Examples - Streaming & KYC Verification

The Quicksilver SDK empowers developers to build dynamic financial applications by providing robust features for real-time streaming payments and comprehensive Know Your Customer (KYC) verification. These examples demonstrate how to leverage these capabilities to create modern, compliant, and highly interactive money flows.

Streaming Payments and Real-Time Events

Streaming payments enable continuous, time-based transfers of funds, perfect for subscription models, pay-per-second services, or real-time content monetization. The SDK integrates with Server-Sent Events (SSE) to provide real-time updates on stream status and batch payments.

This example from examples/5-streaming-and-events.ts demonstrates:

• Creating accounts for a content streamer and viewer.
• Initiating different types of streaming transactions.
• Subscribing to real-time events using StreamConnection to monitor stream status (stream_event) and batch payments (batch_created).
• Performing stream control operations like pause, resume, update, and stop.
• Retrieving stream analytics and checking final transaction status.

For more details on the Transaction model and its subscribe() method, refer to [API Reference - Core Models].

Understanding StreamConnection

The StreamConnection class (from src/realtime/sse.ts) is an EventEmitter that abstracts the complexity of Server-Sent Events (SSE) connections. When you call transaction.subscribe(), client.streams.subscribe(id), client.streams.subscribeToAccount(accountId), or client.streams.subscribeToAll(), an instance of StreamConnection is returned.

You can interact with StreamConnection using standard Node.js EventEmitter methods:

• on('open', listener): Fired when the SSE connection is successfully established.
• on('error', listener): Fired if an error occurs with the connection. It also handles reconnection attempts with exponential backoff.
• on('close', listener): Fired when the connection is explicitly closed using close().
• on('stream_event', listener): Specific to Quicksilver, this event delivers updates on the state of a streaming transaction (e.g., streamstarted, paused, resumed, stopped, completed).
• on('batch_created', listener): Specific to Quicksilver, this event notifies you when a batch payment (a discrete transfer of accumulated funds) has been created within a stream.

The StreamConnection automatically handles reconnection attempts with exponential backoff, making it resilient to transient network issues.

KYC Verification

Know Your Customer (KYC) verification is crucial for compliance and security in financial applications. The Quicksilver SDK provides methods within the Account model to manage the KYC process.

This example from examples/6-kyc-verification.ts demonstrates:

• Creating individual and business accounts.
• Retrieving the initial verification status of accounts using account.getVerificationStatus().
• Submitting KYC documents for verification using account.submitKYC().
• Simulating the administrative process of verifying or rejecting an account using account.verify() and account.rejectVerification().
• Checking account capabilities (canTransact(), canDelegate()) which are tied to verification status.
• Updating account limits and fetching balances after verification.

For more information on the Account model, see [API Reference - Core Models].