Mix Nodes

The Nym mix node binary was built in the building nym section. If you haven’t yet built Nym and want to run the code, go there first.

Any syntax in <> brackets is a user’s unique variable. Exchange with a corresponding name without the <> brackets.

Current version


The nym-mix node binary is currently one point version ahead of the rest of the platform binaries due to a patch applied between releases.

Preliminary steps

Make sure you do the preparation listed in the preliminary steps page before setting up your mix node.

Mix node setup

Now that you have built the codebase, set up your wallet, and have a VPS with the nym-mix node binary, you can set up your mix node with the instructions below.

To begin, move to /target/release directory from which you run the node commands:

cd target/release

Viewing command help

You can check that your binaries are properly compiled with:

./nym-mixnode --help

Which should return a list of all available commands.

Console output

Implementation of a Loopix-based Mixnode

Usage: nym-mixnode [OPTIONS] <COMMAND>

  describe           Describe your mixnode and tell people why they should delegate state to you
  init               Initialise the mixnode
  run                Starts the mixnode
  sign               Sign text to prove ownership of this mixnode
  node-details       Show details of this mixnode
  build-info         Show build information of this binary
  completions        Generate shell completions
  generate-fig-spec  Generate Fig specification
  help               Print this message or the help of the given subcommand(s)

  -c, --config-env-file <CONFIG_ENV_FILE>  Path pointing to an env file that configures the mixnode
      --no-banner                          Flag used for disabling the printed banner in tty
  -h, --help                               Print help
  -V, --version                            Print version

You can also check the various arguments required for individual commands with:

./nym-mixnode <COMMAND> --help

Adding --no-banner startup flag will prevent Nym banner being printed even if run in tty environment.

Initialising your mix node

To check available configuration options for initializing your node use:

./nym-mixnode init --help

Console output

 Initialise the mixnode

Usage: nym-mixnode init [OPTIONS] --id <ID> --host <HOST>

      --id <ID>                        Id of the mixnode we want to create config for
      --host <HOST>                    The host on which the mixnode will be running
      --mix-port <MIX_PORT>            The port on which the mixnode will be listening for mix
      --verloc-port <VERLOC_PORT>      The port on which the mixnode will be listening for verloc
      --http-api-port <HTTP_API_PORT>  The port on which the mixnode will be listening for http
      --nym-apis <NYM_APIS>            Comma separated list of nym-api endpoints of the validators
  -o, --output <OUTPUT>                [default: text] [possible values: text, json]
  -h, --help                           Print help

Initalise your mix node with the following command, replacing the value of --id with the moniker you wish to give your mix node. Your --host must be publicly routable on the internet in order to mix packets, and can be either an Ipv4 or IPv6 address. The $(curl -4 https://ifconfig.me) command returns your IP automatically using an external service. If you enter your IP address manually, enter it without any port information.

./nym-mixnode init --id <NODE_NAME> --host $(curl -4 https://ifconfig.me) 

Console output

.nym-mixnode init --id <YOUR_ID> --host $(curl -4 https://ifconfig.me) --wallet-address <WALLET_ADDRESS>

Initialising mixnode <YOUR_ID>...
Saved mixnet identity and sphinx keypairs
 2023-06-04T08:20:32.862Z INFO  nym_config > Configuration file will be saved to "/home/<USER>/.nym/mixnodes/<YOUR_ID>/config/config.toml"
Saved configuration file to "/home/<USER>/.nym/mixnodes/<YOUR_ID>/config/config.toml"
Mixnode configuration completed.

      _ __  _   _ _ __ ___
     | '_ \| | | | '_ \ _ \
     | | | | |_| | | | | | |
     |_| |_|\__, |_| |_| |_|

             (nym-mixnode - version v1.1.29)

Identity Key: DhmUYedPZvhP9MMwXdNpPaqCxxTQgjAg78s2nqtTTiNF","version":"v1.1.29"},"cost_params
Sphinx Key: CfZSy1jRfrfiVi9JYexjFWPqWkKoY72t7NdpWaq37K8Z
Host: (bind address:
Version: v1.1.29
Mix Port: 1789, Verloc port: 1790, Http Port: 8000

The init command will refuse to destroy existing mix node keys.

During the init process you will have the option to change the http_api, verloc and mixnode ports from their default settings. If you wish to change these in the future you can edit their values in the config.toml file created by the initialization process, which is located at ~/.nym/mixnodes/<YOUR_ID>/.

Bonding your mix node


From v1.1.3, if you unbond your mix node that means you are leaving the mixnet and you will lose all your delegations (permanently). You can join again with the same identity key, however, you will start with no delegations.

You can bond your mix node via the Desktop wallet.

  • Open your wallet, and head to the Bond page, then select the node type Mixnode and input your node details. Press Next.

  • Enter the Amount, Operating cost and Profit margin and press Next.

  • You will be asked to run a the sign command with your gateway - copy and paste the long signature as the value of --contract-msg and run it.

./nym-mixnode sign --id <YOUR_ID> --contract-msg <PAYLOAD_GENERATED_BY_THE_WALLET>

It will look something like this:

Console output

./nym-mixnode sign --id upgrade_test --contract-msg 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

      _ __  _   _ _ __ ___
     | '_ \| | | | '_ \ _ \
     | | | | |_| | | | | | |
     |_| |_|\__, |_| |_| |_|

             (nym-mixnode - version v1.1.29)

>>> attempting to sign 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
>>> decoding the message...
>>> message to sign: {"nonce":0,"algorithm":"ed25519","message_type":"mixnode-bonding","content":{"sender":"n1eufxdlgt0puwrwptgjfqne8pj4nhy2u5ft62uq","proxy":null,"funds":[{"denom":"unym","amount":"100000000"}],"data":{"mix_node":{"host":"","mix_port":1789,"verloc_port":1790,"http_api_port":8000,"sphinx_key":"CfZSy1jRfrfiVi9JYexjFWPqWkKoY72t7NdpWaq37K8Z","identity_key":"DhmUYedPZvhP9MMwXdNpPaqCxxTQgjAg78s2nqtTTiNF","version":"1.1.14"},"cost_params":{"profit_margin_percent":"0.1","interval_operating_cost":{"denom":"unym","amount":"40000000"}}}}}
  • Copy the resulting signature:
>>> The base58-encoded signature is:
  • And paste it into the wallet nodal, press Next and confirm the transaction.

Paste Signature

  • Your node will now be bonded and ready to mix at the beginning of the next epoch (at most 1 hour).

You are asked to sign a transaction on bonding so that the mixnet smart contract is able to map your nym address to your node. This allows us to create a nonce for each account and defend against replay attacks.

Bond via the CLI (power users)

If you want to bond your mix node via the CLI, then check out the relevant section in the Nym CLI docs.

Running your mix node

Now you’ve bonded your mix node, run it with:

./nym-mixnode run --id <YOUR_ID>

If everything worked, you’ll see your node running on the either the Sandbox testnet network explorer or the mainnet network explorer, depending on which network you’re running.

Note that your node’s public identity key is displayed during startup, you can use it to identify your node in the list.

Have a look at the saved configuration files in $HOME/.nym/mixnodes/ to see more configuration options.

Node Description (optional)

In order to easily identify your node via human-readable information later on in the development of the testnet when delegated staking is implemented, you can describe your mix node with the following command:

./nym-mixnode describe --id <YOUR_ID>

Node description is a short text that describes your node. It is displayed in the ./nym-mixnode list command and in the ./nym-mixnode node-details --id <YOUR_ID> command. It also shows up in the node explorer to let people know what your node is about and link to your website.

You can set your node description, by creating a file called description.toml and put it in the same directory as your config.toml file (~/.nym/mixnodes/<YOUR_ID>/description.toml). The file should look like this example:

name = "Winston Smith"
description = "I am the Sphinx"
link = "https://nymtech.net"
location = "Giza, Egypt"

Remember to restart your mix node process in order for the new description to be propagated.

Node Families

Node family involves setting up a group of mix nodes that work together to provide greater privacy and security for network communications. This is achieved by having the nodes in the family share information and routes, creating a decentralized network that makes it difficult for third parties to monitor or track communication traffic.

Create a Node Family

To create a Node family, you will need to install and configure multiple mix nodes, and then use the CLI to link them together into a family. Once your Node family is up and running, you can use it to route your network traffic through a series of nodes, obscuring the original source and destination of the communication.

You can use either nym-cli which can be downloaded from the release page or compiling nyxd.

Change directory by cd <PATH>/<TO>/<THE>/<RELEASE> and run the following on the family head to obtain the signature for the member:

./nym-mixnode sign --id <YOUR_ID> --text <TEXT>

Console output

Using nym-cli:

--mnemonic is the mnemonic of the member wanting to be the head of family.

/nym-cli cosmwasm execute <WALLET_ADDRESS> '{"create_family": {"signature": "<base58-encoded-signature>","family_head": "<TEXT>","owner_signature":"<NODE_OWNER_SIGNATURE>","label": "<NODE_LABEL>"}}' --mnemonic <MNEMONIC_FROM_THE_NODE_TO_THE_HEAD>

Using nyxd:

--from is mnemonic of the member wanting to join the family.

./nyxd tx wasm execute ${MIXNET-CONTRACT} '{"join_family": {"signature": "<base58-encoded-signature>","family_head": "<TEXT>"}}' --node ${VALIDATOR-ENDPOINT} --from mix1 --chain-id nyx --gas-prices 0.025unym --gas auto --gas-adjustment 1.3 -y -b block

To get the node owner signature, use:

./nym-mixnode node-details --id <NODE_ID>

Joining a Node Family

Change directory by cd <PATH>/<TO>/<THE>/<RELEASE> and run the following on the family head to obtain the signature for the member:

./nym-mixnode sign --id <YOUR_ID> --text <TEXT>

Console output

Using nym-cli:

./nym-cli cosmwasm execute <WALLET_ADDRESS> '{"join_family": {"signature": "<base58-encoded-signature>","family_head": "<TEXT>","owner_signautre": "<OWNER_SIGNATURE_FROM_NODE_TO_JOIN>", "label":"<NODE_TO_JOIN_LABEL>"}}'  --mnemonic <MNEMONIC_FROM_NODE_TO_JOIN>

Using nyxd:

./nyxd tx wasm execute ${MIXNET-CONTRACT} '{"join_family": {"signature": "<base58-encoded-signature>","family_head": "<TEXT>"}}' --node ${VALIDATOR-ENDPOINT} --from mix1 --chain-id nyx --gas-prices 0.025unym --gas auto --gas-adjustment 1.3 -y -b block

To get the node owner signature, use:

./nym-mixnode node-details --id <NODE_ID>

Leaving a family

If wanting to leave, run the same initial command as above, followed by:

Using nym-cli:

./nym-cli cosmwasm execute <WALLET_ADDRESS> '{"leave_family": {"signature": "<base58-encoded-signature>","family_head": "<TEXT>","owner_signautre": "<OWNER_IGNATURE_FROM_NODE_TO_LEAVE>"}}'  --mnemonic <MNEMONIC_FROM_NODE_TO_LEAVE>

Using nyxd:

./nyxd tx wasm execute ${MIXNET-CONTRACT} '{"join_family": {"signature": "<base58-encoded-signature>","family_head": "<TEXT>"}}' --node ${VALIDATOR-ENDPOINT} --from mix1 --chain-id nyx --gas-prices 0.025unym --gas auto --gas-adjustment 1.3 -y -b block

Checking that your node is mixing correctly

Network explorers

Once you’ve started your mix node and it connects to the validator, your node will automatically show up in the ‘Mix nodes’ section of either the Nym Network Explorers:

Enter your identity key to find your node. There are numerous statistics about your node on that page that are useful for checking your up-time history, packets mixed, and any delegations your node may have.

There are also 2 community explorers which have been created by Nodes Guru:

For more details see Troubleshooting FAQ


For mix node upgrade, firewall setup, port configuration, API endpoints, VPS suggestions, automation and more, see the maintenance page

Last change: 2023-09-19, commit: 8aa8f07c