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Sia 0.4.6

Build Status

Binaries can be found at our website.

Sia is a new decentralized cloud storage platform aimed at giving users control of their data. Data is split into hundreds of erasure coded pieces and encrypted locally, and then each piece is uploaded to a separate host. A blockchain is used to create cryptographic contracts ensuring that hosts will only get paid if they actually store the data. Out of hundreds of hosts, only a fraction are required to recover the original file.

Anybody can join the network as a host and get income from the storage they contribute. This openness allows Sia to build and take advantage of a global network of small datacenters. Combined with advanced algorithms for storing and retrieving data, Sia is poised to be a highly competitive cloud storage platform. More information about the technology can be found on our website and in the 'doc' folder of the repo.

Sia is currently in beta. The currency was launched on June 7th, 2015, but the storage platform itself remains in beta. Sia is ready for use with small sums of money and non-critical files, but until the network has a more proven track record, we advise against using it as a sole means of storing important data.

This release comes with 2 binaries, siad and siac. siad is a background service, or "daemon," that runs the Sia protocol, and siac is a client that is used to interact with siad. Siad exposes an API on 'localhost:9980' which can be used to interact with the daemon. There is a front-end program called Sia-UI which can be used to interact with the daemon in a more user-friendly way. Documentation on the API can be found in doc/


siad and siac are run via command prompt. On Windows, you can just double- click siad.exe if you don't need to specify any command-line arguments. Otherwise, navigate to the sia folder and click File->Open command prompt. Then, start the siad service by entering siad and pressing Enter. The command prompt may appear to freeze; this means siad is waiting for requests. Windows users may see a warning from the Windows Firewall; be sure to check both boxes ("Private networks" and "Public networks") and click "Allow access." You can now run siac in a separate command prompt to interact with siad. From here, you can send money, mine blocks, upload and download files, and advertise yourself as a host.


  • The client does not appear to join the network.

    There should be at least one peer online for you to connect to, so if you cannot connect, you may be experiencing connection issues. Ensure that you are connected to the Internet. If you are confident that your connection is okay, contact us! Our server may be experiencing problems.

    You can also opt not to connect to join the network by passing the "-n" flag to siad.

  • I can't connect to more than 8 peers.

    Once Sia has connected to 8 peers, it will stop trying to form new connections, but it will still accept incoming connection requests (up to 128 total peers). However, if you are behind a firewall, you will not be able to accept incoming connections. You must configure your firewall to allow Sia connections by forwarding your ports. By default, Sia communicates on ports 9981 and 9982. The specific instructions for forwarding a port vary by router. For more information, consult this guide.

    In future versions, we will add support for UPnP, which may allow you to skip this step if your router supports it.

  • I'm 100% sure my ports are open, but Sia won't let me announce as a host.

    siad tries to verify your connectivity by pinging your external IPv4 address. This method is sufficient for most people, but for unusual setups it may report false negatives. To override this check, you can "force" the announcement by running siac host announce [ip:port]. You can determine your external IP by running siac gateway or using a 3rd-party service.

  • I mined a block, but I didn't receive any money.

    There is a 144-block confirmation delay before you will receive siacoins from mined blocks. If you still have not received the block reward after 144 blocks, it means your block did not made it into the blockchain.

  • siad complains about "locks held too long."

    This is debugging output, and should not occur during normal use. Please contact us if this happens.

If your issue is not addressed above, you can get in touch with us personally:

slack: (ping taek or nemo)


Version Information

  • v0.4.0 introduces wallet seeds, which can be used to regenerate your wallet using only a passphrase. To create a wallet, run siac wallet init. Be sure to write down the passphrase somewhere safe! You will also need it to unlock the wallet each time you start siad.

    As a result, compatibility with the old wallet.dat files has been broken. To transfer funds from v0.3.3.3 to v0.4.0, you must send them from the v0.3.3.3 client to a v0.4.0 address. Note that you can run both clients at once (from different folders).

  • v0.4.0 uses erasure-coding to enable durability, availability, and efficiency when uploading and downloading files. However, the new upload and download algorithms have not yet been perfected. Specifically, you may observe slower- than-expected download speeds. These algorithms will be a top priority in future releases. After all, they are crucial to the Sia platform!

  • The format of the block database has changed, which means you will need to redownload the entire blockchain. This may take anywhere from 10 minutes to 6 hours. Check to see the current block height.

  • Ports are now automatically forwarded using UPnP. If your router supports UPnP, you no longer need to manually set up port forwarding. This should improve the general health of the network. Note that for now, there is no way to disable UPnP, but you can always turn it off in your router settings.

  • Much compatibility with the v0.3.3.3 host and renter has been broken. The .sia format has changed, the network protocol is different, etc. The bottom line is, if you were hosting on v0.3.3.3, you should continue to do so until your contracts expire. If you were renting, you should download those files with the v0.3.3.3 client and reupload them on v0.4.0. We apologize for the inconvenience. Fortunately, storage is cheap and the network is small.

Please tell us about any problems you run into, and any features you want! The advantage of being a beta user is that your feedback will have a large impact on what we do in the next few months. Thank you!

Version History

October 2015:

v0.4.6 (patch)

  • Removed over-agressive consistency check

v0.4.5 (patch)

  • Fixed last prominent bug in block database
  • Closed some dangling resource handles

v0.4.4 (patch)

  • Uploading is much more reliable
  • Price estimations are more accurate
  • Bumped filesize limit to 20 GB

v0.4.3 (patch)

  • Block database is now faster and more stable
  • Wallet no longer freezes when unlocked during IBD
  • Optimized block encoding/decoding

September 2015:

v0.4.2 (patch)

  • HostDB is now smarter
  • Tweaked renter contract creation

v0.4.1 (patch)

  • Added support for loading v0.3.3.x wallets
  • Better pruning of dead nodes
  • Improve database consistency

August 2015:

v0.4.0: Second stable currency release.

  • Wallets are encrypted and generated from seed phrases
  • Files are erasure-coded and transferred in parallel
  • The blockchain is now fully on-disk
  • Added UPnP support

June 2015:

v0.3.3.3 (patch)

  • Host announcements can be "forced"
  • Wallets can be merged
  • Unresponsive addresses are pruned from the node list

v0.3.3.2 (patch)

  • Siafunds can be loaded and sent
  • Added block explorer
  • Patched two critical security vulnerabilities

v0.3.3.1 (hotfix)

  • Mining API sends headers instead of entire blocks
  • Slashed default hosting price

v0.3.3: First stable currency release.

  • Set release target
  • Added progress bars to uploads
  • Rigorous testing of consensus code

May 2015:

v0.3.2: Fourth open beta release.

  • Switched encryption from block cipher to stream cipher
  • Updates are now signed
  • Added API calls to support external miners

v0.3.1: Third open beta release.

  • Blocks are now stored on-disk in a database
  • Files can be shared via .sia files or ASCII-encoded data
  • RPCs are now multiplexed over one physical connection

March 2015:

v0.3.0: Second open beta release.

Jan 2015:

v0.2.0: First open beta release.

Dec 2014:

v0.1.0: Closed beta release.


Blockchain-based marketplace for file storage







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