# Cronos Mainnet: Running Nodes

This is a detailed documentation for setting up a Validator or a full node on Crypto.org Cronos mainnet Beta cronosmainnet_25-1.

# Pre-requisites

# Supported OS

We officially support macOS, Windows and Linux only. Other platforms may work but there is no guarantee. We will extend our support to other platforms after we have stabilized our current architecture.

# Prepare your machine

  • To run Cronos mainnet Beta nodes, you will need a machine with the following minimum requirements:

    • 4-core, x86_64 architecture processor;

    • 16 GB RAM;

    • 1 TB of storage space.

# Step 1. Get the Cronos mainnet Beta binary


The following is the minimal setup for a validator node / full node.

To simplify the following step, we will be using Linux (Intel x86) for illustration. Binary for

Mac (Intel x86 (opens new window) / M1 (opens new window)) and Windows (opens new window) are also available.

  • To install released Cronos mainnet Beta binaries from github:

    $ curl -LOJ https://github.com/crypto-org-chain/cronos/releases/download/v0.6.1/cronos_0.6.1_Linux_x86_64.tar.gz
    $ tar -zxvf cronos_0.6.1_Linux_x86_64.tar.gz

    Afterward, you can check the version of cronosd by

    $ ./cronosd version

# Step 2. Configure cronosd

# Step 2-0 (Optional) Clean up the old blockchain data

  • If you have joined cronostestnet_338-3 before, you would have to clean up the old blockchain data and start over again, it can be done by running:

    $ ./cronosd unsafe-reset-all

    and remove the old genesis file by

    $ rm ~/.cronos/config/genesis.json

Before kick-starting your node, we will have to configure your node so that it connects to the Cronos mainnet Beta:

# Step 2-1 Initialize cronosd

  • First of all, you can initialize cronosd by:

      $ ./cronosd init [moniker] --chain-id cronosmainnet_25-1

    This moniker will be the displayed id of your node when connected to Cronos Chain network.

    When providing the moniker value, make sure you drop the square brackets since they are not needed.

    The example below shows how to initialize a node named pegasus-node :

      $ ./cronosd init pegasus-node --chain-id cronosmainnet_25-1


    • Depending on your cronosd home setting, the cronosd configuration will be initialized to that home directory. To simply the following steps, we will use the default cronosd home directory ~/.cronos/ for illustration.

    • You can also put the cronosd to your binary path and run it by cronosd

# Step 2-2 Configure cronosd

  • Download and replace the Cronos Mainnet Beta genesis.json by:

    $ curl https://raw.githubusercontent.com/crypto-org-chain/cronos-mainnet/master/cronosmainnet_25-1/genesis.json > ~/.cronos/config/genesis.json
  • Verify sha256sum checksum of the downloaded genesis.json. You should see OK! if the sha256sum checksum matches.

    $ if [[ $(sha256sum ~/.cronos/config/genesis.json | awk '{print $1}') = "58f17545056267f57a2d95f4c9c00ac1d689a580e220c5d4de96570fbbc832e1" ]]; then echo "OK"; else echo "MISMATCHED"; fi;


    • For Mac environment, sha256sum was not installed by default. In this case, you may setup sha256sum with this command:

      function sha256sum() { shasum -a 256 "[email protected]" ; } && export -f sha256sum
  • In ~/.cronos/config/app.toml, update minimum gas price to avoid transaction spamming (opens new window)

    $ sed -i.bak -E 's#^(minimum-gas-prices[[:space:]]+=[[:space:]]+).*$#\1"5000000000000basecro"#' ~/.cronos/config/app.toml
  • For network configuration, in ~/.cronos/config/config.toml, please modify the configurations of persistent_peers, create_empty_blocks_interval and timeout_commit by:

    $ sed -i.bak -E 's#^(seeds[[:space:]]+=[[:space:]]+).*$#\1"[email protected]g:26656,[email protected]g:26656,[email protected]g:26656"#' ~/.cronos/config/config.toml
    $ sed -i.bak -E 's#^(create_empty_blocks_interval[[:space:]]+=[[:space:]]+).*$#\1"5s"#' ~/.cronos/config/config.toml
    $ sed -i.bak -E 's#^(timeout_commit[[:space:]]+=[[:space:]]+).*$#\1"5s"#' ~/.cronos/config/config.toml


  • For Mac environment, if jq is missing, you may install it by: brew install jq

# Step 3. Run everything


This page only shows the minimal setup for validator / full node.

Furthermore, you may want to run full nodes

as sentries (see Tendermint (opens new window)), restrict your validator connections to only connect to your full nodes, test secure storage of validator keys etc.

# Step 3-1. Create a new key and address

Run the followings to create a new key. For example, you can create a key with the name Default by:

  $ ./cronosd keys add Default

You should obtain an address with crc prefix, e.g. crc10u5mgfflasrfj9s94mt8l9yucrt2gzhcyt5tsg. This will be the address for performing transactions.

# Step 3-2. Run everything

Once the cronosd has been configured, we are ready to start the node and sync the blockchain data:

  • Start cronosd, e.g.:

  $ ./cronosd start


If you see errors saying too many files opened..., then you need to set a higher number for maximum open file descriptors in your OS.

If you are on OSX or Linux, then the following could be useful:

# Check current max fd

$ ulimit -n

# Set a new max fd


# Example

$ ulimit -Sn 4096

  • (Optional for Linux) Start cronosd with systemd service, e.g.:

  $ curl -s https://raw.githubusercontent.com/crypto-org-chain/cronos-docs/master/systemd/create-service.sh -o create-service.sh && curl -s https://raw.githubusercontent.com/crypto-org-chain/cronos-docs/master/systemd/cronosd.service.template -o cronosd.service.template

  $ chmod +x ./create-service.sh && ./create-service.sh

  $ sudo systemctl start cronosd

  # view log

  $ journalctl -u cronosd -f

Example: /etc/systemd/system/cronosd.service created by script

# /etc/systemd/system/cronosd.service









ExecStart=/usr/local/bin/cronosd start --home /home/ubuntu/.cronos






It should begin fetching blocks from the other peers.

  • You can query the node syncing status by

    $ ./cronosd status 2>&1 | jq '.SyncInfo.catching_up'

    If the above command returns false, It means that your node is fully synced; otherwise, it returns true and implies your node is still catching up.

  • One can check the current block height by querying the public full node by:

    curl -s https://rpc-cronos.crypto.org/commit | jq "{height: .result.signed_header.header.height}"

    and you can check your node's progress (in terms of block height) by

    $ ./cronosd status 2>&1 | jq '.SyncInfo.latest_block_height'

# Cronos mainnet Beta explorer