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Welcome to FLEX SSO API

The FLEX SSO API enables institutions and partners to create PayTags for their customers on the FLEX ecosystem. Your customers can then transact with any other PayTag user across the entire FLEX network, regardless of which partner they come from—creating a truly interconnected payment ecosystem.

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What You Can Do

PayTag Creation

Create PayTags for your customers with BVN validation

Wallet Management

Access partner-scoped wallets and transaction history

Cross-Partner Transactions

Enable P2P transfers, withdrawals, and payments across the entire FLEX ecosystem

Payment Requests

Create and manage payment requests with any PayTag user

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Key Features

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🌐 Cross-Partner Ecosystem

Your customers can transact with any PayTag user on FLEX, regardless of which institution created their PayTag.

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🔐 Partner-Scoped Wallets

Each partner gets isolated wallet instances for their customers, ensuring data privacy and separation while enabling ecosystem-wide transactions.

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✅ OAuth 2.0 Flow

Industry-standard authorization code flow for secure customer authentication.

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🎯 Complete Wallet Experience

Full-featured wallet API including balances, limits, virtual accounts, and statements.

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📱 PayTag System

User-friendly payment addresses (e.g., @johndoe) that work across the entire FLEX ecosystem for seamless peer-to-peer transfers.

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Base URLs

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API Sections

Authentication

OAuth flow, PayTag creation, and BVN verification

Wallet

Balance, history, limits, and virtual accounts

Transactions

P2P, withdrawals, bank transfers, and statements

Payment Requests

Create, accept, decline, and cancel payment requests

PayTag

Search and resolve PayTag profiles

Beneficiaries

Save and manage frequent recipients

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Flutter SDK

If you want FLEX to provide the wallet onboarding and wallet UI inside your Flutter app, use the Flutter SDK instead of building every screen yourself.

Wallet Flutter SDK

Embed onboarding, login, wallet, transfers, history, and QR flows with flex_sdk.

API-led integration

Build your own wallet experience on top of the Wallet SSO API.

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Authentication Types

The SSO API uses two authentication modes:
Required headers:
  • x-client-id: Your partner ID
  • x-api-key: Your API key
Used for creating PayTags and OAuth flow initiation.
Required headers:
  • x-client-id: Your partner ID
  • x-api-key: Your API key
  • Authorization: Bearer {customer_token}
Used for all wallet and transaction operations on behalf of the customer. Enables transactions with any PayTag across the FLEX ecosystem.

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Quick Start

1

Get Partner Credentials

Contact FLEX support to receive:
  • Partner Client ID (x-client-id)
  • Partner API Key (x-api-key)
  • Redirect URLs for OAuth flow
2

Implement OAuth Flow

Follow the authentication guide to implement customer login
3

Create PayTags for Customers

Use the PayTag creation flow to create PayTags on the FLEX ecosystem
4

Build Wallet Features

Complete the integration guide to enable cross-partner transactions

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Integration Flow

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Support

Need help? Reach out to our developer support team:

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API Status Codes

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Next Steps

Authentication Guide

Learn the OAuth 2.0 flow

PayTag Creation

Create PayTags for your customers

Integration Guide

Enable cross-partner transactions

Flutter SDK

Embed the Wallet SSO experience in your Flutter app

API Reference

Explore all endpoints