About Qtum and Mainnet Ignition
Qtum is a decentralized blockchain project built on Bitcoin's UTXO model, with support for Ethereum Virtual Machine based smart contracts, and secured by a proof of stake consensus model. It achieves this through the revolutionary Account Abstraction Layer which allows the EVM to communicate with Qtum's Bitcoin-like UTXO blockchain. For more general information about Qtum as well as links to join our community, go to https://qtum.org
Welcome to the Qtum Ignition Main Network. This is the main network where the tokens hold value and should be guarded very carefully. There will be a testnet setup soon for developers, in the meantime you can use -regtest mode for testing needs. We will announce details about the token swap from QTUM ERC20 coins to QTUM mainnet tokens soon, watch our website
for details about that.
The major features implemented in Qtum Ignition include:
The Ethereum Virtual Machine, which allows for compatibility with most existing Solidity based smart contracts.
The Smart Staking Protocol is complete, which is an optimized Proof of Stake implementation designed for a smart contract platform (however, smart contracts can not participate in staking yet).
An improved smart contract GUI has been implemented that can be used for creating contracts, sending data and Qtum to them, and checking their status by executing them locally, The GUI also offers easy QRC20 tokens management.
Regtest mode, which is ideal for developers who wish to create their own private blockchain. It is tuned specifically to make development easier. It will stake blocks automatically every 30 seconds, and can generate proof-of-work blocks instantly as needed.
The Decentralized Governance Protocol is completely implemented and functional, which allows certain network parameters to be modified without a fork.
For more technical information for how to start developing with Qtum please read the Guide
and also see this tutorial for deploying a simple faucet smart contract
(it hasn't yet been updated for Mainnet for obvious reasons, but all the instructions are the same and you can try them in regtest mode)
Note: Qtum Core is considered beta software. We make no warranties or guarantees of its security or stability.
v0.17.3 - Mandatory update for stakers - Bug fixes
Fix a bug where a staking node would stop producing valid blocks when it receives an invalid header.
Fix a bug that would cause a node to fail at syncing when started with -checklevel>3.
Add new checkpoints.
v0.17.2 - Recommended update - Bug fixes
Update ZMQ version to 4.3.1 (CVE-2019-6250
Change the behavior of the EVM's event emitter to match ethereum's behavior in some cases.
Fix a bug where the staking icon would not show accurate information.
Fix a bug where compilation would fail if the system has secp256k1 library already installed.
Fix a minor typo in Qt wallet.
v0.17.1 - Upgrade Qtum core to bitcoin core 0.17.1 plus other improvements and bug fixes
Upgrade Qtum core to bitcoin core 0.17.1 including partially signed transactions support, external wallet files and more. Check bitcoin 0.17.0
release notes for more details.
Fix a bug which allowed using P2SH addresses as transaction sender in RPC interface, which caused that transaction to be rejected.
Fix an issue which prevented the correct logs to be printed when a state divergence was detected.
Prioritize create contract transactions over send to contract ones when staking.
Fix a bug which allowed node's time manipulation in some cases.
Fix a bug which prevented some EVM globals to be returned correctly when using callcontract RPC call.
Fix a bug which caused fee estimation to be excessively high in some cases.
Fix Solidity compiler link in the GUI wallet.
Make getaccountinfo RPC call help message clearer.
Improve the way encrypted wallet related RPC calls help messages were displayed.
Fix a bug that caused build description to be inaccurate.
v0.16.2 - Recommended update - Improved network security and bug fixes
Implement network spam protection
Only request blocks from peers when their chainwork is strictly greater than the current tip
Add extra header checks for PoS timestamp, block indexes, signature type (LowS), synchronized and rolling checkpoints.
Add recent checkpoints
Update nMinimumChainWork, defaultAssumeValid and chainTxData
Fix failing Qt tests in make check on OSX Mojave
Fix getblocktemplate rpc call for PoS blocks
Fix help messages for walletpassphrase and getnetworkhashps rpc calls
v0.16.1 - Mandatory Update - Critical bug fix
Fix an upstream bitcoin critical bug, more info: CVE-2018-17144
v0.16.0 - Upgrade Qtum core to bitcoin core 0.16 and bug fixes
Upgrade Qtum core to bitcoin core 0.16 including segwit wallet, bech32 addresses, HD-wallets by default and more
Fix a bug where contract transactions with no change would fail in some cases
Fix a display bug where multiple logs would not show corretly in Qt wallet
Update gitian build scripts to support ubuntu bionic as building host
v0.15.3 - Recommended update - Bug fix
Fix a bug with searchlogs and waitforlogs rpc calls that caused duplicacte logs to show in some cases
Add support for building with boost 1.67
v0.15.2 - Recommended update - Improved seeding and bug fixes
Fix a staker halving subsidy calculation bug
Fix some translations errors and typos
Add Support for openssl 1.1
Fix CVE-2018-12356 by hardening the regex
Fix a python tests bug that caused bulk running of tests to fail
Add static seeds
Add new dns seed nodes
Update copyright year
v0.15.1 - Upgrade Qtum core to bitcoin core 0.15.1 and bug fixes
Upgrade Qtum core code to bitcoin core 0.15.1 with important performance improvments and other features, read more about bitcoin core 0.15.0
Fix a bug with reindexing when the data directory is empty
Prevent sending QRC20 tokens to P2SH Qtum addresses in the Qt wallet
Restore JS number as string support for callcontract and sendtocontract rpc calls
Fix a bug where the wrong block hash would be stored in the transaction receipt for miners with -logevents enabled
v0.14.16 - Improvments and Bug fixes
Fixed a bug where transactions with low fees would get stuck in the local mempool.
Fix a bug with clearing cache of StorageResults
Add contract support to "createrawtransaction" rpc call
Add sender support to "sendtoaddress" rpc call
v0.14.15 - Recommended Update
Add EVM global variables to callcontract
Update gitian build script
Update CentOS build instructions
Add exception data to TransactionReceipt
Fixed a bug where the gas price could not be parsed correctly on certain platforms (reported by APIS)
Fixed a bug where the logs were not reverted on disconnect block in certain cases
v0.14.14 - Mandatory Update
New Qt GUI
Fix Qt wallet freeze when syncing from scratch with -logevents or -reindex
Fix a bug with cacheUTXO (hardfork at block 100000 in mainnet, 84500 in testnet)
Add update checking functionality to Qt wallet
Fix a bug in token transfers history dates
Fix a bug with searchlogs rpc call
Add an extra check when adding token addresses
Fix compatibility with boost 1.66
Update nMinimumChainWork and defaultAssumeValid chain params
Add minmempoolgaslimit startup argument
Add Gitian build signatures
v0.14.13 - Mandatory Update
Fix a callcontract bug which in very specific cases could cause the node to fail to sync the blockchain
Add ability to save and restore contract addresses and ABI data
Make the token confirmation view data correct
v0.14.12 - Recommended Update
Added option to disable change address usage
Fixed bug where heavy RPC usage could cause the wallet to crash
v0.14.11 - Optional Update
Changed our versioning scheme to be consistent and avoid the two version number confusion
Add feature to restore wallet in the Qt wallet
Add new RPC call "waitforlogs" that is particularly useful for Dapp developers
Add long-polling support to the gettransaction RPC call
v1.1.4 - Recommended update
Fixed a bug that would cause syncing to stop
Fixed a bug that would cause the wallet to crash when using -logevents
v1.1.3 - Highly recommended update
Fixed a bug that caused contact addresses to show in receive token address dropdown
v1.1.2 - Optional update, but recommended if using QRC tokens
Fixed a bug with token transactions where the transaction ID displayed was incorrect in the Qt wallet
Allow adding 0 balance addresses as the token receiver in the Qt wallet
v1.1.1: When sending to contracts, the sender address is now the default change address to reduce confusion; fix -salvagewallet so it works with token transactions
v1.1.0: Add GUI support Qtum QRC tokens, allowing full management of tokens on the Qtum blockchain from the Qt wallet
Sending to a contract no longer requires ABI data, allowing easy participation in simple crowdsale contracts
v1.0.4: Fix bug where certain circumstances when staking could cause the displayed balance to be inaccurate until completely redownloading the blockchain.
v1.0.3: Fix staker bug that reported false messages; slightly increases staking performance; optimize staker parameters; fix white send button in GUI
v1.0.2: Various UI fixes, minor gas overflow consensus fix, per-txout exploit fix, testnet mode setup and functioning
v1.0.1: Fixed network magic bytes and minimum version to ensure the main network does not conflict with the Skynet network
v1.0: Initial release
Reindex Required When Upgrading from v1.0.1
When you first start the Qtum 1.0.2 GUI wallet after using Qtum v1.0.1 it will prompt you that it must reindex the database. This is normal and is a result of switching our internal database format from per-transaction to per-txout. If you use qtumd -daemon it will silently fail to start. You need to use qtumd -daemon -reindex in this case.
Qtum Documentation and Usage Resources
Basic usage resources:
Official Qtum Usage Guide
Unofficial Qtum staking tutorial
Unofficial Qtum staking tutorial on Raspberry Pi
Unofficial guide for keeping your wallet safe
Unofficial block explorer
Unofficial Raspberry Pi Web UI
Deploying a custom token to Qtum
Early example faucet contract
Unofficial Qtum Hello World tutorial
General Info about Qtum:
Mainnet event AMA
Qtum's PoS vs CASPER
Technical article explaining Qtum's PoS model in depth
Unofficial What is Qtum article
Build Qtum Core
If you want to build it from source, it's recommended to follow the specific "build" documentation
for your platform. But mostly it boils down to the following:
Clone the qtum source code and cd into qtum
git clone --recursive https://github.com/qtumproject/qtum.git
Configure and build the headless qtum binaries as well as the GUI (if Qt is found).
You can disable the GUI build by passing --without-gui to configure.
It is recommended to build and run the unit tests to ensure everything is working correctly:
If you encounter an error like:
make: *** No rule to make target ‘cpp-ethereum/utils/libscrypt/b64.c’, needed by ‘cpp-ethereum/utils/libscrypt/libbitcoinconsensus_la-b64.lo’. Stop.
Then you did not checkout the cpp-ethereum submodule for Qtum. To do that, simply:
git submodule update --init --recursive
Validate and Reproduce Binaries
Qtum uses a tool called Gitian to make reproducible builds that can be verified by anyone. Instructions on setting up a Gitian VM and building Qtum are provided in doc/gitian-building.md
Make sure to check out these resources as well for more information and to keep up to date with all the latest news about Qtum. At least 1 developer is always around, so if you're developing on Qtum and need help, we'd love to welcome you to our community.
/r/Qtum on Reddit
Qtum Telegram Group
@QtumOfficial on Twitter
Qtum on Facebook
Qtum Smart Contract Limitations
EVM smart contracts can not receive coins from or send coins to any address type other than pay-to-pubkeyhash (starts with Q) addresses. This is due to a limitation in the EVM
Contracts are not allowed to create contracts with an initial endowment of coins. The contract must first be created, and then be sent coins in a separate transaction. Humans are also not allowed to create contracts with an initial endowment of coins.
Although all of the infrastructure is present, Qtum Core does not currently parse Solidity event data. You must parse this yourself using either searchlogs or -record-log-opcodes features.
It is not possible to send a contract coins without also executing the contract. This is also the case of Ethereum. This was promised in earlier discussions and technically does work, but due to lack of time for testing this feature was disabled. We hope to reenable this feature with release of the x86 virtual machine in 2018.
In Qtum there can be multiple addresses used to create a proof-of-stake block. However, the EVM can only see the first output using the coinbase operation in Solidity (this address is also the one registered for the continuous staker rewards after 500 blocks).
If you would like to validate that the binaries you download are exactly the same as those provided and built by the Qtum team, then you can compare your binaries to the following sha256sum hashes: