SENT Staking Backend

Running the backend

Pre-requisites

The liboxenc-dev and liboxenmq-dev packages require the development headers by setting up the Oxen Deb Repository. Follow those instructions then they can be installed with apt.

To run the backend on Ubuntu >= 24.04:

apt install build-essential python3-pip python3-dev pybind11-dev liboxenc-dev liboxenmq-dev
python3 -m pip install eth_utils web3 PyNaCl Flask uWSGI

Python bindings for oxen-mq & oxen-encoding

Instructions available at:

• oxen-pyoxenc
• oxen-pyoxenmq

Instance

Before running an instance, oxend must be running and its address/smart contracts configured in config.py.

It's possible to run the service in flask directly but the timers to poll the smart contracts requires WSGI. Both methods are detailed below:

FLASK_APP=sent flask run --reload --debugger
uwsgi --http 127.0.0.1:5000 --master -p 4 -w sent --callable app

You may optionally append --fs-reload sent.py to the uwsgi invocation to automatically restart the server when sent.py is modified.

After the server is running, visit 127.0.0.1:5000/info to verify that the server is up and responding correctly with a payload like the following:

{
  "network": {
    "hard_fork": 21,
    "height": 837,
    "max_stakers": 10,
    "min_operator_stake": 30000000000,
    "nettype": "stagenet",
    "staking_requirement": 120000000000,
    "top_block_hash": "aa32d153fa260a76bd31751bc3b3193565c8cc17ec7ce543585b96d206b37892",
    "version": "11"
  },
  "t": 1720677228.877856
}

Setting up an oxend instance

The default configuration for mainnet.py, testnet.py, devnet.py look for mainnet.sock, testnet.sock, and devnet.sock in this directory, which should be either sockets or symlinks to sockets to a running mainnet/testnet/devnet oxend.

There are a few ways to make this work.

Symlinks

You can add symlinks here to existing oxend sockets. If oxend and the backend code are running as the same user then you can simply create a symlink:

ln -s /var/lib/oxend/oxend.sock mainnet.sock

For a system service oxend (as installed in the debs, via the oxen-node.service systemd service), you can make it work, but will need an extra step to configure socket permissions:

ln -s ~/.oxen/oxend.sock mainnet.sock

and then do one of:

• Set the active group of the running sent staking backend to the _loki user. Whether this is easy or not depends on how the backend service is running.

• Add the _loki group to the supplemental groups of the user that will be running this backend. (This is the more secure option).

  usermod -aG _loki FRONTENDUSERNAME
  

• Add the lmq-umask=0000 option to oxen.conf (or run oxend with the --lmq-umask=0000 option). Note that this is somewhat less secure than the above, because any user or process on the local system will be able to control oxend.

Do NOT:

• Run any production service as root (including under sudo). Don't be tempted just because "it works" under sudo: by running things under root/sudo you compromise the security of your entire system as a solution to properly setting up permissions. Please don't do this, ever.

Make oxend create the socket

The lmq-public=ipc:///path/to/sent-staking-backend/oxend/mainnet.sock can be added to oxen.conf (or run with --lmq-public=...) to have it listen on that socket. Note that when oxend and sent-staking-backend are running as separate users, this has the same permission issues as the Symlinks approach (see above for solutions).

Use TCP OMQ RPC

You can configure oxend with lmq-public=tcp://127.0.0.1:6789 (choose whatever port you like in place of 6789) in the oxen.conf config file [alternatively: run oxend with --lmq-public=tcp://127.0.0.1:6789] and then add/uncomment the mainnet_rpc=... (or testnet_rpc= or devnet_rpc=) line in config.py.