MEV Shield
What it protects against
Section titled “What it protects against”A swap that waits to enter a block can be read by anyone watching the network. A bot can see it, buy just before it and sell just after it, so your swap fills at a worse price. This is front-running, or a sandwich attack, and the profit taken this way is called MEV.
MEV Shield encrypts your signed swap in your browser, so nobody can read it while it waits. Only the validator that builds its block can decrypt it, and it does so inside that block. The encrypted envelope and your swap land in the same block.
When Taoswap uses it
Section titled “When Taoswap uses it”On the swap form, MEV Shield turns itself on for trades worth $100 or more, and when the app cannot tell the value. Below that, it stays off.
You can turn it on or off yourself in Swap Settings. Your choice is saved in this browser and holds until you change one of the two tokens. The $100 rule then decides again.
Batches from the Trade Batch and Smart Actions follow your saved setting, which is on by default, when they trade through a pool.
MEV Shield does not apply to operations without a pool: TAO to Staked TAO and back, moving stake to another validator, and transfers.
Two modes
Section titled “Two modes”| Mode | Signatures | Network fees |
|---|---|---|
| MEV Shield (Relay, 1 signature) | One | Yours; Taoswap pays the relay’s transaction fee |
| MEV Shield (Self-Custody, 2 signatures) | Two | Yours, plus a second, smaller fee for the envelope |
In relay mode, you sign once. Your browser encrypts the swap and sends it to Taoswap’s relay, which submits it. The relay cannot read or change your transaction. It does receive your wallet address, so it knows that you traded and when, but not what. Taoswap keeps a record of each swap it relays, as the Privacy Policy describes.
In Self-Custody mode, you sign your swap, then the encrypted envelope, and your wallet submits both without the relay. The estimated network fee on the form already includes the envelope.
Relay mode is the default. The app switches to Self-Custody on its own when the relay is unavailable, off the main network, or when you use your own node.
To pick a mode, open Swap Settings and tick its row. Untick it to turn the shield off.
What you see
Section titled “What you see”In relay mode, the notification counts three steps, from Step 1/3: Signing your swap… to Step 3/3: Swap executed. In Self-Custody mode, it starts with Signature 1/2: your swap… and Signature 2/2: the MEV protection…. A shielded swap can take slightly longer than a plain one.
You can run one shielded swap at a time. While one is settling, the button reads Previous swap settling….
If the relay is slow or down
Section titled “If the relay is slow or down”- After a while without an answer, the notification says Relay is slow. Your swap may still go through.
- If the relay times out, the app keeps watching the chain: Relay timed out. Watching the chain. Wait for the result before you trade again.
- If the relay missed its window, the notification says no funds moved and offers Retry.
- If no mode is available, the app asks before sending your trade in the clear: Send without MEV Shield? Choose Send unshielded, or Cancel and try again in a moment.
Limits
Section titled “Limits”MEV Shield hides your swap until its block. It does not change the pool price, your price impact or the need for a sensible slippage tolerance.
If you sign through your own node, that node can read your transaction and could fake the encryption key. See Network status.