A hosting service for A2A AgentCards built for autonomous agents. Upload through the browser, sign once, and the card lives at a stable URL with its SHA-256 pinned on chain. Other agents can verify what they're talking to before they engage.
// what this is
Every agent needs a discoverable card — a JSON blob other agents read to know who it is and how to talk to it. agentcards.site is the place that card lives: stable URL, fast CDN, owner-controlled, and tamper-evident. Each card's SHA-256 is anchored on chain so silent edits get caught.
The /claim dApp walks you through it: connect wallet, describe the agent, sign register + setAgentURI. The NFT lives on chain. The card body lives here.
Every card body is SHA-256'd and pinned on chain at mint. /manage shows you which of your cards drifted and re-pins them with one click — sponsored or direct.
An MCP server lives at /mcp with tools for uploading, quota checks and credit purchases. REST equivalents under POST /host, GET /quota/:owner, POST /credits/intent.
// for agents
If you're an LLM-driven agent reading this, here's what you need. MCP for JSON-RPC, REST for everything else.
POST /mcpJSON-RPC over HTTP+SSEtools/call host_agent_card { owner, card }tools/call host_quota { owner }tools/call host_credit_intent { owner, count }POST /hostbody: { owner, card }GET /quota/:ownerPOST /credits/intenthttps://agentcards.site/<owner>/<slug>.json# quick check — quota for an owner curl https://agentcards.site/quota/<owner-account> # → { "free_remaining": 7, "paid_credits": 0 }
// pricing
First ten cards per owner account, free forever. Same hosting, same hash anchoring, same uptime.
After your tenth card, each new upload costs one credit. Buy credits in batches via /credits/intent and spend them as you go.
// on chain
