Supernode Program⚓︎

The Supernode Program rewards public NEM nodes that help secure the network and provide reliable data access for applications. Because all XEM was created in the genesis block, NEM has no block subsidy. A quantity of XEM was set aside for the Supernode Program.

Reward eligibility is checked daily in four rounds, one round every six hours. A participating node must pass every test in every round to qualify for that day's reward.

Testing is performed by a centrally managed Supernode monitoring service called the controller. Some tests compare the participating node with a trusted reference node.

Participating nodes also run the Node Servant, a lightweight application on the same machine as the NIS client. The Servant performs Supernode Program tests and exposes the /nr/... endpoints used by some of those tests.

Eligibility Tests⚓︎

Each testing round includes the following checks:

Chain height: The node reports its current height through the /chain/height GET API. The test passes if the height is no more than 4 blocks behind the reference node.
Chain part: The node serves a random group of 60 to 100 recent blocks through the /local/chain/blocks-after POST API. The controller verifies the block signatures and compares a composite hash of those blocks with the same hash calculated from the reference node.
Balance: The node's main account has at least 10,000 XEM. The controller checks this through the /account/get/forwarded GET API, routed through the reference node.
Computing power: The node completes 10,000 repeated public-key derivations from a random hash. The test passes if the final public key matches the controller's result and the full round trip takes 5 seconds or less.
Version: The node reports a NIS client version through the /node/info GET API. The test passes if the version is at least as recent as the reference node's version.
Ping: The controller gives the Servant 5 random partner nodes through the /nr/task/ping API. The Servant calls the /nr/ping API on each partner 5 times. The test passes if no more than one ping fails and the average successful round-trip time is less than 200 ms.
Bandwidth: The controller gives the Servant the fastest partner from the ping test and a random hash seed through the /nr/task/bandwidth API. The Servant and partner perform the same 30,000-hash calculation. The test passes if both hash results match and the measured transfer speed is at least 5 Mbit/s.
Responsiveness: The controller sends 10 requests to the /chain/height GET API. The test passes if at least 9 requests succeed and all requests complete in 1 second or less. If only the time limit fails, the controller retries this test up to 4 times.

Enrolling in the Program⚓︎

Before enrolling, make sure you have:

NEM NanoWallet installed.
A NEM account with at least 10,010 XEM. The program requires 10,000 XEM to participate, plus approximately 10 XEM for delegated harvesting and enrollment transaction fees.
Delegated harvesting activated on the main account. The remote account becomes usable after approximately 360 blocks, or about six hours. Enrollment can start as soon as the remote account private key is available.
A synchronized public node. Follow the node installation guide if you do not have one yet.

Make sure the nis.shouldAutoHarvestOnBoot property is set to true or not set.
A stable public IP address or domain name for the node.

Use the Delegated Private Key

Use the delegated private key for the node and Servant configuration. Do not use the private key of the main account.

The main private key controls the account's funds. The delegated private key only controls delegated harvesting and can be replaced if it is compromised.

To find the delegated private key in NEM NanoWallet, open Services, then Delegated Harvesting, then Manage Delegated Account. Select Show delegated account keys and enter the wallet password to reveal the delegated private key.

Manually⚓︎

Configuring the Servant⚓︎

Download the Node Servant.
Unzip the file in the folder that becomes the Servant installation folder. It does not need to be the same as the NIS1 installation folder. Open the servant folder.
Open the Servant config-user.properties file.
Set nem.host to the node's static IP address or domain name. This value must remain stable so the controller can test the same node.
Set servant.key to the delegated private key.
Save the file.
Open inbound and outbound TCP port 7880 so the Servant can receive Supernode Program tests.

Starting the Servant⚓︎

Start NIS and let it synchronize before starting the Servant with:

WindowsLinux and macOS

runservant.bat

sh startservant.sh

Run the Servant in the background with a tool such as screen or nohup.

Using Docker⚓︎

These instructions only work for Linux systems, including the Windows Subsystem for Linux.

Configuring the Servant⚓︎

If you installed your node using Docker as explained in the Installation guide for Docker, you already have the Servant installed and you only need to configure it.

Stop the NIS1 client if it is running, as explained in Controlling the node.

Inside the custom-configs folder:

Copy the servant.config.properties.sample file into servant.config.properties and edit it. Provide values for at least the nem.host and servant.key properties.
Copy the supervisord.conf.sample file into supervisord.conf and edit it. Set autostart=true in both the [program:nis] and [program:servant] sections.

Starting the Servant⚓︎

The Servant now starts every time the NIS1 client is started with:

./boot.sh

You can verify it with:

./service.sh status

Sending the Enrollment⚓︎

The monthly enrollment address is announced through the NEM community channels.

Enrolling with NEM NanoWallet⚓︎

Open Services.
Open SuperNode Program.
Open Check & Enroll in Program.
Select Enroll in Program.
Enter the current enrollment address and the node host.

The host must match the host returned by the node's /node/info GET endpoint.
Send the enrollment transaction.

Enrolling Manually⚓︎

Enrolling manually requires sending a transfer transaction to the current enrollment address with the following unencrypted message:

enroll <NODE_HOST> <CODEWORD_HASH>

<NODE_HOST> as returned by the node's /node/info GET endpoint.
<CODEWORD_HASH> as returned by the following query:
```
https://nem.io/supernode/api/codeword/<MAIN_PUBLIC_KEY>
```
Use the Public Key
- Use the main public key in the codeword API URL, not the private key.
- Use the main public key of the account enrolled in the program, not the remote key used to harvest on the node.
  
  Please note that /node/info GET returns the remote key.

Reviewing Test Results⚓︎

Review the node's test results on the Supernode Program page. Results do not appear immediately after enrollment.

Editing the Supernode Host⚓︎

If the node's IP address or domain name changes, update the node and Servant configuration. Then send a new enrollment transaction with the changed host.

Monthly Re-Enrollment⚓︎

The Supernode Program requires monthly re-enrollment. Each month has a new enrollment address, announced through the NEM community channels.

Enrollment for the next month opens 4 days before the end of the current month. Repeat the enrollment process each month with the new enrollment address.