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Claude for Windows ships Entra Continuous Access Evaluation switched on by default
RuntimeWire's comparison of two shipped Claude for Windows builds found CAE markers, a local authentication broker and sovereign-cloud handling, while Microsoft's published certification record for Claude still answers No on CAE.
The Engineer · Build desk
What happened
- The newer build carries explicit support for Entra Continuous Access Evaluation, a local Windows authentication broker and additional credential paths for managed corporate environments.
- In the code RuntimeWire reviewed, the CAE option is enabled by default.
- Microsoft's App Certification page says Claude supports Entra ID and Conditional Access, and answers No to the question of whether the certified application supports Continuous Access Evaluation.
Compiled by The EngineerSomething wrong?How this is made
Why it matters
- contradiction A security reviewer reading Microsoft's certification page and one reading the shipped binary come away with opposite answers on CAE support, and Anthropic has not said which product each record describes.
- capability An administrator who disables a compromised account can expect Claude's Graph access to stop within minutes rather than at the end of a token lifetime, so long as the client honours the challenge it has asked to receive.
- decision Leaving CAE and broker mode on becomes an endpoint configuration call for whoever manages the fleet, because the build ships environment variables whose only purpose is turning each of them off.
- constraint Any argument that Anthropic has out-integrated OpenAI on Windows identity rests on an absence of public evidence about a competitor's client, which limits how far the comparison can be pushed.
Continuous Access Evaluation moves revocation out of the token lifetime. Ordinary access tokens generally have to expire before some changes can be enforced [7]. Under CAE the resource service reacts while the token is still alive, and Microsoft says events such as account disablement, password changes, elevated user risk and explicit session revocation can be enforced close to real time on sessions whose access tokens run up to 28 hours [6]. None of that happens unless the client cooperates. The application declares Microsoft's cp1 capability, and Microsoft says Graph sends the claims challenges CAE requires only to clients that explicitly advertise it [8]. A client that stays quiet is never challenged [2].
That is the exchange the configuration description RuntimeWire read describes from the client side: CAE-capable Graph tokens that are long-lived, up to roughly 28 hours, while remaining revocable within minutes [5]. Long lifetimes mean fewer interactive sign-ins. Handling the challenge is what makes the long lifetime survivable for whoever owns the tenant.
The six new markers RuntimeWire lists divide into three M365 CAE configuration names and three local-auth names, and two of those three exist to switch something off [3][1]. In the code reviewed, the CAE option is enabled by default [9]. The same static analysis turned up sovereign-cloud handling and additional enterprise credential options [4]. Shipping the default on and providing MCP_LOCAL_AUTH_CAE_DISABLE and MCP_LOCAL_AUTH_BROKER_DISABLE suggests a team planning for enterprise deployment on managed Windows fleets.
Microsoft's App Certification page tells a buyer something else. It says Claude supports Entra ID and Conditional Access, and to the specific question of whether the certified application supports Continuous Access Evaluation, the answer is "No" [10]. That record was last updated by the developer on August 4 and published by Microsoft on August 7 [11]. RuntimeWire notes the certification appears to cover Claude's Microsoft 365 Office application and its nested authentication flow [12]. Under that reading, both records are accurate about different software. RuntimeWire asked Anthropic whether the broker and CAE implementation is intended for its existing Microsoft 365 connector, a Windows-specific implementation or another enterprise deployment architecture, and the company had not responded by publication time [13][14].
Static analysis of two distributed binaries, 1.49585.0 against 1.46388.4 from two days earlier, establishes that the markers are present and that the default is on [2][9]. It does not establish intent, a commercial arrangement with Microsoft, or that the path is live in any tenant today. RuntimeWire reports it found no public evidence that OpenAI's own Windows client ever received integration at this depth [15], and an absence in the public record is not an inspection of OpenAI's binary. For the identity-as-distribution reading to firm up, the certification record would need to change to match the shipped default, or Anthropic would need to state which product each record governs.
What to watch
- Whether Anthropic says which product the certification record covers, or the record's CAE answer changes from No to Yes.
- Whether MCP_LOCAL_AUTH_BROKER_MODE and the two disable variables appear in Anthropic's published enterprise deployment guidance.
- Whether a later Claude for Windows build keeps CAE enabled by default or retains the disable switches.