Europe 2026
One Login to Rule Them All: Cross-App Access for MCP — Garrett Galow, WorkOS
Overview
This talk addresses the friction of repeated authentication for Multi-Cloud Platform (MCP) tools, where users must consent to access for each tool individually. It introduces Cross-App Access (XAA), a solution that leverages an Identity Provider (IDP) to act as a trust intermediary. XAA enables MCP clients to obtain credentials for MCP servers without manual user intervention after an initial single sign-on, streamlining the user experience and improving security management for IT.
Who should watch
- AI engineers and builders using MCP tools like Cursor or Claude.
- Product Managers and engineers looking to simplify authentication flows for enterprise users.
- IT administrators concerned with managing AI agent access and security.
- Developers building or integrating with MCP clients or servers.
Key takeaways
- MCP tools often require users to repeatedly authenticate and grant consent for each tool, creating a cumbersome user experience and security blind spots.
- Cross-App Access (XAA) uses an Identity Provider (IDP) to bridge trust between MCP clients and servers, allowing clients to request credentials for servers they haven't directly connected to before.
- The XAA flow involves an initial SSO to the IDP, followed by the client requesting an ID Jag token from the IDP for a specific server, which the server then validates to issue an access token.
- This process makes authentication largely invisible to the user after the initial SSO, eliminating consent screens for individual tool connections.
- XAA enhances security by allowing IT to manage access centrally through the IDP and by enabling shorter-lived access tokens that expire if user access is revoked.
- Implementing XAA requires configuration on the IT side (trust relationship between apps in the IDP), on the MCP client side (requesting ID Jag tokens), and on the MCP server side (validating ID Jag tokens and issuing access tokens).
- While XAA primarily addresses authentication, authorization (e.g., specific scopes) is still managed by the resource server, though future extensions may integrate scoped access.
- The ecosystem is still evolving, with ongoing work to ensure broad support for XAA across different IDPs like Microsoft Entra and various authentication protocols.
Notable quotes
*MCP's model assumes none of these apps know anything about each other, forcing repeated authentication flows.*
*The real problem comes in for the IT team; MCP's model doesn't work the way they want it to work.*
*Cross-app access is basically a way in which the identity provider can act as a stand-in, a trust provider between applications.*
Unofficial community note. Prefer the recording for nuance.