AI Agent Authorization Comparisons
Choose an authorization design by comparing security boundaries, not slogans. These pages explain what API keys, OAuth, MCP, and Grantex each do—and where they work together.
Comparisons and security guide
Every page states scope, limitations, and implementation consequences. Grantex complements OAuth 2.0 and MCP; it is not an identity provider, model runtime, payment processor, or merchant connector.
API keys
Compare shared credentials with scoped, per-agent grants and explicit verification.
Read comparison →OAuth 2.0
See how Grantex complements OAuth rather than replacing application and user authorization.
Read comparison →MCP authorization
Compare MCP server auth options and review @grantex/mcp-auth 2.0.2 evaluation limits.
Read comparison →Securing AI agents
A practical control map for identity, least privilege, verification, revocation, and audit.
Read comparison →The short distinction
Authentication and connectivity
- API keys identify a credential, often with broad shared authority.
- OAuth 2.0 delegates application access for a user or client.
- MCP connects models and agent applications to tools.
Agent-specific authority
- Grantex identifies the acting agent and principal.
- Signed grants carry narrow scopes, expiry, and delegation context.
- Receiving services verify grants and enforce policy before acting.
A critical verification boundary
Local JWT verification checks signatures and claims after JWKS retrieval. It does not prove current revocation unless the verifier performs an online state check or synchronizes revocation data. This distinction is documented in the quickstart and release status.