AgentCard

This is a reference for the verification API’s payload adapter. For apps you can use inside a Desk, see Desk apps.

venue: agentcards. Over HTTP, agentcard, agentcardai and alchemyagentcard also resolve to it. AgentCard by Alchemy provides single-use cards and an experimental connected-card purchase flow. It is distinct from agentcard.sh. Its official MCP runs locally as npx -y agentcard-mcp; it also has a REST API. Submit official MCP calls as {name, arguments}. create_card and create_connected_purchase are payments, request_limit_increase changes permissions, and card-credential or checkout-code retrieval also releases payment authority. cancel_card closes an unused issued card; it does not refund a completed purchase. Historical CLI-shaped inputs below remain supported.

What to send

Bare, or wrapped in {spend} or {purchase}. kind may be given as action instead.

`actionType`	Payload	`actionFamily`
`purchase`	`{merchant, amount, currency?, item?, url?, category?, cardId?}`. `kind` may be `purchase`, `spend`, `buy`, `checkout` or `authorization`.	`payment`
`card_request`	`{kind: "card_request", amount}`. `request_card`, `issue_card` and `new_card` also work.	`payment`
`limit_change`	`{kind: "limit_change", amount}`. `limit_increase` and `set_limit` also work.	`permission`

Only a payload with both merchant and amount is detected without venue. Card requests and limit changes need venue: "agentcards".

No live lookup

AgentCard has no public endpoint to look up a merchant. Every purchase carries a note that the merchant, item and category are reported by the agent and unverified.

Notes the classifier adds

A card’s cap is the amount rounded up to whole dollars. A cap above the $150 per-card beta limit is flagged, because one card cannot pay it.
A currency other than USD is flagged. Card caps are in whole US dollars.
A limit change is the agent asking for more spending authority. The note tells the judge to require explicit authority in your rules. The default account limit is $100, and raising it needs the account owner to approve an emailed link within 24 hours.

Example

const action = {
  merchant: "Best Buy",
  amount: 400,
  currency: "USD",
  item: "Sony WH-1000XM5 wireless headphones",
  category: "electronics",
};

const res = await fetch("https://harness.chance.cc/api/v1/intent", {
  method: "POST",
  headers: { "x-api-key": process.env.CHANCE_API_KEY!, "Content-Type": "application/json" },
  body: JSON.stringify({
    intent: "Software subscriptions for the team only, max $100 a month per vendor. No physical goods.",
    venue: "agentcards",
    action,
  }),
});
const result = await res.json();
if (result.verdict !== "ALLOW") throw new Error(result.reasoning ?? result.error);
// Only now request the card (agentcard request new) and pay the merchant.

The classifier notes that the

400 cap is above the

150 per-card limit, and that the merchant is unverified.

From an MCP client

Instruct the agent to call verify_intent before any AgentCard purchase, card request or limit change, with your rules as intent, the spend as action and venue: "agentcards", and to act only on ALLOW.

Integrate

Chance verification

Payload adapters

HTTP endpoints

What to send

No live lookup

Notes the classifier adds

Example

From an MCP client

​What to send

​No live lookup

​Notes the classifier adds

​Example

​From an MCP client

What to send

No live lookup

Notes the classifier adds

Example

From an MCP client