Reference: https://blog.1inch.io/the-1inch-limit-order-protocol-v2-is-released-81c6802db1bd
1inch DEX aggregator has limit orders, but they offer a way to do gasless swaps for erc20 tokens. If a wallet doesn't have any ETH, how does this work with a swap? Are users giving 1inch full access and private key to 1inch in order to do this?
1inch Limit Order Protocol works with off-chain digital signatures, but it requires ERC20 approval transaction or ERC20 to support permit (signature-based approval). For sure it doesn't require sharing of private key.
More info about ERC20 permit functionality can be found here: https://help.1inch.io/en/articles/5435386-permit-712-signed-token-approvals-and-how-they-work-on-1inch
Workflow of placing limit orders is described here: https://help.1inch.io/en/articles/4656415-how-to-place-a-limit-order-on-1inch
