FAQ
General Questions
What is Fluxis?
Fluxis is a payment infrastructure platform that enables businesses to accept cryptocurrency payments across multiple blockchain networks. We provide a unified API that simplifies the integration of digital asset payments into your existing systems, whether you're running an e-commerce store, a mobile app, or a physical point of sale terminal.
How does Fluxis differ from other crypto payment processors?
Fluxis uses the NASPIP (Native Asset Signed Payment Instructions Protocol) standard, which provides:
- Multi-network support - Accept EVM stablecoins on supported networks (e.g., Polygon, Base, Avalanche, Arbitrum, and additional networks per your account configuration) from a single integration
- Asset flexibility - Support multiple stablecoins and cryptocurrencies simultaneously
- Cryptographic security - All payment instructions are signed and verifiable
- Standardized protocol - Compatible with any NASPIP-compliant wallet
Learn more in our Comparison Guide.
Do I need blockchain knowledge to integrate Fluxis?
No. Fluxis abstracts away the complexity of blockchain interactions. You work with a simple REST API—create payment requests, monitor status changes, and receive webhook notifications. Our API handles all blockchain-specific operations behind the scenes.
What cryptocurrencies can I accept?
Fluxis supports any EVM-compatible token on supported networks. Most merchants accept stablecoins like USDC and USDT to avoid volatility. You can configure which assets to accept through your Point of Sale payment options.
See the full list of supported networks and assets in our UAI documentation.
Getting Started
How do I sign up as a merchant?
Follow our Merchant Sign Up guide. You'll need:
- Legal business name
- Tax identification number
- Country of registration
- Owner email address
After submission, our team reviews your application (1-2 business days) and sends you API credentials upon approval.
How long does the approval process take?
Typically 1-2 business days. We verify your business information to ensure compliance with KYB (Know Your Business) requirements. You'll receive an email notification once your application is approved or if additional information is needed.
What are the integration requirements?
You need:
- Backend server - To securely store API credentials and handle authentication
- HTTPS endpoint - For receiving webhook notifications (recommended)
- Basic REST API knowledge - To make HTTP requests to our API
Our Authentication & Configuration guide walks you through the complete setup process.
Is there a sandbox or test environment?
Yes. Fluxis provides a staging environment for integration testing before production go-live.
- Staging API host:
https://api.stgfluxis.us - Production API host:
https://api.fluxis.us
Staging API keys are issued by your Fluxis representative (format: fxs.stg.<uuid>). Use staging to build and test your integration; production credentials are enabled after staging approval.
See the API Integration Guide for environment details.
Point of Sales
What is a Point of Sale?
A Point of Sale (PoS) is a payment collection endpoint within Fluxis. Think of it as a virtual cash register where you generate payment requests. Each PoS can have its own configuration, including which cryptocurrencies to accept and merchant branding. Webhooks are configured at the account level (POST /v1/account/{accountID}/webhook), not per PoS — see Webhooks.
Read more in our Point of Sale Guide.
How many Point of Sales can I create?
There's no limit on the number of Point of Sales you can create. Many merchants create separate PoS instances for:
- Different physical locations
- Different business units or departments
- Different product categories
- Development, staging, and production environments
Can I update my Point of Sale configuration?
Yes. You can update your Point of Sale's name, payment options, and merchant information at any time through the API. Use the update Point of Sale endpoint in our API Reference.
What are payment options?
Payment options are the list of cryptocurrencies and networks your Point of Sale accepts. They're defined using Unique Asset Identifiers (UAIs). For example:
npolygon_t0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359- USDC on Polygonnerc20_t0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48- USDC on Ethereum
When you create a payment request, customers can pay with any of the configured payment options.
Payment Requests
How long does a payment request stay active?
Expiration depends on the payment flow:
- Payment intention (cashier mode): The active intention expires 5 minutes after creation.
- Payment request (after the payer selects an asset): The request is typically valid for 8 minutes from assignment (Unix
expirationtimestamp in the API response).
If a request expires before payment completes, create a new payment request or payment intention. Once status is expired, the platform does not continue matching new on-chain deposits to that request—encourage payers to complete payment before expiry and show a countdown in your UI.
What happens if a customer pays after expiration?
Payments must reach the assigned address while the payment request is still in created or processing status. After the request is marked expired, create a new payment request for any further payment attempts.
Can I create payment requests without a fixed amount?
Currently, all payment requests require a specific amount. The amount field ensures proper payment verification and status tracking. For variable pricing scenarios, calculate the amount in your application before creating the payment request.
What is a NASPIP token?
NASPIP (Native Asset Signed Payment Instructions Protocol) is the cryptographically signed token that contains all payment instructions. When you create a payment request, Fluxis generates a NASPIP token that you can:
- Display as a QR code for mobile wallets
- Share as a payment link for web wallets
- Share as a deep link or hosted checkout URL (wallet-dependent proximity/NFC support varies by wallet app)
The token includes the payment address, amount, asset, network, and expiration—everything a wallet needs to complete the payment.
Learn more about NASPIP.
Can I reuse a payment request?
No. Each payment request is single-use and tied to a specific transaction. Once completed, expired, or cancelled, you must create a new payment request for subsequent transactions. This ensures payment integrity and proper accounting.
Payment Monitoring
How do I know when a payment is completed?
There are two approaches:
-
Webhooks (Recommended) - Configure a webhook URL to receive real-time notifications when payment status changes. See Webhooks.
-
Polling - Periodically check the payment request status using the GET endpoint. See our API Reference.
For production systems, we strongly recommend implementing webhooks for instant notifications.
What is the difference between 'processing' and 'completed'?
processing- Payment detected on-chain; awaiting finality checkscompleted- Payment amount matches the request and finality requirements are metconfirmed- A confirmed ledger transaction has been recorded for the payment
Wait for completed (or your agreed terminal status) before fulfilling orders. Use webhooks rather than polling when possible.
What if a customer underpays or overpays?
Payment requests can result in three edge case states:
underpaid- Customer paid less than the requested amountoverpaid- Customer paid more than the requested amountfailed- Unexpected error during processing
For underpaid or overpaid payments, use the Refunds API (POST /v1/refunds/payment-request/{paymentRequestID}) to return funds to a specified on-chain address. Amount is optional—for overpaid payments, omitting amount refunds the excess by default.
Contact [email protected] if you need help choosing the correct resolution for your business rules.
See Payment Flow Edge Cases, the API Integration Guide, and Webhooks.
How many blockchain confirmations does Fluxis wait for?
Finality requirements are network-specific and configured per deployment. Fluxis waits until the configured finality threshold is met before treating a payment as final (typically reflected as completed or confirmed status).
Production block monitoring currently runs on Polygon, Base, Avalanche, and Arbitrum. Other networks may appear in payment options (UAIs) but are not all actively monitored in every environment—confirm supported networks with your Fluxis representative.
Do not hard-code confirmation counts in your integration; rely on payment request status and webhooks instead.
Security & Authentication
How do I keep my API credentials secure?
Follow these best practices:
- Never commit credentials to version control systems
- Use environment variables or a secrets manager (AWS Secrets Manager, HashiCorp Vault)
- Rotate credentials regularly for enhanced security
- Limit access to only team members who need it
- Monitor usage for suspicious activity
See our Security Best Practices guide.
How long are access tokens valid?
Access tokens expire after 1 hour. Cache and reuse tokens until they expire rather than requesting a new token for every API call. Implement automatic token refresh in your application to maintain uninterrupted service.
Can I revoke API credentials?
Yes. Organization administrators can disable API keys from the Fluxis dashboard. Disabled keys can no longer obtain access tokens. If you suspect a credential is compromised, disable it immediately and request a replacement from your Fluxis representative.
How do I verify webhook authenticity?
When you create an account webhook, Fluxis returns a secret once. Each delivery includes X-Request-Signature and X-Request-Timestamp headers. Verify the HMAC-SHA256 signature over the full JSON body before processing the payload.
See Webhook Signature Verification for the algorithm, worked example, and test endpoint. Registration and event types are covered in Webhooks.
Billing & Pricing
How much does Fluxis cost?
Pricing information and plans are available by contacting our sales team at [email protected]. We offer flexible pricing based on transaction volume, features, and support requirements.
Are there transaction fees?
Transaction fees vary by plan and volume. Contact [email protected] for detailed pricing information tailored to your business needs.
Do I pay blockchain network fees?
Customers pay the blockchain network fees (gas fees) when sending their payment. Fluxis handles consolidation and treasury management, which may have associated costs depending on your plan.
Technical Questions
What API rate limits exist?
Rate limits are designed to be generous for normal usage while preventing abuse. Specific limits depend on your plan. If you encounter rate limiting errors, implement exponential backoff and contact support to discuss increasing your limits.
Which programming languages are supported?
Fluxis is a REST API that works with any programming language capable of making HTTP requests.
Official SDKs for Node.js/TypeScript, Python, and Go are planned but not yet released. Integrate via HTTP using the API Integration Guide and API Reference.
Join the early access list via SDK Documentation if you want SDK notifications.
Can I use Fluxis in a mobile app?
Yes. However, never store API credentials in client-side code (mobile apps, web browsers). Instead:
- Your mobile app communicates with your backend server
- Your backend server securely authenticates with Fluxis
- Your backend creates payment requests and returns them to your app
- Your app displays the NASPIP token (as QR code) to the customer
This architecture keeps credentials secure while enabling mobile integration.
Does Fluxis support webhooks?
Yes. Webhooks are the recommended way to receive real-time payment status updates. Register webhook endpoints at the account level via POST /v1/account/{accountID}/webhook. Fluxis will POST payment status changes to your endpoint when matching events occur for that account.
See Webhooks and the API Integration Guide.
Learn more in our Webhooks Documentation.
What HTTP methods does the API use?
The Fluxis API follows RESTful conventions:
- GET - Retrieve resources (payment requests, Point of Sales, etc.)
- POST - Create new resources (payment requests, Point of Sales, etc.)
- PUT - Update existing resources (Point of Sale configuration, etc.)
- DELETE - Remove resources (Point of Sales, etc.)
See our API Reference for complete endpoint documentation.
Troubleshooting
I'm getting authentication errors. What should I check?
Common authentication issues:
- Invalid credentials - Verify your API key and secret; obtain a new token via
POST /v1/auth/token - Expired token - Access tokens expire after 1 hour; request a new one
- Missing headers - Protected routes require both
Authorization: Bearer <token>andx-fluxis-api-key: <api_key> - Wrong environment - Use staging (
api.stgfluxis.us+fxs.stg.*keys) vs production (api.fluxis.us) consistently
Test your authentication in our API Playground - Authentication.
Payment request creation fails. Why?
Common causes:
- Invalid Point of Sale ID - Verify the PoS exists and belongs to your organization
- Invalid UAI - Check that the Unique Asset ID is properly formatted
- Invalid amount - Amount must be a positive decimal string (e.g., "49.99")
- Expired token - Refresh your authentication token
Review the error message in the API response for specific details.
Customer paid but status isn't updating. What's wrong?
Check these scenarios:
- Wrong address - Customer may have sent payment to an incorrect address
- Wrong network - Payment sent on different network than specified
- Wrong asset - Payment sent with different token than requested
- Pending confirmation - Transaction is still awaiting blockchain confirmations
- Network congestion - Blockchain network may be experiencing delays
Ask the customer for their transaction hash and verify on a blockchain explorer.
Webhooks aren't being received. How do I debug?
Troubleshooting steps:
- Confirm account webhook registration - Use
POST /v1/account/{accountID}/webhook(not PoS settings) - Verify URL is public - Test accessing your webhook endpoint externally
- Check SSL certificate - Ensure valid HTTPS certificate
- Review server logs - Look for incoming requests from Fluxis
- Send a test delivery -
POST /v1/account/{accountID}/webhook/{webhookID}/test - Verify no firewall blocks - Ensure Fluxis IPs aren't blocked
- Check endpoint response - Webhook handler should return 2xx status code
If deliveries arrive but your handler rejects them, see Webhook Signature Verification for canonical JSON and HMAC troubleshooting.
Contact support if issues persist after these checks.
Support & Resources
How do I contact support?
- Email: [email protected]
- Response time: Within 24 hours on business days
- For urgent issues: Include "URGENT" in your email subject
Where can I find code examples?
- API Playground: Interactive examples for all endpoints at /api
- Tutorials: Step-by-step guides in our Developers section
- SDK Documentation: Language-specific examples in our SDK docs
Is there a developer community?
We're building our developer community resources. Stay tuned for:
- Developer Discord/Slack channel
- GitHub discussions
- Community forum
- Regular office hours
Subscribe to our newsletter or follow our blog for announcements.
Where can I report bugs or request features?
For bug reports or feature requests:
- Email: [email protected]
- Include: Detailed description, steps to reproduce, expected vs actual behavior
- Feature requests: Include use case and business justification
Check our Roadmap to see upcoming features.
Still Have Questions?
If your question isn't answered here, please contact us at [email protected]. We're here to help!