ICON Developer Portal

ICON Developer Portal

ICON Network is a decentralized smart contract protocol based on ‘loopchain’, a high-performance blockchain engine. The ICON Network aims to remove barriers among different blockchains and allow them to exchange values without intermediaries. By realizing this goal, ICON will realize the mass adoption of blockchain technology and Hyperconnect the World.

Get Started


Becoming a Public Representative (P-Rep)

P-Reps are the consensus nodes that produce, verify blocks and participate in network policy decisions on the ICON Network. To register and become a P-Rep will consist of the following three steps,

1. Install P-Rep tools (CLI for on-chain P-Rep operations)

2. Register as a P-Rep via P-Rep tools

3. Build MainNet P-Rep node

1. Install P-Rep Tools

Quick Install

$ virtualenv venv -p python3    # Create a python 3.6.5+ virtual environment.
$ source venv/bin/activate        # Enter the virtual environment.
(venv) $ pip install preptools

Manual Install

For manual installation and P-Rep tool commands, see full documentation

2. Register via P-Rep Tools

(Registration fee is 2,000 ICX)

There are three ways supply P-Rep registration info to P-Rep Tools; using a json configuration file, using optional arguments, or using interactive command line.

(venv) $ cat registerPRep.json
    "name": "banana node",
    "country": "USA",
    "city": "New York",
    "email": "[email protected]",
    "website": "https://icon.banana.com",
    "details": "https://icon.banana.com/json",
    "p2pEndpoint": "node.example.com:7100"

# Using json file
(venv) $ preptools registerPRep --prep-json registerPRep.json -k keystore

# Using optional argument and interactive command line
(venv) $ preptools registerPRep -k keystore --name "kokoa node" --email "[email protected]"
> Password: 
 > country : USA
 > city : New York
 > website : https://icon.kokoa.com
 > details : https://icon.kokoa.com/json/details.json
 > p2pEndpoint : node.example.com:7100

[Request] ======================================================================
    "from_": "hxef73db5d0ad02eb1fadb37d0041be96bfa56d4e6",
    "to": "cx0000000000000000000000000000000000000000",
    "value": 2000000000000000000000,
    "step_limit": 268435456,
    "nid": 3,
    "nonce": null,
    "version": 3,
    "timestamp": null,
    "method": "registerPRep",
    "data_type": "call",
    "params": {
        "name": "kokoa node",
        "email": "[email protected]",
        "country": "USA",
        "city": "New York",
        "website": "https://icon.kokoa.com",
        "details": "https://icon.kokoa.com/json/details.json",
        "p2pEndpoint": "node.example.com:7100"

See registerPRep command details

The "details" parameter is an external json file that holds additional information about the P-Rep. We strongly recommend that you register this information. Example,

    "representative": {
        "logo": {
            "logo_256": "https://icon.foundation/img/img-256.png",
            "logo_1024": "https://icon.foundation/img/img-1024.png",
            "logo_svg": "https://icon.foundation/img/img-logo.svg"
        "media": {
            "steemit": "",
            "twitter": "",
            "youtube": "",
            "facebook": "",
            "github": "",
            "reddit": "",
            "keybase": "",
              "telegram": "",
            "wechat": ""
  },  "server": {
        "location": {
            "country": "",
            "city": ""
        "server_type": "",
        "api_endpoint": ""

3. Build MainNet P-Rep Node

Examples using Ubuntu 16.04+


The specifications below are recommended for main P-Reps (top 22). Sub P-Reps (outside of top 22) can run lower-end specs as they do not produce/validate blocks but only serve as citizen nodes. Current blockchain size is 153G as of this update (2020/3/17).


DescriptionMinimum SpecificationsRecommended Specifications
CPU modelIntel(R) Xeon(R) CPU @ 3.00GHzIntel(R) Xeon(R) CPU @ 3.00GHz
vCPU (core)1636


OS Requirement

  • Linux (CentOS 7 or Ubuntu 16.04+)

Open Ports

  • TCP 7100: gRPC port used for peer-to-peer connection between peer nodes.
  • TCP 9000: JSON-RPC or RESTful API port serving application requests.

3.1 Install Docker

Docker 18.x+

## Update the apt package index:
$ sudo apt-get update

## Install necessary packages:
$ sudo apt-get install  -y systemd apt-transport-https ca-certificates curl gnupg-agent software-properties-common 

## Add Docker's official GPG key:
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

## Add the apt repository
$ add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

## Update the apt package index:
$ sudo apt-get update

## Install docker-ce:
$ sudo apt-get -y install docker-ce docker-ce-cli containerd.io

## Add your user to the docker group with the following command.
$ sudo usermod -aG docker $(whoami)

## Set Docker to start automatically at boot time:
$ sudo systemctl enable docker.service

## Finally, start the Docker service:
$ sudo systemctl start docker.service

## Then we'll verify docker is installed successfully by checking the version:
$ docker version

3.2 Install Docker Compose

## Install python-pip
$ sudo apt-get install -y python-pip

## Then install Docker Compose:
$ sudo pip install docker-compose

## To verify the successful Docker Compose installation, run:
$ docker-compose version

3.3 Running a P-Rep Node Container using docker-compose

Create a file named docker-compose.yml in a text editor and add the following content:

version: "3"
     image: "iconloop/prep-node"
     container_name: "prep-mainnet"
     network_mode: host     
     restart: "always"
        NETWORK_ENV: "mainnet"
        LOG_OUTPUT_TYPE: "file"
        SWITCH_BH_VERSION3: "10324749"
        CERT_PATH: "/cert"
        ICON_LOG_LEVEL: "DEBUG"        
        FASTEST_START: "yes" # Restore from lastest snapshot DB
        - SYS_TIME      
        - ./data:/data # mount a data volumes
        - ./cert:/cert # Automatically generate cert key files here
        - 9000:9000
        - 7100:7100

Run docker-compose

$ docker-compose up -d

The parameter provided FASTEST_START: "yes" will download the latest full-hour blockchain snapshot, and the remaining blocks will be synchronized automatically. You can check server status and current block height via this API: http://{YOUR_NODE_IP}:9000/api/v1/status/peer.

Citizen Node

Citizen nodes are non-producing nodes on the ICON network. A non-producing node is a node that is not configured to produce blocks, instead it is constantly synchronizing the latest blocks from the network and can be used for on-chain queries. Citizen nodes DO NOT require registration.

ICON node software is identical for P-Rep nodes and Citizen nodes, one can follow the same procedures to set up a P-Rep node, without registration, to operate a Citizen node.

Experiment on TestNet

TestNet Pagoda is available for node operation testing, you can experiment with this docker-compose template.

Pagoda Network Information

API endpointhttps://zicon.net.solidwallet.io/api/v3
Network ID (nid)80
Transaction feeon
SCORE auditon

To receive test ICX, please send email to [email protected] with the following information.

  • Testnet node URL
  • Address to receive the testnet ICX. Address should start with hx followed by a 20-byte string.

Having Trouble?

For troubleshoots and other questions, please join ICON P-Rep MainNet or ICON P-Rep TestNet Telegram Channels.

Updated about a month ago


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