ExactInputRouter02

contracts/src/ExactInputRouter02.sol — implements IExactInputRouter. No owner, no state beyond two immutables.

Adapts Uniswap SwapRouter02.exactInputSingle to IExactInputRouter so SwapAdapter never sends arbitrary calldata. Fee is constructor-immutable (4663 MAG7/USDG pools exist at 3000 — see phase-1-live).

#Storage

Constructor reverts on a zero router or zero fee.

#Interface

swapExactIn(tokenIn, tokenOut, amountIn, minAmountOut, recipient) → amountOut:

1. Pulls tokenIn from the caller (the SwapAdapter).
2. Approves SwapRouter02 for exactly amountIn.
3. Calls exactInputSingle with the immutable fee and sqrtPriceLimitX96 = 0.
4. Zeroes the approval.

#Deployment status

🟡 Implemented and unit-tested (ExactInputRouter02.t.sol, against a mock SwapRouter02). It is deployed only by the guarded DeployMainnet / DeployPhase2 scripts, wrapping the cited SwapRouter02 at 0xCaf681a66D020601342297493863E78C959E5cb2. It does not exist on testnet.

#Security assumptions

• Immutability is the point: after deployment, nothing about the downstream router or fee tier can change.
• Slippage protection is entirely the caller's minAmountOut; the wrapper adds none of its own.