Services — the AI agent directory

Services in the directory
Service	Tags	Interfaces	Payments	Auth	Score
Agentic Commerce Protocol (ACP) Open spec from OpenAI and Stripe for agent-initiated checkout — product feeds, checkout endpoints, and scoped delegated payment tokens with the merchant staying merchant of record OpenAPIllms.txt	acp+5	OpenAPI+1	ACP	none, Payments	5/5
Official MCP Registry Open catalog of MCP servers with a public API agents and clients can query for installable tools OpenAPI	mcp+3	OpenAPI	—	none, Platforms	5/5
Universal Commerce Protocol (UCP) Open commerce standard from Google and Shopify for agentic shopping journeys across retailers, pairing with AP2 for the payment leg OpenAPIllms.txt	ucp+5	OpenAPI+1	UCP	none, Payments	5/5
Agent2Agent (A2A) Open protocol for agent-to-agent discovery, task delegation, and streaming updates across vendors OpenAPIllms.txt	a2a+4	OpenAPI+1	—	none, Platforms	4/5
Visa Trusted Agent Protocol Open framework using HTTP Message Signatures (RFC 9421) so merchants can recognize and trust a legitimate agent before it transacts OpenAPI	tap+4	OpenAPI	TAP	none, Payments	4/5
Coinlib Crypto analysis, guides and coin FAQs over a hosted MCP server and a free key-less JSON API MCPOpenAPIllms.txt	crypto+6	MCP+2	—	none, Search	3/5