Support
We're here to help you get the most out of Crumb. Whether you're a merchant setting up your Square connection or a developer integrating with our MCP endpoint, find the resources you need below.
Contact Us
Send us a message and we'll get back to you. We'll follow up by email if you leave the page.
Merchant Support
If you're a Square merchant using Crumb, we can help with:
- Square connection issues — trouble authorizing your Square account, OAuth errors, or reconnecting after credential changes.
- Catalog sync — products not appearing, inventory discrepancies, or location mapping questions.
- Payments and checkout — questions about how orders flow through Square-hosted checkout, transaction fees, or settlement.
- Account management — disconnecting your Square account, understanding your data, or closing your Crumb connection.
Developer Support
Building with the Crumb MCP endpoint? We can help with:
- MCP integration — connecting your AI agent to the Crumb endpoint, tool discovery, and authentication.
- API behavior — unexpected responses, error codes, rate limiting, or tool parameter questions.
- Cart and checkout flows — managing cart state, generating payment links, and handling order lifecycle.
https://crumb.llc/mcp/v3Frequently Asked Questions
How does Crumb billing work?
Crumb charges a small transaction fee on completed orders only. There are no monthly fees, setup charges, or minimum commitments. You pay nothing until a customer completes a purchase through an AI agent using your Crumb-connected catalog.
How do I disconnect my Square account?
Visit the merchant portal and click "Leave Marketplace." This revokes Crumb's access to your Square account and removes your catalog from the platform. You can also revoke access directly from your Square Dashboard under App Permissions.
What data does Crumb access from my Square account?
Crumb accesses your catalog (products, categories, variations), location information, and inventory data to make your products discoverable by AI agents. We also facilitate order creation through Square's checkout API. We never access your financial reports, employee data, or customer personal information beyond what's needed to process orders. See our Privacy Policy for full details.
Which AI agents work with Crumb?
Crumb works with any AI agent that supports the Model Context Protocol (MCP), including ChatGPT, Claude, Gemini, and custom MCP clients. Our Streamable HTTP endpoint is compatible with the open MCP specification.
Is my customer's payment information safe?
Yes. Crumb never handles, stores, or transmits payment card data. All payments are processed through Square's PCI-compliant hosted checkout. Customers pay directly on a Square-hosted payment page, and funds settle to your Square account.
How quickly does my catalog sync?
Your catalog syncs when you first connect your Square account and refreshes periodically. Product changes made in Square (new items, price updates, inventory changes) are reflected in Crumb automatically. If you need an immediate refresh, contact support.