Engineering articles from Flex

June 23, 2026

MCP Use Cases: How We Built a Custom MCP Server for a Non-Technical Merchant

A real MCP use case: how Flex built a custom MCP server so a non-technical merchant could manage subscriptions and payments by chatting with an AI, with no API, no dashboard, and no support tickets.

Roni Khudanyan
Read

May 21, 2026

Introducing Flex MCP: Connect Your AI Assistant Directly to Flex

Flex MCP is a new MCP server that connects AI assistants like Claude, Cursor, Codex, and Windsurf directly to your Flex account, so you can look up orders, reconcile payments, manage billing, and run reports without leaving your coding or productivity tools.

Kevin Wentland
Read

March 26, 2026

The Flex AI Investigation Agent for HSA/FSA Payments

We built a Slack agent that can trace a transaction end to end—and, when it finds a bug, open a pull request with a proposed fix.

Varsha Parthasarathy
Read

February 11, 2026

Securing Flex Checkout Order Confirmations with Webhooks

Our engineering team explains how to listen to and verify webhooks in your Flex-powered checkout to secure order confirmations and reduce fraudulent orders.

David Barratt
Read