Plasm is a Substrate Runtime Module Library which allows developers to add Plasma functions to their Substrate chain easily and seamlessly. Since Plasm is an SRML, developers can also make both plasma parent chains and plasma child chains with Substrate.
WARNING: This is a proof-of-concept prototype. This implementation is NOT ready for production use.
- Introduction
- Demo
- Plasm ver0.2.0
- Future Works
- Build Nodes on Docker
- Build Nodes for Developer
- Example Trait
Plasm is a Substrate Runtime Module Library which allows developers to add Plasma functions to their Substrate chain. By adding a Plasm Substrate Runtime Module Library, you can get scalable blockchains within a few minutes.
Some people might not know Substrate Runtime Module Library. Basically speaking, Substrate consists of 2 components, Substrate Core and Substrate Runtime Module Library aka SRML. We can customize Substrate Core with SRML and make an original Substrate chain.
Other people might not know Plasma. Plasma is a layer2 scaling solution which makes it possible for scalable computation by structuring economic incentives to operate the blockchain autonomously without the operator’s management. Ideally, it brings infinite scalability into your blockchain.
Based on the above, Plasm has some features.
- The first Rust implementation of Plasma SRML.
- Plasm is a simple but versatile SRML and makes it easier for developers to make a Plasma chain with Substrate.
- Plasm deals with many types of “Plasmas” in the future. Currently, we are providing UTXO models.
- Substrate chain can be both a plasma parent chain and a plasma child chain.
Since we are making an SRML, we can also make a Plasma chain with Substrate. Once Polkadot is launched, we will connect our root chain to Polkadot, and we aim to be one of the parachains.
In addition, Plasm makes it easier even for other developers to make a Plasma chain.
You can see our demo
Plasm ver0.2.0 is a prototype which has the following functions.
- Plasma MVP implementation
- Plasm-Parent provides the parent chain’s specification. Mainly, Plasm-Parent has the logic of each exit game.
- Plasm-Child provides the child chain’s specification.
- Plasm UTXO/Merkle provides the data structure which manages transactions.
- Plasma Client implementation
- Plasm Util is a wrapper function to call the endpoint of blockchains.
- Plasm Operator is monitoring a parent chain and a child chain to make the deposit/exit successful.
- Plasm CLI is a CLI tool to call the endpoint.
- Plasm Wallet is an application to send, withdraw and receive tokens.
As a next step, let’s make a wallet demo application on your laptop and see what’s happening.
Clone Plasm from our GitHub.
$ git clone https://github.com/stakedtechnologies/Plasm.git
$ cd Plasm
$ git checkout v0.2.0
Build Plasm Node. After a successful build, you can run Plasma nodes.
$ cargo build
$ ./target/debug/plasm-node --dev
Open another terminal and clone Plasm-Client from our GitHub.
$ git clone https://github.com/stakedtechnologies/plasm-client.git
$ cd plasm-client
$ git checkout v0.2.0
Start Plasm Operator. The operator is monitoring both the parent chain and the child chain. When the parent chain deposits tokens to the child chain or the child chain exits tokens to the parent chain, the operator writes the root hash of the child chain on the parent chain.
$ cd packages/operator
$ cp ../../env.sample .env
$ yarn install
$ yarn start
If you can see the output below, this project has been successful.
Yeah, you made it, but what actually happened? Let me clarify! (You can skip if you want. This is complicated, so we will publish another article focused on this topic.)
Plasm-Operator gets an event which the plasma child/parent chain issues and processes the following steps. Parent chain’s events
- When an operator receives a Submit event, she finalizes the status of the child chain.
- When an operator receives a Deposit event, she sends tokens to the issuer.
- When an operator receives an ExitStart event, she deletes the UTXO which was used for exiting on the child chain. Child chain’s events. When an operator receives a Submit event, she submits the root hash to the parent chain. The Submit event on a child chain is issued regularly. （You can decide this logic. For this time, 1 time in 5 blocks.)
Open another terminal and move to plasm-client root directory. Then, start Plasm Wallet UI Demo Application.
$ cd packages/wallet
$ yarn install
$ yarn dev
After that, let’s go to localhost:8000 on your browser. We will create 2 different accounts and send/receive tokens by using the wallet application I mentioned above.
First, you need to register your demo account. Since a default operator is Alice, you should add //Alice ①. Then, create an account ②. You can check Alice’s balance ③.
To send tokens from Alice to Bob, Alice to Tom and Bob to Tom, generate Bob’s and Tom’s account as well.
As a next step, we will send tokens from Alice to Bob and Alice to Tom on the parent chain.
Third, we will send tokens from the parent chain to the child chain. For this time, Bob deposits 5,000,000 tokens to the child chain. Just keep in mind, it takes time to increase ChildBalance because the operator checks the event and executes a transaction.
Fourth, let’s send some tokens from Bob to Tom on the child chain.
Bob has 5,000,000 tokens. He sent 1,000,000 tokens out of 5,000,000 to Tom.
Exit tokens from Tom’s account on the child chain to his account on the parent chain. If you type your account name, you can find UTXO lists you have. A child chain has all transaction histories you made and tokens are exited based on UTXO.
Press the ExitStart button so that you can exit your tokens to the parent chain.
BUT, you have to wait about 60 seconds. It is a Plasma challenge period which we decided. Full node holders can challenge the legitimacy of exits in it.
Click ExitFinalize.
Then,
Finally, the exit is successful. Well done!! This is a simple demo, but it’s one giant leap for the Polkadot/Substrate community!!
ver0.2.0rc1 : Actually, we just have one node in this tutorial because we used balances SRML, the default setting. We will divide this node into a parent node and a child node using PlasmUtxo SRML.
ver0.5.0 : Connect our root chain to Polkadot Testnet.
v0.7.0 : Plasma Cash implementation
v1.0.0 : Plasma Chamber implementation
Another Important Task : Improve ExitGame implementation
> docker run -p 9944:9944 stakedtechnologies/plasm-node> docker run -p 9955:9944 stakedtechnologies/plasm-child-node> cd plasm
> ./build
> cargo build
> ./target/debug/plasm-node --base-path /tmp/parent --port 30333 --ws-port 9944 --dev> cd plasm/child
> ./build
> cargo build
> ./target/debug/plasm-child-node --base-path /tmp/child --port 30334 --ws-port 9955 --dev> docker run -p 9944:9944 stakedtechnologies/plasm-node> docker run -p 9955:9944 stakedtechnologies/plasm-child-node> cd plasm
> ./build
> cargo build
> ./target/debug/plasm-node --base-path /tmp/parent --port 30333 --ws-port 9944 --dev> cd plasm/child
> ./build
> cargo build
> ./target/debug/plasm-child-node --base-path /tmp/child --port 30334 --ws-port 9955 --devPlease check here.
Plasm is licensed under the GPL, Version3.0 by Staked Technologies Inc.
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