Play with pDiem
The pdiem full stack includes:
- A local Diem testnet:
- A Phala Network local testnet with the pdiem contract:
- A relayer to connect the both networks:
With the pdiem full stack running, we are going to send some Diem transactions to the pdiem deposit account, and check if the pdiem contract has received it.
Create Diem accounts
Start the diem-cli from the same directory by:
1docker-compose run --rm --entrypoint /bin/bash -- diem-cli ./diem-cli.sh
Then run the following commands to prepare the accounts:
1# Create two accounts 2diem% account create 3diem% account create 4# Mint some funds 5diem% account mint 0 100 XUS 6diem% account mint 1 100 XUS
diem-cli tool is a light wallet connecting to the diem node via RPC. It can be used to manage accounts, transfer tokens, and query the blockchain. In the above steps, we created two accounts (indexed by 0 & 1), and mint some test
XUS token to the account.
account 0is a special account that hard-coded in the pdiem-m3 demo contract as the deposit address. Usually
diem-cligenerates random accounts. But in the pdiem-m3 demo, the seed to generate the wallets is pinned with a special file client.mnemonic so that everytime it generates the same hard-coded account.
Simple diem-to-pdiem transfer
Simple transfer refers to the transfer between the admin address (
account 0, hardcoded in the pdiem-m3 contract).
To send Diem assets to pdiem, just transfer it to the admin address (
account 0) in
diem-cli. For example, we can send
10 XUS to
account 0 like this:
1diem% transfer 1 0 10 XUS
And that’s all!
Behind the scene,
pdiem-relayer picked up the deposit transaction, sent a regular Substrate extrinsic to the
pdiem confidential contract on Phala to sync the transaction. After the validation of the incoming transaction and the proof, the
pdiem contract will accept it. Usually it takes 30 seconds for the relayer to pick up the transaction, and relay to
Balances in pdiem
All the transactiosn received by
pdiem contract are validated against the latest Diem ledger state, which is protected by a PoS-like consensus. The validated transactions are stored inside the
pdiem contract storage, and can be checked by anyone:
Prepare subaccounts for two-way transfer
pdiem-m3 uses Diem’s subaccount feature to create deposit accounts. Any user can create its Diem deposit subaccount by sending a
1./phala-console.sh pdiem-new-account 0 '//Bob'
The above command will send
Command::NewAccount to the
pdiem contract from Substrate account “Bob”. You can create as many accounts as you want. It takes 2-3 blocks to process the command.
pdiem-new-accountis the sequence id of the new account transaction on Diem. Similar to the other blockchains, Diem also requires every transaction has incremented sequence id. So when creating another new subaccount, run
./phala-console.sh pdiem-new-account 1 '//Charlie'.
Then you can get a full list of the Diem accounts by a query:
As shown in the screenshot, Bob just created its deposit Diem address
Deposit (diem → pdiem)
Get your deposit address from the last step. And now you can deposit some
XUS on the Diem side in diem-cli:
1diem% transfer 0x57c76da2e144c0357336ace2f3f8ac9b 0x4DB6A10FCEB765C55ADC3751474AE8D1 10 XUS
diem-clitakes the source account and the destination account as the first two arguments. It accepts either two account references (e.g. 0 for
account 0in the local wallet), or two hex-encoded addresses. In the example above,
0x4DB6A10FCEB765C55ADC3751474AE8D1is Bob’s the deposit subaccount.
The corss-chain transfer takes around 4-6 blocks to complete. Check the balance by:
In this example, Bob’s Diem account will get
10 XUS, which is
freefield in the
pdiem-balancesoutputs (6 decimals).
Withdraw (pdiem → diem)
You can withdraw assets from
pdiem back to diem by
1./phala-console.sh pdiem-withdraw 4DB6A10FCEB765C55ADC3751474AE8D1 '10 XUS' '//Bob'
In the command above the arguments are:
4DB6A10FCEB765C55ADC3751474AE8D1: The Diem address to withdraw
'10 XUS': The amount of the assets
'//Bob': The SURI of the Substrate account private key to withdraw
pdiem-withdraw command sends a
Command::TransferXUS transaction to the
pdiem contract via the Phala blockchain. The contract then creates a Diem transaction from the subaccount to the withdrawal target, sign it, and push it to a queue. Once the
pdiem-relayer noticed new transactions in the queue, it relays them to the Diem blockchain.
The withdrawal transactions are queued until it gets confirmed on Diem. When confirmed, the outgoing transactions are observed by the
pdiem-relayer, and an evidence is sent back to the
pdiem contract. Finally the
pdiem contract will confirm the withdrawal transactions are executed.
You can check your
pdiem balance at any point:
You can still see the withdrawal amount under the “locked” balances until transaction is confimed on Diem. The above screenshot has two sides. The left side shows the withdrawal funds was locked and pending confirmation, while the right side shows the locked funds were removed because the outgoing tx is confirmed. Finally the sequence under the deposit account was incremented to 1.