# Purse Payment Platform

> Purse is an orchestration payment platform providing a unified API to integrate multiple payment methods, secure checkout solutions, and advanced payment management features. This documentation helps merchants integrate Purse API and SDK into their e-commerce systems.

Purse simplifies payment integration by acting as a single gateway to connect merchants with the entire payment ecosystem. The platform offers multiple integration modes (Headless SDK, Hosted Fields, Hosted Form, Hosted Page) to match different business needs, from full UI control to quick plug-and-play solutions.

**Key capabilities:**
- Unified API for 100+ payment methods (cards, wallets, BNPL, alternative payments)
- PCI-DSS compliant checkout solutions
- Secure vault for payment method tokenization
- Advanced routing and real-time monitoring
- OAuth2 authentication with access token management
- Webhook notifications for payment events

**Integration requirements:**
- API credentials: ENTITY_ID, API_KEY, CLIENT_ID, CLIENT_SECRET
- HTTPS-enabled server for secure transactions
- Domain whitelisting by Purse integration team
- Basic understanding of REST APIs and JSON

## Getting Started

- [Getting Started with Purse API](https://docs.upstreampay.com/docs/integrate/getting-started): Complete guide covering prerequisites, OAuth2 authentication, API credentials setup, and token management. Essential first step for all integrations.
- [Introduction to Purse](https://docs.upstreampay.com/docs/understand/introduction): Overview of Purse platform, payment ecosystem, and how online transactions work.
- [Integration Modes Overview](https://docs.upstreampay.com/docs/integrate/purse-checkout/integration-modes): Comparison of Headless SDK, Hosted Fields, Hosted Form, and Hosted Page integration modes with effort levels and capabilities.

## API Integration

- [Simple Payment Tutorial](https://docs.upstreampay.com/docs/integrate/purse-api/tutorials/simple-payment): Step-by-step tutorial for creating a basic payment flow with client session creation and payment processing.
- [Payment Operations](https://docs.upstreampay.com/docs/integrate/purse-api/tutorials/payment-operations): Guide for capture, refund, void, and other payment operations with code examples.
- [Webhooks Integration](https://docs.upstreampay.com/docs/integrate/purse-api/tutorials/webhooks): How to receive and validate webhook notifications for payment events.
- [Best Practices](https://docs.upstreampay.com/docs/integrate/purse-api/best-practices): Idempotency, security, error handling, webhook validation, and performance optimization guidelines.

## Checkout Integration Modes

- [Headless Checkout SDK](https://docs.upstreampay.com/docs/integrate/purse-checkout/headless-checkout/): Full control over checkout flow with API-driven customization. Highest integration effort, full UI customization, supports all payment methods.
- [Hosted Fields](https://docs.upstreampay.com/docs/integrate/purse-checkout/hosted-fields/): Embed secure payment fields directly into your checkout page. Medium integration effort, full UI customization, credit card only.
- [Hosted Form](https://docs.upstreampay.com/docs/integrate/purse-checkout/hosted-form/): Simple secure payment form with minimal integration. Low integration effort, limited UI customization, supports all payment methods.
- [Hosted Page](https://docs.upstreampay.com/docs/integrate/purse-checkout/hosted-page/): Pre-built secure payment interface served by Purse. Lowest integration effort, limited UI customization, supports all methods including pay-by-link and MOTO.

## API Reference

- [API v2 Documentation](https://docs.upstreampay.com/api-v2): Complete OpenAPI specification for Purse Orchestration API v2 with all endpoints, request/response schemas, and authentication details.
- [API v1 Documentation (deprecated)](https://docs.upstreampay.com/openapi): Legacy API v1 documentation, deprecated in favor of API v2.
- [Wallet API](https://docs.upstreampay.com/wallet): API for managing stored payment methods and tokenized cards.

## Key Concepts & Glossary

- [Payment Concepts](https://docs.upstreampay.com/docs/understand/payment-concepts): Core payment concepts including authorization, capture, refund, void, and payment lifecycle.
- [Use Cases](https://docs.upstreampay.com/docs/understand/use-cases): Common payment scenarios and how to implement them with Purse.
- [API Glossary](https://docs.upstreampay.com/docs/references/glossary/api): Definitions of key API terms and concepts.
- [Entity Glossary](https://docs.upstreampay.com/docs/references/glossary/entity): Understanding entities and hierarchical organization.
- [Convention Guide](https://docs.upstreampay.com/docs/references/convention): API naming conventions, data formats, and standards.
- [SDK CDN URLs](https://docs.upstreampay.com/docs/references/sdk-cdn-urls): CDN links for loading Purse SDK in your application.

## Payment Partners

- [Payment Partners Directory](https://docs.upstreampay.com/docs/partners): Complete list of 100+ supported payment service providers and payment methods with integration guides for each partner.