.name}
+            </option>
+          ))}
+        </select>
+      </div>
+
+      <div style={{ marginBottom: '16px' }}>
+        <label style={{ display: 'block', marginBottom: '8px', fontWeight: '600' }}>Test Scenario:</label>
+        <select
+          value={selectedScenario}
+          onChange={(e) => {
+            setSelectedScenario(e.target.value)
+            onScenarioSelect?.(e.target.value)
+          }}
+          style={{ width: '100%', padding: '8px', borderRadius: '4px', border: '1px solid #ccc' }}
+        >
+          <option value="">Select test scenario...</option>
+          {scenarios.map(scenario => (
+            <option key={scenario.id} value={scenario.id}>
+              {scenario.name} - {scenario.description}
+            </option>
+          ))}
+        </select>
+      </div>
+
+      {paymentId && (
+        <div style={{ marginTop: '12px', padding: '8px', background: '#f8f9fa', borderRadius: '4px' }}>
+          <small style={{ color: '#6c757d' }}>
+            Payment ID: <code>{paymentId}</code>
+          </small>
+        </div>
+      )}
+    </div>
+  )
+}
+
 export default {
   BillingDashboardWidget,
   formatCurrency,
   getPaymentStatusColor,
   PaymentStatusBadge,
+  TestModeWarningBanner,
+  TestModeBadge,
+  TestPaymentControls,
 }

src/index.ts

@@ -1,98 +1,18 @@
-import type { Config } from 'payload'
 
-import type { BillingPluginConfig, CustomerInfoExtractor } from './types'
+export { billingPlugin } from './plugin/index.js'
+export { mollieProvider, stripeProvider } from './providers/index.js'
+export type { BillingPluginConfig, CustomerInfoExtractor, AdvancedTestProviderConfig } from './plugin/config.js'
+export type { Invoice, Payment, Refund } from './plugin/types/index.js'
+export type { PaymentProvider, ProviderData } from './providers/types.js'
 
-import { createCustomersCollection } from './collections/customers'
-import { createInvoicesCollection } from './collections/invoices'
-import { createPaymentsCollection } from './collections/payments'
-import { createRefundsCollection } from './collections/refunds'
-
-export * from './types'
-
-// Default customer info extractor for the built-in customer collection
-export const defaultCustomerInfoExtractor: CustomerInfoExtractor = (customer) => {
-  return {
-    name: customer.name || '',
-    email: customer.email || '',
-    phone: customer.phone,
-    company: customer.company,
-    taxId: customer.taxId,
-    billingAddress: customer.address ? {
-      line1: customer.address.line1 || '',
-      line2: customer.address.line2,
-      city: customer.address.city || '',
-      state: customer.address.state,
-      postalCode: customer.address.postalCode || '',
-      country: customer.address.country || '',
-    } : undefined,
-  }
-}
-
-export const billingPlugin = (pluginConfig: BillingPluginConfig = {}) => (config: Config): Config => {
-  if (pluginConfig.disabled) {
-    return config
-  }
-
-  // Initialize collections
-  if (!config.collections) {
-    config.collections = []
-  }
-
-  const customerSlug = pluginConfig.collections?.customers || 'customers'
-
-  config.collections.push(
-    createPaymentsCollection(pluginConfig.collections?.payments || 'payments'),
-    createCustomersCollection(customerSlug),
-    createInvoicesCollection(
-      pluginConfig.collections?.invoices || 'invoices',
-      pluginConfig.collections?.customerRelation !== false ? customerSlug : undefined,
-      pluginConfig.customerInfoExtractor
-    ),
-    createRefundsCollection(pluginConfig.collections?.refunds || 'refunds'),
-  )
-
-  // Initialize endpoints
-  if (!config.endpoints) {
-    config.endpoints = []
-  }
-
-  config.endpoints?.push(
-    // Webhook endpoints
-    {
-      handler: (_req) => {
-        try {
-          const provider = null
-          if (!provider) {
-            return Response.json({ error: 'Provider not found' }, { status: 404 })
-          }
-
-          // TODO: Process webhook event and update database
-
-          return Response.json({ received: true })
-        } catch (error) {
-          // TODO: Use proper logger instead of console
-          // eslint-disable-next-line no-console
-          console.error('[BILLING] Webhook error:', error)
-          return Response.json({ error: 'Webhook processing failed' }, { status: 400 })
-        }
-      },
-      method: 'post',
-      path: '/billing/webhooks/:provider'
-    },
-  )
-
-  // Initialize providers and onInit hook
-  const incomingOnInit = config.onInit
-
-  config.onInit = async (payload) => {
-    // Execute any existing onInit functions first
-    if (incomingOnInit) {
-      await incomingOnInit(payload)
-    }
-
-  }
-
-  return config
-}
-
-export default billingPlugin
+// Export all providers
+export { testProvider } from './providers/test.js'
+export type {
+  StripeProviderConfig,
+  MollieProviderConfig,
+  TestProviderConfig,
+  TestProviderConfigResponse,
+  PaymentOutcome,
+  PaymentMethod,
+  PaymentScenario
+} from './providers/index.js'

src/plugin/config.ts

@@ -0,0 +1,60 @@
+import { CollectionConfig } from 'payload'
+import { FieldsOverride } from './utils'
+import { PaymentProvider } from './types/index'
+
+export const defaults = {
+  paymentsCollection: 'payments',
+  invoicesCollection: 'invoices',
+  refundsCollection: 'refunds',
+  customerRelationSlug: 'customer'
+}
+
+// Provider configurations
+
+export interface TestProviderConfig {
+  autoComplete?: boolean
+  defaultDelay?: number
+  enabled: boolean
+  failureRate?: number
+  simulateFailures?: boolean
+}
+
+// Re-export the actual test provider config instead of duplicating
+export type { TestProviderConfig as AdvancedTestProviderConfig } from '../providers/test'
+
+// Customer info extractor callback type
+export interface CustomerInfoExtractor {
+  (customer: any): {
+    name: string
+    email: string
+    phone?: string
+    company?: string
+    taxId?: string
+    billingAddress?: {
+      line1: string
+      line2?: string
+      city: string
+      state?: string
+      postalCode: string
+      country: string
+    }
+  }
+}
+
+// Plugin configuration
+export interface BillingPluginConfig {
+  admin?: {
+    customComponents?: boolean
+    dashboard?: boolean
+  }
+  collections?: {
+    invoices?: string | (Partial<CollectionConfig> & {fields?: FieldsOverride})
+    payments?: string | (Partial<CollectionConfig> & {fields?: FieldsOverride})
+    refunds?: string | (Partial<CollectionConfig> & {fields?: FieldsOverride})
+  }
+  customerInfoExtractor?: CustomerInfoExtractor // Callback to extract customer info from relationship
+  customerRelationSlug?: string // Customer collection slug for relationship
+  disabled?: boolean
+  providers?: PaymentProvider[]
+}
+

src/plugin/index.ts

@@ -0,0 +1,56 @@
+import { createInvoicesCollection, createPaymentsCollection, createRefundsCollection } from '../collections/index'
+import type { BillingPluginConfig } from './config'
+import type { Config, Payload } from 'payload'
+import { createSingleton } from './singleton'
+import type { PaymentProvider } from '../providers/index'
+
+const singleton = createSingleton(Symbol('billingPlugin'))
+
+type BillingPlugin = {
+  config: BillingPluginConfig
+  providerConfig: {
+    [key: string]: PaymentProvider
+  }
+}
+
+export const useBillingPlugin = (payload: Payload) => singleton.get(payload) as BillingPlugin
+
+export const billingPlugin = (pluginConfig: BillingPluginConfig = {}) => (config: Config): Config => {
+  if (pluginConfig.disabled) {
+    return config
+  }
+
+  config.collections = [
+    ...(config.collections || []),
+    createPaymentsCollection(pluginConfig),
+    createInvoicesCollection(pluginConfig),
+    createRefundsCollection(pluginConfig),
+  ];
+
+  (pluginConfig.providers || [])
+    .filter(provider => provider.onConfig)
+    .forEach(provider => provider.onConfig!(config, pluginConfig))
+
+  const incomingOnInit = config.onInit
+  config.onInit = async (payload) => {
+    if (incomingOnInit) {
+      await incomingOnInit(payload)
+    }
+    singleton.set(payload, {
+      config: pluginConfig,
+      providerConfig: (pluginConfig.providers || []).reduce(
+        (record, provider) => {
+          record[provider.key] = provider
+          return record
+        },
+        {} as Record<string, PaymentProvider>
+      )
+    } satisfies BillingPlugin)
+    await Promise.all((pluginConfig.providers || [])
+      .filter(provider => provider.onInit)
+      .map(provider => provider.onInit!(payload)))
+  }
+
+  return config
+}
+export default billingPlugin

src/plugin/singleton.ts

@@ -0,0 +1,11 @@
+export const createSingleton = <T>(s?: symbol | string) => {
+  const symbol = !s ? Symbol() : s
+  return {
+    get(container: any) {
+      return container[symbol] as T
+    },
+    set(container: any, value: T) {
+      container[symbol] = value
+    },
+  }
+}

src/plugin/types/id.ts

@@ -0,0 +1 @@
+export type Id = string | number

src/plugin/types/index.ts

@@ -0,0 +1,5 @@
+export * from './id.js'
+export * from './invoices.js'
+export * from './payments.js'
+export * from './refunds.js'
+export * from '../../providers/types.js'

src/plugin/types/invoices.ts

@@ -0,0 +1,116 @@
+import { Payment } from './payments'
+import { Id } from './id'
+
+export interface Invoice<TCustomer = unknown> {
+  id: Id;
+  /**
+   * Invoice number (e.g., INV-001)
+   */
+  number: string;
+  /**
+   * Link to customer record (optional)
+   */
+  customer?: (Id | null) | TCustomer;
+  /**
+   * Customer billing information (auto-populated from customer relationship)
+   */
+  customerInfo?: {
+    /**
+     * Customer name
+     */
+    name?: string | null;
+    /**
+     * Customer email address
+     */
+    email?: string | null;
+    /**
+     * Customer phone number
+     */
+    phone?: string | null;
+    /**
+     * Company name (optional)
+     */
+    company?: string | null;
+    /**
+     * Tax ID or VAT number
+     */
+    taxId?: string | null;
+  };
+  /**
+   * Billing address (auto-populated from customer relationship)
+   */
+  billingAddress?: {
+    /**
+     * Address line 1
+     */
+    line1?: string | null;
+    /**
+     * Address line 2
+     */
+    line2?: string | null;
+    city?: string | null;
+    /**
+     * State or province
+     */
+    state?: string | null;
+    /**
+     * Postal or ZIP code
+     */
+    postalCode?: string | null;
+    /**
+     * Country code (e.g., US, GB)
+     */
+    country?: string | null;
+  };
+  status: 'draft' | 'open' | 'paid' | 'void' | 'uncollectible';
+  /**
+   * ISO 4217 currency code (e.g., USD, EUR)
+   */
+  currency: string;
+  items: {
+    description: string;
+    quantity: number;
+    /**
+     * Amount in cents
+     */
+    unitAmount: number;
+    /**
+     * Calculated: quantity × unitAmount
+     */
+    totalAmount?: number | null;
+    id?: Id | null;
+  }[];
+  /**
+   * Sum of all line items
+   */
+  subtotal?: number | null;
+  /**
+   * Tax amount in cents
+   */
+  taxAmount?: number | null;
+  /**
+   * Total amount (subtotal + tax)
+   */
+  amount?: number | null;
+  dueDate?: string | null;
+  paidAt?: string | null;
+  payment?: (number | null) | Payment;
+  /**
+   * Internal notes
+   */
+  notes?: string | null;
+  /**
+   * Additional invoice metadata
+   */
+  metadata?:
+    | {
+    [k: string]: unknown;
+  }
+    | unknown[]
+    | string
+    | number
+    | boolean
+    | null;
+  updatedAt: string;
+  createdAt: string;
+}

src/plugin/types/payments.ts

@@ -0,0 +1,57 @@
+import { Refund } from './refunds'
+import { Invoice } from './invoices'
+import { Id } from './id'
+
+export interface Payment {
+  id: Id;
+  provider: 'stripe' | 'mollie' | 'test';
+  /**
+   * The payment ID from the payment provider
+   */
+  providerId: Id;
+  status: 'pending' | 'processing' | 'succeeded' | 'failed' | 'canceled' | 'refunded' | 'partially_refunded';
+  /**
+   * Amount in cents (e.g., 2000 = $20.00)
+   */
+  amount: number;
+  /**
+   * ISO 4217 currency code (e.g., USD, EUR)
+   */
+  currency: string;
+  /**
+   * Payment description
+   */
+  description?: string | null;
+  invoice?: (Id | null) | Invoice;
+  /**
+   * Additional metadata for the payment
+   */
+  metadata?:
+    | {
+    [k: string]: unknown;
+  }
+    | unknown[]
+    | string
+    | number
+    | boolean
+    | null;
+  /**
+   * Raw data from the payment provider
+   */
+  providerData?:
+    | {
+    [k: string]: unknown;
+  }
+    | unknown[]
+    | string
+    | number
+    | boolean
+    | null;
+  refunds?: (number | Refund)[] | null;
+  /**
+   * Version number for optimistic locking (auto-incremented on updates)
+   */
+  version?: number;
+  updatedAt: string;
+  createdAt: string;
+}

src/plugin/types/refunds.ts

@@ -0,0 +1,53 @@
+import { Payment } from './payments'
+
+export interface Refund {
+  id: number;
+  /**
+   * The refund ID from the payment provider
+   */
+  providerId: string;
+  payment: number | Payment;
+  status: 'pending' | 'processing' | 'succeeded' | 'failed' | 'canceled';
+  /**
+   * Refund amount in cents
+   */
+  amount: number;
+  /**
+   * ISO 4217 currency code (e.g., USD, EUR)
+   */
+  currency: string;
+  /**
+   * Reason for the refund
+   */
+  reason?: ('duplicate' | 'fraudulent' | 'requested_by_customer' | 'other') | null;
+  /**
+   * Additional details about the refund
+   */
+  description?: string | null;
+  /**
+   * Additional refund metadata
+   */
+  metadata?:
+    | {
+    [k: string]: unknown;
+  }
+    | unknown[]
+    | string
+    | number
+    | boolean
+    | null;
+  /**
+   * Raw data from the payment provider
+   */
+  providerData?:
+    | {
+    [k: string]: unknown;
+  }
+    | unknown[]
+    | string
+    | number
+    | boolean
+    | null;
+  updatedAt: string;
+  createdAt: string;
+}

src/plugin/utils.ts

@@ -0,0 +1,15 @@
+import type { CollectionConfig, CollectionSlug, Field } from 'payload'
+import type { Id } from './types/index'
+
+export type FieldsOverride = (args: { defaultFields: Field[] }) => Field[]
+
+export const extractSlug =
+  (arg: string | Partial<CollectionConfig>) => (typeof arg === 'string' ? arg : arg.slug!) as CollectionSlug
+
+/**
+ * Safely cast ID types for PayloadCMS operations
+ * This utility provides a typed way to handle the mismatch between our Id type and PayloadCMS expectations
+ */
+export function toPayloadId(id: Id): any {
+  return id as any
+}

src/providers/currency.ts

@@ -0,0 +1,94 @@
+/**
+ * Currency utilities for payment processing
+ */
+
+// Currencies that don't use centesimal units (no decimal places)
+const NON_CENTESIMAL_CURRENCIES = new Set([
+  'BIF', // Burundian Franc
+  'CLP', // Chilean Peso
+  'DJF', // Djiboutian Franc
+  'GNF', // Guinean Franc
+  'JPY', // Japanese Yen
+  'KMF', // Comorian Franc
+  'KRW', // South Korean Won
+  'MGA', // Malagasy Ariary
+  'PYG', // Paraguayan Guaraní
+  'RWF', // Rwandan Franc
+  'UGX', // Ugandan Shilling
+  'VND', // Vietnamese Đồng
+  'VUV', // Vanuatu Vatu
+  'XAF', // Central African CFA Franc
+  'XOF', // West African CFA Franc
+  'XPF', // CFP Franc
+])
+
+// Currencies that use 3 decimal places
+const THREE_DECIMAL_CURRENCIES = new Set([
+  'BHD', // Bahraini Dinar
+  'IQD', // Iraqi Dinar
+  'JOD', // Jordanian Dinar
+  'KWD', // Kuwaiti Dinar
+  'LYD', // Libyan Dinar
+  'OMR', // Omani Rial
+  'TND', // Tunisian Dinar
+])
+
+/**
+ * Convert amount from smallest unit to decimal for display
+ * @param amount - Amount in smallest unit (e.g., cents for USD)
+ * @param currency - ISO 4217 currency code
+ * @returns Formatted amount string for the payment provider
+ */
+export function formatAmountForProvider(amount: number, currency: string): string {
+  const upperCurrency = currency.toUpperCase()
+
+  if (NON_CENTESIMAL_CURRENCIES.has(upperCurrency)) {
+    // No decimal places
+    return amount.toString()
+  }
+
+  if (THREE_DECIMAL_CURRENCIES.has(upperCurrency)) {
+    // 3 decimal places
+    return (amount / 1000).toFixed(3)
+  }
+
+  // Default: 2 decimal places (most currencies)
+  return (amount / 100).toFixed(2)
+}
+
+/**
+ * Get the number of decimal places for a currency
+ * @param currency - ISO 4217 currency code
+ * @returns Number of decimal places
+ */
+export function getCurrencyDecimals(currency: string): number {
+  const upperCurrency = currency.toUpperCase()
+
+  if (NON_CENTESIMAL_CURRENCIES.has(upperCurrency)) {
+    return 0
+  }
+
+  if (THREE_DECIMAL_CURRENCIES.has(upperCurrency)) {
+    return 3
+  }
+
+  return 2
+}
+
+/**
+ * Validate currency code format
+ * @param currency - Currency code to validate
+ * @returns True if valid ISO 4217 format
+ */
+export function isValidCurrencyCode(currency: string): boolean {
+  return /^[A-Z]{3}$/.test(currency.toUpperCase())
+}
+
+/**
+ * Validate amount is positive and within reasonable limits
+ * @param amount - Amount to validate
+ * @returns True if valid
+ */
+export function isValidAmount(amount: number): boolean {
+  return Number.isInteger(amount) && amount > 0 && amount <= 99999999999 // Max ~999 million in major units
+}

src/providers/index.ts

@@ -0,0 +1,10 @@
+export * from './mollie'
+export * from './stripe'
+export * from './test'
+export * from './types'
+export * from './currency'
+
+// Re-export provider configurations and types
+export type { StripeProviderConfig } from './stripe'
+export type { MollieProviderConfig } from './mollie'
+export type { TestProviderConfig, TestProviderConfigResponse, PaymentOutcome, PaymentMethod, PaymentScenario } from './test'

src/providers/mollie.ts

@@ -0,0 +1,159 @@
+import type { Payment } from '../plugin/types/payments'
+import type { PaymentProvider } from '../plugin/types/index'
+import type { Payload } from 'payload'
+import { createSingleton } from '../plugin/singleton'
+import type { createMollieClient, MollieClient } from '@mollie/api-client'
+import {
+  webhookResponses,
+  findPaymentByProviderId,
+  updatePaymentStatus,
+  updateInvoiceOnPaymentSuccess,
+  handleWebhookError,
+  validateProductionUrl
+} from './utils'
+import { formatAmountForProvider, isValidAmount, isValidCurrencyCode } from './currency'
+
+const symbol = Symbol('mollie')
+export type MollieProviderConfig = Parameters<typeof createMollieClient>[0]
+
+/**
+ * Type-safe mapping of Mollie payment status to internal status
+ */
+function mapMollieStatusToPaymentStatus(mollieStatus: string): Payment['status'] {
+  // Define known Mollie statuses for type safety
+  const mollieStatusMap: Record<string, Payment['status']> = {
+    'paid': 'succeeded',
+    'failed': 'failed',
+    'canceled': 'canceled',
+    'expired': 'canceled',
+    'pending': 'pending',
+    'open': 'pending',
+    'authorized': 'pending',
+  }
+
+  return mollieStatusMap[mollieStatus] || 'processing'
+}
+
+export const mollieProvider = (mollieConfig: MollieProviderConfig & {
+  webhookUrl?: string
+  redirectUrl?: string
+}) => {
+  // Validate required configuration at initialization
+  if (!mollieConfig.apiKey) {
+    throw new Error('Mollie API key is required')
+  }
+
+  const singleton = createSingleton<MollieClient>(symbol)
+  return {
+    key: 'mollie',
+    onConfig: (config, pluginConfig) => {
+      // Always register Mollie webhook since it doesn't require a separate webhook secret
+      // Mollie validates webhooks through payment ID verification
+      config.endpoints = [
+        ...(config.endpoints || []),
+        {
+          path: '/payload-billing/mollie/webhook',
+          method: 'post',
+          handler: async (req) => {
+            try {
+              const payload = req.payload
+              const mollieClient = singleton.get(payload)
+
+              // Parse the webhook body to get the Mollie payment ID
+              if (!req.text) {
+                return webhookResponses.missingBody()
+              }
+              const body = await req.text()
+              if (!body || !body.startsWith('id=')) {
+                return webhookResponses.invalidPayload()
+              }
+
+              const molliePaymentId = body.slice(3) // Remove 'id=' prefix
+
+              // Fetch the payment details from Mollie
+              const molliePayment = await mollieClient.payments.get(molliePaymentId)
+
+              // Find the corresponding payment in our database
+              const payment = await findPaymentByProviderId(payload, molliePaymentId, pluginConfig)
+
+              if (!payment) {
+                return webhookResponses.paymentNotFound()
+              }
+
+              // Map Mollie status to our status using proper type-safe mapping
+              const status = mapMollieStatusToPaymentStatus(molliePayment.status)
+
+              // Update the payment status and provider data
+              const updateSuccess = await updatePaymentStatus(
+                payload,
+                payment.id,
+                status,
+                molliePayment.toPlainObject(),
+                pluginConfig
+              )
+
+              // If payment is successful and update succeeded, update the invoice
+              if (status === 'succeeded' && updateSuccess) {
+                await updateInvoiceOnPaymentSuccess(payload, payment, pluginConfig)
+              } else if (!updateSuccess) {
+                console.warn(`[Mollie Webhook] Failed to update payment ${payment.id}, skipping invoice update`)
+              }
+
+              return webhookResponses.success()
+            } catch (error) {
+              return handleWebhookError('Mollie', error)
+            }
+          }
+        }
+      ]
+    },
+    onInit: async (payload: Payload) => {
+      const createMollieClient = (await import('@mollie/api-client')).default
+      const mollieClient = createMollieClient(mollieConfig)
+      singleton.set(payload, mollieClient)
+    },
+    initPayment: async (payload, payment) => {
+      // Validate required fields
+      if (!payment.amount) {
+        throw new Error('Amount is required')
+      }
+      if (!payment.currency) {
+        throw new Error('Currency is required')
+      }
+
+      // Validate amount
+      if (!isValidAmount(payment.amount)) {
+        throw new Error('Invalid amount: must be a positive integer within reasonable limits')
+      }
+
+      // Validate currency code
+      if (!isValidCurrencyCode(payment.currency)) {
+        throw new Error('Invalid currency: must be a 3-letter ISO code')
+      }
+
+      // Setup URLs with development defaults
+      const isProduction = process.env.NODE_ENV === 'production'
+      const redirectUrl = mollieConfig.redirectUrl ||
+        (!isProduction ? 'https://localhost:3000/payment/success' : undefined)
+      const webhookUrl = mollieConfig.webhookUrl ||
+        `${process.env.PAYLOAD_PUBLIC_SERVER_URL || (!isProduction ? 'https://localhost:3000' : '')}/api/payload-billing/mollie/webhook`
+
+      // Validate URLs for production
+      validateProductionUrl(redirectUrl, 'Redirect')
+      validateProductionUrl(webhookUrl, 'Webhook')
+
+      const molliePayment = await singleton.get(payload).payments.create({
+        amount: {
+          value: formatAmountForProvider(payment.amount, payment.currency),
+          currency: payment.currency.toUpperCase()
+        },
+        description: payment.description || '',
+        redirectUrl,
+        webhookUrl,
+      });
+      payment.providerId = molliePayment.id
+      payment.providerData = molliePayment.toPlainObject()
+      return payment
+    },
+  } satisfies PaymentProvider
+}

src/providers/stripe.ts

@@ -0,0 +1,260 @@
+import type { Payment } from '../plugin/types/payments'
+import type { PaymentProvider, ProviderData } from '../plugin/types/index'
+import type { Payload } from 'payload'
+import { createSingleton } from '../plugin/singleton'
+import type Stripe from 'stripe'
+import {
+  webhookResponses,
+  findPaymentByProviderId,
+  updatePaymentStatus,
+  updateInvoiceOnPaymentSuccess,
+  handleWebhookError,
+  logWebhookEvent
+} from './utils'
+import { isValidAmount, isValidCurrencyCode } from './currency'
+
+const symbol = Symbol('stripe')
+
+export interface StripeProviderConfig {
+  secretKey: string
+  webhookSecret?: string
+  apiVersion?: Stripe.StripeConfig['apiVersion']
+  returnUrl?: string
+  webhookUrl?: string
+}
+
+// Default API version for consistency
+const DEFAULT_API_VERSION: Stripe.StripeConfig['apiVersion'] = '2025-08-27.basil'
+
+export const stripeProvider = (stripeConfig: StripeProviderConfig) => {
+  // Validate required configuration at initialization
+  if (!stripeConfig.secretKey) {
+    throw new Error('Stripe secret key is required')
+  }
+
+  const singleton = createSingleton<Stripe>(symbol)
+
+  return {
+    key: 'stripe',
+    onConfig: (config, pluginConfig) => {
+      // Only register webhook endpoint if webhook secret is configured
+      if (stripeConfig.webhookSecret) {
+        config.endpoints = [
+          ...(config.endpoints || []),
+          {
+            path: '/payload-billing/stripe/webhook',
+            method: 'post',
+            handler: async (req) => {
+            try {
+              const payload = req.payload
+              const stripe = singleton.get(payload)
+
+              // Get the raw body for signature verification
+              let body: string
+              try {
+                if (!req.text) {
+                  return webhookResponses.missingBody()
+                }
+                body = await req.text()
+                if (!body) {
+                  return webhookResponses.missingBody()
+                }
+              } catch (error) {
+                return handleWebhookError('Stripe', error, 'Failed to read request body')
+              }
+
+              const signature = req.headers.get('stripe-signature')
+
+              if (!signature) {
+                return webhookResponses.error('Missing webhook signature', 400)
+              }
+
+              // webhookSecret is guaranteed to exist since we only register this endpoint when it's configured
+
+              // Verify webhook signature and construct event
+              let event: Stripe.Event
+              try {
+                event = stripe.webhooks.constructEvent(body, signature, stripeConfig.webhookSecret!)
+              } catch (err) {
+                return handleWebhookError('Stripe', err, 'Signature verification failed')
+              }
+
+              // Handle different event types
+              switch (event.type) {
+                case 'payment_intent.succeeded':
+                case 'payment_intent.payment_failed':
+                case 'payment_intent.canceled': {
+                  const paymentIntent = event.data.object
+
+                  // Find the corresponding payment in our database
+                  const payment = await findPaymentByProviderId(payload, paymentIntent.id, pluginConfig)
+
+                  if (!payment) {
+                    logWebhookEvent('Stripe', `Payment not found for intent: ${paymentIntent.id}`)
+                    return webhookResponses.success() // Still return 200 to acknowledge receipt
+                  }
+
+                  // Map Stripe status to our status
+                  let status: Payment['status'] = 'pending'
+
+                  if (paymentIntent.status === 'succeeded') {
+                    status = 'succeeded'
+                  } else if (paymentIntent.status === 'canceled') {
+                    status = 'canceled'
+                  } else if (paymentIntent.status === 'requires_payment_method' ||
+                             paymentIntent.status === 'requires_confirmation' ||
+                             paymentIntent.status === 'requires_action') {
+                    status = 'pending'
+                  } else if (paymentIntent.status === 'processing') {
+                    status = 'processing'
+                  } else {
+                    status = 'failed'
+                  }
+
+                  // Update the payment status and provider data
+                  const providerData: ProviderData<Stripe.PaymentIntent> = {
+                    raw: paymentIntent,
+                    timestamp: new Date().toISOString(),
+                    provider: 'stripe'
+                  }
+                  const updateSuccess = await updatePaymentStatus(
+                    payload,
+                    payment.id,
+                    status,
+                    providerData,
+                    pluginConfig
+                  )
+
+                  // If payment is successful and update succeeded, update the invoice
+                  if (status === 'succeeded' && updateSuccess) {
+                    await updateInvoiceOnPaymentSuccess(payload, payment, pluginConfig)
+                  } else if (!updateSuccess) {
+                    console.warn(`[Stripe Webhook] Failed to update payment ${payment.id}, skipping invoice update`)
+                  }
+                  break
+                }
+
+                case 'charge.refunded': {
+                  const charge = event.data.object
+
+                  // Find the payment by charge ID or payment intent
+                  let payment: Payment | null = null
+
+                  // First try to find by payment intent ID
+                  if (charge.payment_intent) {
+                    payment = await findPaymentByProviderId(
+                      payload,
+                      charge.payment_intent as string,
+                      pluginConfig
+                    )
+                  }
+
+                  // If not found, try charge ID
+                  if (!payment) {
+                    payment = await findPaymentByProviderId(payload, charge.id, pluginConfig)
+                  }
+
+                  if (payment) {
+                    // Determine if fully or partially refunded
+                    const isFullyRefunded = charge.amount_refunded === charge.amount
+
+                    const providerData: ProviderData<Stripe.Charge> = {
+                      raw: charge,
+                      timestamp: new Date().toISOString(),
+                      provider: 'stripe'
+                    }
+                    const updateSuccess = await updatePaymentStatus(
+                      payload,
+                      payment.id,
+                      isFullyRefunded ? 'refunded' : 'partially_refunded',
+                      providerData,
+                      pluginConfig
+                    )
+
+                    if (!updateSuccess) {
+                      console.warn(`[Stripe Webhook] Failed to update refund status for payment ${payment.id}`)
+                    }
+                  }
+                  break
+                }
+
+                default:
+                  // Unhandled event type
+                  logWebhookEvent('Stripe', `Unhandled event type: ${event.type}`)
+              }
+
+              return webhookResponses.success()
+            } catch (error) {
+              return handleWebhookError('Stripe', error)
+            }
+            }
+          }
+        ]
+      } else {
+        // Log that webhook endpoint is not registered
+        console.warn('[Stripe Provider] Webhook endpoint not registered - webhookSecret not configured')
+      }
+    },
+    onInit: async (payload: Payload) => {
+      const { default: Stripe } = await import('stripe')
+      const stripe = new Stripe(stripeConfig.secretKey, {
+        apiVersion: stripeConfig.apiVersion || DEFAULT_API_VERSION,
+      })
+      singleton.set(payload, stripe)
+    },
+    initPayment: async (payload, payment) => {
+      // Validate required fields
+      if (!payment.amount) {
+        throw new Error('Amount is required')
+      }
+      if (!payment.currency) {
+        throw new Error('Currency is required')
+      }
+
+      // Validate amount
+      if (!isValidAmount(payment.amount)) {
+        throw new Error('Invalid amount: must be a positive integer within reasonable limits')
+      }
+
+      // Validate currency code
+      if (!isValidCurrencyCode(payment.currency)) {
+        throw new Error('Invalid currency: must be a 3-letter ISO code')
+      }
+
+      // Validate description length if provided
+      if (payment.description && payment.description.length > 1000) {
+        throw new Error('Description must be 1000 characters or less')
+      }
+
+      const stripe = singleton.get(payload)
+
+      // Create a payment intent
+      const paymentIntent = await stripe.paymentIntents.create({
+        amount: payment.amount, // Stripe handles currency conversion internally
+        currency: payment.currency.toLowerCase(),
+        description: payment.description || undefined,
+        metadata: {
+          payloadPaymentId: payment.id?.toString() || '',
+          ...(typeof payment.metadata === 'object' &&
+              payment.metadata !== null &&
+              !Array.isArray(payment.metadata)
+              ? payment.metadata
+              : {})
+        } as Stripe.MetadataParam,
+        automatic_payment_methods: {
+          enabled: true,
+        },
+      })
+
+      payment.providerId = paymentIntent.id
+      const providerData: ProviderData<Stripe.PaymentIntent> = {
+        raw: { ...paymentIntent, client_secret: paymentIntent.client_secret },
+        timestamp: new Date().toISOString(),
+        provider: 'stripe'
+      }
+      payment.providerData = providerData
+
+      return payment
+    },
+  } satisfies PaymentProvider
+}

src/providers/test.ts

@@ -0,0 +1,801 @@
+import type { Payment } from '../plugin/types/payments'
+import type { PaymentProvider, ProviderData } from '../plugin/types/index'
+import type { BillingPluginConfig } from '../plugin/config'
+import type { Payload } from 'payload'
+import { handleWebhookError, logWebhookEvent } from './utils'
+import { isValidAmount, isValidCurrencyCode } from './currency'
+
+export type PaymentOutcome = 'paid' | 'failed' | 'cancelled' | 'expired' | 'pending'
+
+export type PaymentMethod = 'ideal' | 'creditcard' | 'paypal' | 'applepay' | 'banktransfer'
+
+export interface PaymentScenario {
+  id: string
+  name: string
+  description: string
+  outcome: PaymentOutcome
+  delay?: number // Delay in milliseconds before processing
+  method?: PaymentMethod
+}
+
+export interface TestProviderConfig {
+  enabled: boolean
+  scenarios?: PaymentScenario[]
+  customUiRoute?: string
+  testModeIndicators?: {
+    showWarningBanners?: boolean
+    showTestBadges?: boolean
+    consoleWarnings?: boolean
+  }
+  defaultDelay?: number
+  baseUrl?: string
+}
+
+export interface TestProviderConfigResponse {
+  enabled: boolean
+  scenarios: PaymentScenario[]
+  methods: Array<{
+    id: string
+    name: string
+    icon: string
+  }>
+  testModeIndicators: {
+    showWarningBanners: boolean
+    showTestBadges: boolean
+    consoleWarnings: boolean
+  }
+  defaultDelay: number
+  customUiRoute: string
+}
+
+// Properly typed session interface
+export interface TestPaymentSession {
+  id: string
+  payment: Partial<Payment>
+  scenario?: PaymentScenario
+  method?: PaymentMethod
+  createdAt: Date
+  status: PaymentOutcome
+}
+
+// Use the proper BillingPluginConfig type
+
+// Default payment scenarios
+const DEFAULT_SCENARIOS: PaymentScenario[] = [
+  {
+    id: 'instant-success',
+    name: 'Instant Success',
+    description: 'Payment succeeds immediately',
+    outcome: 'paid',
+    delay: 0
+  },
+  {
+    id: 'delayed-success',
+    name: 'Delayed Success',
+    description: 'Payment succeeds after a delay',
+    outcome: 'paid',
+    delay: 3000
+  },
+  {
+    id: 'cancelled-payment',
+    name: 'Cancelled Payment',
+    description: 'User cancels the payment',
+    outcome: 'cancelled',
+    delay: 1000
+  },
+  {
+    id: 'declined-payment',
+    name: 'Declined Payment',
+    description: 'Payment is declined by the provider',
+    outcome: 'failed',
+    delay: 2000
+  },
+  {
+    id: 'expired-payment',
+    name: 'Expired Payment',
+    description: 'Payment expires before completion',
+    outcome: 'expired',
+    delay: 5000
+  },
+  {
+    id: 'pending-payment',
+    name: 'Pending Payment',
+    description: 'Payment remains in pending state',
+    outcome: 'pending',
+    delay: 1500
+  }
+]
+
+// Payment method configurations
+const PAYMENT_METHODS: Record<PaymentMethod, { name: string; icon: string }> = {
+  ideal: { name: 'iDEAL', icon: '🏦' },
+  creditcard: { name: 'Credit Card', icon: '💳' },
+  paypal: { name: 'PayPal', icon: '🅿️' },
+  applepay: { name: 'Apple Pay', icon: '🍎' },
+  banktransfer: { name: 'Bank Transfer', icon: '🏛️' }
+}
+
+// In-memory storage for test payment sessions
+const testPaymentSessions = new Map<string, TestPaymentSession>()
+
+export const testProvider = (testConfig: TestProviderConfig) => {
+  if (!testConfig.enabled) {
+    throw new Error('Test provider is disabled')
+  }
+
+  const scenarios = testConfig.scenarios || DEFAULT_SCENARIOS
+  const baseUrl = testConfig.baseUrl || (process.env.PAYLOAD_PUBLIC_SERVER_URL || 'http://localhost:3000')
+  const uiRoute = testConfig.customUiRoute || '/test-payment'
+
+  // Log test mode warnings if enabled
+  if (testConfig.testModeIndicators?.consoleWarnings !== false) {
+    console.warn('🧪 [TEST PROVIDER] Payment system is running in test mode')
+  }
+
+  return {
+    key: 'test',
+    onConfig: (config, pluginConfig) => {
+      // Register test payment UI endpoint
+      config.endpoints = [
+        ...(config.endpoints || []),
+        {
+          path: '/payload-billing/test/payment/:id',
+          method: 'get',
+          handler: async (req) => {
+            // Extract payment ID from URL path
+            const urlParts = req.url?.split('/') || []
+            const paymentId = urlParts[urlParts.length - 1]
+            if (!paymentId) {
+              return new Response('Payment ID required', { status: 400 })
+            }
+
+            const session = testPaymentSessions.get(paymentId)
+            if (!session) {
+              return new Response('Payment session not found', { status: 404 })
+            }
+
+            // Generate test payment UI
+            const html = generateTestPaymentUI(session, scenarios, uiRoute, baseUrl, testConfig)
+            return new Response(html, {
+              headers: { 'Content-Type': 'text/html' }
+            })
+          }
+        },
+        {
+          path: '/payload-billing/test/config',
+          method: 'get',
+          handler: async (req) => {
+            const response: TestProviderConfigResponse = {
+              enabled: testConfig.enabled,
+              scenarios: scenarios,
+              methods: Object.entries(PAYMENT_METHODS).map(([id, method]) => ({
+                id,
+                name: method.name,
+                icon: method.icon
+              })),
+              testModeIndicators: testConfig.testModeIndicators || {
+                showWarningBanners: true,
+                showTestBadges: true,
+                consoleWarnings: true
+              },
+              defaultDelay: testConfig.defaultDelay || 1000,
+              customUiRoute: uiRoute
+            }
+            return new Response(JSON.stringify(response), {
+              headers: { 'Content-Type': 'application/json' }
+            })
+          }
+        },
+        {
+          path: '/payload-billing/test/process',
+          method: 'post',
+          handler: async (req) => {
+            try {
+              const payload = req.payload
+              const body = await req.json?.() || {}
+              const { paymentId, scenarioId, method } = body as any
+
+              const session = testPaymentSessions.get(paymentId)
+              if (!session) {
+                return new Response(JSON.stringify({ error: 'Payment session not found' }), {
+                  status: 404,
+                  headers: { 'Content-Type': 'application/json' }
+                })
+              }
+
+              const scenario = scenarios.find(s => s.id === scenarioId)
+              if (!scenario) {
+                return new Response(JSON.stringify({ error: 'Invalid scenario' }), {
+                  status: 400,
+                  headers: { 'Content-Type': 'application/json' }
+                })
+              }
+
+              // Update session with selected scenario and method
+              session.scenario = scenario
+              session.method = method
+              session.status = 'pending'
+
+              // Process payment after delay
+              setTimeout(() => {
+                processTestPayment(payload, session, pluginConfig).catch(async (error) => {
+                  console.error('[Test Provider] Failed to process payment:', error)
+                  session.status = 'failed'
+
+                  // Also update the payment record in database
+                  try {
+                    const paymentsCollection = (typeof pluginConfig.collections?.payments === 'string'
+                      ? pluginConfig.collections.payments
+                      : 'payments') as any
+                    const payments = await payload.find({
+                      collection: paymentsCollection,
+                      where: { providerId: { equals: session.id } },
+                      limit: 1
+                    })
+
+                    if (payments.docs.length > 0) {
+                      await payload.update({
+                        collection: paymentsCollection,
+                        id: payments.docs[0].id,
+                        data: {
+                          status: 'failed',
+                          providerData: {
+                            raw: { error: error.message, processedAt: new Date().toISOString() },
+                            timestamp: new Date().toISOString(),
+                            provider: 'test'
+                          }
+                        }
+                      })
+                    }
+                  } catch (dbError) {
+                    console.error('[Test Provider] Failed to update payment in database:', dbError)
+                  }
+                })
+              }, scenario.delay || testConfig.defaultDelay || 1000)
+
+              return new Response(JSON.stringify({
+                success: true,
+                status: 'processing',
+                scenario: scenario.name,
+                delay: scenario.delay || testConfig.defaultDelay || 1000
+              }), {
+                headers: { 'Content-Type': 'application/json' }
+              })
+            } catch (error) {
+              return handleWebhookError('Test Provider', error, 'Failed to process test payment')
+            }
+          }
+        },
+        {
+          path: '/payload-billing/test/status/:id',
+          method: 'get',
+          handler: async (req) => {
+            // Extract payment ID from URL path
+            const urlParts = req.url?.split('/') || []
+            const paymentId = urlParts[urlParts.length - 1]
+            if (!paymentId) {
+              return new Response(JSON.stringify({ error: 'Payment ID required' }), {
+                status: 400,
+                headers: { 'Content-Type': 'application/json' }
+              })
+            }
+
+            const session = testPaymentSessions.get(paymentId)
+            if (!session) {
+              return new Response(JSON.stringify({ error: 'Payment session not found' }), {
+                status: 404,
+                headers: { 'Content-Type': 'application/json' }
+              })
+            }
+
+            return new Response(JSON.stringify({
+              status: session.status,
+              scenario: session.scenario?.name,
+              method: session.method ? PAYMENT_METHODS[session.method]?.name : undefined
+            }), {
+              headers: { 'Content-Type': 'application/json' }
+            })
+          }
+        }
+      ]
+    },
+    onInit: async (payload: Payload) => {
+      logWebhookEvent('Test Provider', 'Test payment provider initialized')
+
+      // Clean up old sessions periodically (older than 1 hour)
+      setInterval(() => {
+        const oneHourAgo = new Date(Date.now() - 60 * 60 * 1000)
+        testPaymentSessions.forEach((session, id) => {
+          if (session.createdAt < oneHourAgo) {
+            testPaymentSessions.delete(id)
+          }
+        })
+      }, 10 * 60 * 1000) // Clean every 10 minutes
+    },
+    initPayment: async (payload, payment) => {
+      // Validate required fields
+      if (!payment.amount) {
+        throw new Error('Amount is required')
+      }
+      if (!payment.currency) {
+        throw new Error('Currency is required')
+      }
+
+      // Validate amount
+      if (!isValidAmount(payment.amount)) {
+        throw new Error('Invalid amount: must be a positive integer within reasonable limits')
+      }
+
+      // Validate currency code
+      if (!isValidCurrencyCode(payment.currency)) {
+        throw new Error('Invalid currency: must be a 3-letter ISO code')
+      }
+
+      // Generate unique test payment ID
+      const testPaymentId = `test_pay_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`
+
+      // Create test payment session
+      const session = {
+        id: testPaymentId,
+        payment: { ...payment },
+        createdAt: new Date(),
+        status: 'pending' as PaymentOutcome
+      }
+
+      testPaymentSessions.set(testPaymentId, session)
+
+      // Set provider ID and data
+      payment.providerId = testPaymentId
+      const providerData: ProviderData = {
+        raw: {
+          id: testPaymentId,
+          amount: payment.amount,
+          currency: payment.currency,
+          description: payment.description,
+          status: 'pending',
+          testMode: true,
+          paymentUrl: `${baseUrl}/api/payload-billing/test/payment/${testPaymentId}`,
+          scenarios: scenarios.map(s => ({ id: s.id, name: s.name, description: s.description })),
+          methods: Object.entries(PAYMENT_METHODS).map(([key, value]) => ({
+            id: key,
+            name: value.name,
+            icon: value.icon
+          }))
+        },
+        timestamp: new Date().toISOString(),
+        provider: 'test'
+      }
+      payment.providerData = providerData
+
+      return payment
+    },
+  } satisfies PaymentProvider
+}
+
+// Helper function to process test payment based on scenario
+async function processTestPayment(
+  payload: Payload,
+  session: TestPaymentSession,
+  pluginConfig: BillingPluginConfig
+): Promise<void> {
+  try {
+    if (!session.scenario) return
+
+    // Map scenario outcome to payment status
+    let finalStatus: Payment['status'] = 'pending'
+    switch (session.scenario.outcome) {
+      case 'paid':
+        finalStatus = 'succeeded'
+        break
+      case 'failed':
+        finalStatus = 'failed'
+        break
+      case 'cancelled':
+        finalStatus = 'canceled'
+        break
+      case 'expired':
+        finalStatus = 'canceled' // Treat expired as canceled
+        break
+      case 'pending':
+        finalStatus = 'pending'
+        break
+    }
+
+    // Update session status
+    session.status = session.scenario.outcome
+
+    // Find and update the payment in the database
+    const paymentsCollection = (typeof pluginConfig.collections?.payments === 'string'
+      ? pluginConfig.collections.payments
+      : 'payments') as any
+    const payments = await payload.find({
+      collection: paymentsCollection,
+      where: {
+        providerId: {
+          equals: session.id
+        }
+      },
+      limit: 1
+    })
+
+    if (payments.docs.length > 0) {
+      const payment = payments.docs[0]
+
+      // Update payment with final status and provider data
+      const updatedProviderData: ProviderData = {
+        raw: {
+          ...session.payment,
+          id: session.id,
+          status: session.scenario.outcome,
+          scenario: session.scenario.name,
+          method: session.method,
+          processedAt: new Date().toISOString(),
+          testMode: true
+        },
+        timestamp: new Date().toISOString(),
+        provider: 'test'
+      }
+
+      await payload.update({
+        collection: paymentsCollection,
+        id: payment.id,
+        data: {
+          status: finalStatus,
+          providerData: updatedProviderData
+        }
+      })
+
+      logWebhookEvent('Test Provider', `Payment ${session.id} processed with outcome: ${session.scenario.outcome}`)
+    }
+  } catch (error) {
+    console.error('[Test Provider] Failed to process payment:', error)
+    session.status = 'failed'
+  }
+}
+
+// Helper function to generate test payment UI
+function generateTestPaymentUI(
+  session: TestPaymentSession,
+  scenarios: PaymentScenario[],
+  uiRoute: string,
+  baseUrl: string,
+  testConfig: TestProviderConfig
+): string {
+  const payment = session.payment
+  const testModeIndicators = testConfig.testModeIndicators || {}
+
+  return `<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Test Payment - ${payment.description || 'Payment'}</title>
+    <style>
+        * { box-sizing: border-box; margin: 0; padding: 0; }
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            min-height: 100vh;
+            padding: 20px;
+        }
+        .container {
+            max-width: 600px;
+            margin: 0 auto;
+            background: white;
+            border-radius: 12px;
+            box-shadow: 0 20px 40px rgba(0,0,0,0.1);
+            overflow: hidden;
+        }
+        ${testModeIndicators.showWarningBanners !== false ? `
+        .test-banner {
+            background: linear-gradient(90deg, #ff6b6b, #ffa726);
+            color: white;
+            padding: 12px 20px;
+            text-align: center;
+            font-weight: 600;
+            font-size: 14px;
+        }
+        ` : ''}
+        .header {
+            background: #f8f9fa;
+            padding: 30px 40px 20px;
+            border-bottom: 1px solid #e9ecef;
+        }
+        .title {
+            font-size: 24px;
+            font-weight: 700;
+            color: #2c3e50;
+            margin-bottom: 8px;
+        }
+        .amount {
+            font-size: 32px;
+            font-weight: 800;
+            color: #27ae60;
+            margin-bottom: 16px;
+        }
+        .description {
+            color: #6c757d;
+            font-size: 16px;
+            line-height: 1.5;
+        }
+        .content { padding: 40px; }
+        .section { margin-bottom: 30px; }
+        .section-title {
+            font-size: 18px;
+            font-weight: 600;
+            color: #2c3e50;
+            margin-bottom: 16px;
+            display: flex;
+            align-items: center;
+            gap: 8px;
+        }
+        .payment-methods {
+            display: grid;
+            grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
+            gap: 12px;
+            margin-bottom: 20px;
+        }
+        .method {
+            border: 2px solid #e9ecef;
+            border-radius: 8px;
+            padding: 16px 12px;
+            text-align: center;
+            cursor: pointer;
+            transition: all 0.2s;
+            background: white;
+        }
+        .method:hover {
+            border-color: #007bff;
+            background: #f8f9ff;
+        }
+        .method.selected {
+            border-color: #007bff;
+            background: #007bff;
+            color: white;
+        }
+        .method-icon { font-size: 24px; margin-bottom: 8px; }
+        .method-name { font-size: 12px; font-weight: 500; }
+        .scenarios {
+            display: grid;
+            gap: 12px;
+            margin-bottom: 20px;
+        }
+        .scenario {
+            border: 2px solid #e9ecef;
+            border-radius: 8px;
+            padding: 16px;
+            cursor: pointer;
+            transition: all 0.2s;
+            background: white;
+        }
+        .scenario:hover {
+            border-color: #28a745;
+            background: #f8fff9;
+        }
+        .scenario.selected {
+            border-color: #28a745;
+            background: #28a745;
+            color: white;
+        }
+        .scenario-name { font-weight: 600; margin-bottom: 4px; }
+        .scenario-desc { font-size: 14px; opacity: 0.8; }
+        .process-btn {
+            width: 100%;
+            background: linear-gradient(135deg, #007bff, #0056b3);
+            color: white;
+            border: none;
+            padding: 16px;
+            border-radius: 8px;
+            font-size: 16px;
+            font-weight: 600;
+            cursor: pointer;
+            transition: all 0.2s;
+            margin-top: 20px;
+        }
+        .process-btn:hover:not(:disabled) {
+            transform: translateY(-2px);
+            box-shadow: 0 8px 20px rgba(0,123,255,0.3);
+        }
+        .process-btn:disabled {
+            opacity: 0.6;
+            cursor: not-allowed;
+            transform: none;
+        }
+        .status {
+            text-align: center;
+            padding: 20px;
+            border-radius: 8px;
+            margin-top: 20px;
+            font-weight: 600;
+        }
+        .status.processing { background: #fff3cd; color: #856404; }
+        .status.success { background: #d4edda; color: #155724; }
+        .status.error { background: #f8d7da; color: #721c24; }
+        .loading {
+            display: inline-block;
+            width: 20px;
+            height: 20px;
+            border: 3px solid #f3f3f3;
+            border-top: 3px solid #007bff;
+            border-radius: 50%;
+            animation: spin 1s linear infinite;
+            margin-right: 10px;
+        }
+        @keyframes spin {
+            0% { transform: rotate(0deg); }
+            100% { transform: rotate(360deg); }
+        }
+        ${testModeIndicators.showTestBadges !== false ? `
+        .test-badge {
+            display: inline-block;
+            background: #6c757d;
+            color: white;
+            padding: 4px 8px;
+            border-radius: 4px;
+            font-size: 12px;
+            font-weight: 600;
+            text-transform: uppercase;
+            margin-left: 8px;
+        }
+        ` : ''}
+    </style>
+</head>
+<body>
+    <div class="container">
+        ${testModeIndicators.showWarningBanners !== false ? `
+        <div class="test-banner">
+            🧪 TEST MODE - This is a simulated payment for development purposes
+        </div>
+        ` : ''}
+
+        <div class="header">
+            <div class="title">
+                Test Payment Checkout
+                ${testModeIndicators.showTestBadges !== false ? '<span class="test-badge">Test</span>' : ''}
+            </div>
+            <div class="amount">${payment.currency?.toUpperCase()} ${payment.amount ? (payment.amount / 100).toFixed(2) : '0.00'}</div>
+            ${payment.description ? `<div class="description">${payment.description}</div>` : ''}
+        </div>
+
+        <div class="content">
+            <div class="section">
+                <div class="section-title">
+                    💳 Select Payment Method
+                </div>
+                <div class="payment-methods">
+                    ${Object.entries(PAYMENT_METHODS).map(([key, method]) => `
+                        <div class="method" data-method="${key}">
+                            <div class="method-icon">${method.icon}</div>
+                            <div class="method-name">${method.name}</div>
+                        </div>
+                    `).join('')}
+                </div>
+            </div>
+
+            <div class="section">
+                <div class="section-title">
+                    🎭 Select Test Scenario
+                </div>
+                <div class="scenarios">
+                    ${scenarios.map(scenario => `
+                        <div class="scenario" data-scenario="${scenario.id}">
+                            <div class="scenario-name">${scenario.name}</div>
+                            <div class="scenario-desc">${scenario.description}</div>
+                        </div>
+                    `).join('')}
+                </div>
+            </div>
+
+            <button class="process-btn" id="processBtn" disabled>
+                Process Test Payment
+            </button>
+
+            <div id="status" class="status" style="display: none;"></div>
+        </div>
+    </div>
+
+    <script>
+        let selectedMethod = null;
+        let selectedScenario = null;
+
+        // Payment method selection
+        document.querySelectorAll('.method').forEach(method => {
+            method.addEventListener('click', () => {
+                document.querySelectorAll('.method').forEach(m => m.classList.remove('selected'));
+                method.classList.add('selected');
+                selectedMethod = method.dataset.method;
+                updateProcessButton();
+            });
+        });
+
+        // Scenario selection
+        document.querySelectorAll('.scenario').forEach(scenario => {
+            scenario.addEventListener('click', () => {
+                document.querySelectorAll('.scenario').forEach(s => s.classList.remove('selected'));
+                scenario.classList.add('selected');
+                selectedScenario = scenario.dataset.scenario;
+                updateProcessButton();
+            });
+        });
+
+        function updateProcessButton() {
+            const btn = document.getElementById('processBtn');
+            btn.disabled = !selectedMethod || !selectedScenario;
+        }
+
+        // Process payment
+        document.getElementById('processBtn').addEventListener('click', async () => {
+            const btn = document.getElementById('processBtn');
+            const status = document.getElementById('status');
+
+            btn.disabled = true;
+            btn.innerHTML = '<span class="loading"></span>Processing...';
+
+            try {
+                const response = await fetch('/api/payload-billing/test/process', {
+                    method: 'POST',
+                    headers: { 'Content-Type': 'application/json' },
+                    body: JSON.stringify({
+                        paymentId: '${session.id}',
+                        scenarioId: selectedScenario,
+                        method: selectedMethod
+                    })
+                });
+
+                const result = await response.json();
+
+                if (result.success) {
+                    status.className = 'status processing';
+                    status.style.display = 'block';
+                    status.innerHTML = \`<span class="loading"></span>Processing payment with \${result.scenario}...\`;
+
+                    // Poll for status updates
+                    setTimeout(() => pollStatus(), result.delay || 1000);
+                } else {
+                    throw new Error(result.error || 'Failed to process payment');
+                }
+            } catch (error) {
+                status.className = 'status error';
+                status.style.display = 'block';
+                status.textContent = 'Error: ' + error.message;
+                btn.disabled = false;
+                btn.textContent = 'Process Test Payment';
+            }
+        });
+
+        async function pollStatus() {
+            try {
+                const response = await fetch('/api/payload-billing/test/status/${session.id}');
+                const result = await response.json();
+
+                const status = document.getElementById('status');
+                const btn = document.getElementById('processBtn');
+
+                if (result.status === 'paid') {
+                    status.className = 'status success';
+                    status.textContent = '✅ Payment successful!';
+                    setTimeout(() => {
+                        window.location.href = '${baseUrl}/success';
+                    }, 2000);
+                } else if (result.status === 'failed' || result.status === 'cancelled' || result.status === 'expired') {
+                    status.className = 'status error';
+                    status.textContent = \`❌ Payment \${result.status}\`;
+                    btn.disabled = false;
+                    btn.textContent = 'Try Again';
+                } else if (result.status === 'pending') {
+                    status.className = 'status processing';
+                    status.innerHTML = '<span class="loading"></span>Payment is still pending...';
+                    setTimeout(() => pollStatus(), 2000);
+                }
+            } catch (error) {
+                console.error('Failed to poll status:', error);
+            }
+        }
+
+        ${testModeIndicators.consoleWarnings !== false ? `
+        console.warn('🧪 TEST MODE: This is a simulated payment interface for development purposes');
+        ` : ''}
+    </script>
+</body>
+</html>`
+}

src/providers/types.ts

@@ -0,0 +1,21 @@
+import type { Payment } from '../plugin/types/payments'
+import type { Config, Payload } from 'payload'
+import type { BillingPluginConfig } from '../plugin/config'
+
+export type InitPayment = (payload: Payload, payment: Partial<Payment>) => Promise<Partial<Payment>>
+
+export type PaymentProvider = {
+  key: string
+  onConfig?: (config: Config, pluginConfig: BillingPluginConfig) => void
+  onInit?: (payload: Payload) => Promise<void> | void
+  initPayment: InitPayment
+}
+
+/**
+ * Type-safe provider data wrapper
+ */
+export type ProviderData<T = unknown> = {
+  raw: T
+  timestamp: string
+  provider: string
+}

src/providers/utils.ts

@@ -0,0 +1,207 @@
+import type { Payload } from 'payload'
+import type { Payment } from '../plugin/types/payments'
+import type { BillingPluginConfig } from '../plugin/config'
+import type { ProviderData } from './types'
+import { defaults } from '../plugin/config'
+import { extractSlug, toPayloadId } from '../plugin/utils'
+
+/**
+ * Common webhook response utilities
+ * Note: Always return 200 for webhook acknowledgment to prevent information disclosure
+ */
+export const webhookResponses = {
+  success: () => Response.json({ received: true }, { status: 200 }),
+  error: (message: string, status = 400) => {
+    // Log error internally but don't expose details
+    console.error('[Webhook] Error:', message)
+    return Response.json({ error: 'Invalid request' }, { status })
+  },
+  missingBody: () => Response.json({ received: true }, { status: 200 }),
+  paymentNotFound: () => Response.json({ received: true }, { status: 200 }),
+  invalidPayload: () => Response.json({ received: true }, { status: 200 }),
+}
+
+/**
+ * Find a payment by provider ID
+ */
+export async function findPaymentByProviderId(
+  payload: Payload,
+  providerId: string,
+  pluginConfig: BillingPluginConfig
+): Promise<Payment | null> {
+  const paymentsCollection = extractSlug(pluginConfig.collections?.payments || defaults.paymentsCollection)
+
+  const payments = await payload.find({
+    collection: paymentsCollection,
+    where: {
+      providerId: {
+        equals: providerId
+      }
+    }
+  })
+
+  return payments.docs.length > 0 ? payments.docs[0] as Payment : null
+}
+
+/**
+ * Update payment status and provider data with optimistic locking
+ */
+export async function updatePaymentStatus(
+  payload: Payload,
+  paymentId: string | number,
+  status: Payment['status'],
+  providerData: ProviderData<any>,
+  pluginConfig: BillingPluginConfig
+): Promise<boolean> {
+  const paymentsCollection = extractSlug(pluginConfig.collections?.payments || defaults.paymentsCollection)
+
+  try {
+    // First, fetch the current payment to get the current version
+    const currentPayment = await payload.findByID({
+      collection: paymentsCollection,
+      id: toPayloadId(paymentId),
+    }) as Payment
+
+    if (!currentPayment) {
+      console.error(`[Payment Update] Payment ${paymentId} not found`)
+      return false
+    }
+
+    const currentVersion = currentPayment.version || 1
+
+    // Attempt to update with optimistic locking
+    // We'll use a transaction to ensure atomicity
+    const transactionID = await payload.db.beginTransaction()
+
+    if (!transactionID) {
+      console.error(`[Payment Update] Failed to begin transaction`)
+      return false
+    }
+
+    try {
+      // Re-fetch within transaction to ensure consistency
+      const paymentInTransaction = await payload.findByID({
+        collection: paymentsCollection,
+        id: toPayloadId(paymentId),
+        req: { transactionID: transactionID }
+      }) as Payment
+
+      // Check if version still matches
+      if ((paymentInTransaction.version || 1) !== currentVersion) {
+        // Version conflict detected - payment was modified by another process
+        console.warn(`[Payment Update] Version conflict for payment ${paymentId} (expected version: ${currentVersion}, got: ${paymentInTransaction.version})`)
+        await payload.db.rollbackTransaction(transactionID)
+        return false
+      }
+
+      // Update with new version
+      await payload.update({
+        collection: paymentsCollection,
+        id: toPayloadId(paymentId),
+        data: {
+          status,
+          providerData: {
+            ...providerData,
+            webhookProcessedAt: new Date().toISOString()
+          },
+          version: currentVersion + 1
+        },
+        req: { transactionID: transactionID }
+      })
+
+      await payload.db.commitTransaction(transactionID)
+      return true
+    } catch (error) {
+      await payload.db.rollbackTransaction(transactionID)
+      throw error
+    }
+  } catch (error) {
+    console.error(`[Payment Update] Failed to update payment ${paymentId}:`, error)
+    return false
+  }
+}
+
+/**
+ * Update invoice status when payment succeeds
+ */
+export async function updateInvoiceOnPaymentSuccess(
+  payload: Payload,
+  payment: Payment,
+  pluginConfig: BillingPluginConfig
+): Promise<void> {
+  if (!payment.invoice) return
+
+  const invoicesCollection = extractSlug(pluginConfig.collections?.invoices || defaults.invoicesCollection)
+  const invoiceId = typeof payment.invoice === 'object'
+    ? payment.invoice.id
+    : payment.invoice
+
+  await payload.update({
+    collection: invoicesCollection,
+    id: toPayloadId(invoiceId),
+    data: {
+      status: 'paid',
+      payment: toPayloadId(payment.id)
+    }
+  })
+}
+
+/**
+ * Handle webhook errors with consistent logging
+ */
+export function handleWebhookError(
+  provider: string,
+  error: unknown,
+  context?: string
+): Response {
+  const message = error instanceof Error ? error.message : 'Unknown error'
+  const fullContext = context ? `[${provider} Webhook - ${context}]` : `[${provider} Webhook]`
+
+  // Log detailed error internally for debugging
+  console.error(`${fullContext} Error:`, error)
+
+  // Return generic response to avoid information disclosure
+  return Response.json({
+    received: false,
+    error: 'Processing error'
+  }, { status: 200 })
+}
+
+/**
+ * Log webhook events
+ */
+export function logWebhookEvent(
+  provider: string,
+  event: string,
+  details?: any
+): void {
+  console.log(`[${provider} Webhook] ${event}`, details ? JSON.stringify(details) : '')
+}
+
+/**
+ * Validate URL for production use
+ */
+export function validateProductionUrl(url: string | undefined, urlType: string): void {
+  const isProduction = process.env.NODE_ENV === 'production'
+
+  if (!isProduction) return
+
+  if (!url) {
+    throw new Error(`${urlType} URL is required for production`)
+  }
+
+  if (url.includes('localhost') || url.includes('127.0.0.1')) {
+    throw new Error(`${urlType} URL cannot use localhost in production`)
+  }
+
+  if (!url.startsWith('https://')) {
+    throw new Error(`${urlType} URL must use HTTPS in production`)
+  }
+
+  // Basic URL validation
+  try {
+    new URL(url)
+  } catch {
+    throw new Error(`${urlType} URL is not a valid URL`)
+  }
+}

src/types/index.ts

@@ -1,260 +0,0 @@
-import type { Config } from 'payload'
-
-// Base payment provider interface
-export interface PaymentProvider {
-  cancelPayment(id: string): Promise<Payment>
-  createPayment(options: CreatePaymentOptions): Promise<Payment>
-  handleWebhook(request: Request, signature?: string): Promise<WebhookEvent>
-  name: string
-  refundPayment(id: string, amount?: number): Promise<Refund>
-  retrievePayment(id: string): Promise<Payment>
-}
-
-// Payment types
-export interface CreatePaymentOptions {
-  amount: number
-  cancelUrl?: string
-  currency: string
-  customer?: string
-  description?: string
-  metadata?: Record<string, unknown>
-  returnUrl?: string
-}
-
-export interface Payment {
-  amount: number
-  createdAt: string
-  currency: string
-  customer?: string
-  description?: string
-  id: string
-  metadata?: Record<string, unknown>
-  provider: string
-  providerData?: Record<string, unknown>
-  status: PaymentStatus
-  updatedAt: string
-}
-
-export interface Refund {
-  amount: number
-  createdAt: string
-  currency: string
-  id: string
-  paymentId: string
-  providerData?: Record<string, unknown>
-  reason?: string
-  status: RefundStatus
-}
-
-export interface WebhookEvent {
-  data: Record<string, unknown>
-  id: string
-  provider: string
-  type: string
-  verified: boolean
-}
-
-// Status enums
-export type PaymentStatus = 
-  | 'canceled'
-  | 'failed'
-  | 'partially_refunded'
-  | 'pending'
-  | 'processing'
-  | 'refunded'
-  | 'succeeded'
-
-export type RefundStatus =
-  | 'canceled'
-  | 'failed'
-  | 'pending'
-  | 'processing'
-  | 'succeeded'
-
-// Provider configurations
-export interface StripeConfig {
-  apiVersion?: string
-  publishableKey: string
-  secretKey: string
-  webhookEndpointSecret: string
-}
-
-export interface MollieConfig {
-  apiKey: string
-  testMode?: boolean
-  webhookUrl: string
-}
-
-export interface TestProviderConfig {
-  autoComplete?: boolean
-  defaultDelay?: number
-  enabled: boolean
-  failureRate?: number
-  simulateFailures?: boolean
-}
-
-// Customer info extractor callback type
-export interface CustomerInfoExtractor {
-  (customer: any): {
-    name: string
-    email: string
-    phone?: string
-    company?: string
-    taxId?: string
-    billingAddress?: {
-      line1: string
-      line2?: string
-      city: string
-      state?: string
-      postalCode: string
-      country: string
-    }
-  }
-}
-
-// Plugin configuration
-export interface BillingPluginConfig {
-  admin?: {
-    customComponents?: boolean
-    dashboard?: boolean
-  }
-  collections?: {
-    customerRelation?: boolean | string // false to disable, string for custom collection slug
-    customers?: string
-    invoices?: string
-    payments?: string
-    refunds?: string
-  }
-  customerInfoExtractor?: CustomerInfoExtractor // Callback to extract customer info from relationship
-  disabled?: boolean
-  providers?: {
-    mollie?: MollieConfig
-    stripe?: StripeConfig
-    test?: TestProviderConfig
-  }
-  webhooks?: {
-    basePath?: string
-    cors?: boolean
-  }
-}
-
-// Collection types
-export interface PaymentRecord {
-  amount: number
-  createdAt: string
-  currency: string
-  customer?: string
-  description?: string
-  id: string
-  metadata?: Record<string, unknown>
-  provider: string
-  providerData?: Record<string, unknown>
-  providerId: string
-  status: PaymentStatus
-  updatedAt: string
-}
-
-export interface CustomerRecord {
-  address?: {
-    city?: string
-    country?: string
-    line1?: string
-    line2?: string
-    postalCode?: string
-    state?: string
-  }
-  createdAt: string
-  email?: string
-  id: string
-  metadata?: Record<string, unknown>
-  name?: string
-  phone?: string
-  providerIds?: Record<string, string>
-  updatedAt: string
-}
-
-export interface InvoiceRecord {
-  amount: number
-  billingAddress?: {
-    city: string
-    country: string
-    line1: string
-    line2?: string
-    postalCode: string
-    state?: string
-  }
-  createdAt: string
-  currency: string
-  customer?: string // Optional relationship to customer collection
-  customerInfo?: {
-    company?: string
-    email: string
-    name: string
-    phone?: string
-    taxId?: string
-  }
-  dueDate?: string
-  id: string
-  items: InvoiceItem[]
-  metadata?: Record<string, unknown>
-  number: string
-  paidAt?: string
-  status: InvoiceStatus
-  updatedAt: string
-}
-
-export interface InvoiceItem {
-  description: string
-  quantity: number
-  totalAmount: number
-  unitAmount: number
-}
-
-export type InvoiceStatus = 
-  | 'draft'
-  | 'open' 
-  | 'paid'
-  | 'uncollectible'
-  | 'void'
-
-// Plugin type
-export interface BillingPluginOptions extends BillingPluginConfig {
-  disabled?: boolean
-}
-
-// Error types
-export class BillingError extends Error {
-  constructor(
-    message: string,
-    public code: string,
-    public provider?: string,
-    public details?: Record<string, unknown>
-  ) {
-    super(message)
-    this.name = 'BillingError'
-  }
-}
-
-export class PaymentProviderError extends BillingError {
-  constructor(
-    message: string,
-    provider: string,
-    code?: string,
-    details?: Record<string, unknown>
-  ) {
-    super(message, code || 'PROVIDER_ERROR', provider, details)
-    this.name = 'PaymentProviderError'
-  }
-}
-
-export class WebhookError extends BillingError {
-  constructor(
-    message: string,
-    provider: string,
-    code?: string,
-    details?: Record<string, unknown>
-  ) {
-    super(message, code || 'WEBHOOK_ERROR', provider, details)
-    this.name = 'WebhookError'
-  }
-}

src/types/payload.ts

@@ -1,178 +0,0 @@
-/**
- * PayloadCMS type definitions for hooks and handlers
- */
-
-import type { PayloadRequest, User } from 'payload'
-
-// Collection hook types
-export interface CollectionBeforeChangeHook<T = Record<string, unknown>> {
-  data: T
-  operation: 'create' | 'delete' | 'update'
-  originalDoc?: T
-  req: PayloadRequest
-}
-
-export interface CollectionAfterChangeHook<T = Record<string, unknown>> {
-  doc: T
-  operation: 'create' | 'delete' | 'update'
-  previousDoc?: T
-  req: PayloadRequest
-}
-
-export interface CollectionBeforeValidateHook<T = Record<string, unknown>> {
-  data?: T
-  operation: 'create' | 'update'
-  originalDoc?: T
-  req: PayloadRequest
-}
-
-// Access control types
-export interface AccessArgs<T = unknown> {
-  data?: T
-  id?: number | string
-  req: {
-    payload: unknown
-    user: null | User
-  }
-}
-
-// Invoice item type for hooks
-export interface InvoiceItemData {
-  description: string
-  quantity: number
-  totalAmount?: number
-  unitAmount: number
-}
-
-// Invoice data type for hooks
-export interface InvoiceData {
-  amount?: number
-  billingAddress?: {
-    city?: string
-    country?: string
-    line1?: string
-    line2?: string
-    postalCode?: string
-    state?: string
-  }
-  currency?: string
-  customer?: string // Optional relationship
-  customerInfo?: {
-    company?: string
-    email?: string
-    name?: string
-    phone?: string
-    taxId?: string
-  }
-  dueDate?: string
-  items?: InvoiceItemData[]
-  metadata?: Record<string, unknown>
-  notes?: string
-  number?: string
-  paidAt?: string
-  payment?: string
-  status?: string
-  subtotal?: number
-  taxAmount?: number
-}
-
-// Payment data type for hooks
-export interface PaymentData {
-  amount?: number
-  currency?: string
-  customer?: string
-  description?: string
-  invoice?: string
-  metadata?: Record<string, unknown>
-  provider?: string
-  providerData?: Record<string, unknown>
-  providerId?: string | number
-  status?: string
-}
-
-// Customer data type for hooks
-export interface CustomerData {
-  address?: {
-    city?: string
-    country?: string
-    line1?: string
-    line2?: string
-    postalCode?: string
-    state?: string
-  }
-  email?: string
-  metadata?: Record<string, unknown>
-  name?: string
-  phone?: string
-  providerIds?: Record<string, string | number>
-}
-
-// Refund data type for hooks
-export interface RefundData {
-  amount?: number
-  currency?: string
-  description?: string
-  metadata?: Record<string, unknown>
-  payment?: { id: string | number } | string
-  providerData?: Record<string, unknown>
-  providerId?: string | number
-  reason?: string
-  status?: string
-}
-
-// Document types with required fields after creation
-export interface PaymentDocument extends PaymentData {
-  amount: number
-  createdAt: string
-  currency: string
-  id: string | number
-  provider: string
-  providerId: string | number
-  status: string
-  updatedAt: string
-}
-
-export interface CustomerDocument extends CustomerData {
-  createdAt: string
-  id: string | number
-  updatedAt: string
-}
-
-export interface InvoiceDocument extends InvoiceData {
-  amount: number
-  createdAt: string
-  currency: string
-  customer?: string // Optional relationship
-  customerInfo?: { // Optional when customer relationship exists
-    company?: string
-    email: string
-    name: string
-    phone?: string
-    taxId?: string
-  }
-  billingAddress?: { // Optional when customer relationship exists
-    city: string
-    country: string
-    line1: string
-    line2?: string
-    postalCode: string
-    state?: string
-  }
-  id: string | number
-  items: InvoiceItemData[]
-  number: string
-  status: string
-  updatedAt: string
-}
-
-export interface RefundDocument extends RefundData {
-  amount: number
-  createdAt: string
-  currency: string
-  id: string | number
-  payment: { id: string } | string
-  providerId: string
-  refunds?: string[]
-  status: string
-  updatedAt: string
-}