Agentpin · thirdkeyai bundle Domain-anchored cryptographic identity protocol for AI agents — ES256 JWT credentials, 12-step verification, TOFU key pinning, revocation, delegation chains, mutual authentication, and (v0.3.0, four-language parity) A2A AgentCard extension types + signed AgentCard builder + LocalAgentCardStore + A2aAgentCardResolver + AllowedDomains type for cross-protocol use with SchemaPin v1.4, plus DNS TXT cross-verification at _agentpin.{domain} for second-channel trust independent of HTTPS hosting
