Metadium Dev Guide EN
User Manual:
Open the PDF directly: View PDF 
.
Page Count: 14
| Download | |
| Open PDF In Browser | View PDF |
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
Date: 2019/03/15
Author: Jeffrey Song (CTO)
Metadium Blockchain:
Dev Guide Document
1
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
Table of Contents
Introduction
Metadium Blockchain Full Client (gmet)
Download Source Code
Install
Address Format
Coin Balance
Interface (JSON RPC)
Transaction Fee
Block Explorer
Testnet META Faucet
Block Finality
BIP32 HD wallet Rule (Reference)
How to Connect Metamask with Metadium Testnet
Link
Source Code
Open API Server
Block Explorer
Test Meta Faucet
Gmet Install Guide
Contact
Technical Support
2
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
1. Introduction
This document is prepared for the Metadium Blockchain Integration as a reference
document for the exchange technical team and any individual developers to support
Metadium Blockchain. The current document is based on Metadium Mainnet and Testnet
(Kalmia v2).
2. Metadium Blockchain Full Client (gmet)
In order to connect with Metadium blockchain, you must install Metadium client, gmet, and
finish complete block sync.
● Download Source Code
The Metadium Client is called Go-Metadium (gmet) and was made by forking Ethereum's
Go-Ethereum client. The corresponding source code can be downloaded from the Github
Repository master branch.
● Install
Please refer to the readme file in the github repository for installation instructions.
If you prefer docker environment, please use docker images to build go-metadium which
has the least dependency issues.
Developer has to install the following libraries to launch gmet at Ubuntu 18.04.2 LTS
(GNU/Linux 4.15.0-1021-aws x86_64) machine.
sudo apt-get install -y libtbb2 libzstd1 libjemalloc1 libsnappy1v5 liblz4-1 libstdc++6
After installing, run “gmet metadium new-account” to create an account on your local node.
You should now be able to run gmet and connect to either Mainnet or Testnet network.
Make sure to check the different options and commands with “gmet --help”
Below is the recommended command to start gmet node as a full data sync node.
## MAINNET
{data_folder}/bin/gmet --syncmode full --datadir {data_folder} --rpc --rpcaddr 0.0.0.0
## TESTNET
{data_folder}/bin/gmet - -testnet --syncmode full --datadir {data_folder} --rpc --rpcaddr
0.0.0.0
If you would like to start gmet with fast sync, please give the same command without
“--syncmode full” option.
3
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
Note that you don’t need to specify bootnode. Pre-defined bootnodes are embedded in the
binary code of gmet executable. If you want add extra bootnode, please specify extra boot
node manually when you start gmet at the command line.
● Address Format
Since the address system of Metadium is the same as that of Ethereum, it is possible to use
the Ethereum address as it is (e.g., 0x0300cef240e54a14329f2dd4bf21bc5ca394eec1). In
other words, the exchange that supports Metadium ERC20 can use the same address
without changing the customer's cold wallet address. You can download Metadium Keepin
App for both Android and iOS mobile phone.
● Coin Balance
The Metadium Team has frozen the Metadium ERC20 contract at 3 AM UTC on February 22,
2019. A snapshot of the frozen ERC20 token has been recorded in the genesis block when
Mainnet started. The amount is converted to at a 1: 1 ratio (i.e., 100 ERC20 Meta Token =
100 Metadium Mainnet Coin). If you are ERC20 META holder, please go to Metadium block
explorer and check your balance with the same address. Mainnet Block Explorer
● Interface (JSON RPC)
Metadium supports all Go-Ethereum RPC without modification. Below is the cURL command
for testing using Metadium Testnet/Mainnet Open API server.
The default RPC port for gmet is 8588 for both Mainnet and Testnet, and you can change it
to 8545, which is the same as geth, using the “--rpcport 8545” option when running gmet if
you prefer.
Moreover, the default P2P port for gmet is 8589 for both Mainnet and Testnet,
## MAINNET
curl -i -X POST -H "Content-Type: application/json" -d '{"jsonrp
c":"2.0","method":"eth_getBalance","params":["0x47f7b1714603beEBf0643e7bA5c7D7c9b7
eF7D27", "latest"],"id":1}' https://api.metadium.com/prod
## TESTNET
curl -i -X POST -H "Content-Type: application/json" -d '{"jsonrp
c":"2.0","method":"eth_getBalance","params":["0x47f7b1714603beEBf0643e7bA5c7D7c9b7
eF7D27", "latest"],"id":1}' https://api.metadium.com/dev
● Network ID & Chain ID
Metadium uses the same network ID and chain ID pair. Please use 11 for the mainnet and 12
for the testnet especially when you are using Metamask like applications.
4
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
● Transaction Fee
Gmet 's default gas price is 80 Gwei, and if it is lower than this, confirmation may be
delayed. When you create a withdrawal transaction on the exchange, you must read and use
the current network's gas price through the eth_gasPrice RPC as shown below.
This is how to get gas price to use for sending transaction.
## MAINNET
curl -i -X POST -H "Content-Type: application/json" -d
'{"jsonrpc":"2.0","method":"eth_gasPrice","params":[],"id":1}'
https://api.metadium.com/prod
## TESTNET
curl -i -X POST -H "Content-Type: application/json" -d
'{"jsonrpc":"2.0","method":"eth_gasPrice","params":[],"id":1}'
https://api.metadium.com/dev
3. Block Explorer
Metadium Block Explorer is a web tool that provides detailed information about Metadium
blocks, addresses, and transactions. It provides almost all the functions of Etherscan
including contract verification, read, write, and much more. It has also unique Open API
services to subscribers for free. Don't miss out – subscribe today! Please try by yourself at
Mainnet Explorer and Testnet Explorer.
4. Testnet META Faucet
Testnet META, a native coin used in the Metadium blockchain, can be obtained from the
Testnet Meta Faucet. Faucet sends a 10 META coin immediately to the requested address.
Please note that the faucet has a limitation depending on the balance of the requested
address, requester’s IP address, and the time interval of the consecutive requests for
transmission.
If you need a large amount of META to use in the dev/ staging system of the exchange, you
can contact tech@metadium.com to get it.
5. Block Interval
Metadium's consensus algorithm is SPoA (Staking-based Proof of Authority) and the details
of the consensus algorithm will be released to the public in a separate sheet.
Testnet
Mainnet
5
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
Block Interval with pending
transactions
immediate
immediate
Block Interval with no
pending transaction
5 second
5 second
6. BIP32 HD wallet Rule (Reference)
Metadium Mainnet is registered in SLIP-0044 (Registered coin types for BIP-0044). The
basic path of private key generated by mnemonic is as follows.
m/44'/916'/0'/0
https://github.com/satoshilabs/slips/blob/master/slip-0044.md
The basic path should be used when creating an app or web service that directly generates a
private key for Metadium blockchain.
7. How to Connect Metamask with Metadium Testnet
Metamask can be used to send / receive META with Metadium blockchain. It is also possible
to distribute and interact with contracts at http://remix.ethereum.org/ using metamask.
Remember to set the gas price to 80 GWei or higher when you send via metamask.
Step#1: Install Metamask Chrome Extension Web Store
Step#2: At Networks → Choose “Custom RPC”
6
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
Step#3: At Settings → Choose “Show Advanced Options”
7
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
Step#4: Type Metadium Network Info → Save → Close Settings
●
Setting for Mainnet
8
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
1.
2.
3.
4.
●
New RPC URL: https://api.metadium.com/prod
ChainID: 11
Symbol: META
Nickname: META Mainnet
Setting for Testnet
5.
6.
7.
8.
New RPC URL: https://api.metadium.com/dev
ChainID: 12
Symbol: META
Nickname: META Testnet
Step#5: You are now connected to Metadium Network (either Mainnet or Testnet)
Step#6: Check your balance
Step#7: Click Send → Fill To/Amount fields → Choose “Advanced Options”
9
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
Step#8: Change Gas Price (GWEI) to 80 at least → Save → Next → Confirm
10
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
11
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
12
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
Step#9: Copy source or destination address → Go Metadium Block Explorer → Copy Address
to search window and Enter → See transaction lists of address
Step#10: Check your balance
13
Mar 15, 2019
Copyright © 2019 Metadium Technology,Inc. All rights reserved.
8. Link
● Source Code
https://github.com/metadium/go-metadium
● Open API Server
https://api.metadium.com/prod and https://api.metadium.com/dev
● Block Explorer
https://explorer.metadium.com and https://testnetexplorer.metadium.com
● Test Meta Faucet
https://testnetfaucet.metadium.com
● Gmet Install Guide
https://github.com/METADIUM/go-metadium/blob/master/README.md
9. Contact
● Technical Support
tech@metadium.com
14
Mar 15, 2019
Source Exif Data:
File Type : PDF File Type Extension : pdf MIME Type : application/pdf PDF Version : 1.5 Linearized : Yes Producer : Skia/PDF m75 Page Count : 14EXIF Metadata provided by EXIF.tools