Overseas App API Integration Services | Payments, Brokerage, Investments & Wallet Apps API Integration

Team Overview

We are a technical team focused on app interface integration and authorized API connections, with years of fintech and mobile project experience. Our services cover protocol analysis, API refactoring, Open Data integration, third-party platform integrations, and automated data delivery, ensuring compliance, security, and production readiness.

Compliance Commitment: All projects are based on client authorization or public/authorized APIs (Open Data / Public API / Authorized interfaces). We sign NDAs before work and comply with local laws and privacy protections. For any required reverse-engineering work, we use terms such as “reverse engineering” and “data extraction” to ensure retrievability and legal compliance.

Our Core Capabilities

Payments & Wallets: top-ups, scan/QR payments, reconciliation and settlement flows
Brokerage & Investments: account holdings queries, order matching, order receipts and historical trades integration
Authentication & Security: OAuth2, JWT, HTTPS/TLS, two-factor authentication and certificate validation
API Standardization: OpenAPI/Swagger definitions, Postman collections and sample code
Automation & Delivery: scripted data scraping, scheduled tasks (cron/webhook), CI testing scripts

Target App Scenarios & Technical Implementation Highlights

Below are typical interfaces and feature implementation highlights tailored to the target apps you provided. Each implementation includes API specifications, authentication notes and example requests/responses.

PagueVeloz: Payment gateway integration, including merchant order API, asynchronous callbacks (webhook) signature verification, accounting reconciliation interface, refunds and settlement reports export; supports localized payment methods (Boleto, PIX, bank cards).
DSB Agent: Agent/broker side implementations: authentication, task assignment and trade entry interfaces, with offline queue and synchronization mechanisms (queue retries, idempotent tokens), plus mobile SDK samples and admin backend API.
Angel One: Stocks, Mutual Fund[com.msf.angelmobile]: Broker-side: market data subscription (WebSocket/push), order placement (limit/market), portfolio holdings query, fund purchases/redemptions flows and order status callbacks, with compliance logs and risk triggers notes.
i-invest: Invest & Save: Savings/term investment product account opening, risk qualification checks, scheduled investment plan management, yield calculation interface and periodic reconciliation tasks, with auto-clearing with bank gateways and reconciliation streams.
Réparez, Revendez, Économisez: French market repair/second-hand/saving platform interfaces, provide product listing/status synchronization, payments and returns flow, order and logistics tracking, receipt image upload and content compliance checks (privacy filtering).
OmniWallet: Multi-currency account management, built-in P2P transfers, QR payments, transaction detail export, rate calculation and loyalty/reward interfaces, with real-time balance consistency checks and reconciliation scripts.

Deliverables (Standard Package)

Runnable API implementations (Node.js / Python / Java), with authentication middleware and error handling strategies
Postman/Insomnia collections, including headers, signatures and sample environment variables
Standard API documentation (OpenAPI/Swagger) and API test cases
Automation scripts (data collection/sync/reconciliation) and deployment guidance (Docker / CI optional)
Security & Compliance: authentication workflows, data masking strategies and log retention recommendations

Technical & Security Details

Transport security: enforce HTTPS/TLS, certificate pinning and HSTS support
Authentication methods: supports OAuth2 authorization code, client credentials, JWT, and API Key hybrid approaches
Idempotency design: idempotent keys, idempotent retry strategies and transaction rollback recommendations
Observability: API tracing, error code taxonomy and monitoring/alert integration (Prometheus/Grafana)
Compliance & Privacy: data minimization, encryption of sensitive fields, and log masking practices

Pricing & Delivery Timeline

Base service starting at $300 (includes requirements assessment and initial API delivery); complex integrations quoted per project.
Typical delivery cycle: 5-10 business days to deliver first version of APIs and documentation; complex brokerage or multi-party settlement scenarios may require timeline adjustments.
Supports NDA and staged acceptance payments. Demo samples can be provided before delivery to confirm features.

FAQ

What information do you need from us?

Please provide target app name (e.g., PagueVeloz, Angel One, etc.), detailed functionality requirements, whether you already have authorized API credentials or documentation, and desired delivery format.

Is multilingual support and localization available?

Yes. We provide multilingual field adaptation and localization guidance (e.g., French/Portuguese payment channels, local tax fields, etc.).

How do you ensure compliance?

All work is based on client authorization or public APIs, with legal/compliance teams consulted for licensing and privacy impact assessments when required.

Professional Overseas App API Integration & API Integration - Supporting Payments, Brokerage and Wallet Apps