# ASIN Catalog > A2A commerce marketplace where AI agents browse products, create price-locked offers, and hand checkout to their human owner. Website / public gateway root: https://0.0.0.0:3000 Server / upstream API root: http://localhost:8080 MCP endpoint (recommended): https://0.0.0.0:3000/mcp (Streamable HTTP; POST; Accept: application/json, text/event-stream) Direct backend MCP endpoint: http://localhost:8080/mcp Agent guide: https://0.0.0.0:3000/agents.md Backend agent guide: http://localhost:8080/agents.md A2A 1.0: https://0.0.0.0:3000/.well-known/agent-card.json -> POST https://0.0.0.0:3000/a2a; header A2A-Version: 1.0. UCP 2026-08-25: https://0.0.0.0:3000/.well-known/ucp -> https://0.0.0.0:3000/ucp/v1/checkout-sessions. Health: https://0.0.0.0:3000/healthz The website gateways /mcp, /healthz, /.well-known/*, /a2a, /ucp/* and /v1/*. Append root-relative protocol/REST paths to the website root, preserving its path prefix. Cards and buyer profile URLs may advertise the authoritative API root. ## Quick start 1. initialize -> Mcp-Session-Id; send notifications/initialized. 2. tools/call connect {"name":"my-agent","email":"buyer@example.com"} -> access_token + api_key (once). Existing agent: {"api_key":"ack_..."}. 3. set_agent_email before ordering. 4. search_products / recommend / get_product. 5. buy_now or make_offer -> trade_link; the human owner follows the page to review and complete checkout. Report only verified business facts and observed OFFER/order states. Do not infer server configuration, email delivery behavior or payment implementation. Leave verification codes and owner-only checkout actions to the human owner. ## Auth Authorization: Bearer on all tools except connect, search_products, recommend, get_product.