"Non-custodial" is only a promise until you can see it. A swap interface never touches your funds if, and only if, every transaction goes from your wallet straight to a known contract, and nothing it asks you to sign gives it more power than the trade needs. Here is how to check.
Approvals
On EVM chains a contract can only move your tokens after you approve it. Many sites ask for an unlimited approval once, so the next trade needs one signature less; the downside is that a bug in that contract can drain the whole balance later. Soheil approves the exact amount of each trade, to the contract that executes it, and nothing more. You can see the amount in your wallet's approval screen, and revoke any approval later with a tool such as revoke.cash.
The contract you call
Your wallet shows the address the transaction goes to. On the trust page every partner's contracts are listed with explorer links; a route step names its partner, so you can match them. If an address ever differs from the listed ones, do not sign.
Amounts and recipients are fixed server-side
The transaction you sign is built from the quote you saw, on the server, from the server's own copy of the route. A changed page cannot alter amounts, recipient or fee. On Solana the instructions are checked one by one before you sign; on Bitcoin the transaction is checked so it cannot send more than quoted.
Proof you can look at
The trust page shows verified trades with their explorer links and the public fee wallets, so what the site earns is on-chain for anyone to follow. Your own Activity page lists every transaction you made here with its hash.
What stays your responsibility
The partners' contracts carry smart-contract risk, bridges carry bridge risk, and prices move. Non-custodial removes the risk that the interface runs off with your funds; it does not remove market risk. Trade amounts you are comfortable with.
Do it
More guides
- How to bridge to Hyperliquid (HyperEVM) from any chain
- How to buy TAO (Bittensor) with any token
- Health factor explained: how to borrow without being liquidated
- What a swap or bridge really costs: every fee, explained
Information, not financial advice. Soheil.fi is non-custodial; every transaction is signed in your own wallet.