Frequently Asked Questions (FAQ)

This page will be updated regularly as more important questions are asked by the community.

What is XELIS?

It's a layer-1 private cryptocurrency blockchain. You can launch your own token or decentralized application.

What is the ticker?

Ticker for XELIS asset is XEL.

What is the main usage of XELIS?

It is used to pay fees, deploy Smart Contracts, create new assets, and store/transfer value.

When is the Mainnet launch?

The official launch date is 20/04/2024 at 3PM UTC.

What is the estimated coin emission per year?

Here is the estimated circulating supply for the next 5 years:

• First year: ~2 831 221 XEL circulating supply
• Second year: ~5 226 799 XEL circulating supply
• Third year: ~7 253 766 XEL circulating supply
• Fourth year: ~8 968 841 XEL circulating supply
• Fifth year: ~10 420 016 XEL circulating supply

NOTE: Maximum supply is 18.4M XEL

Is there any real world application of this?

Absolutely! There are a lot of tangible applications. One notable example is creating your own local currency foundation with peace of mind. No counterfeiting, no scrutinizing eyes, 100% uptime, decentralized and secure transactions.

Where are my coins stored?

Your balance is stored on chain, not on your computer or in your wallet.
The wallet allows you to manage these funds as long as you have access to it.

Always keep your seed or a backup of your wallet file. This ensures you can access your funds if your device is lost or unusable.

What does a "private" blockchain mean?

The account balance are private. They are homomorphically encrypted. Others cannot see your wallet balance on the public ledger.

What is Homomorphic Encryption for dummies?

Homomorphic Encryption allows computations on encrypted data without prior decryption; in this context, it provides nodes the ability to validate transactions without ever knowing the balance of each participant.

What is BlockDAG? Why is it used?

A BlockDAG differs from a traditional blockchain by using a Directed Acyclic Graph data structure. In a BlockDAG, multiple blocks can coexist at the same height with various types, but each can be distinguished by a unique topological height.

The primary reason for using this structure is to achieve fast block time validation; XELIS block time is ~15s.
The DAG significantly reduces the number of orphan blocks by merging them instead of creating split branches, inherently enhancing scalability while mitigating centralization and chain split.

More info here: BlockDAG.

Why is XELIS an account-based model?

Account based blockchains offer way more advantages than drawbacks from our point of view.
It's a more flexible system than traditional UTXO model, eliminating the need to follow inputs / outputs.
It allows real fungibility of coins. 1 XEL = 1 XEL. No tainted coins.

Node pruning is possible, removing old blocks while maintaining the verifiability of blockchain state. Additionally, it enables a fast-sync feature - download the latest state of the chain and join the network instantly.

No need to full scan the chain to know your wallet balance, request the latest state and you're ready to use it.

More info here: Features.

How are you encrypting the balance homomorphically?

We use ElGamal with the Ristretto255 points on Curve25519 (which achieves ~128 bits of security).
While homomorphic encryptions are generally computation-intensive, we need to use addition and subtraction for transactions.

Is this a fork of an existing crypto project?

XELIS is NOT a fork. Everything is written in Rust from scratch using open source libraries.
If you want to know how the protocol works in detail, start here: Features.

Github repository: https://github.com/xelis-project/xelis-blockchain (opens in a new tab)

Why another crypto project?

Not the same vision as other blockchains, different choices made and strong commitment to build a fast / robust / long lasting financial system.
The cryptocurrency world is still young and the technology and continues to evolve each day. We want to be part of it by contributing to it.

Did you already launch a project before XELIS?

No, none of us have created a project like this before; this is our first one. However, some of us may have participated or contributed to other projects as community developers.

Was there any premine?

There is no premine or any allocation of coins whatsoever. We have set a dev fee within the protocol for every block.

More info here: Funding.

I saw Atomic Unit of 8 for the coin. What does that mean?

We store the balance as an unsigned integer to facilitate computations with encryption, and the client shifts the balance by 8 decimals after decryption.

Ex: 100000000 = 1.00000000 XEL

Unsigned integers are used to have exact precision on addition / subtraction in financial systems.
Try the following in Python to have an example of floating point issue: 3.33-3.13

Will Testnet coins be transferred to Mainnet?

No. Coins will never be transferred or transferable from Testnet to Mainnet.
Testnet can be reset at any time and its coins have no value.

One network is for development, and the other is for the future of financial freedom.

Is there any incentive toward mining or running a node in Testnet?

No immediate incentive is offered, but potential gifts may be given later down the road. Being an early adopter, running a node, and participating in mining can help us find bugs and move faster toward our goal of a stable running blockchain. It benefits everyone involved in the project.

What are your primary focuses for the project?

• Providing simple, functioning tools, up-to-date documentation, including easy-to-integrate APIs for devs.
• A POW CPU/GPU friendly mining algo.
• Decentralization, security and speed (no chain split, double spend, or any kind of network downtime).
• Optimization (blockchain size, bandwidth transfer, transaction execution and encryption speed).
• Community driven decisions.

More info here: Objectives.

What is the consensus algorithm that XELIS uses?

XELIS is a Proof-Of-Work (PoW) network. We are currently working on a CPU/GPU friendly mining algorithm that is both ASIC and FPGA resistant.

The longest chain is the one selected by nodes, based on topoheight.
During chain split at same height, the main chain is selected based on the cumulative difficulty of each branch tip.

Does XELIS support Smart Contracts?

Yes, smart contracts are expressed using an interpreted language, known as XELIS-VM. The language has various primitives and features, such as recursive functions. Functions are implemented with a configurable depth limitation to mitigate risk of network attacks and congestion.

More info here: Smart Contracts.
Github repository: https://github.com/xelis-project/xelis-vm (opens in a new tab)

Please note the smart contracts are not currently available within the network.

Can my wallet be offline when I mine or receive a transaction?

Of course, it can be offline! Your wallet balance is stored in the network ledger, which is maintained by all the nodes. An online wallet simply keeps a live connection to a remote node and displays your latest balance. Now, don't forget to assign your wallet address to your miner. If you find a solution that's accepted by the network, you'll receive the reward regardless of your wallet's connectivity.

What kind of reward can I expect from mining?

It starts at around ~1.41 XEL per block and decreases for each subsequent block. This reduction isn't based on halving logic but rather on the supply and emission factor of 20. It's also possible to mine a side block on the BlockDAG and receive a smaller portion of the reward.
More info here: Block Types

I want to work with the team. How can I apply?

Currently, we don't have any open positions. We will announce job openings and create a dedicated page in the documentation when they become available. However, if you want to stand out and improve your chances, you can contribute by submitting valuable PRs, actively engage with the community and developers, and more. We always appreciate proactive involvement and contributions. This is an initiative that carries significant weight if you want to work more closely with the team.

Why does the blockchain size vary between nodes?

XELIS uses Sled as the primary storage for the ledger, which includes block headers, transactions, encrypted account balances, etc... However, Sled is still in beta and has pending issues with garbage collection overhead, such as write amplification. This can result in different sizes across devices and nodes. For now, we continue to use Sled, but we might consider switching to an alternative like RocksDB.