> ## Documentation Index
> Fetch the complete documentation index at: https://docs.withflex.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Product Updates
> Keep track of all the latest updates and improvements to Flex.
## Shopify Marketing App, Rebuilt
We rebuilt the Flex Shopify Marketing App to make it even easier to add HSA/FSA education to your storefront. New theme sections and blocks include product eligibility badges, announcement banners, FAQs, subscription messaging, and a "How to Checkout with Flex" walkthrough. These components help educate shoppers and improve conversion, all without custom development. Blocks are available directly in your Shopify Theme editor.
[Shopify Marketing App →](https://apps.shopify.com/flex-marketing)
## Dashboard AI Assistant
You can now ask questions and get help directly in the Flex Dashboard with our new AI assistant. Look up orders and customers, ask questions about your account, and get answers to common HSA/FSA and integration topics without searching through documentation. Responses are grounded in your Flex account, providing answers specific to your business.
## Streamlined Onboarding
The redesigned onboarding flow makes it easier to connect your store, configure payouts, and complete setup in one place. With a more streamlined experience, new merchants can get up and running faster, so they're ready to grow with HSA/FSA payments.
## Coupons on Subscriptions
Coupons can now be applied to subscriptions through the Flex API.
## Subscription Trial End at Checkout
Checkout sessions now support setting a `trial_end` when creating subscriptions, giving you more control over trial periods.
## Faster Invoice & Subscription Responses
Optimized API responses when expanding invoice and subscription objects for faster response times.
## Invoice paid\_at Timestamp
Invoices now expose a `paid_at` timestamp via the API for easier reconciliation.
## Shopify Order Reconciliation
Transactions and payout reports now include the Shopify order number for faster reconciliation.
## Timezone-Sensitive Receipts
Receipts now display the Date of Service and use the viewer's local timezone, keeping documentation accurate.
## Flex MCP Server
Introducing the Flex MCP Server. You can now connect AI tools like Claude, Cursor, Windsurf, and VS Code to your Flex account and manage products, checkout sessions, disputes, subscriptions, and more using natural language. The server exposes the Flex API as a set of tools and supports both OAuth and API key authentication, allowing your team to complete common tasks without leaving the tools they already use.
[MCP Docs →](/developer-guides/integration/mcp/overview)
## Redesigned Dashboard Home
The Flex Dashboard now opens to a redesigned homepage. You'll see recent activity, notifications, and product updates in a single view, while detailed reporting moves to a dedicated Analytics page. This provides a faster overview of your account while keeping reporting and analysis in a dedicated workspace.
[Dashboard Home →](https://dashboard.withflex.com)
## Consumer Portal: Claim Submission & TPA-Specific Letters
Customers can now submit HSA/FSA reimbursement claims directly from the Flex Consumer Portal. For orders that require a Letter of Medical Necessity, customers can select their administrator, complete the required documentation, and submit their claim in one place. This creates a self-service reimbursement experience and reduces documentation requests to your support team. This feature is rolling out to consumers throughout the week.
[Learn More →](https://www.withflex.com/blog/letter-of-medical-necessity-problem-reimbursement)
## Marketplace Redesign
Building on last month's Marketplace updates, we've introduced new designs, updated navigation, and faster browsing. Search now uses semantic matching, helping shoppers discover relevant HSA/FSA-eligible products even when they don't use exact keywords. We've also added new promotional placements that give brands more opportunities to reach high-intent shoppers. We're continuing to invest in the Marketplace experience, with more updates coming soon.
[Marketplace →](https://www.withflex.com)
## Custom Terms of Service at Checkout
You can now add your own terms of service to the Flex checkout. Custom terms appear below the standard Flex Terms and Privacy notice, and can optionally require customer acceptance before payment. This is useful for merchants with their own purchase agreements, membership terms, or program requirements.
```json theme={null}
{
"checkout_session": {
"custom_text": {
"terms_of_service_acceptance": {
"message": "I agree to Acme's program terms."
},
"terms_of_service_checkbox_required": true
}
}
}
```
## Chat Support in the Flex Consumer Portal
Customers can now get instant answers to common HSA/FSA, payment, receipt, and documentation questions directly in the consumer portal.
## Future Use Payment Links
Payment Links now support `setup_future_use`, allowing cards to be saved for future off-session charges.
## Expandable Balance Transactions
The `balance_transaction` is now expandable on Charge, Refund, Payout, and Dispute objects, with additional filtering support.
## Line Items Export
Added a new Line Items export with line-item-level detail for a selected date range.
## More Precise API Errors
Refund, product creation, and subscription endpoints now return clearer validation errors for invalid requests.
***
Deprecation Notices
## Manual Payment-Intent Capture
We're retiring the `POST /v1/payment_intents/:id/capture` endpoint in favor of `POST /v1/checkout/sessions/:id/capture`, which is now the standard capture path for Flex. The checkout session endpoint correctly handles split-cart allocations and partial captures.
**Who this affects:** Merchants using the `/payment_intents/:id/capture` endpoint. All affected merchants have already been contacted directly. If you currently use this endpoint, switch to `POST /v1/checkout/sessions/:id/capture`. See the [Capture Checkout Session docs](https://docs.withflex.com/api-reference/checkout-sessions/capture-checkout-session) for more information. If you have questions, reach out to your Flex contact or email [support@withflex.com](mailto:support@withflex.com).
**Timeline:** The endpoint will be removed at the end of June 2026.
## Top-Level Refunds
We're retiring the `POST /v1/refunds` endpoint in favor of `POST /v1/checkout/sessions/:id/refund`, which is now the standard refund path for Flex. The checkout session endpoint correctly handles split-cart allocations and partial refunds.
**Who this affects:** This endpoint is not currently used by merchant integrations. We're sharing this update as part of our API deprecation process. `POST /v1/refunds` will be migrated to `POST /v1/checkout/sessions/:id/refund`. See the [Refund Checkout Session docs](https://docs.withflex.com/api-reference/checkout-sessions/refund-checkout-session). If you have questions, reach out to your Flex contact or email [support@withflex.com](mailto:support@withflex.com).
**Timeline:** The endpoint will be removed at the end of June 2026.
## Dispute Management
Dispute management is now available in the Flex Dashboard. Merchants can view, manage, and respond to disputes with full visibility into status and the ability to submit responses directly within Flex. This gives your team a single place to handle the full dispute lifecycle without relying on external systems.
## Redesigned Marketplace & Homepage
The Flex Marketplace is now the primary experience on [withflex.com](https://www.withflex.com). Visitors land directly in the Marketplace with improved search and product discovery, making it easier for HSA/FSA shoppers to find eligible brands and products. This helps drive more high-intent traffic to merchants using Flex.
## Checkout Performance
Improved checkout performance across browsers, with the largest gains on Safari.
## Report Date Picker Navigation
The report date picker now supports year navigation, making it easier to move across longer time ranges.
## Product Name Updates via API
Product names can now be updated via the PATCH /v1/products endpoint.
## Organization Name Sync
Updating your organization name in the dashboard now automatically updates the checkout page.
## Flex Consumer Portal
Introducing the [Flex Consumer Portal](https://www.withflex.com/portal). Customers can now view their order history and access key documentation in one place. After signing in, they can explore past orders, review payment details, and download receipts and Letters of Medical Necessity directly. This gives customers a self-serve way to manage their purchases and reduces support requests.
## Expanded Reporting and Exports
The Reports page has been redesigned to give you direct access to key data across your business. We've added new reports, including checkout sessions, subscriptions, products, line items, and customers. An improved export modal provides more context before export to reduce guesswork. Select your date range and export your data directly from the Flex dashboard.
## Receipt Redesign
Receipts have been upgraded with clearer formatting and more detailed information, including improved customer, line item, eligibility, payment, and refund details. Flex will also generate updated receipts when new charges or refunds occur, ensuring documentation stays accurate over time. This reduces support requests and makes it easier for customers to submit accurate receipts to their HSA/FSA administrators.
## Upgraded Recognized User Flow
The checkout experience for returning customers with a valid Letter of Medical Necessity has been improved. Customers can now complete verification more quickly and continue to payment. These updates create a clearer, more streamlined experience for high-intent users and help improve conversion.
## Resend Checkout Documentation
Merchants can now resend checkout documentation, including receipts and Letters of Medical Necessity, directly from the dashboard. Customers can also access these documents through the consumer portal, but if needed, merchants can quickly reissue them.
## Subscription Coupons
Coupons can now be applied to subscriptions across different intervals or limited to the first billing cycle.
## Custom Shipping Rate Name
Checkout now displays your custom shipping rate names instead of a generic "Shipping" label.
## Off-Session Payment Failure Notifications
Customers returning from a failed off-session payment now see a clear "card declined" message instead of a silent redirect.
## Date Filtering for Checkout Sessions API
The checkout sessions API now supports date-based filtering, making it easier to query sessions within a specific range.
## Persistent Email Filters in Dashboard
Email filters on the checkout sessions page now persist when navigating between list and detail views.
## 3DS Results on Charges
3DS authentication results are now recorded on charge objects, with improved handling for more reliable authentication.
## Refund Status Webhook Events
Refund webhook events are now fully supported, enabling real-time tracking of refund status across its lifecycle.
## New Developer Documentation
Added documentation for off-session checkouts, API product creation, refund workflows, and HSA/FSA test cards.
## Multi-Category LMN Support
Flex can now support multi-category Letters of Medical Necessity during checkout. If your brand sells different types of products, such as skincare and supplements, customers can select multiple health conditions within a single session. When approved, multiple LMNs are provided to the customer within the same checkout flow, reducing friction and improving completion rates for mixed carts.
## Improved LMN Chat Performance
We've optimized the performance of the Letter of Medical Necessity (LMN) chat interface to reduce latency and improve responsiveness. Customers now move through the consultation more smoothly, creating a better experience that helps improve completion rates and overall conversion. LMNs provided through Flex continue to be clinically reviewed. This update will be rolled out to merchants over the next few weeks.
## Setup Mode
Create checkout sessions in setup mode, allowing customers to save their HSA or FSA card without being charged immediately. This supports workflows like off-session billing, where the card can be charged later for one time payments or recurring purchases. The checkout experience will adapt to show a simplified card-saving flow.
## Enhanced Dispute Management
We've built full dispute handling into the Flex API. This includes visibility into dispute status, management capabilities, and the ability to submit responses directly through Flex. Merchants are able to manage disputes end-to-end without relying on external systems.
## Checkout Session Actions
Manage checkout sessions directly from the Dashboard with a new actions dropdown. For sessions using manual capture, you can capture authorized payments, cancel uncaptured holds, or reauthorize expired payment intents, all without needing to contact support or use the API.
## Quick Create Price
Added the 'Create Price' action to the quick create menu making it faster and easier to create a price from any page.
## Improved Payment Decline Messages
Checkout now surfaces the more specific error message from the card issuer when an HSA/FSA payment is declined.
## Refund Page Improvements
Added a max refund button and small UX improvements to the refund flow.
## HSA/FSA Card Detection
We've enhanced how Flex identifies HSA/FSA cards using BIN lookup data. This update improves underlying payment classification and supports future functionality.
## Card Funding
The funding field is now exposed on the Card API response.
## Checkout Session Expired Webhook Event
You can now subscribe to the checkout.session.expired webhook event to get notified when a checkout session ends without a completed purchase. This lets you know when a customer drops off, enabling follow-up workflows like abandoned cart recovery or broader checkout performance analysis.
## Custom Fees for Shopify & WooCommerce
Merchants using Shopify or WooCommerce can now include custom fees in Flex checkout sessions. These may include recycling fees, service charges, or other surcharges. Fees appear clearly in the checkout summary using the custom name provided.
To use this feature, add an array of fees to the checkout\_session object when creating a session.
```json theme={null}
{
"checkout_session": {
"fees": [
{
"name": "Mattress Recycling Fee",
"fee_type": "custom",
"amount": 10000
}
]
}
}
```
## Custom Checkout Text Now Supports Linking
Custom checkout text now supports hyperlinks. Links open in a new tab to prevent customers from leaving the checkout flow. This is useful for linking to terms of service, return policies, HSA/FSA eligibility guides, or support pages, helping reduce customer confusion by providing easy access to important information during checkout.
```json theme={null}
{
"checkout_session": {
"custom_text": {
"submit": {
"message": "Your custom message here (1-1200 characters) with a custom link."
}
}
}
}
```
## Improved Create Price Modal
The create price modal on the Payment Links page has been redesigned for better speed and usability. It now includes cleaner styling, a dedicated currency input, and more reliable form handling, making it easier to add prices when setting up new payment links.
## Consultation Fee Handling
Improved how Flex handles consultation fees for customers who do not qualify for a Letter of Medical Necessity.
## Receipts for Subscription Trials
Improved receipts to more accurately display one-time charges alongside free-trial subscription items when purchased together.
## Shipping Display Name
Shipping options now support a custom display\_name field in webhooks and API responses for clearer identification.
## Split Payment Helper Text
Updated checkout messaging to better explain split payment options and reimbursement steps when HSA/FSA funds are insufficient.
## Off-Session LMN Redirect Support
Off-session charges that require a Letter of Medical Necessity now return a next\_action redirect instead of an error.
## Dashboard Pagination Improvements
Improved pagination behavior across dashboard pages.
## Redesigned Flex Marketplace
We’ve launched a fully redesigned Marketplace to improve how consumers discover HSA/FSA-eligible brands. With better navigation, enhanced search, and dedicated category pages, it’s now easier for shoppers to find what they need. The new structure also lays the foundation for product-level discovery, coming soon. These updates are designed to improve visibility, drive higher intent traffic, and help merchants grow their revenue. [Shop Now](https://www.withflex.com/shop).
## Custom Fees at Checkout
Merchants can now apply custom fees directly to a checkout session, including recycling fees, service fees, or other surcharges. These fees are automatically distributed proportionally across eligible and ineligible items, ensuring accurate HSA/FSA handling in mixed carts.
To use this feature, add an array of fees to the checkout\_session object when creating a session.
```json theme={null}
{
"checkout_session": {
"fees": [
{
"name": "Service Fee",
"fee_type": "custom",
"amount": 1000
}
]
}
}
```
## Custom Checkout Text
Merchants can now add custom text to select areas of the Flex checkout experience, giving you more control to inform your customers during checkout. This can be done via the API by including the custom\_text property when creating a checkout session.
```json theme={null}
{
"checkout_session": {
"custom_text": {
"submit": {
"message": "Your custom message here (1-1200 characters)"
}
}
}
}
```
## Subscription Payment Method Updates
Merchants can now generate a shareable URL that allows customers to update their payment method on an active subscription. This improves flexibility, reduces churn from expired or invalid cards, and enables more robust subscription management through both the Flex Dashboard and API.
Example API request:
```bash theme={null}
curl --request POST \
--url https://api.withflex.com/v1/subscriptions/{id}/update_payment_method_url \
--header "Authorization: Bearer " \
--header "Content-Type: application/json"
```
## Redesigned Notification Emails
Flex notification emails have been migrated to Postmark’s template system to improve formatting, ensure consistent branding, and increase reliability across customer communications. This update applies to key touchpoints, including Letters of Medical Necessity, purchase receipts, and reimbursement notifications.
## Redesigned Dashboard Overview
We rolled out a redesigned Dashboard Overview that makes your HSA/FSA channel easier to measure and optimize. The new experience brings together expanded metrics (like AOV, customer conversion, and returning customer rate), clearer performance insights, and a modern interface that highlights what’s driving growth. [Read more](https://www.withflex.com/blog/new-and-improved-dashboard-overview).
## New RevenueCat Integration
Our new partnership with RevenueCat now enables compliant HSA/FSA payments directly inside your iOS, Android, and web apps. With just two setup steps, developers can unlock a new pre-tax revenue stream for eligible digital health subscriptions. [Read more](https://www.withflex.com/blog/flex-revenuecat-enabling-hsa-fsa-payments-for-in-app-subscriptions).
## Shopline Integration
Flex is now integrated with SHOPLINE, making it easy for merchants to accept HSA/FSA payments directly at checkout. Setup takes only a few clicks, helping SHOPLINE’s 600,000+ merchants tap into consumers using their pre-tax health dollars. [Read more](https://www.withflex.com/blog/flex-shopline-powering-hsa-fsa-payments-for-shopline).
## Analytics
The new Analytics tab in the dashboard gives you clear visibility into your HSA/FSA channel—so you can quickly see what’s working, spot drop-offs, and identify which customers and products drive the most value. Track key metrics like AOV, sales, conversion rate, and more. This is our first iteration of Analytics, and we’ll be expanding it with deeper insights in future releases.
## Payouts API
Access the same reconciliation details you see in payments exports — now directly via API for automated workflows.
## Order Summary
We’ve updated how order summaries appear at checkout, giving customers a clearer view of their purchase and boosting confidence before payment.
## Dashboard ARN and Client Reference ID Visibility
You can now view both Acquirer Reference Numbers (ARNs) and Client Reference IDs directly in the dashboard. This makes it easier to track transactions end-to-end, resolve disputes quickly, and align with your internal systems.
## Checkout Session Filters & Reimbursements
New statuses and filters make it easier to review past checkout sessions, including those that are reimbursements.
## Flex Secures \$15M in Series A
We’re excited to announce Flex’s \$15M Series A funding round led by First Round and Core VC, and Cameron Ventures with continued support from Rethink Impact, YC, and Liquid2.
Since launching, we’ve been on a mission to modernize HSA/FSA payments. In that time, we’ve helped retailers like you unlock new revenue streams by making it simple for customers to spend their pre-tax health dollars directly at checkout.
This funding allows us to expand our reach across the enterprise space, helping even more health and wellness brands grow—and making healthcare spending easier and more accessible for millions of Americans.
Thank you for being part of our journey. We couldn’t do this without your partnership and trust.
## Expanded API Capabilities
We added two new fields payment\_intents and amount\_received fields to checkout sessions. This enables you to see each checkout session’s associated payments, whether they were made via partial purchase or split cart, all in one API call.
## Line-Item Tax Support
We now support tax at the line item level, enabling tax handling across different product categories.
## Improved WooCommerce Plugin Stability
We resolved conflicts with other WordPress plugins, ensuring seamless compatibility with Flex.
## Shopify Subscription Support
We now support Shopify subscriptions with HSA/FSA reimbursement. After a customer checks out, they’ll be prompted to complete a Letter of Medical Necessity post-purchase. If approved, they’ll receive the documents needed to submit a reimbursement to their provider. Dashboard tracking is coming soon to help you measure reimbursement success.
## Checkout Customizations
You can now customize the Flex checkout to better match your brand. Add your logo, adjust the colors, and create a more consistent customer experience from start to finish.
## Improvements to Partial Purchase
Your customers can now choose how much of their order to place on their HSA/FSA card. This improved flow helps maximize pre-tax benefit usage and reduces failed payments, leading to better conversion and a smoother checkout experience.
## Reports Page & Exports
You can now export key reports directly from the Flex dashboard — no custom requests or workarounds needed. Customize your date range before exporting to save time and avoid post-processing. This is just the beginning — more reports and analytics are on the way.
## RevenueCat integration
Introducing the new Flex RevenueCat Integration. Connecting your subscription-based app to HSA/FSA payments used to require custom development and manual workarounds. Now, setup just takes a few clicks with no heavy lifting required. With the Flex and Revenue Cat integration it’s easy to offer compliant, tax-free payment options for eligible subscriptions, without disrupting your current flow. Reach out to your account manager to test the integration.
## Dashboard Onboarding
Getting started with Flex is now faster and easier. New merchants can access onboarding directly in the dashboard — from connecting payouts to inviting team members, everything you need to launch is now in one place. Don’t worry — if you still need help, Benny will be there to assist you.
## Updated Documentation
The Flex docs just got a major upgrade. We’ve added an AI assistant to help answer questions in real time, improved search to help you find the right article faster, introduced an interactive API reference so you can test endpoints directly from the page, and added a changelog so you can track what’s new as we continue to ship.
## WooCommerce
Introducing the new Flex WooCommerce Integration. Access to the \$150B in tax-free HSA/FSA funds on WooCommerce used to mean complex development, unclear documentation, and no support. Flex simplifies everything with a clean, minimal-dev integration that handles payments, compliance, and support so you don't have to. Reach out to Flex to get started with WooCommerce.
## Off-Session API
Flex now supports off-session payments — the ability to charge a customer when they're not actively present in the checkout flow. This will enable Flex to create more automated, seamless payment experiences for merchants, while maintaining full compliance and reliability behind the scenes. With off-session payments, you can let shoppers skip re-entering payment info for a faster checkout experience.
## Dashboard Navigation
Flex dashboard updates are here — and it's just the beginning. We've refreshed the look, revamped navigation, and added a collapsible sidebar so you have more room to work and quicker access to the pages you use most. Stay tuned for more updates focused on making your workflows faster, smoother, and smarter.
## Shopify Marketing App
We're launching a new Flex Shopify Marketing app to help you drive awareness, educate customers, and increase conversion — all with just a few clicks. The app makes it easy to add assets like product badges and modals directly to your Shopify store. It's currently in review, and your account manager will follow up as soon as it's approved.
## Partial Purchase
We've launched Partial Purchase, a powerful new feature designed to improve conversion for merchants with higher-priced products or higher average order values.
If an HSA/FSA card is declined due to insufficient funds, Flex will now charge the available balance on the HSA/FSA card and prompt the user to enter a credit or debit card to complete the purchase.
## Order + Subscription Page
The dashboard Order and Subscription pages have a new look. We've combined key data — including line items, customer info, payment details, and developer data — to give you a more holistic view of each checkout session.
## Filter By Email
You can now filter by customer email on both the Order and Subscription Summary pages, making it easier to quickly locate the relevant record. A full suite of filters is in the works and coming soon.
## Refunds
Custom refunds can now be issued directly from an Order page. A line item summary is shown so you can refund the correct amount from any individual item. For a quick option, select Max Refund to automatically apply the full amount.