The Recorder
Click through the dApp you already know, as your Safe. Your Safe gets the batch.
What it does
The Recorder is a Chrome extension. From the Safe's build page you pick a dApp, and the Recorder opens it in a new tab where the connected wallet is your Safe. You click through Aave, Uniswap, whatever you use, exactly as you would with your own wallet. Every transaction the dApp asks for is recorded instead of sent. When you press Finish, the recorded calls are one batch, ready to propose to the Safe.
Finish pauses rather than ends. If you forgot a step, press Resume recording on the build page: the dApp opens again on the same private copy, with every call so far already done, and the next one joins the same batch. A paused recording is cleared after about ten minutes, so propose or resume before then. End recording throws the batch away.
What could go wrong without it
Without it, doing anything with a Safe on a dApp means one of two things: hand building the calls in a transaction builder, or connecting the Safe through a wallet bridge that the dApp may or may not support. Both are how a multi-million-dollar treasury ends up run from one person's hot wallet because it was easier.
What you see in the app
The dApp runs against a private copy of the chain that only your session can see, so its balances and positions are the Safe's real ones and its transactions land nowhere. A dock beside the page shows what has been recorded so far. If another wallet extension is installed, the dock warns you that a click could bypass the recording.
Back in the app, the batch panel lists each call. You can remove a call or drag it to reorder, but you cannot edit one. Propose runs a simulation on exactly the calls being signed, then signs with your own wallet and sends the proposal to the Safe. When the batch moves an amount that can change before it executes, such as a swap, Tamias adds one last call to it: Bounds, which undoes the whole batch if it would leave the Safe's balances outside what the owners signed. Nothing executes until the Safe's threshold is met.
What it does not do
The Recorder never holds a key and can never send a transaction. It refuses every kind of signing request, so a flow that needs a signature rather than a transaction cannot be recorded. That includes Permit2 approvals, CoW Swap orders and RFQ quotes from 1inch or 0x. An on-chain approve is recorded like any other call.
One recording is one chain. It works on the chains Tamias runs on and nowhere else, and only in Chrome. The Safe web app itself is excluded, so you cannot record a recording.