# Developer Quick Start

This section covers the core technical concepts you need to integrate with the API. Whether you're building your first integration or need a reference for specific implementation details, these guides will help you build secure, reliable, and scalable applications.

## What You'll Learn

These guides walk you through the fundamental patterns and protocols used throughout the API:

### [Authentication →](/guides/authentication)

Learn how to authenticate your API requests using API keys and tokens. This guide covers credential management, authentication headers, and security best practices.

**Key topics:** API keys, bearer tokens, credential rotation, security considerations

### [Request Signing →](/guides/requestsigning)

Understand how to cryptographically sign your API requests to ensure authenticity and integrity. Request signing adds an additional layer of security beyond authentication.

### [Idempotence →](/guides/idempotence)

Prevent duplicate transactions and ensure safe retry logic using idempotency keys. Learn how to make your integrations resilient to network failures and timeouts.

### [Pagination →](/guides/pagination)

Efficiently retrieve large datasets using cursor-based pagination. This guide explains how to iterate through list endpoints and handle large result sets.

### [Subscriptions →](/guides/subscriptions)

Set up webhooks to receive real-time notifications about events on the platform. Subscriptions enable event-driven architectures and automated workflows.

- **[Subscription Events](/guides/subscriptions_events)** - Complete reference of all available webhook events


## Integration Checklist

Before you start building, make sure you have:

✅ API credentials (sandbox and/or production)

✅ Development environment configured

✅ Webhook endpoint URL (for subscriptions)

## Quick Integration Flow

1. **Authenticate** - Set up your API credentials and test authentication
2. **Make your first request** - Create a test resource using proper request signing
3. **Handle responses** - Implement error handling and idempotency
4. **Set up webhooks** - Subscribe to relevant events for your use case
5. **Test thoroughly** - Use sandbox environment before going live


## Next Steps

- Ready to onboard users? See the [Concepts > Applications](/guides/applications) guide
- Building specific workflows? Check out [Developer Use Case Guides](/guides/usecases)
- Want to start with the UI before you code up to the API? Follow the [Business Quick Start](/guides/business_quickstart_overview) guide


## Support

If you run into issues or have questions:

- Check the [API Documentation](/api-docs/openapi/rail-spec) for detailed endpoint references
- Review error codes and troubleshooting tips in each guide
- Contact developer support for integration assistance