> ## Documentation Index
> Fetch the complete documentation index at: https://developer.fexpayments.com/llms.txt
> Use this file to discover all available pages before exploring further.

# FEX Developer Portal

> Wallet-based payment infrastructure for POS, web, and mobile integrations.

# Build wallet-based payments with FEX

Accept payments across **POS, web, and mobile** using QR flows, wallet approvals, refunds, and real-time webhooks.

<Card title="What is FEX?" icon="wallet">
  FEX is an alternative payment method that lets customers pay directly from funded wallet balances, without relying on traditional card rails.
</Card>

## Start here

<Steps>
  <Step title="Get your credentials">
    Receive your `merchant_id`, `client_id`, and `client_secret` from your platform administrator and store them securely.
  </Step>

  <Step title="Generate an access token">
    Authenticate using the OAuth2 client credentials flow before calling any merchant API.
  </Step>

  <Step title="Create your first payment">
    Start with the Standard QR flow to create a payment intent and display a QR code to the customer.
  </Step>

  <Step title="Handle payment confirmation">
    Verify incoming webhooks and mark orders as paid when you receive `payment.completed`.
  </Step>
</Steps>

## Payment flows

<CardGroup cols={2}>
  <Card title="Standard QR" icon="qr-code" href="/standard-qr-flow">
    Create a payment intent, display a QR code, and let the customer confirm in their wallet app.
  </Card>

  <Card title="Reverse QR" icon="scan-line" href="/reverse-qr-flow-counter-scan">
    Scan the customer’s wallet QR at the counter and trigger an approval request.
  </Card>
</CardGroup>

## Integration guides

<CardGroup cols={2}>
  <Card title="Overview" icon="compass" href="/overview">
    Learn the two supported payment flows and choose the right checkout experience.
  </Card>

  <Card title="Getting Your Credentials" icon="key" href="/getting-your-credentials">
    Set up merchant credentials and store secrets securely.
  </Card>

  <Card title="Generating an Access Token" icon="shield-check" href="/generating-an-access-token">
    Authenticate with OAuth2 and implement safe token refresh logic.
  </Card>

  <Card title="Standard QR Flow" icon="qr-code" href="/standard-qr-flow">
    Build the merchant-initiated QR flow end to end.
  </Card>

  <Card title="Reverse QR Flow" icon="scan-line" href="/reverse-qr-flow-counter-scan">
    Build the counter-scan flow where the customer presents their wallet QR.
  </Card>

  <Card title="Webhooks" icon="webhook" href="/webhooks">
    Verify signatures and handle payment lifecycle events reliably.
  </Card>

  <Card title="Cancellations & Refunds" icon="rotate-ccw" href="/cancellations-and-refunds">
    Cancel pending intents and refund completed payments.
  </Card>

  <Card title="Transaction History" icon="receipt" href="/transaction-history">
    Retrieve paginated merchant transaction history for reporting and reconciliation.
  </Card>

  <Card title="Counter Management" icon="store" href="/counter-management">
    Register terminals, manage counters, and rotate webhook secrets.
  </Card>

  <Card title="Error Reference" icon="alert-circle" href="/error-reference">
    Understand common API errors and recommended retry behavior.
  </Card>

  <Card title="Quick-Start Checklist" icon="check-circle" href="/quick-start-checklist">
    Validate your setup before going live.
  </Card>
</CardGroup>

## What you can build

<CardGroup cols={3}>
  <Card title="POS payments" icon="store">
    Use merchant-generated QR or reverse QR for in-person checkout at the counter.
  </Card>

  <Card title="Web checkout" icon="monitor">
    Display QR on desktop checkout and let customers approve on mobile.
  </Card>

  <Card title="Mobile experiences" icon="smartphone">
    Extend wallet-based payments into app and mobile commerce flows.
  </Card>
</CardGroup>

## Platform highlights

* **Wallet-based payments** for direct, card-free transactions
* **POS and ecommerce support** across in-person and online flows
* **Real-time webhooks** for payment lifecycle events
* **Refund workflows** for post-payment operations
* **Secure authentication** using OAuth2 and signed webhook delivery

## Core concepts

### Wallets

Customers fund their FEX wallet using supported bank transfer or cash-based funding methods, then use those balances to pay merchants.

### Allocations

FEX uses an allocation model to organize funds into spending buckets. Allocations can include constraints such as merchant restrictions or expiration dates, and eligible payments draw from the most restrictive allocation first.

## Build confidently

Use the guides in this portal to:

* authenticate securely
* create payment intents
* display QR codes
* receive confirmation via webhook
* manage transactions and refunds

<Card title="Ready to integrate?" icon="arrow-right" href="/getting-your-credentials">
  Start with credentials setup and launch your first FEX payment flow.
</Card>