Anyone can fork Sia to customize it, create a new product, or even create a new coin.
A hard fork in the crypto world usually refers to changing the code of a crypto project so that a new blockchain and a new coin is created, where there would now be two versions of the blockchain and coin (similar to Bitcoin Cash splitting off from Bitcoin). Typically, if a user has coins in the wallet of the original blockchain when this type of fork occurs, they will have an equal amount of coins on the new blockchain at the time of the fork, doubling their coins as a result - though the new coins may be worthless or worth very little to start.
Because Sia is open source and is available on Gitlab, anyone can fork Sia or any other part of the project (such as the Sia-UI) and change it or create a new product based upon it. A software project like Sia can also be forked and improved upon without creating a new blockchain and a new coin, such as if someone wanted to improve the official wallet software by making a better user interface. There were nearly 500 forks of the basic Sia project on GitHub before Sia moved to their own self-hosted Gitlab, though many of those forks are of old versions of Sia and do not create a new blockchain or coin.
If any third party sees fit to do so, though, they can fork the Sia blockchain and create a new coin. Whether or not that version of Sia would gain any support is questionable, as it would also separate all hosts and renters between the two networks - hosts and renters on the third-party fork couldn't communicate with hosts and renters on the main Sia project, limiting utility of the actual Sia storage product significantly on the third-party fork unless it also had a large number of users switch over from the official Sia project.
A list of all Sia network forks we're aware of.
Forks are listed in chronological order of public announcement. We'd also recommend reviewing the "Blockchains of the Sia Family" on SiaMining, which provides a great overview of the different forks from a comparison perspective.
These forks were routine, fake, or scams.Insignificant Forks
A list of all active Sia network forks we're aware of.
A fork by the Sia team to create and fund the Sia Foundation.
In the latter half of 2020, a proposal was put forward to create an entity called the Sia Foundation. This entity would become a nonprofit organization responsible for maintaining the core Sia protocol, while Nebulous Labs branched off to focus on Skynet and become Skynet Labs as the for-profit side of the Sia ecosystem. Community input was collected on the fork proposal, which was overall positive. Luke Champine and Eddie Wang were the two initial board members selected for the Foundation, with Luke leaving Nebulous to head the core Sia protocol development.
The benefits of the Foundation were explained as a way to fund Sia core development, and to also support community resources such as community websites and hackathons using an increased block reward and a subsidy from those funds. The fork became active in early February 2021 with an increased block reward to fund the Sia Foundation and its initiatives.
The community reception to this fork was mixed.
Initially the majority of community members were in support of the fork and the Foundation, but over time some users' opinions changed as the Foundation plans continued to change. In particular, some users objected to the fixed block reward subsidy continuing indefinitely, as it serves as a money printer for the Foundation and may put downward price pressure on Siacoins long-term. There were also concerns about the actual amount of separation between the Foundation and Nebulous, as David Vorick continued to be the main spokesperson for the Foundation even though he would not be holding a position within it.
More information on potential issues with the Sia Foundation can be found in our Concerns About Sia and Skynet page.
The fork resulted in a new primary chain for Sia, which is now the active and supported chain. All other chains are abandoned. The fork created a block subsidy of 30,000 SC for the Sia Foundation every block, for a total block reward of 60,000 SC with half of that mandated to go to the Sia Foundation. This results in Foundation funding of approximately $1 million to $2.5 million a month based on recent Siacoin prices. No new coins are created for Siacoin owners, and the event is otherwise insignificant to normal Sia users.
Mining Sia is unchanged, except that the block reward is increased to 60,000 SC with 30,000 SC mandated to go to the Sia Foundation. Miners will still receive 30,000 SC per block. Only certain mining hardware is capable of mining Sia - see our page on Mining for more info.
Renters and hosts on the Sia network will likely want to follow the new chain and update to Sia v1.5.4+, as this is the chain which will continue to receive Sia updates and new features from Nebulous.
Announced October 15, 2018 - A fork originally supported by Nebulous which aims to build second-layer apps on top of the Sia protocol.
Sia community member FaustianAGI (Kenneth Scott Bell), the organizer of the "Community Fork" proposal, was not entirely satisfied with Nebulous' reasons for forking or their decision to refuse a development fee as part of the new fork. Joined by several other known Sia community members, the group organized a fork called ScPrime (originally SiaPrime). While the stated goal of ScPrime is to build second-layer apps on top of the Sia network, the project has also elected to retain the original Blake2b algorithm, giving miners rejected by the Sia ASIC fork a place to redirect their hashrate.
Even though more progress has been made with ScPrime than with any other Sia fork, as of March 2021 overall the project does not appear to have made much significant progress. Since launch, the project has also seen the loss of the involvement of some important original Sia community members which originally supported the project.
Community opinion of the ScPrime project was originally positive. ScPrime incorporated many well-regarded Sia community members, promised to retain Siafunds as a condition of Nebulous' support, and committed to giving Nebulous a grant of a portion of the original token supply of the ScPrime network.
However, the ScPrime project and its members grew increasingly critical of Nebulous and the original Sia project, making demands such as concessions to promote ScPrime through Sia channels - without contributing much, if anything, to the Sia project in return. This continued to the point where ScPrime discussion has essentially been banned in official Sia channels due to the adversarial nature of the majority of ScPrime supporters.
An airdrop was created for Siacoin holders which provided 1 SCP for every 5 SC held. Details can be found here.
Mining remains open to all units utilizing the original the Blake2b algorithm. Mining statistics on ScPrime hashrate compared to the main Sia network can be viewed at Keops Pan-Sia Stats.
Renters and hosts on ScPrime are separate from Sia renters and hosts, so users looking to rent or host storage will need to decide which platform they wish to use. ScPrime appears to offer incentives for hosts in the form of free SCP if they meet certain criteria. Statistics on the number of ScPrime hosts and storage compared to the main Sia network can be viewed at Keops Pan-Sia Stats.
A list of all Sia network forks with no current development activity.
Announced October 1, 2018 - A fork by the Sia team to invalidate non-Obelisk miners at the end of October 2018.
On October 1, 2018, David Vorick announced the intention to fork the Sia network away from the Blake2b algorithm and to an alternate version of the algorithm that only the Obelisk SC1 ASIC miner can use. The alternate algorithm only accepts hashes made having a nonce value divisible by 1009, which effectively reduces all non-Obelisk units to about 0.1% of their normal hashrate and renders them useless on the Sia network.
The decision to fork was made in response to a "Community Fork" proposal calling for Sia to fork to the alternate algorithm in order to grant Obelisk buyers exclusivity and attempt to mitigate legal troubles for Obelisk. The proposal requested a temporary fork to the alternate algorithm to provide Obelisk ROI, and then a fork back to Blake2b to allow all miners back on the network. It also suggested implementing a development fee from blocks mined in order to fund Nebulous Labs and expedite Sia development.
However, the reasons given for the fork decision by the development team were to essentially punish other ASIC manufacturers like Bitmain and Innosilicon for what the Sia team considers unfair business practices, such as not communicating with the community, not announcing their devices in advance, not releasing batch counts, marking up hardware, and self-mining by manufacturers. The team has stated that the fork will be permanent and will not switch back to Blake2b. They will also not implement a development fee, and will stick to traditional fundraising methods.
The Sia developers say that they will help to support the old chain with the regular Blake2b algorithm if a group of users chooses to continue to maintain and run it. A few groups have come forward with new forks as a result, such as ScPrime and SiaClassic.
This fork was made obsolete in February 2021 with the Sia Foundation Fork.
The community reception to this fork was mixed.
In general, Obelisk SC1 buyers appeared to be in favor of a fork because with the other ASICs on the Sia network, SC1 profitability was essentially impossible. Kicking all other units off the network made mining with SC1s profitable again, so long as another ASIC manufacturer didn't release a new ASIC with the new algorithm. However, there were doubts by some users that other ASIC manufacturers will build another miner for Sia after being forked off the network, as they might fear being forked off again. Those opposed to Bitmain's business practices were happy to see a blockchain developer finally stand up to what they consider to be abusive ASIC manufacturers, and hope that it will serve as an example to other blockchain projects.
However, there were also many users opposed to the fork who see nothing wrong with the business practices of the third-party ASIC manufacturers, citing them as what any competitive business would do, and question that the reason for the fork is actually as stated. Some argue that third-party ASICs were not attacking the Sia network and were mining normally alongside everyone else, and so they should not have been removed from the network. Additionally, the fact that only Obelisks are allowed to mine on the new Sia fork has raised concerns about conflicts of interest and favoritism, as the Obelisk project was also owned by the Sia developers. Several users believe that Sia was simply upset that their Obelisk project was beaten to market by other fairly competing manufacturers, and the fork is in retaliation for this and is not a good enough reason to fork.
There was concern from all sides that kicking all current ASICs off the network and only allowing Obelisks to mine would reduce the hashrate of the network to a fraction of what it was pre-fork, making an attack on the network more possible and lowering network security. Some users were concered that Bitmain or Innosilicon would not tolerate being forked off the Sia network, and would retaliate by building superior next-generation ASICs which can mine the alternate algorithm and then deploy them in great numbers - either specifically to attack the Sia network, or simply because they would be profitable again with a large reduction in hashrate. In June 2020, another ASIC miner has been announced, and yet another is suspected to be in development.
The fork resulted in multiple chains and networks, as more than one group announced plans to maintain a new fork of Sia. Two Sia releases were made in mid-October 2018: v1.3.5 which was the last Blake2b release, and v1.3.7+ which was the new release activating the new chain at block 179,000. Most exchanges and mining pools supported this Sia chain.
After this fork, only Obelisk SC1 units were able to mine the on the main Sia network. Non-Obelisk Blake2b miners who try to mine on the new chain would see their units stop working, and can switch to one of the other Sia forks maintaining the Blake2b algorithm. New ASICs compatible with this fork are appearing in 2020, however - see our page on Mining for more info.
Renters and hosts on the Sia network needed to follow this chain and update to Sia v1.4.0+, as this is the chain which continued to receive Sia updates and new features from Nebulous.
Announced early 2018 as the Toaster fork - a Sia competitor aiming to make the Sia protocol more consumer friendly.
Hyperspace was a third-party hard fork of Sia which occurred in July 2018. This fork was intended to coincide with the launch of Obelisks in early-mid July, as Hyperspace hoped to offer an alternative to the currently oversaturated mining environment of the official Sia blockchain - however, due to continued Obelisk delays, Hyperspace launched as planned on July 26, 2018.
The fork was a result of a difference in opinion regarding management and other strategies around the official Sia product. Hyperspace planned to continue development on their own version of the Sia storage project, as well as to fork the blockchain and create an alternate coin called "Space Cash". The fork used the Blake2b algorithm so that Sia mining devices at that time would be compatible with the fork. It also planned to add a development subsidy similar to Decred in lieu of Siafunds. Hyperspace also launched an open source mining pool, called "Toastpool", which it claimed would support multiple coins.
Community opinion of the Hyperspace project was mixed - some users were thankful to have an alternative to the Sia project and a promise of a consumer-oriented experience, while others saw Hyperspace as trying to steal Sia's work and rebrand it. There was also displeasure expressed by Nebulous (the developers of Sia) over Hyperspace's removal of Siafunds from the forked product.
With Sia's decision to fork all existing non-Obelisk miners off the Sia network, Hyperspace gained a small amount of attention as miners searched for an alternative to mining Sia. Most miners appear to have stayed on the old Sia version now called SiaClassic.
An "airdrop" occured based on a snapshot of block 161358 of the Sia network, which was mined on July 1, 2018 at about 02:50 GMT. Users who had coins in an official wallet at the time of this block received 1 Space Cash for every 10 Siacoins they held. Information on this airdrop is no longer available.
As of April 2019, the Hyperspace project appears to be dead, with no significant activity since December 2018.
Announced October 13, 2018 - A fork attempting to claim ownership of the "original" Sia chain.
Shortly after Nebulous' announcement of the Sia ASIC Fork, an organization announced itself as the SiaClassic Foundation with the intention of maintaining a fork of the Sia network. The foundation claimed to be registered as a non-profit organization, and its members had not been significantly involved in the Sia community outside of what appears to be a large-scale mining operation by it's director, Jason Gantt.
As explained in the announcement of the foundation above, SiaClassic appeared to be frustrated with the decision of Nebulous to fork. They appeared to want to continue to develop the Sia product in line with their own vision, and claimed to have a first-year budget of over $6 million dollars on Sia's Discord (specifically, "over twice" Nebulous' budget of $3 million at the time). However, with no solid announcement of team members outside of a few foundation executives and a PR representative, the project never materialized.
Community opinion of the SiaClassic fork was overwhelmingly negative.
The initial announcement of SiaClassic claimed to involve known "community members", but none ever surfaced. The biggest reason for the negative reception was the SiaClassic Foundation's attitude towards their approach of the Sia project. They claimed to represent the "original" Sia chain and product, despite the fact that Sia's founder (David Vorick) was the one to announce the Sia ASIC Fork and continues to lead primary development of Sia. SiaClassic claimed to be the de-facto Sia v1.3.4, even though they they were not involved in developing or releasing that version.
Innosilicon (one manufacturer of miners Sia chose to fork off) had announced support specifically for the SiaClassic fork, leading some Sia community members to believe that the two are related. The foundation never provided any details on exactly how they planned to build upon and improve the Sia project in a way which wasn't already being done by Nebulous or one of the other community forks. SiaClassic also appeared to be undetermined as to whether or not they will retain Siafunds in their product, and David Vorick had come out publicly with a negative opinion of the organization for various reasons, including lack of actual community member support and a lawsuit inquiry against Nebulous from Jason Gantt regarding Gantt's mining operation and being forked off the main Sia network.
The SiaClassic Foundation never did release any software client of their own, or any details on the plans of their fork, aside from claiming ownership of the older official Sia versions. As of May 2020, the SiaClassic website no longer exists. The SiaClassic project therefore appears to be completely dead.
A small number of ASIC miners continue to operate on the SiaClassic network, but it is likely that these machines are colocated and the owners are not aware of the fork, even years later. Occasional inquiries related to such situations still occur in Sia channels, but unfortunately for these miners their SiaClassic coins are essentially worthless.
There have been other insignificant forks in Sia's history as well.
Other forks which are not notable enough to compile detailed information on include: