Syscoin Core 4.2.0

Syscoin Core installation binaries can be downloaded from and the source-code is available from the Syscoin Core source repository.

4.2.0 Release Notes

Syscoin Core version 4.2.0 is now available from: DO NOT USE UNTIL BLOCK 1004200

This release includes new features, various bug fixes and performance improvements, as well as updated translations.

Please report bugs using the issue tracker at GitHub:

Upgrade Instructions: Basic upgrade instructions below:

How to Upgrade

If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer (on Windows) or just copy over /Applications/Syscoin-Qt (on Mac) or syscoind/syscoin-qt (on Linux).

If you are upgrading from a version older than 4.2.0, PLEASE READ:

This should reindex your local node and synchronize with the network from genesis.


Syscoin Core is supported and extensively tested on operating systems using the Linux kernel, macOS 10.12+, and Windows 7 and newer. It is not recommended to use Syscoin Core on unsupported systems.

A target block height of 1004200 has been set as the upgrade blockheight. This will happen at approximately April 30th 2021, 8PM UTC. A more accurate countdown counter can be found at

Nodes not upgraded to Syscoin Core 4.2 will NOT be able to sync up to the network past block 1004200 After the block height, 2 new changes will be activated on the network

  1. The Syscoin Platform Token protocol will be on utxo model
  2. Masternodes will be deterministic

This upgrade brought in upstream changes from Bitcoin from 0.20.0 - 0.21.0 and tracking on the latest commit on master branch. For changelog brought in from upstream, please see the release notes from Bitcoin Core.

This upgrade also brought in upstream changes from Dash, including the following Dash improvement proposals. Please refer to the DIP for more information

Syscoin Core should also work on most other Unix-like systems but is not as frequently tested on them.

From Syscoin Core 4.1.0 onwards, macOS versions earlier than 10.12 are no longer supported. Additionally, Syscoin Core does not yet change appearance when macOS “dark mode” is activated.

Notable changes

  • rpc: deprecate addresses and reqSigs from rpc outputs #20286.
    • The following RPC calls are affected: gettxout, getrawtransaction, decoderawtransaction, decodescript, gettransaction, and REST endpoints: /rest/tx, /rest/getutxos, /rest/block.
    • Two fields, addresses and reqSigs, are removed from the output of the above commands. And new sane field address is added.
    • Adding -deprecatedrpc=addresses to startup argument will leave reqSigs and addresses intact

Syscoin Core Changes

Bitcoin 0.21+ Core engine is now used to power consensus and security of Syscoin Core. The changeset is here in this Pull request:

Syscoin Platform Token protocol change

Masternode upgrade

  • Masternode are now deterministic following dash’s DIP-0003

Bridge Freeze

Auxpow ID change

  • Auxpow ID has been changed to 16

Updated RPCs

  • All asset and masternode related RPCs have been updated to reflect the rewrite of the asset and masternode changes

New RPCs

  • listunspentasset: Helper function which just calls listunspent to find unspent UTXO’s for an asset.
  • signmessagebech32: Sign a message with bech32 (sys1) address.
  • assettransactionnotarize: Update notary signature on an asset transaction. Will require re-signing transaction before submitting to network.
  • getnotarysighash: Get sighash for notary to sign off on, use assettransactionnotarize to update the transaction after re-singing once sighash is used to create a notarized signature.



Thanks to everyone for the continued support of Syscoin. Special shout-out to c_e_d, Alternating and Johnp for their dedicated involvement with the 4.2 testnet.