From zero to your
first cross-margin trade.
Eight short steps, in plain language, on a free testnet. Nothing here uses real money, you'll faucet your own test funds in step two. Tap each step to expand it.
Open the app and connect a browser wallet, Rabby or MetaMask both work. You sign one message (not a transaction, no gas) so Atrium can read your balance and positions. No password, no account, no custody.
SIWE, Sign-In-With-Ethereum · network: Arbitrum Sepolia (421614)RabbyBROWSER WALLETMetaMaskBROWSER WALLETone signatureSIWE · NO GASOpen the app ↗Wrong network? The app shows a one-click "Switch to Arbitrum Sepolia" button.
Atrium ships its own faucet so you can run the whole flow. Claim test USDC plus a little test ETH from the in-app faucet. The ETH covers gas; the USDC becomes your collateral. None of it has real value.
In-app testnet faucet · cooldown enforced per wallettest USDCCOLLATERALtest ETHGASper-walletCOOLDOWNOpen the faucet ↗Already claimed and still in cooldown? The button shows the exact wait. That is honest, not a failure.
The vault is called Coffer. Depositing your USDC mints you shares that the margin engine reads as collateral. Your wallet pops up twice (an approval, then the deposit) and the balance updates only after it confirms on-chain.
Coffer is an ERC-4626 vault · TVL, your value, and shares all read live from RPCERC-4626VAULT STANDARDapprove + depositTWO TXmints sharesYOUR COLLATERALOpen the vault ↗Every leg is conserved: USDC in, value increase, TVL increase, new shares. You can verify each.
Your portfolio shows one buying-power number across every venue. With no open position it honestly reads $0, never an invented number. The idea: required margin drops when your positions offset, so the same collateral backs more.
Buying power = Plinth cross-product margin · total collateral · open notional · 24h P&Lone numberBUYING POWERall venuesCROSS-MARGIN$0 when flatNEVER INVENTEDOpen the portfolio ↗Required margin drops when positions offset, so the same collateral backs more.
Pick a venue, type a size, and the margin impact panel computes live from the real SPAN engine: initial margin, maintenance margin, buying power, liquidation buffer. The preview updates as you change the size.
Live fills are gated behind the 48-hour timelock per venue · the form previews margin until the venue is enabledSPAN engineREAL MARGIN MATHinitial + maint.BOTH SHOWNliq. bufferLIVE PREVIEWOpen the trade desk ↗Fills stay behind the per-venue timelock until the venue is enabled. The preview is real either way.
Atrium makes AI agents first-class users through bounded mandates. You set caps the agent physically cannot exceed (per-action cap, daily limit, expiry, venue allowlist) and sign one EIP-712 message. One tap revokes everything.
Primary type IntentSigil · domain AtriumSigil · Kill Switch routes through Sigil.revoke_all_on_behalf_ofper-action capMAX PER TRADEexpiryAUTO-REVOKESvenue allowlistWHERE IT MAY TRADEOpen agents ↗The Kill Switch revokes every mandate at once, and the revoke counts against you, not the switch.
Atrium never holds your funds, and it proves it. Lantern publishes a signed Merkle root of all balances about every 10 minutes. Click verify and the server checks your wallet's inclusion proof against the on-chain root, a real result, never a fake 'verified'.
Latest signed root · attested block · leaf count · published about every 10 minutessigned rootPUBLISHED ON-CHAINinclusion proofYOUR BALANCE~10 minATTESTATION CADENCEOpen proof of reserves ↗The check returns a real result against the on-chain root, never a hardcoded "verified".
Verifier Mode is the judge-facing walkthrough: seven steps run against live contracts (deposit, open, see the saving, trigger chaos mode, run a liquidation drill, verify reserves, kill-switch revoke). Each step runs its real action with an Arbiscan link, or shows an honest "not ready" blocker.
Live on /verify · every step real or honestly gated · no faked successesdeposit + openSTEPS 1-2saving + chaosSTEPS 3-4liq + reserves + killSTEPS 5-7Open Verifier Mode ↗Each step runs its real action with an Arbiscan link, or shows an honest "not ready" blocker.
What's real, and what's coming.
Testnet only
TESTNETNo economic value anywhere. All funds come from the faucet. Nothing you do here touches real money.
Cross-chain transfer
TESTNETBuilt, but the CCIP lane to the destination chain isn't deployed on testnet yet. The button is disabled with an honest reason and shows your real balances.
Tax export
TESTNETGated on the Tablet service, which deploys later. The export buttons are disabled with a clear note rather than returning an error.
Full honesty list
TESTNETEverything mocked, relayed, or pending on testnet is published live in the app. No number presents a mock as a real upstream.
Ready when you are.
The whole flow runs against live contracts on Arbitrum Sepolia. No real funds, no risk, just the product, working.