Flex MCP - Flex Documentation
What is MCP?
The Model Context Protocol is an open standard for connecting AI assistants to external tools and data. Once you wire up the Flex MCP, your AI assistant gets a set of typed tools — create_product, list_payment_intents, refund_capture, and so on — that mirror the Flex API. The assistant chooses which to call based on your prompt; you stay in control through tool-use approval prompts in the client.
What you can do with the Flex MCP
- Customer support — Look up an order or payment intent by ID in plain English, with the full context the API returns.
- Reconciliation — Pull yesterday’s captured payments, group by product, and compare against your fulfillment system.
- Refunds & disputes — Draft a dispute response from order details, or issue a refund after a customer support conversation.
- Subscription ops — Query active subscriptions, find upcoming renewals, or update billing details on a customer.
- Reporting — Ask for weekly capture volume, top products by revenue, or a list of new customers in a date range.
See the Tools & sample prompts page for concrete examples you can copy into your assistant.
Authentication
The Flex MCP supports two ways to authenticate, and you should pick based on which client you’re using:
| Auth mode | Best for | How it works |
|---|---|---|
| OAuth | Claude.ai, Claude Desktop, any client with a browser | Click “Connect”, sign in with your Flex account, approve access. No API key to manage. |
| API key | Claude Code and other headless agents | Paste an fsk_… (live) or fsk_test_… (test) API key in the client’s MCP config. |
Both modes scope access to your partner — you only ever see your own data. See Authentication for details on how test mode works in each.
An MCP client connected to your Flex account has the same level of access as the credentials you provide. With OAuth, that’s the same access as the signed-in user; with an API key, it’s whatever scopes that key was issued. AI assistants can make mistakes — read the Security best practices before connecting a live (non-test) account.
Get started
Quick start
Connect Claude.ai, Claude Code, or another MCP client in under five minutes.
Tools & sample prompts
See the tools the Flex MCP exposes, with copy-paste prompts you can try.
Authentication
OAuth vs. API key, plus how test mode behaves in each.
Security best practices
Scope your keys, stay in test mode while experimenting, and rotate credentials.