Technical Reference

Overview

The "Technical Reference" section provides developers with detailed technical insights into JuChain, including API specifications, smart contract ABIs, consensus mechanism parameters, and other critical configuration details. This chapter serves as a technical handbook for developers, aiding in interactions with the JuChain Testnet or Mainnet, debugging applications, and optimizing development workflows. JuChain’s design emphasizes high performance, low cost, and EVM compatibility, with all reference information built around these principles.

1. JSON-RPC API Reference

JuChain offers a standard JSON-RPC API for blockchain interaction. Below are commonly used methods and their parameters, applicable to the Testnet (https://testnet-rpc.juchain.org) and Mainnet (to be provided upon launch).

1.1 Configuration

Endpoint: https://testnet-rpc.juchain.org
Protocol: HTTP/HTTPS or WebSocket (wss://testnet-rpc.juchain.org)

1.2 Common Methods

eth_blockNumber

Description: Returns the current block height.

Request:

{
  "jsonrpc": "2.0",
  "method": "eth_blockNumber",
  "params": [],
  "id": 1
}

Response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x1a2b3c" // Hexadecimal block height
}

Example (cURL):

curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' https://testnet-rpc.juchain.org

eth_getBalance

Description: Queries the JU balance of a specified address.
Parameters:
- address: 20-byte address (e.g., "0x1234567890abcdef1234567890abcdef12345678")
- block: Block tag (e.g., "latest")

Request:

{
  "jsonrpc": "2.0",
  "method": "eth_getBalance",
  "params": ["0x1234567890abcdef1234567890abcdef12345678", "latest"],
  "id": 2
}

Response:

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": "0x16345785d8a0000" // Balance in wei
}

eth_sendRawTransaction

Description: Submits a signed transaction.
Parameters:
- rawTx: Signed transaction data (hex string)

Request:

{
  "jsonrpc": "2.0",
  "method": "eth_sendRawTransaction",
  "params": ["0xf86c018502540be400825208941234567890abcdef1234567890abcdef1234567888016345785d8a00008025a0..."],
  "id": 3
}

Response:

{
  "jsonrpc": "2.0",
  "id": 3,
  "result": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890" // Transaction hash
}

eth_call

Description: Executes a read-only smart contract call.
Parameters:
- transaction: Object with to (contract address) and data (method signature and parameters)
- block: Block tag

Request:

{
  "jsonrpc": "2.0",
  "method": "eth_call",
  "params": [{"to": "0xContractAddress", "data": "0x6d4ce63c"}, "latest"],
  "id": 4
}

Response:

{
  "jsonrpc": "2.0",
  "id": 4,
  "result": "0x000000000000000000000000000000000000000000000000000000000000002a" // Return value (e.g., 42)
}

1.3 Full API List

Additional methods (e.g., eth_getTransactionByHash, eth_getBlockByNumber) are Ethereum-compatible. Refer to the Ethereum JSON-RPC Documentation.

2. Smart Contract ABI

Below is an example ABI for JuChain’s core contracts, facilitating interaction with JU tokens and other functionalities.

2.1 JU Token ABI

Contract Address: TBD (to be updated upon Mainnet launch).
Standard: ERC-20 (if applicable; JU as a native token may not require this in all contexts).

Core Methods:

[
  {
    "constant": true,
    "inputs": [{"name": "_owner", "type": "address"}],
    "name": "balanceOf",
    "outputs": [{"name": "balance", "type": "uint256"}],
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {"name": "_to", "type": "address"},
      {"name": "_value", "type": "uint256"}
    ],
    "name": "transfer",
    "outputs": [{"name": "success", "type": "bool"}],
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {"name": "_spender", "type": "address"},
      {"name": "_value", "type": "uint256"}
    ],
    "name": "approve",
    "outputs": [{"name": "success", "type": "bool"}],
    "type": "function"
  }
]

Note: JU is JuChain’s native token, so some interactions (e.g., transfers) may use native ETH-like calls (msg.value) rather than ERC-20 methods unless wrapped (e.g., WJU).

3. JPoSA Parameters

JPoSA (JuChain Proof of Stake Authorization) is JuChain’s consensus mechanism. Key parameters are listed below:

3.1 Consensus Parameters

Block Time: 1 second
Transaction Finality: 2-3 seconds (2-3 blocks)
Max Core Validators: 21
Minimum Staking Requirement: 10,000 JU (adjustable on Testnet)
Validation Cycle: Default 7,200 blocks (~6 hours), adjustable between 3,600-14,400 blocks

3.2 Fault Tolerance

Byzantine Fault Tolerance: Tolerates up to 1/3 validator failures or malicious behavior (max 7 core validators).
Penalty Mechanism: Missing 100 consecutive blocks results in a 5% JU stake deduction.

3.3 Rewards

Block Reward: 2 JU per block (Testnet), dynamically adjusted
Delegation Reward Split: 70:30 between validators and delegators

4. Network Configuration

4.1 Testnet

RPC Endpoint: https://testnet-rpc.juchain.org
WebSocket: wss://testnet-ws.juchain.org
Network ID: 202599
Currency Symbol: JU
Block Explorer: https://explorer-testnet.juchain.org

4.2 Gas Parameters

Gas Price: Minimum 1 gwei (10⁹ wei), recommended 1-5 gwei
Gas Limits:
- Per Transaction: Default 5,500,000
- Per Block: Default 30,000,000
Unit Conversion: 1 JU = 10¹⁸ wei

4.3 Node Requirements

Full Node:
- CPU: 4 cores
- Memory: 8 GB
- Storage: 500 GB SSD
Validator Node: Increase memory to 16 GB, requires 24/7 uptime

5. Error Codes

Common errors and their resolutions:

Error Code

Description

Resolution

-32000

Insufficient funds

Check account balance and acquire JU

-32603

Out of gas

Increase transaction gas limit

429

Too Many Requests

Wait 1 minute or check rate limits

Transaction reverted

Verify contract logic or input parameters

6. Tools and SDKs

6.1 Truffle Configuration

Example (truffle-config.js):

const HDWalletProvider = require("@truffle/hdwallet-provider");
module.exports = {
  networks: {
    juchain_testnet: {
      provider: () => new HDWalletProvider("mnemonic", "https://testnet-rpc.juchain.org"),
      network_id: 202599,
      gas: 5500000,
      gasPrice: 1000000000,
    },
  },
};

7. Additional References

EVM Compatibility: JuChain supports all Ethereum opcodes. See the Ethereum Yellow Paper.
Block Structure:
- Header: Version, previous hash, timestamp, Merkle root
- Body: Transaction list
State Database: Based on Merkle Patricia Trie (MPT). Refer to Ethereum Trie Documentation.

Summary

This technical reference equips developers with detailed information for interacting with JuChain, covering API calls, contract ABIs, consensus parameters, and network configurations. Paired with the [Developer Guide] and [Tutorials and Examples], you can efficiently build, deploy, and troubleshoot dApps. For further assistance, visit the [Community and Support] page.

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Last updated 24 days ago