This is a Javascript library that allows you to interact with OmiseGo's MoreVP implementation of Plasma. It provides functions to:
omg-js
follows a modified semver with the first part referring to its own library versioning and the second part referring to its compatible elixir-omg
version.
The project is organized into 3 submodules:
You can use any of them separately, or all at once by importing the parent @omisego/omg-js
package.
Requires Node >= 8.11.3 < 13.0.0
npm install @omisego/omg-js
You can add omg-js
to a website quickly. Just add this script tag.
<script src="https://unpkg.com/@omisego/browser-omg-js"></script>
omg-js
can easily be integrated with React Native projects.
First, add this postinstall script to your project's package.json
"scripts": {
"postinstall": "omgjs-nodeify"
}
Then install the react native compatible library.
npm install @omisego/react-native-omg-js
Sending a transaction
How to sign a transaction
Both Alice's and Bob's Ethereum accounts need to have some ETH in them. The ETH is used for gas costs on the rootchain, fees on the childchain and the actual ETH transferred from Alice to Bob.
If you want to run the ERC20 examples, make sure the token address is recorded in your .env
and either Alice or Bob has a balance on the rootchain.
You can find example code inside the examples
folder.
To run the examples:
npm install
from root of omg-js
.
Step inside the /examples
directory.
Run npm install
.
Create .env
file inside the root of the /examples
directory with the appropriate values (see /examples/env.example
for an example)
Refer to below explanation of .env
variables
ETH_NODE= <entry point to an ethereum node>
WATCHER_URL= <url of an informational watcher>
WATCHER_PROXY_URL= <*optional* proxy server to catch all watcher requests>
PLASMAFRAMEWORK_CONTRACT_ADDRESS= <address of the plasma_framework contract>
ERC20_CONTRACT_ADDRESS= <*optional* address of the erc20 contract that Alice will deposit and transfer to Bob>
ALICE_ETH_ADDRESS= <address of Alice's account>
ALICE_ETH_ADDRESS_PRIVATE_KEY= <Alice's private key>
BOB_ETH_ADDRESS= <address of Bob's account>
BOB_ETH_ADDRESS_PRIVATE_KEY= <Bob's private key>
MILLIS_TO_WAIT_FOR_NEXT_BLOCK= <interval when checking for block confirmation>
BLOCKS_TO_WAIT_FOR_TXN= <amount of blocks to wait for confirmation>
Let's run through a story between Alice and Bob. In this story, Alice will first deposit some ETH from the root chain into the child chain. Then Alice will transfer some of that ETH to Bob on the child chain. Bob will then exit his funds from the child chain back into the root chain. His root chain balance will be reflected with the extra ETH that Alice sent to him on the child chain.
Note you can modify the values of the passed flags to suit your needs
From the /examples
folder run the following scripts:
Get Alice's and Bob's balances
node print-balance --owner=alice
node print-balance --owner=bob
Get Alice's and Bob's Childchain UTXOs
node print-utxos --owner=alice
node print-utxos --owner=bob
Deposit some ETH from Alice's Rootchain to the Childchain
node deposit-eth --owner=alice --amount=0.01
Send some ETH from Alice's Childchain to Bob's Childchain
node transaction-eth --from=alice --to=bob --amount=0.001
Alice has now sent some ETH to Bob. This should be reflected in Bob's childchain balance.
Exit one of Bob's Childchain UTXOs to the Rootchain
node exit-eth --owner=bob
Checking Bob's final rootchain balance you will notice it will be a little less than expected. This is because of rootchain gas costs Bob had to pay to exit the childchain.
Bob starts and piggyback's an inflight exit for his ouput on a transaction sent by Alice
node inflight-exit-eth --from=alice --to=bob --amount=0.01
Before we begin, we need to deploy and mint some ERC20 tokens. From the examples folder run the following command:
npm run deploy-test-erc20 --prefix ../packages/integration-tests
Use the ERC20 contract address from the output above to configure ERC20_CONTRACT_ADDRESS
in your .env
file.
Now let's run through the same story above but for ERC20 deposit/transaction/exit.
Deposit some ERC20 from Alice's Rootchain to the Childchain
node deposit-erc20 --owner=alice --amount=10
Send some ERC20 from Alice's Childchain to Bob's Childchain
node transaction-erc20 --from=alice --to=bob --amount=1
Exit one of Bob's Childchain ERC20 UTXOs to the Rootchain
node exit-erc20 --owner=bob