Execution

Execute swaps through any protocol.

Tycho Execution provides tools for encoding and executing swaps against Tycho Router and protocol executors. It is divided into two main components:

• Encoding: A Rust crate that encodes swaps and generates calldata for execution.

• Executing: Solidity contracts for executing trades on-chain.

The source code for Tycho Execution lives at crates/tycho-execution inside the Tycho monorepo. For a practical example of its usage, please refer to our Quickstart.

Token transfers

You can transfer tokens in one of three ways with Tycho Execution:

• Permit2

• Standard ERC20 Approvals

• Using Vault funds

See how to change between these options when encoding here.

Permit2

Tycho Execution supports Permit2 for token approvals. Before executing a swap via our router, you must approve the Permit2 contract for the specified token and amount. This ensures the router has the necessary permissions to execute trades on your behalf.

Permit2 handling is not part of the encoding step. You are responsible for creating and signing the permit yourself. The Permit2 utility struct is publicly exported from the encoding crate, so you can use it to build the PermitSingle and obtain the data needed for signing.

For more details on Permit2 and how to use it, see the Permit2 official documentation.

Standard ERC20 Approvals

Tycho also supports traditional ERC20 approvals. In this model, you explicitly call approve on the token contract to grant the router permission to transfer tokens on your behalf. This is widely supported and may be preferred in environments where Permit2 is not yet available.

Using the Vault

The TychoRouterV3 includes a built-in vault (ERC6909) that lets you deposit, hold, and withdraw tokens directly in the router contract. The vault tracks per-user balances, so your tokens are only accessible by you.

The router draws from your deposited balance instead of performing a transferFrom on your wallet. This saves gas (no approval or external transfer needed) and lets you use fees, proceeds from previous trades, or pre-positioned liquidity directly.

Fees earned through the fee-taking system are automatically credited to the fee receiver's vault balance, making them immediately available for future swaps or withdrawals.

More on the Vault here.

Security and Audits

The Tycho Router V2 and V3 have been audited by Maximilian Krüger. Past audits are here.

Security Checklist

Follow this checklist when using TychoRouterV3. It covers essential security requirements but is not exhaustive.

• Always set expectedAmountOut and minAmountOut on TychoRouterV3's swap... functions. expectedAmountOut is your quoted output; minAmountOut is the amount below which the swap reverts.

  • Example: if you expect 1000 USDC and accept 5% slippage, set expectedAmountOut to 1000 * 10**6 and minAmountOut to 950 * 10**6.

  • minAmountOut must be non-zero and no greater than expectedAmountOut — see Slippage bounds.

  • The router sets no lower bound, so a minAmountOut far below your quote still passes: a faulty swap sequence, slippage or an attack can then leave you with far less than you quoted.

• Verify the price data behind minAmountOut against at least one other independent price source. A minAmountOut derived from a bad quote can sit far below the fair output, so the guardrail fails to protect you and the losses can be large.

• Never approve infinite allowances, including those for Permit2.

• Set Permit2 allowance and deadline as low as is practical.

If you discover potential security issues or have suggestions for improvements, please reach out through our official channels.