Frequently Asked Questions (FAQ)
What is XELIS?
XELIS is a layer-1, account-based cryptocurrency network built on a BlockDAG. It combines Proof of Work, confidential balances and transfers, and smart contracts for creating assets and decentralized applications.
What is the ticker?
The ticker of the native XELIS asset is XEL.
What is the main usage of XELIS?
XEL is used to pay transaction fees, deploy and interact with smart contracts, create assets, and transfer value.
When did Mainnet launch?
Mainnet launched on April 20, 2024, at 3 PM UTC.
What is the estimated coin emission per year?
XELIS has a maximum supply of 18.4 million XEL. New coins are issued through block rewards, which decrease gradually as the emitted supply grows, using an emission speed factor of 20.
There is no fixed annual issuance or periodic halving of the base block reward. The reward calculation accounts for the target block interval, while actual issuance depends on the blocks ordered in the DAG and the rules active at their block versions. The target interval changed from 15 seconds to 5 seconds in V3, and V6 removed the reduced reward for side blocks.
For current network supply and block rewards, consult the block explorer . Historical annual projections should not be treated as current supply figures.
Is there any real world application of this?
XELIS supports payments with confidential amounts, custom assets such as community tokens, and decentralized applications. Smart contracts can implement applications such as token issuance, voting, and automated exchanges.
See Smart Contracts and Confidential Assets.
Where are my coins stored?
Your encrypted balances are recorded in the network ledger. Your wallet holds the keys needed to decrypt your balances and authorize spending.
Keep a secure backup of your recovery seed. If you back up an encrypted wallet file, also retain the password needed to open it. Anyone with your spending key or recovery seed can control your funds.
What does a “private” blockchain mean?
XELIS is a public network with confidential account balances and transfer amounts. These values are encrypted, and zero-knowledge proofs allow nodes to validate transfers without learning the amounts.
This does not hide every part of a transaction: account addresses and transaction relationships remain visible. Smart contract data is not automatically confidential; its visibility depends on the data and operations used by the contract.
See Homomorphic Encryption and Zero-Knowledge Proofs.
What is Homomorphic Encryption for dummies?
Homomorphic encryption allows calculations on encrypted values without decrypting them first. In XELIS, nodes can add to or subtract from encrypted balances, while zero-knowledge proofs establish that the transfers are valid without revealing the amounts.
What is BlockDAG? Why is it used?
A BlockDAG uses a Directed Acyclic Graph instead of a single linear chain. Multiple blocks can coexist at the same block height, and blocks included in the ledger receive a position in its topological order, called a topoheight.
This allows the network to include work from parallel branches and reduces wasted mining work. XELIS targets an average block interval of 5 seconds; individual intervals vary, and a block’s topological position can change during a reorganization before it becomes stable.
See BlockDAG.
Why is XELIS an account-based model?
The account model records balances and account state directly, rather than tracking individual unspent transaction outputs. This fits encrypted balances, asset management, and smart contract state.
It also supports pruning old history and fast synchronization from recent chain state. A wallet can retrieve its latest encrypted balances without downloading the entire blockchain; retrieving historical transactions is a separate operation.
How are you encrypting the balance homomorphically?
XELIS uses Twisted ElGamal encryption with the Ristretto255 group, built on Curve25519 and targeting approximately 128-bit security. Its additive properties allow nodes to update encrypted balances. Zero-knowledge proofs provide the additional checks needed to validate transactions.
Is this a fork of an existing crypto project?
No. The core protocol is implemented in Rust and was built from scratch using open-source libraries.
Source code: xelis-blockchain .
Why another crypto project?
XELIS brings together confidential balances and transfers, a Proof-of-Work BlockDAG, and programmable smart contracts. The project focuses on privacy, scalability, decentralization, and tools that are accessible to users and developers.
When we started the project, we wanted to create a cryptocurrency that was more secure, private, and scalable than existing options. We also wanted to provide a platform that was easy to use and accessible to developers, while also being scalable enough to handle a large number of transactions. No other project we found combined these features in a single protocol, so we decided to build our own.
See Objectives.
Did you already launch a project before XELIS?
XELIS was the founding team’s first project of this kind. Some members had previously participated in or contributed to other projects as community developers.
Was there any premine?
There was no premine. Development is funded through a protocol-defined share of block rewards.
The development share was 10% before block height 3,250,000, and is 5% from that height onward. This change in the development share is separate from the gradual decrease in the base block reward.
See Funding.
I saw Atomic Unit of 8 for the coin. What does that mean?
XEL has 8 decimal places. Its smallest unit is 0.00000001 XEL, so 100,000,000 atomic units = 1 XEL.
Amounts are represented as integers in atomic units before encryption, and wallets display decrypted amounts with the appropriate decimal precision. Integer arithmetic avoids floating-point rounding errors when adding or subtracting amounts.
Will Testnet coins be transferred to Mainnet?
No. Mainnet, Testnet, and Devnet have separate ledgers. Testnet coins cannot be converted or transferred to Mainnet, and test networks can be reset.
Is there any incentive toward mining or running a node in Testnet?
Testnet is for testing software, mining, wallets, and applications without using mainnet funds. Running a node, mining test blocks, and reporting bugs help improve the network. Participation does not imply eligibility for mainnet coins or other rewards.
What are your primary focuses for the project?
- Privacy for account balances and transfer amounts.
- Accessible tools, documentation, and APIs for users and developers.
- CPU/GPU mining with a memory-focused Proof-of-Work algorithm.
- Decentralization, security, and fast block processing.
- Efficient storage, synchronization, transaction execution, and cryptography.
- Smart contracts, confidential assets, and community contributions.
See Objectives.
What is the consensus algorithm that XELIS uses?
XELIS uses Proof of Work with XELIS Hash through different variants. The algorithm is designed for CPU/GPU mining and aims to limit the efficiency advantage of specialized hardware.
Nodes use cumulative difficulty and the BlockDAG ordering rules to select and order blocks. Topoheight records a block’s position in that order; it is not a measure of accumulated mining work.
See XELIS Hash and BlockDAG.
How does XELIS adjust mining difficulty?
Since block version V6, XELIS uses a DAG-aware, adaptive Gamma–Poisson algorithm to target an average block interval of 5 seconds. It measures work across parallel DAG branches and smooths random block arrivals while adapting to changes in hashrate. Earlier block versions use the historical Kalman filter algorithm.
Does XELIS support Smart Contracts?
Yes. Smart contracts have been enabled since block version V3. They are written in Silex, a statically typed language compiled to bytecode and executed by XVM, the XELIS Virtual Machine.
Contracts can maintain state, create and manage assets, and interact with other contracts. Execution is metered and subject to resource limits. V6 added contract events for applications and contracts to consume.
See Silex, Create Your First Contract, and the XVM source code .
Can my wallet be offline when I mine or receive a transaction?
Yes. Transfers and mining rewards are recorded in the network ledger even when your wallet is offline. The wallet retrieves its updated balance when it reconnects and synchronizes.
Configure your miner or mining pool with the correct wallet address. The mining software still needs a connection to a node or pool, even though the wallet application can remain closed.
What kind of reward can I expect from mining?
The base block reward decreases with the remaining unissued supply and is scaled to the target block interval. It is not a fixed 1.41 XEL per block, and the base reward does not follow a periodic halving schedule.
Since V6, side blocks use the same base reward calculation as normal blocks, without the earlier side-block reduction. Orphaned blocks do not receive rewards. The protocol allocates 5% of the block reward to development at heights from 3,250,000 onward.
Your actual mining income also depends on your share of network hashrate, accepted work, applicable transaction fees, and any pool fees or payout rules. Consult the block explorer for recent block rewards.
I want to work with the team. How can I apply?
You can contribute code, documentation, translations, testing, or bug reports through the project’s GitHub repositories . For collaboration opportunities, contact the team through the community channels.
Which database does the daemon use?
RocksDB is the default storage backend when RocksDB support is enabled in the build. Sled remains an optional alternative when Sled support is compiled in.
Use --use-db-backend rocksdb or --use-db-backend sled to select an available backend. Switching this option does not migrate an existing database; use the backend that matches your data directory.
This setting applies to the daemon’s blockchain storage, not the wallet’s encrypted storage.
See Daemon Configuration.
Why does the blockchain size vary between nodes?
Disk usage depends on the storage backend, pruning settings, synchronization height, and database maintenance. An archival node retains more history than a pruned node.
RocksDB and Sled organize data differently. Compaction, compression settings, and space awaiting reclamation can also cause nodes with the same logical ledger state to occupy different amounts of disk space. A larger database alone does not imply that the node has a different chain.