OAuth 2.1
A modernized consolidation of the classic OAuth 2.0 authorization framework, being standardized by the IETF. It mandates the use of PKCE, disables implicit grant flows, and enforces strict redirect_uri validation, serving as a security foundation for AI agent device-control scenarios.
Core Facts
Timeline (last 90 days)
Anthropic is advancing native OAuth 2.1 support in the MCP protocol.
PKCE is a security extension in OAuth 2.1 designed for public clients, where the client submits a hash of the code verifier and must include the original verifier when exchanging for a token, making it impossible to redeem the token even if the authorization code is intercepted.
The authentication scheme recommended by the official MCP specification is OAuth 2.1 with PKCE.
OAuth 2.1 is a security-hardened version of OAuth 2.0 that mandates the use of PKCE and deprecates several insecure authorization flows.
OAuth 2.1 is a security-hardened version of the OAuth 2.0 authorization framework that mandates the use of PKCE to prevent authorization code interception attacks.
PKCE is an important security enhancement in OAuth 2.1 compared to 2.0, defending against authorization code interception attacks through a paired verification mechanism of code_verifier and code_challenge.
OAuth 2.0 is an authorization framework that implements identity authentication in conjunction with the OIDC extension.
OAuth 2.1 mandates the use of PKCE (Proof Key for Code Exchange) to prevent authorization code interception attacks.
The OAuth 2.1 draft upgrades PKCE from optional to mandatory and prohibits implicit grants and resource owner password credential grants.
Remote MCP Servers are required to implement the OAuth 2.1 authentication flow, which mandates the use of PKCE to prevent authorization code interception attacks and disables implicit grants.
3 more timeline events
All Facts (14)
MCP's permission model draws on the OAuth 2.0 authorization code flow, requiring explicit user authorization for tool invocation.
75%Partially VerifiedMCP对外公网服务支持基于OAuth 2.1授权框架和JWT的Token认证机制
65%UnverifiedThe authentication scheme recommended by the official MCP specification is OAuth 2.1 with PKCE.
60%UnverifiedOAuth 2.0 is an authorization framework that implements identity authentication in conjunction with the OIDC extension.
60%UnverifiedOAuth 2.1 mandates the use of PKCE (Proof Key for Code Exchange) to prevent authorization code interception attacks.
60%UnverifiedAnthropic is advancing native OAuth 2.1 support in the MCP protocol.
50%UnverifiedPKCE is a security extension in OAuth 2.1 designed for public clients, where the client submits a hash of the code verifier and must include the original verifier when exchanging for a token, making it impossible to redeem the token even if the authorization code is intercepted.
50%UnverifiedOAuth 2.1 is a security-hardened version of OAuth 2.0 that mandates the use of PKCE and deprecates several insecure authorization flows.
50%UnverifiedOAuth 2.1 is a security-hardened version of the OAuth 2.0 authorization framework that mandates the use of PKCE to prevent authorization code interception attacks.
50%UnverifiedPKCE is an important security enhancement in OAuth 2.1 compared to 2.0, defending against authorization code interception attacks through a paired verification mechanism of code_verifier and code_challenge.
50%UnverifiedThe OAuth 2.1 draft upgrades PKCE from optional to mandatory and prohibits implicit grants and resource owner password credential grants.
50%UnverifiedRemote MCP Servers are required to implement the OAuth 2.1 authentication flow, which mandates the use of PKCE to prevent authorization code interception attacks and disables implicit grants.
50%UnverifiedPKCE（Proof Key for Code Exchange）扩展通过生成随机 code_verifier 并验证其哈希值，可防止 Authorization Code 被劫持后滥用
50%UnverifiedIn MCP version 1.1 released by Anthropic in 2025, OAuth 2.1 authorization flows and tool permission scope declarations were introduced.
60%