AI agents turn crypto wallets into policy engines

A crypto wallet is turning from a key with a human approving every transaction into a policy engine. AI agents move authorization away from a manual signature, transaction by transaction, toward rules written into the account: session keys, spending caps, allowlisted addresses, signed mandates.

The shift matters because the standard wallet model – one private key, one human, one approval per action – breaks down when an automated agent needs to execute dozens of trades, rebalance positions, or sweep yield across protocols without a human clicking "confirm" each time. The agent cannot hold the key itself without creating a security hole. The solution is a wallet that acts as a rulebook, not a lockbox.

Session keys let an agent operate within a defined window – say, 24 hours – with a preset spending limit and a restricted set of contract interactions. The wallet enforces the boundary. If the agent tries to send funds to an address outside the allowlist or exceed the daily cap, the transaction fails. The human never sees the intermediate approvals, only the aggregate result or an exception alert.

Spending caps and allowlisted addresses work the same way at the account level. A wallet configured to let an AI agent trade only on Uniswap V3, with a maximum of 10 ETH per day, and only to addresses on a pre-approved list, removes the need for per-transaction oversight without exposing the full balance. The agent gets enough rope to execute its strategy, not enough to drain the account.

Signed mandates take the idea further. A human signs a single message that delegates specific authority to an agent – trade this pair, rebalance when the ratio hits 60/40, withdraw rewards to this address. The mandate itself is a smart contract condition. The agent executes within its scope until the mandate expires or is revoked.