KeeperCard — spending cards for AI agents

Give your agent a card, not your keys.

Issue a scoped, revocable spending card from your wallet. Any AI agent plugs it in over MCP and pays within your limits — no keys, no gas, dead the moment you revoke. Every confirmed payment gets an on-chain receipt written by KeeperHub.

Built on:BaseERC-7710EIP-7702x402KeeperHubMCPSigNoz

Three moves, and the agent never touches money.

You issue

Set the terms — budget per period, per-payment cap, merchant allowlist, expiry — or draft them in plain language. Your wallet signs the delegation in the browser; the server stores it beside a fresh agent key that holds nothing.

The agent plugs in

One claude mcp add, a Cursor deeplink, or a pasted connector URL. The tool list is the permission surface: a pay-only card never sees execute.

It pays, with a receipt

Each pay is checked against the terms, redeemed gaslessly on Base in USDC from your wallet, then KeeperHub writes an on-chain receipt (PaymentAnchor) on Base Sepolia.

Everything a card should be, rebuilt for agents.

Scope

Terms the chain enforces

Period budget, lifetime cap, per-payment max, merchant allowlist, expiry, usage count. The enforcers check every one again on-chain, so the server can never approve what the chain would reject.

ERC-7710 caveats · Base mainnet

Kill switch

Revoke, and it's dead

Freeze or revoke a card — or its whole sub-card tree — and every payment stops. Sub-cards nest tighter terms for sub-agents and die with their parent.

server-side instantly · on-chain underneath

Receipt

A receipt for every payment

Every confirmed payment gets an on-chain receipt (PaymentAnchor) written by KeeperHub on Base Sepolia, so anyone can check what was paid, to whom, and when.

PaymentAnchor · KeeperHub · Base Sepolia

Rails

Pays the open web

paid_fetch settles HTTP 402 challenges automatically; a fiat lane buys over Visa rails; contract cards run scoped swaps and approvals atomically.

x402 · Visa (test mode) · contract calls

Operate

Built to run, not to demo

Signed webhooks with retries, roles over shared cards, a CSV-exportable audit log, budget alerts, and a typed SDK. Every hop traced into SigNoz.

webhooks · teams · audit · SDK

One line in any harness.

# Lane A · secret in the URL path
claude mcp add --transport http remit https://<host>/c/<card-secret>/mcp

# Lane C · OAuth 2.1, card-picker consent
claude mcp add --transport http remit https://<host>/mcp
# the client discovers the OAuth lane on the 401, registers itself, # and opens a browser: you pick which card to grant.

Claude Codeclaude.aiCursorVS CodeCodexGemini CLIGooseWindsurfChatGPTOpenClawAmpDroid

The card is the connection. Behind the URL sits a scoped delegation; the agent holds the card, never the money. Rotate the secret from the dashboard and the old URL dies instantly.

Refusals are typed — over_period_limit, merchant_not_allowed, price_exceeds_max — so an agent can relay them honestly instead of guessing.