Wasm Operation

1. Prerequisite

1.1 VPS Requirements

The simplest way is to use a cloud server. You can freely choose any hosting provider.

1.1.1 Mainnet Hardware Configuration

Taking AWS as an example, BEVM mainnet recommended configuration should not be lower than:

CPU: 4 cores
Memory: 16GB
Bandwidth: 50Mbps
Disk: SSD 300GB+
Operating System: Ubuntu 22.04+

Cloud servers need to open p2p port (default port=30333) to increase connectivity

To open ports on AWS, you typically configure rules in the Security Group. Follow these steps:

1. Log in to AWS Management Console and go to EC2 service
2. In the navigation pane, select "Security Groups"
3. Select the security group you want to modify
4. Select the "Inbound Rules" tab, then click "Edit inbound rules"
5. Click "Add rule"
6. In the "Type" dropdown, select the protocol type (e.g., TCP)
7. In "Port range", enter 30333
8. For "Source", you can choose:
   - Allow any IP access (0.0.0.0/0)
   - Allow only specific IP ranges (enter IP/mask format)
9. Click "Save rules"

For example, to allow all IPs through TCP port 30333:
Type: TCP
Port range: 30333
Source: 0.0.0.0/0

To open port 30333 on Alibaba Cloud, configure the security group's inbound rules as follows:

1. Log in to Alibaba Cloud Console and go to "ECS"
2. Find the ECS instance that needs port opening, click the instance ID
3. In the left menu, select "Security Groups"
4. In "Security Group Rules" tab, find "Inbound" rules, click "Quick Add"
5. In the "Security Group Inbound" window:
   - Rule Direction: "Inbound"
   - Authorization Policy: "Allow"
   - Protocol Type: "Custom TCP"
   - Port Range: "30333/30333"
   - Authorization Object: "0.0.0.0/0" (allow all IPs) or specify IP range
6. Click "OK" to complete

After adding the inbound rule, the service can be accessed through the instance's public IP and port 30333.

1.2 Installing BEVM Using Docker

1.2.1 Configuration File

For validator nodes, we recommend the following configuration:

Replace "Your-Node-Name" with your node name

{
    "chain": "mainnet",
    "log-dir": "./log",
    "enable-console-log": false,
    "no-mdns": true,
    "validator": true,
    "unsafe-rpc-external": true,
    "offchain-worker": "when-authority",
    "rpc-methods": "unsafe",
    "log": "info,runtime=info",
    "port": 30333,
    "rpc-port": 8087,
    "pruning": "archive",
    "db-cache": 2048,
    "name": "Your-Node-Name",
    "base-path": "data",
    "keystore-path": "keystore",
    "bootnodes": [],
    "telemetry-url": "wss://telemetry-mainnet.bevm.io/submit 1"
}

After the node starts successfully, you can see your node on BEVM Telemetry.

For Docker installation, refer here.

1.2.2 Using Docker Image

Place the above configuration file in the current directory, named config.json. Run the following command:

{
    "chain": "mainnet",
    "log-dir": "/log",
    "enable-console-log": false,
    "no-mdns": true,
    "validator": true,
    "unsafe-rpc-external": true,
    "offchain-worker": "when-authority",
    "rpc-methods": "unsafe",
    "log": "info,runtime=info",
    "port": 30333,
    "rpc-port": 8087,
    "pruning": "archive",
    "db-cache": 2048,
    "name": "Your-Node-Name",
    "base-path": "/data",
    "keystore-path": "/keystore",
    "bootnodes": []
}

Chain options:

chain=mainnet: BEVM mainnet
chain=testnet: BEVM-testnet (no longer maintained, may stop operation)
chain=signet: BEVM-signet (new test network started with BEVM v0.3.0)

Run the following command to start the node in the background:

sudo docker pull btclayer2/bevm:v0.1.5
sudo docker run -d --restart always --name bevm-node \
  -p 8087:8087 -p 30333:30333 \
  -v $PWD/config.json:/config.json -v $PWD/data:/data \
  -v $PWD/log:/log -v $PWD/keystore:/keystore \
  btclayer2/bevm:v0.1.5 /usr/local/bin/bevm \
  --config /config.json

Enter the container:

docker exec -it bevm-node /bin/bash

The parameters correspond to those in the configuration file. For background running Docker, you can check logs with:

tail -f log/bevm.log # View all logs

When the logs show block synchronization starting, it indicates the node has started successfully:

2024-01-30 06:42:24 ✨ Imported #2229 (0x835e…88ea)    
2024-01-30 06:42:27 💤 Idle (4 peers), best: #2229 (0x2823…340a), finalized #2227 (0xabfa…613d), ⬇ 16.5kiB/s ⬆ 17.9kiB/s    
2024-01-30 06:42:30 ✨ Imported #2230 (0x1dde…0ce9)    
2024-01-30 06:42:30 ♻️  Reorg on #2230,0x1dde…0ce9 to #2230,0x937b…545e, common ancestor #2228,0xf384…0db5    
2024-01-30 06:42:30 ✨ Imported #2230 (0x937b…545e)    
2024-01-30 06:42:32 💤 Idle (4 peers), best: #2230 (0x937b…545e), finalized #2228 (0xf384…0db5), ⬇ 17.8kiB/s ⬆ 18.8kiB/s

If you need to use RPC service externally, add rpc-external: true to the configuration file.

When configuring, it's recommended to change the name item in the configuration file.

Port mapping must be consistent with config.json, otherwise RPC will not work normally.

1.3 Direct Binary Download

Download the compiled binary from GitHub releases.

Sync to Latest Chain State

Start syncing the blockchain with this command:

$ ./bevm-v0.1.5 --chain=mainnet --pruning=archive --name="Your Node Name"

# After syncing completes, restart in validator mode:
$ ./bevm-v0.1.5 --chain=mainnet --validator

Or start directly in validator mode for syncing:

# Using --validator will automatically enable archive mode (--pruning=archive)
$ ./bevm-v0.1.5 --chain=mainnet --validator

Note: Make sure to wait for synchronization to complete and set up Session Keys before letting the node participate in election.

If synchronization is abnormal, ensure system time matches network time, delete the database, and resync.

1.4 Creating BEVM Account

You can create a BEVM account on wallet.bevm.io and transfer BEVM to this account for transaction fees and future staking costs.

2. Registering Validator Node

After creating a BEVM account, you can register as a validator node on wallet.bevm.io

Note:

(1) Validator node names only support numbers and letters (case-sensitive)

(2) Register transaction will charge 100 BEVM whether successful or not

(3) Each BEVM account can only register once.

(4) Before registering, ensure you have sufficient balance for transaction fees and self-voting amount (1000 BEVM in the example).

(5) Newly registered nodes are automatically nominated for election, no additional operation needed.

(6) Besides initial staking during registration, you can stake more through voting.

(7) After the election period ends, the top 40 nodes (parameter set through governance) by total stake will become validators participating in consensus.

Chain Account Registration:

router: identity -> setIdentity

3. Setting Session Keys

You can generate Session Keys by executing this command on your node machine:

Install curl: apt install curl

$ curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "author_rotateKeys", "params":[]}' http://localhost:$YOUR_RPC_PORT

Where YOUR_RPC_PORT is the port specified by rpc-port when starting the node, default is 8087.

Example response:

{
  "jsonrpc":"2.0",
  "result":"0xcf888ade403573be237e2af023c5b5ff1e4fd24cb96893b034ca8d616fe551c96cccd879274db47800e2a035adef9d7657ee2579ceaf25a3bc507931e5e5241558764dd425290713cb62101ca62edf2bcfbeedc38b3ed36db080d0bb9561ba507a14389a5dbd1b5708314fb1bc204c384c41b4389e7add1b6bec10490ff52b7b",
  "id":1
}

The result field is your Session Keys. Set them through setKeys in Developer>Extrinsic:

Currently, proof can be set to 0x.

4. Binding EVM Address (Optional)

Binding an EVM address is prerequisite for becoming an L-BTC staking mining validator node (can accept LBTC token staking, participate in BEVM mining).

Validator nodes not participating in L-BTC staking mining (i.e., without bound EVM address) can still receive BTC gas rewards and BEVM transaction fee rewards(Different from the BEVM assigned with the Mother Consensus).

5. Checking Validator Node Setup

curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "xstaking_checkCandidate", "params":["5Uix8A8MpxJK8q2GMbSkENL9obg6gd4S6eJD9H5DErtA94i8"]}' http://localhost:8087

Four "true" values in response indicate complete setup:

{"jsonrpc":"2.0","result":[true,true,true,true],"id":1}

These four values represent:

Whether nominated (validator.isChilled is false)
Whether meeting minimum voting amount (self-vote at least 100 BEVM and total votes at least 1000 BEVM)
Whether Session Keys are set
Whether participating in LBTC staking mining

5. Backup Node

Since improper node deployment causing block anomalies will be penalized, you can deploy backup nodes.

Copy the same config.json configuration and keys, just change "validator=false".

Start backup node in "pruning=archive" mode.

This way, when the main node has issues, the backup can take over to avoid penalties.

6. Verifying Block Production

Validator rotation period: Era = 4 Session = 4 * 1 hour = 4 hours

After setup, it takes up to 4 hours for new validators to produce blocks.

After being elected validator, seeing Prepared block for proposing at ... in logs indicates successful block production:

2024-01-30 17:39:42:008 INFO tokio-runtime-worker sc_basic_authorship::basic_authorship  🙌 Starting consensus session on top of parent 0xe05e784c7198ff0719411ed75fe3a207f7fdc89b0ed5e3fbae75a3f2a7bf5504
2024-01-30 17:39:42:021 INFO tokio-runtime-worker sc_basic_authorship::basic_authorship  🎁 Prepared block for proposing at 4002 (13 ms) [hash: 0x236a33a2f071abb9f0f4ee31a367b509c560018807bf21b454ea0d368cd8812a; parent_hash: 0xe05e…5504; extrinsics (4): [0x8d22…b8ad, 0x9b60…0aa1, 0xccdc…3742, 0x56df…c0a3]
2024-01-30 17:39:42:027 INFO tokio-runtime-worker babe  🔖 Pre-sealed block for proposal at 4002. Hash now 0x4c4eec78a6f480a337f2ddd79c5f839959d8e082e3ec9f4adc7f640f70d66024, previously 0x236a33a2f071abb9f0f4ee31a367b509c560018807bf21b454ea0d368cd8812a.

7. Validator Withdrawal

7.1 Forced Withdrawal

When a validator's reward pool is penalized to 0 or other penalties occur, the validator is kicked out of the current validator set and becomes withdrawn. To rejoin staking, manual nomination is required.

7.2 Voluntary Withdrawal

7.3 Manual Nomination

8. Important Notes

Before first halving (every 4 years), each session (1 hour) issues 7500 BEVM, 20% directly to validators, 80% stored in their reward pool
Validator election occurs every 4 sessions (4 hours)
If node self-stake is less than 100 BEVM or total votes less than 1000 BEVM, will be forced to withdraw during validator election
Candidate status validators neither receive rewards nor penalties

9. Node Penalties

BEVM issues rewards each session while penalizing potentially malicious nodes. Penalty types generally include double-signing and node offline. Once malicious behavior is detected, the BTC gas rewards in the offending node's reward pool will be penalized to the Treasury according to the reported malicious coefficient:

penalty = max(reward_pot_balance * F, minimum_penalty)

Where:

penalty: BTC gas amount to be penalized
reward_pot_balance: Node's BE reward pool amount
F: Penalty coefficient, calculated by babe and im-online modules:
- babe: Node double-signing penalty details
- im-online: Node offline penalty details
minimum_penalty: Minimum penalty value, meaning each penalty is at least minimum_penalty.

BEVM validator node misconduct does not penalize BEVM principal and BEVM transaction fees, only penalizes BTC gas in the reward pool.

When a node's reward pool is completely penalized, the node will be forced to withdraw.

if penalty > reward_pot_balance { 
    // force the validator(offender) to be chilled 
}

10. Validator Rewards Withdrawal (BTC and BEVM)

10.1 Wallets

For wasm account: https://wallet.bevm.io/ (need to install https://polkadot.js.org/extension/)

For evm account: Metamask Quick Add: https://chainlist.org/?search=BEVM+Mainnet

10.2 Query BTC and BEVM Balance

To query BTC balance and BEVM balance, use the respective interfaces in the wallet.

Query BTC Balance

Query BEVM Balance

10.3 Claim BTC and BEVM from Validator Spot to Wasm Account

Use the claim function in the wallet interface to transfer rewards from validator spot to your wasm account.

10.4 Deposit BTC from Wasm to EVM

Use the deposit function to transfer BTC from your wasm account to EVM account.

10.5 Deposit BEVM from Wasm to EVM

Transfer(EVM<-->Wasm)

10.6 Bridge BTC to Bitcoin Mainnet

Visit https://www.bevm.io/bridge-mainnet to bridge your BTC to Bitcoin mainnet.

11. Multi-signature Account as Validator Node

The validator node operations for multi-signature accounts are the same as for regular accounts, with the difference being in multi-signature account interactions.

Multi-signature Account Reference Documents

Creating a multi-signature account: https://wallet.bevm.io/ (need to install https://polkadot.js.org/extension/)

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