Test app
The app as it will work, on a test network: sign in with your fingerprint or face, start a deal, invite the other side with a link, pay into the escrow, deliver, release the money or open a dispute, and withdraw. The signatures and the escrow contract are real; the money is test money with no value.
This app works only at test.fairmid.com/app/. Open it there to sign in.
Testnet: test money only, it has no value
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You are invited to a test deal
If you accept, you are . Test money only.
What you both agree to
The addresses
Anyone can pick a name: the address under their name in “From” is what proves who sent this.
Check that you know this arbiter. The other side chose them, and they never confirm anything. They are contacted only if there is a dispute, and can then give everything to one side. If they never answer, a dispute cannot be decided and you can only . If there is a dispute, you two pay their fee directly, not from the escrow.
These are accounts on the Base Sepolia test network. Never send real money or real crypto to them on any network.
Create your test account or sign in below first.
You are asked to decide a test deal
The buyer and the seller of this test deal disagree, and they named you as their arbiter. Read what they agreed and what they wrote below, ask both of them what happened, then give everything to one side. You cannot split it. The buyer and the seller pay your fee to you directly, not from the escrow. Test money only.
These are accounts on the Base Sepolia test network. Never send real money or real crypto to them on any network.
Your deals
No sign-up, no password and no seed phrase. Your account is protected by a passkey: your fingerprint, face or screen lock. Fairmid never sees it.
Your device asks for your fingerprint, face or screen lock.
Made one at this address before, in the app or on the testnet page? Use it on any device that has it.
What should others call you?
Your name shows in your deals and invitations, always next to your address. Anyone can pick any free name, so the address is what proves who someone is.
Test deal
Waiting for you in the escrow:
Money from finished deals stays in the escrow until you withdraw it to your account.
No test deals on this device yet.
The addresses here are accounts on the Base Sepolia test network. Never send real money or real crypto to them on any network.
Shows deals from your other devices too. Asks for your passkey once.
Your account
- Name
- None on this device yet
- Address
- Test USDC
- –
- Added here
Only for the Base Sepolia test network. Never send real money or real crypto to this address on any network: this app cannot move it.
The buyer pays with test USDC. Circle, the company behind USDC, gives it out free: the button copies your address and opens its faucet. There, pick Base Sepolia, not another network, and paste the address.
More: check the account, forget it here
Send a test transaction
Optional. It moves no money: it sets up your account on the test network and shows that everything works, from your passkey to the network. Fairmid pays its network fee.
Create the account first.
See the transaction on Blockscout
This browser keeps only your account's public details and your test deals with their notes for an arbiter, never your passkey. Forgetting removes both from this device. Your deals stay on our test server and in the escrow and come back with "Check for updates"; an open invitation link cannot be shown again, so cancel that deal and make a new one. To use the account again, sign in with the same passkey. It holds only test money.
New deal · 1 of 5
Which side are you on?
Anyone can start a deal, the one who pays or the one who delivers. Nothing is paid now: the buyer pays into the escrow after the other side accepts.
What is the deal?
Price and checking time
Who is the arbiter?
Check and create
What you both agree to
The details
Create your test account first.
Your invitation link. Whoever has it can accept the deal, so send it only to the other side, by chat or email.