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index f2fbebb..de50a79 100644
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+++ b/README.md
@@ -616,6 +616,13 @@ and more.
   search engine—that shield you from the ads, trackers, and other creepy stuff
   trying to follow you across the web.
 
+- **[CardZero](https://cardzero.ai)**: CardZero is the first payment wallet
+  built for AI agents. Each agent gets its own ERC-4337 smart contract wallet
+  on Base, funded with USDC. Human owners set spending rules via a web
+  dashboard — per-transaction limits, daily caps, address whitelists, and
+  emergency freeze. Agents pay autonomously within those rules. Supports x402
+  payment protocol for paying API paywalls.
+
 - **[Coinbase](https://www.coinbase.com)**: Coinbase is a secure online platform
   for buying, selling, transferring, and storing cryptocurrency.