OAuth

Definition

OAuth (Open Authorization) is an open standard for access delegation. OAuth 2.0 lets clients obtain limited access to protected resources without sharing passwords — the dominant auth pattern for APIs, SaaS connectors, and AI agent tool protocols.

Key Points

• OAuth 2.0 is the current mainstream version for web, mobile, and machine clients
• Often paired with openid-connect (OIDC) for identity / issuer discovery
• MCP 2026-07-28 hardens OAuth/OIDC deployments (e.g. iss validation, application_type) for multi-server agent setups (2026-07-28-mcp-official-blog-rc)
• Used extensively in AI agent workflows for least-privilege tool and data access

Related

• openid-connect
• model-context-protocol
• enterprise-mcp-adoption
• aaif
• least-privilege
• cybersecurity
• supply-chain-attacks

Sources

• 2026-07-28-mcp-official-blog-rc
• 2026-07-28-mcp-2026-07-28-stateless-spec