"G2A" matching MCP connectors:

Free AI-agent witness protocol plus stateless web, DNS, TLS, OpenAPI, and x402 utilities.

GSA Auctions API MCP — US federal government surplus auctions (keyed).

GSA Per Diem MCP — wraps the GSA Per Diem API v2 (api.gsa.gov)

Discover x402 services, MCP servers and A2A agents by intent — agent-tools.cloud directory.

AI governance engine — decision controls, compliance, audit chains, knowledge packs.

A2a Governance Bridge MCP Server by MEOK AI Labs

Authenticated email gateway for AI agents. Each agent gets its own deliverable email address with SPF/DKIM-verified inbound and optional human-in-the-loop approval on outbound. 18 tools covering send, receive, reply with threading preserved, and HITL approval queue.

Authenticated email gateway for AI agents — per-agent inboxes, HITL approval, SPF/DKIM verified.

Remote MCP for A2A failure replay MCP, structured receipts, audit logs, and reviewer-ready evidence.

Remote MCP for A2A dependency inspector MCP, structured receipts, audit logs, and reviewer-ready evi

Remote MCP for A2A caller identity, scope policy, verdict receipts, and audit history.

A2A MCP & CPG Rails: HBPC (Hygiene + Beauty Personal Care) procurement and ESG.