3 Best APIs for Mobile SDKs in Nigeria

Interswitch Group is Nigeria's pioneering payment infrastructure company and the creator of the Verve card network — the most widely used debit card in Nigeria with over 35 million cardholders. Founded in 2002 and listed on the Nigerian Stock Exchange, Interswitch owns and operates Nigeria's core payment switching infrastructure, connecting virtually all Nigerian banks. The company provides developer access to its infrastructure through the Interswitch Developer Center and the Quickteller Business platform. What the API Does The Interswitch API ecosystem covers multiple products: (1) Quickteller SVA — access to 3,000+ billers for airtime vending, utility payments, and transfers to all Nigerian banks and selected African mobile wallets; (2) Quickteller Business — a comprehensive payment gateway for card acceptance, USSD, QR, hosted fields, and mobile SDKs; (3) Virtual Accounts — for NGN collections via dedicated account numbers; (4) NIP Instant Transfers — for bank-to-bank transfers across the Nigerian banking system. How Developers Use It Developers sign up at docs.interswitchgroup.com, create an app in the developer console, and obtain a Client ID and Secret Key for OAuth 2.0 authentication. The API uses standard OAuth 2.0 authorization to generate access tokens. A sandbox environment is available for testing with test credentials. Integration options include REST API, hosted fields (for PCI-compliant card capture), web gateway, and mobile SDKs. Pricing Integration is free — no setup or monthly fees. Local transactions (cards, USSD, QR): 1.5% capped at ₦2,000. 7.5% VAT applies to all transaction fees. Volume-based custom pricing available for high-volume merchants — contact sales. Authentication OAuth 2.0 using Client ID and Secret Key from the developer console. Access tokens are generated and included in API request headers. Token expiry and refresh are managed per OAuth 2.0 standards. Compliance Interswitch is CBN-licensed, PCIDSS certified, and regulated as a switching and processing company under Nigerian financial regulations. As an NSE-listed company it is subject to SEC and public disclosure requirements. Challenges and Gotchas (1) OAuth 2.0 is more complex to implement than simple Bearer token APIs — requires proper token management. (2) Quickteller SVA and Quickteller Business are separate products with different documentation. (3) Settlement takes up to 48 hours — not instant. (4) Verve card processing is Interswitch's core strength; for international card processing, competitors like Paystack may offer better rates. Company Background Interswitch was founded in 2002 by Mitchell Elegbe in Lagos. The company processes hundreds of millions of transactions monthly and serves over 40,000 merchants across Nigeria. Interswitch is valued at over $1 billion, making it one of Africa's fintech unicorns. Products include Verve, Quickteller, Paydirect, and eClat. FAQs Q: What is the fee for local card transactions? A: 1.5% capped at ₦2,000, plus 7.5% VAT on the fee. Q: Does Interswitch support 3,000+ billers? A: Yes. Quickteller SVA gives access to airtime, utilities, and thousands of Nigerian billers. Q: What authentication does Interswitch use? A: OAuth 2.0. You get a Client ID and Secret Key from the developer console to generate access tokens. Q: Is there a sandbox? A: Yes. Available at docs.interswitchgroup.com with test credentials. Interswitch's Verve card network — with over 40 million active cards issued by virtually every Nigerian bank — is one of the most important domestic payment assets in the country. Merchants and platforms integrated with Interswitch gain acceptance of Verve cards, which are the primary debit cards for millions of Nigerian bank customers who may not have international Visa or Mastercard credentials. For consumer-facing Nigerian businesses where Verve card acceptance determines accessibility to a large portion of the Nigerian banked population, Interswitch integration is often essential rather than optional. The NIP (NIBSS Instant Payment) switch that Interswitch helps power enables instant settlement between banks across Nigeria, with transactions completing within seconds rather than the 24-hour windows of older payment systems. For Nigerian businesses where payment confirmation delays affect operational workflows — logistics companies confirming payment before dispatch, service providers starting work after payment, retailers managing inventory allocation — NIP instant payment confirmation through Interswitch's infrastructure removes settlement uncertainty from business operations. Interswitch's three-plus decades of operation in Nigeria represent institutional knowledge of Nigerian payment infrastructure that newer entrants cannot match. The company has navigated multiple CBN regulatory cycles, multiple technology infrastructure shifts, and the evolution of Nigerian consumer payment behavior from cash to cards to mobile. For Nigerian enterprises selecting long-term payment infrastructure partners, this institutional longevity and demonstrated resilience is a meaningful factor in vendor selection.

Firebase Cloud Storage is a cloud file storage service built on top of Google Cloud Storage and integrated into the Firebase mobile and web application development platform. It provides client-side SDKs for iOS, Android, and web applications that allow users to upload and download files directly from their devices to cloud storage without routing file transfers through an application server. Security rules on the Firebase side control which users can access which files, making Firebase Storage a complete solution for user-generated content in mobile and web apps. The client SDK design of Firebase Storage is what distinguishes it from server-side cloud storage integrations. Rather than an application server receiving a file upload and then storing it to cloud storage, Firebase Storage allows the mobile or web client to upload directly to cloud storage while Firebase Security Rules enforce access control. This eliminates the server-side upload bottleneck and removes the need for server infrastructure scaled to handle file upload bandwidth — uploads go directly from the user's device to Firebase's global infrastructure. Firebase Security Rules for Storage use a flexible, expression-based language to define which authenticated users can read or write which files based on paths, user identity, file metadata, and custom claims in the user's JWT token. For example, a rule can specify that authenticated users can only upload to a path containing their own user ID and that uploads must be under 5MB and of image MIME types. These rules are evaluated server-side, so they cannot be bypassed by modifying client code. Resumable uploads in Firebase Storage allow large file uploads to be paused, resumed, and continued even if the network connection is interrupted. This is especially important for Nigerian mobile users who may experience intermittent connectivity during uploads. The Firebase SDK handles resumable upload state management automatically, so a large video or document upload that is interrupted by a network drop can resume from where it left off when connectivity is restored, without restarting the entire upload. Download URLs generated by Firebase Storage are publicly accessible HTTPS URLs for stored files that do not expire. These URLs are served through Google's global CDN infrastructure, meaning files stored in Firebase Storage are delivered through Google's edge network for fast download anywhere in the world including Nigeria. For Nigerian social apps, messaging platforms, and content sharing services that need to serve user-uploaded images and videos to other users at low latency, Firebase Storage CDN delivery is a straightforward solution. Firebase Storage events can trigger Cloud Functions for Firebase, enabling serverless file processing workflows. When a user uploads an image, a Cloud Function can automatically generate thumbnail versions at multiple sizes, extract metadata, run content moderation checks using Vision AI, or send push notifications to other users. For Nigerian app developers who want automatic post-upload processing without managing dedicated processing infrastructure, this event-driven Firebase Storage and Cloud Functions integration provides a complete serverless pipeline. Metadata on stored objects can include custom key-value pairs set at upload time or updated afterward. This allows applications to store contextual information alongside stored files — upload source, processing status flags, user-defined tags — queryable through the Firebase Storage SDK and useful for building file management features within applications. The Firebase Storage SDK is available for iOS (Swift and Objective-C), Android (Java and Kotlin), JavaScript (for web apps, React Native, and Flutter web), and Flutter (via the FlutterFire plugin). Nigerian mobile developers working in React Native or Flutter — the dominant cross-platform frameworks in the Nigerian developer community — have first-class Firebase Storage SDK support through community-maintained and Google-supported plugin packages. Firebase Storage pricing uses the Google Cloud Storage pricing model, billed through the underlying GCS bucket. The free Spark plan includes 5GB of storage and 1GB/day of downloads, sufficient for development and small production apps. The Blaze pay-as-you-go plan follows GCS pricing with no cap, enabling production apps with significant storage needs to scale without changing storage providers as user volume grows.