> For the complete documentation index, see [llms.txt](https://plexo.gitbook.io/rest-api/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://plexo.gitbook.io/rest-api/getting-started/what-is-plexo.md).

# What is Plexo?

*Brief explanation: Plexo is a payment gateway that securely transmits payment information between customers, merchants, processors, and banks to authorize and complete transactions.*

## What is a Payment Gateway?

A payment gateway is a service that:

1. **Securely captures** payment information from customers
2. **Encrypts and transmits** data to payment processors
3. **Routes authorization requests** to card networks and banks
4. **Returns responses** (approved/declined) to merchants
5. **Facilitates settlement** of funds to merchant accounts

Think of a payment gateway as the digital equivalent of a physical point-of-sale (POS) terminal.

## How Plexo Works

Plexo is a comprehensive payment gateway platform that connects merchants in Uruguay to multiple payment processors and card networks.

### Plexo's Role

* Acts as the intermediary between merchants and payment processors
* Provides a unified API for multiple processors
* Manages payment method configurations
* Ensures secure data transmission and compliance
* Offers features like tokenization, 3D Secure, and fraud prevention

### Architecture

```mermaid
flowchart TD
    Customer[Customer]
    Merchant[Merchant Website/App]
    Gateway[Plexo API Gateway]
    Tokenization[Tokenization Service]
    Routing[Payment Routing]
    Vault[Token Vault]
    Processor[Payment Processor]
    ThreeDS[3DS Provider]
    Network[Card Network<br/>VISA/Mastercard/etc]
    Bank[Issuing Bank]

    Customer --> Merchant
    Merchant --> Gateway
    Gateway <--> Tokenization
    Gateway --> Routing
    Tokenization --> Vault
    Routing --> Processor
    Processor <--> ThreeDS
    Processor --> Network
    Network --> Bank
```

## Integration Models

### Hosted (Recommended)

* Plexo-hosted payment page
* Delivered via redirect
* Reduced PCI scope (no card data touches merchant servers)
* Supports checkout and tokenization sessions
* Best for: Most merchants, fastest integration

**Session Types:**

* **Checkout Session**: Complete payment flow with tokenization and purchase (auth+capture)
* **Tokenization Session**: Capture and store card information only, then notify via callback with tokenized payment instrument

**Display Options:**

* **Redirect**: Full-page redirect to Plexo checkout
* **Iframe**: Embed Plexo checkout within merchant page

### Direct API (PCI Certified Clients)

* For PCI DSS certified merchants only
* Merchant handles card capture and tokenization
* Send plain card PAN or network tokens directly via API
* Full control over payment UX and flow
* Best for: Large merchants with PCI certification and compliance resources

## Key Features

### Multi-Processor Support

* Connect to 10+ payment processors
* Single API for all processors
* Automatic routing and failover
* Processor-specific optimizations

### Payment Method Diversity

* 14+ card brands (VISA, MASTERCARD, OCA, etc.)
* Alternative methods (PIX)
* Digital wallets (Google Pay, Apple Pay)
* Credit, debit, and prepaid cards

### Security & Compliance

* **PCI DSS Level 1** compliant infrastructure
* **Tokenization** for secure card storage
* **3D Secure (3DS)** authentication via Cybersource
* **TLS 1.2+** encryption for all API calls
* **HTTPS callbacks** for asynchronous status updates

### Tokenization

* Store customer payment methods securely
* Enable recurring/subscription payments
* One-click checkout experiences
* Network tokenization support

### Fraud Prevention

* 3D Secure authentication
* AVS (Address Verification System)
* CVV verification
* Velocity checks
* Integration with fraud management platforms (Koin, Kount and Decision Manager)

### Transaction Management

* Authorization and capture
* Refunds (full and partial)
* Voids and cancellations
* Transaction status tracking
* Real-time notifications

### Developer Experience

* RESTful API with comprehensive documentation
* Swagger/OpenAPI specifications
* Testing environment with mock processor support
* Detailed error codes and messages

### Reporting & Analytics

* Transaction history and search

### Dual Mode Support

**Gateway Mode:**

* Merchants use own processor credentials
* Direct processor relationships
* Full settlement control

**PayFac Mode:**

* Plexo manages processor relationships
* Faster merchant onboarding
* Sub-merchant aggregation

## Payment Flow

### Standard Hosted Checkout Flow

**1. Merchant Creates Session**

* Merchant server calls Plexo API to create checkout session
* Receives session URL and session ID
* Session can be for payment or tokenization only

**2. Customer Redirected to Plexo Checkout**

* Customer is redirected to Plexo-hosted checkout page
* Customer enters card details on Plexo's secure page

**3. Plexo Captures Payment Information**

* Validates card details
* Tokenizes card data securely
* Stores in PCI-compliant vault

**4. 3DS Authentication (if enabled)**

* Redirects to 3DS challenge page
* Customer authenticates with issuing bank
* Returns authentication result

**5. Authorization Request (if payment session)**

* Plexo sends authorization to processor
* Processor forwards to card network
* Card network contacts issuing bank
* Bank approves or declines transaction

**6. Authorization Response**

* Response flows back through network
* Plexo normalizes response format
* Customer redirected back to merchant
* Merchant receives callback notification

**7. Capture (if two-step flow)**

* Merchant confirms shipment/service
* Sends capture request to Plexo API
* Plexo initiates fund transfer

**8. Settlement**

* Processor settles funds to merchant account
* Typically 1-3 business days

### Payment Flow Variations

**Purchase (Primary Flow - Auth + Capture in One Step):**

```mermaid
flowchart LR
    Purchase[Purchase Request] --> AuthCapture[Authorization & Capture] --> Settlement[Settlement]
```

This is the main supported flow where authorization and capture happen together in a single transaction.

**Separated Authorization and Capture (Also Supported):**

```mermaid
flowchart LR
    Auth[Authorization] --> Hold[Hold Funds] --> Capture[Capture Later] --> Settlement[Settlement]
```

Allows merchants to authorize funds first, then capture later when goods ship or service is delivered.

**Tokenized Purchase:**

```mermaid
flowchart LR
    Token[Retrieve Token] --> Purchase[Purchase with Token] --> Settlement[Settlement]
```

**PIX Payment:**

```mermaid
flowchart LR
    Generate[Generate QR Code] --> Scan[Customer Scans] --> Confirm[Instant Confirmation] --> Settlement[Settlement]
```

## Related Resources

* [Merchants](/rest-api/core-concepts/merchants.md)
* [Supported Payment Methods](/rest-api/reference/supported-payment-methods.md)
* [Supported Payment Methods and Processors](/rest-api/reference/supported-payment-methods.md)
* [Transaction Lifecycle](/rest-api/core-concepts/transaction-lifecycle.md)
* [Security](/rest-api/core-concepts/security.md)
* [Quick Start Guide](/rest-api/getting-started/readme.md)