Bitcoin Wiki - User contributions [en]

Difficulty

2016-04-09T12:32:20Z

Anduck: removed http://blockexplorer.com/q/estimate - not working link

''See also: [[target]]''

=== What is "difficulty"? ===

Difficulty is a measure of how difficult it is to find a hash below a given target.

The Bitcoin network has a global block difficulty. Valid blocks must have a hash below this target.
Mining pools also have a pool-specific share difficulty setting a lower limit for shares.

=== How often does the network difficulty change? ===

Every 2016 [[block|blocks]].

=== What is the formula for difficulty? ===

difficulty = difficulty_1_target / current_target

(target is a 256 bit number)

difficulty_1_target can be different for various ways to measure difficulty.
Traditionally, it represents a hash where the leading 32 bits are zero and the rest are one (this is known as "pool difficulty" or "pdiff").
The Bitcoin protocol represents targets as a custom floating point type with limited precision; as a result, Bitcoin clients often approximate difficulty based on this (this is known as "bdiff").

===How is difficulty stored in blocks?===

Each block stores a packed representation (called "Bits") for its actual hexadecimal [[target]]. The target can be derived from it via a predefined formula. For example, if the packed target in the block is 0x1b0404cb, the hexadecimal target is
0x0404cb * 2**(8*(0x1b - 3)) = 0x00000000000404CB000000000000000000000000000000000000000000000000

Note that the 0x0404cb value is a signed value in this format. The largest legal value for this field is 0x7fffff. To make a larger value you must shift it down one full byte. Also 0x008000 is the smallest positive valid value.

===How is difficulty calculated? What is the difference between bdiff and pdiff?===

The highest possible target (difficulty 1) is defined as 0x1d00ffff, which gives us a hex target of
0x00ffff * 2**(8*(0x1d - 3)) = 0x00000000FFFF0000000000000000000000000000000000000000000000000000

It should be noted that pooled mining often uses non-truncated targets, which puts "pool difficulty 1" at
0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

So the difficulty at 0x1b0404cb is therefore:
0x00000000FFFF0000000000000000000000000000000000000000000000000000 /
0x00000000000404CB000000000000000000000000000000000000000000000000
= 16307.420938523983 (bdiff)
And:
0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF /
0x00000000000404CB000000000000000000000000000000000000000000000000
= 16307.669773817162 (pdiff)

Here's a fast way to calculate bitcoin difficulty. It uses a modified Taylor series for the logarithm (you can see tutorials on flipcode and wikipedia) and relies on logs to transform the difficulty calculation:

<source lang="cpp">
#include <iostream>
#include <cmath>

inline float fast_log(float val)
{
int * const exp_ptr = reinterpret_cast <int *>(&val);
int x = *exp_ptr;
const int log_2 = ((x >> 23) & 255) - 128;
x &= ~(255 << 23);
x += 127 << 23;
*exp_ptr = x;

val = ((-1.0f/3) * val + 2) * val - 2.0f/3;
return ((val + log_2) * 0.69314718f);
}

float difficulty(unsigned int bits)
{
static double max_body = fast_log(0x00ffff), scaland = fast_log(256);
return exp(max_body - fast_log(bits & 0x00ffffff) + scaland * (0x1d - ((bits & 0xff000000) >> 24)));
}

int main()
{
std::cout << difficulty(0x1b0404cb) << std::endl;
return 0;
}
</source>

To see the math to go from the normal difficulty calculations (which require large big ints bigger than the space in any normal integer) to the calculation above, here's some python:

<source lang="python">
import decimal, math
l = math.log
e = math.e

print 0x00ffff * 2**(8*(0x1d - 3)) / float(0x0404cb * 2**(8*(0x1b - 3)))
print l(0x00ffff * 2**(8*(0x1d - 3)) / float(0x0404cb * 2**(8*(0x1b - 3))))
print l(0x00ffff * 2**(8*(0x1d - 3))) - l(0x0404cb * 2**(8*(0x1b - 3)))
print l(0x00ffff) + l(2**(8*(0x1d - 3))) - l(0x0404cb) - l(2**(8*(0x1b - 3)))
print l(0x00ffff) + (8*(0x1d - 3))*l(2) - l(0x0404cb) - (8*(0x1b - 3))*l(2)
print l(0x00ffff / float(0x0404cb)) + (8*(0x1d - 3))*l(2) - (8*(0x1b - 3))*l(2)
print l(0x00ffff / float(0x0404cb)) + (0x1d - 0x1b)*l(2**8)
</source>

=== What is the current difficulty? ===
[http://blockexplorer.com/q/getdifficulty Current difficulty], as output by Bitcoin's getDifficulty.

[http://bitcoin.sipa.be Graphs]

=== What is the maximum difficulty? ===

There is no minimum target. The maximum difficulty is roughly: maximum_target / 1 (since 0 would result in infinity), which is a ridiculously huge number (about 2^224).

The actual maximum difficulty is when current_target=0, but we would not be able to calculate the difficulty if that happened. (fortunately it never will, so we're ok.)

=== Can the network difficulty go down? ===
Yes it can. See discussion in [[target]].

=== What is the minimum difficulty? ===
The minimum difficulty, when the target is at the maximum allowed value, is 1.

=== What network hash rate results in a given difficulty? ===
The difficulty is adjusted every 2016 blocks based on the [[Block_timestamp|time]] it took to find the previous 2016 blocks. At the desired rate of one block each 10 minutes, 2016 blocks would take exactly two weeks to find. If the previous 2016 blocks took more than two weeks to find, the difficulty is reduced. If they took less than two weeks, the difficulty is increased. The change in difficulty is in proportion to the amount of time over or under two weeks the previous 2016 blocks took to find.

To find a block, the hash must be less than the target. The hash is effectively a random number between 0 and 2**256-1. The offset for difficulty 1 is
0xffff * 2**208
and for difficulty D is
(0xffff * 2**208)/D

The expected number of hashes we need to calculate to find a block with difficulty D is therefore
D * 2**256 / (0xffff * 2**208)
or just
D * 2**48 / 0xffff

The difficulty is set such that the previous 2016 blocks would have been found at the rate of one every 10 minutes, so we were calculating (D * 2**48 / 0xffff) hashes in 600 seconds. That means the hash rate of the network was
D * 2**48 / 0xffff / 600
over the previous 2016 blocks. Can be further simplified to
D * 2**32 / 600
without much loss of accuracy.

At difficulty 1, that is around 7 Mhashes per second.

At the time of writing, the difficulty is 22012.4941572, which means that over the previous set of 2016 blocks found the average network hash rate was
22012.4941572 * 2**32 / 600 = around 157 Ghashes per second.

=== How soon might I expect to generate a block? ===
(The [https://www.bitcointalk.org/index.php?topic=1682.0 eternal question].)

The average time to find a block can be approximated by calculating:
time = difficulty * 2**32 / hashrate
where difficulty is the current difficulty, hashrate is the number of hashes your miner calculates per second, and time is the average in seconds between the blocks you find.

For example, using Python we calculate the average time to generate a block using a 1Ghash/s mining rig when the difficulty is 20000:
$ python -c "print 20000 * 2**32 / 10**9 / 60 / 60.0"
23.85
and find that it takes just under 24 hours on average.

* Any one grinding of the hash stands the same chance of "winning" as any other. The numbers game is how many attempts your hardware can make per second.
* You need to know the difficulty (above) and your khash/sec rate (reported by the client).
** [[Mining Hardware Comparison]] has some stats that may help you predict what you could get.
* Visit a calculator or perform the maths yourself,
** http://www.alloscomp.com/bitcoin/calculator.php
** http://www.vnbitcoin.org/bitcoincalculator.php
** https://bitknock.com/calculator
* Remember it's just probability! There are no guarantees you will win every N days.

==Related Links==

* [https://docs.google.com/spreadsheet/ccc?key=0AiFMBvXvL2dtdEZkR2J4eU5rS3B4ei1iUmJxSWNlQ0E Bitcoin Difficulty History]
* [https://www.bitcoinmining.com/what-is-bitcoin-mining-difficulty/ What is Bitcoin Mining Difficulty?]
* See also: [[target]]

[[Category:Technical]]
[[Category:Vocabulary]]

[[pl:Trudność]]

Virtual private server

2015-10-31T20:41:15Z

Anduck:

{{PfD|Not inherently bitcoin related}}
A '''virtual private server''' ('''VPS''') is a virtual machine sold as a service by an Internet hosting provider.

Once you decided to create or start a new website, a host of challenges await you. One of the biggest challenges you will face in this regard is the decision on which hosting package to avail in order to run your website successfully.
Generally, people who are new to this have a small budget which they need to manage appropriately. Hence, they have few options to be able to choose from. If your website is not yet very popular, then shared hosting is an ideal solution for you. However, there is a major risk that the website will outgrow the capacity offered by shared hosting. In such cases, it is considered preferable to select a virtual private server due to its numerous advantages, features and security for a price which is just slightly higher if compared to a shared hosting server.

==A brief introduction==
A virtual private server refers to a virtual machine which is generally sold as a service by service providers which provide Internet hosting. A VPS tends to run its own copy of operating systems where the customers are granted super user-level access to the server, basically allowing them to install nearly any software that can run on the relevant operating system.
For most purposes, a virtual private server is similar to a physical server and since they are software-defined, they can be more easily configured and created.

==How to choose a VPS==

Once you decide to switch to a VPS, you should take into consideration certain factors which will help you in deciding the appropriate VPS for you. Compared to shared hosting, a VPS server requires you to consider a lot more factors in order to reach an informed decision related to a VPS which is best suited to running your website. Some of the factors that you need to think about before selecting a VPS include:

===Is the VPS managed or unmanaged?===

While using a shared hosting server, you do not have access to the entire server, unlike in a VPS, where the entire virtual server is under your complete control. Hence, either you or someone you employ will have to look after the server and ensure that its performance remains optimum. If your VPS provider takes charge of maintaining the server, it is known as a managed server. On the other hand, in an unmanaged VPS, the entire responsibility of the server will rest on your shoulders.
If the VPS you select is unmanaged, then as mentioned earlier, you will have to ensure that the server stays in good health and performs efficiently. If your server crashes or if you face any sort of security issue, be it a virus or a breach, then you will be responsible for restoring your server as the only administrator of the entire virtual private server. Hence, if you are well-versed in the functioning of servers and are knowledgeable with stuff such as rebooting, restarting, shutting down and repairing the server, you should consider opting for unmanaged hosting. On the other hand, if the last sentenced sounded alien to you, then you should consider paying slightly more and opting for a managed VPS.
Furthermore, different providers offer different plans related to managed hosting and often, even the same vendor can offer a variety of plans for managed hosting. It would be a good idea to remember this as well when considering a managed hosting plan for your VPS.

===Deciding between Windows and Linux===
One of the most important factors that you need to keep in mind is the operating system of your server. Currently, Linux and Windows are the two most popular operating systems being offered by providers. Since Linux is an open source software, it costs less than Windows. In addition, it is also considered to be more user friendly while supporting a far greater range of applications as well.
On the other hand, there are still some applications which are only supported on Windows and not on Linux. Hence, if you use technologies such as ASP.NET and ASP, then you may be better off with Windows rather than Linux.

===What configuration do you want for your server?===

The configuration you select for your server will have a significant effect on the speed and performance of your server. You should know that the following factors are important when considering the configuration of your server:
*The RAM that will be allocated to you.
*The size of your share in the disk.
*The capacity of the processor you will receive.

Of course, this is not a comprehensive list; it only mentions a few of the important factors to consider while deciding the configuration of your server. You should also gain information on the quality of the actual machine on which your VPS has been created. It should have a high capacity while also being of a reputed brand.

===The scalability and redundancy of your server===

The scalability of your server refers to its adaptability to sudden increases in the load on the server by making use of the redundant resources which are present in the system.
On the other hand, redundancy refers to a backup system in place for the server. There should be a UPS or a generator on hand in case there is a power failure. In case there is an issue with the service provided by the ISP, backups should be in place in order to maintain the operations of the server.
Together, scalability and redundancy are integral in the efficient and consistent performance of your server.

===Monthly quota for bandwidth===
Your VPS provider will fix the bandwidth for your server. You may have to pay extra in order to increase your bandwidth limit. While choosing an appropriate VPS, make sure that you aren’t being required to pay extra for bandwidth which will be consumed on a normal basis for your server.

===Customer Support===
You could end up purchasing the most expensive VPS in the world and yet, problems are bound to arise. On such occasions, an excellent customer support is almost an integral requirement. If the issue does not allow your server to operate properly and the customer support does not respond within an appropriate time limit, then you will end up losing customers. Hence, make sure that the customer support of the VPS providers is up to the mark.
Affordability
Of course, one of the most important factors in selecting a VPS is the cost attached to it. VPS providers will charge more for managed hosting and for using high end resources. Hence, you need to select a VPS which will not only operate effectively, but will also not cause a sizeable hole in your wallet.

===Trial Period===
Often, hosting providers will offer you a free trial period which you can utilize in order to get acquainted with the server and the provider as well. You should try to find out the length of the trial period and use various programs in order to track relevant statistics related to the server such as responses and server uptime.
There will be a point in your life where the needs of your website will be too much for a shared hosting server to manage and VPS hosting will eventually become a necessity for you. Meanwhile, you need to take great care to ensure that the VPS which you select is appropriate for your needs and requirements. Hence, you need to start by making a list of your requirements and then comparing various servers before coming to a conclusion on the best possible server for you.

==Is it possible to pay for VPS with bitcoins?==
Bitcoins refer to a digital currency which is both created as well as held electronically. Instead of being printed like euros or dollars, bitcoins are created by people as well as businesses by using software which can solve mathematical problems.
Over the past few years, bitcoins have steadily grown in popularity and hence, due to their phenomenal demand, in value as well. In fact, bitcoins are probably the most popular digital currency in the world right now. Taking note of this, many websites have started allowing payments to be made via bitcoins as well as more traditional means such as PayPal or credit cards.
Of course, virtual private server providers have noted this trend as well. Not to be left behind, there are several providers all over the world who allow you to pay for servers via bitcoins in addition to other methods as well.
Now, you can maintain a high level of anonymity by paying for VPS through bitcoins.

===Advantages of opting for purchases through bitcoin===
Of course, there are several advantages that can be availed by you if you want to use bitcoins to purchase your VPS. These benefits are only available to those using bitcoins and include:
*Complete user anonymity :
The best thing about bitcoin purchases is that they are discreet. You have the option to publish your own bitcoin transactions but if you don’t, then there is no way for anyone to track your transactions. This is due to the fact that, like cash purchases, the transaction itself can never be associated to the person carrying it out hence, will not trace back to him. Even the anonymous bitcoin address generated changes on each transaction, thus completely preserving your anonymity.
Hence, if you want to make sure that no one else knows about your VPS purchase, then you can use bitcoins as a valid method of payment.

*Avoiding third party interruptions:
One of the reasons bitcoins has attained massive popularity is due to the fact that banks, governments and any other financial entities cannot interrupt or stop any user transactions being made through bitcoins. Furthermore, they have no power to freeze any bitcoin accounts either. Since the system is a peer to peer system, its users experience a degree of freedom much greater than that experienced by people using the national currency.
Thus, you could use servers from other countries as well without facing any difficulties or additional duties from the governments of either country.

*Transaction fees are incredibly low:
If you want to select a VPS provider located in a foreign country, you will be subject to a ridiculous amount in fees and service charges. Furthermore, you are also likely to suffer losses due to the exchange rate. On the other hand, since the government has absolutely no involvement in transactions made by bitcoins, the fees are actually minimal and may even be considered negligible by some.
Furthermore, due to the fact that bitcoin transactions take place almost immediately, you will also be able to skip the waiting period which is generally considered a norm while making online transactions. Furthermore, there aren’t any authorization requirements as well, thus saving you even more time.

*Mobile payments are possible as well:
As is true for many online payment systems, you can pay through any device which can connect to the Internet. Hence, you can make payments for your virtual private server through even your cell phone and you will still not be required to disclose any information regarding yourself.
Of course, it is also important and pertinent to mention that making a purchase through bitcoins will not have any negative effects on the quality of the VPS you are being provided with.

===Offshore Bitcoins VPS===
Often, for purposes of anonymity, people prefer offshore VPS as compared to those available within their country. Offshore VPS are more difficult to trace and hence, offer greater anonymity. On the other hand, others prefer offshore servers due to a greater protection of freedom offered by the foreign country as compared to their own. Meanwhile, some decide to opt for offshore servers as they are promised far greater speeds by the providers as compared to the options present within their own country.
There are a variety of offshore countries which provide Bitcoin VPS options. All you are required to do is to pay anonymously through bitcoins and you will be provided with a wide variety of VPS options, of which you can select the one most suited to your needs. You can select from top of the line options to more budget friendly options as well.
Bitcoin users can often even avail additional protection from attacks via services offered by the providers such as Bitcoin DDos protection, which can allow you to fend off any attack whatsoever.

===Recurring payments with bitcoin===
The main problem faced by users paying for VPS through bitcoin is the fact that while payments to VPS service providers are generally monthly, bitcoin generally does not support recurring payments. This is mainly due to the fact that bitcoin is a push technology i.e. a transaction which has to be initiated by the publisher rather than the client or the receiver.
In order to be able to make consistent or recurring payments with bitcoins, it would be a good idea to generate and then email the service provider with a new bitcoin address for each transaction which should be paid before the cutoff. You should then track the address in order to ensure that timely payment has been made.

==Cloud servers==
Cloud servers are a type of virtual private servers with far greater advantages offered to those deciding to purchase them. In fact, they are touted to be the next generation of virtual private servers.
Difference between cloud servers and traditional VPS
There are three main differences between cloud servers and traditional VPS, namely:
*While a VPS is based on a single physical server which is split up between users a cloud server makes use of resources which are distributed through many physical servers.
*While a VPS has to be manually updated by the provider or tech support, a cloud server is built with scalability in mind and hence, can quickly and efficiently be updates via the administrative panel.
*Since you have to bear the cost of hardware for a cloud server, it can end up being rather expensive. You can compromise by deciding to opt for a hosted private cloud, though that will result in you losing control of the entire server. On the other hand, a traditional VPS is always significantly less expensive than cloud servers.

===Advantages of cloud servers===

Cloud servers are virtual servers which perform on cloud computing environment. This is the reason cloud servers are often also called Virtual Dedicated Servers. Even though it is true that every cloud server can be considered to be a virtual dedicated server, the opposite is not true. This is due to the fact that since virtual dedicated servers are place on only one hardware server, when any of the hardware fails, the server will suffer from failure as well.
On the other hand, cloud servers generally operate as software independent units which means that all its required software is installed and hence, it is not depended on centrally installed software.
There are a myriad of advantages afforded to those who decide to opt for cloud servers, some of which include:
*You will be able to boast the freedom of modifying any of the server software according to your requirements. Included in this is the operating system kernel which is generally not modifiable in other servers such as private virtual servers.
*You will also be provided with security as well as stability since any problem that occurs is limited to and from your environment. Furthermore, even if other users somehow overload their cloud servers, since you have dedicated resources, your performance will not be affected at all. Furthermore, as previously mentioned, you will be free from any hardware problems as well.
*Cloud servers can probably boast the most optimum stability / cost ratio performance. Again, they do not suffer from hardware issues while still being safe, secure and stable.
*Furthermore, cloud servers are also more economical as well as more efficient than the traditional dedicated servers. For more or less the same price, cloud servers will not only attain more resources, they will be faster as well. In web hosting language, your website will not only be significantly faster on a cloud server, it will not cost you extra as compared to a traditional service.
*The modifiability of cloud servers is not only limited to its software as well. You can easily add any upgrades such as disk space, memory and CPU without facing any significant issues. Of course, this is also very affordable and does not result in high additional costs.

===Conclusion===
From the above mentioned reasons, it is clear to see why cloud servers are such a favorite amongst the VPS crowd. Not only do they offer several benefits and are more secure, stable and efficient, they are extremely economical as well which is why they are preferred especially by those who are new to the business of running websites and hence, do not have a large or flexible budget.

<references />

[[Category:Web hosting]]
{{wp|Virtual_private_server}}

Original Bitcoin client/API calls list

2015-07-07T13:58:22Z

Anduck: Undo revision 57127 by Anduck (talk)

Bitcoin API call list (as of version 0.8.0)

Note: up-to-date API reference can be [https://bitcoin.org/en/developer-reference#bitcoin-core-apis found here].

== Common operations ==

=== Listing my bitcoin addresses ===

Listing the bitcoin [[address|addresses]] in your wallet is easily done via ''listreceivedbyaddress''. It normally lists only addresses which already have received transactions, however you can list all the addresses by setting the first argument to 0, and the second one to true.

[[accounts explained|Accounts]] are used to organize addresses.

== Full list ==

Required arguments are denoted inside < and > Optional arguments are inside [ and ].

{|class="wikitable"
! Command !! Parameters !! Description !! Requires unlocked wallet? (v0.4.0+)
|-
| addmultisigaddress || <nrequired> <'["key","key"]'> [account] || Add a nrequired-to-sign multisignature address to the wallet. Each key is a bitcoin address or hex-encoded public key. If [account] is specified, assign address to [account]. Returns a string containing the address. || N
|-
| addnode || <node> <add/remove/onetry> || '''version 0.8''' Attempts add or remove <node> from the addnode list or try a connection to <node> once. || N
|-
| backupwallet || <destination> || Safely copies wallet.dat to destination, which can be a directory or a path with filename. || N
|-
| createmultisig || <nrequired> <'["key,"key"]'> || Creates a multi-signature address and returns a json object ||
|-
| createrawtransaction || [{"txid":txid,"vout":n},...] {address:amount,...} || '''version 0.7''' Creates a [[Raw Transactions|raw transaction]] spending given inputs. || N
|-
| decoderawtransaction || <hex string> || '''version 0.7''' Produces a human-readable JSON object for a [[Raw Transactions|raw transaction]]. || N
|-
| dumpprivkey || <bitcoinaddress> || Reveals the private key corresponding to <bitcoinaddress> || Y
|-
| encryptwallet || <passphrase> || Encrypts the wallet with <passphrase>. || N
|-
| getaccount || <bitcoinaddress> || Returns the account associated with the given address. || N
|-
| getaccountaddress || <account> || Returns the current bitcoin address for receiving payments to this account. If <account> does not exist, it will be created along with an associated new address that will be returned. || N
|-
| getaddednodeinfo || <dns> [node] || '''version 0.8''' Returns information about the given added node, or all added nodes
(note that onetry addnodes are not listed here)
If dns is false, only a list of added nodes will be provided,
otherwise connected information will also be available.
|-
| getaddressesbyaccount || <account> || Returns the list of addresses for the given account. || N
|-
| getbalance || [account] [minconf=1] || If [account] is not specified, returns the server's total available balance.<br/>If [account] is specified, returns the balance in the account. || N
|-
| getbestblockhash || || '''version 0.9''' Returns the hash of the best (tip) block in the longest block chain. || N
|-
| getblock || <hash> || Returns information about the block with the given hash. || N
|-
| getblockcount || || Returns the number of blocks in the longest block chain. || N
|-
| getblockhash || <index> || Returns hash of block in best-block-chain at <index>; index 0 is the [[genesis block]] || N
|-
| getblocknumber || || '''Deprecated'''. '''Removed in version 0.7'''. Use getblockcount. || N
|-
| getblocktemplate || [params] || Returns data needed to construct a block to work on. See [[ BIP_0022]] for more info on params.|| N
|-
| getconnectioncount || || Returns the number of connections to other nodes. || N
|-
| getdifficulty || || Returns the proof-of-work difficulty as a multiple of the minimum difficulty. || N
|-
| getgenerate || || Returns true or false whether bitcoind is currently generating hashes || N
|-
| gethashespersec || || Returns a recent hashes per second performance measurement while generating. || N
|-
| getinfo || || Returns an object containing various state info. || N
|-
| getmemorypool || [data] || '''Replaced in v0.7.0 with getblocktemplate, submitblock, getrawmempool''' || N
|-
| getmininginfo || || Returns an object containing mining-related information:
* blocks
* currentblocksize
* currentblocktx
* difficulty
* errors
* generate
* genproclimit
* hashespersec
* pooledtx
* testnet
|| N
|-
| getnewaddress || [account] || Returns a new bitcoin address for receiving payments. If [account] is specified payments received with the address will be credited to [account]. || N
|-
| getpeerinfo || || '''version 0.7''' Returns data about each connected node. || N
|-
| getrawchangeaddress || [account]|| '''version 0.9''' Returns a new Bitcoin address, for receiving change. This is for use with raw transactions, NOT normal use. || N
|-
| getrawmempool || || '''version 0.7''' Returns all transaction ids in memory pool || N
|-
| getrawtransaction || <txid> [verbose=0] || '''version 0.7''' Returns [[Raw Transactions|raw transaction]] representation for given transaction id. || N
|-
| getreceivedbyaccount || [account] [minconf=1] || Returns the total amount received by addresses with [account] in transactions with at least [minconf] confirmations. If [account] not provided return will include all transactions to all accounts. (version 0.3.24) || N
|-
| getreceivedbyaddress || <bitcoinaddress> [minconf=1] || Returns the amount received by <bitcoinaddress> in transactions with at least [minconf] confirmations. It correctly handles the case where someone has sent to the address in multiple transactions. Keep in mind that addresses are only ever used for receiving transactions. Works only for addresses in the local wallet, external addresses will always show 0. || N
|-
| gettransaction || <txid> || Returns an object about the given transaction containing:
* "amount" : total amount of the transaction
* "confirmations" : number of confirmations of the transaction
* "txid" : the transaction ID
* "time" : time associated with the transaction<ref>From block timestamp, unless transaction was already in memory pool then the local time when the client added the transaction to its memory pool</ref>.
* "details" - An array of objects containing:
** "account"
** "address"
** "category"
** "amount"
** "fee"
|| N
|-
| gettxout || <txid> <n> [includemempool=true] || Returns details about an unspent transaction output (UTXO) || N
|-
| gettxoutsetinfo || || Returns statistics about the unspent transaction output (UTXO) set || N
|-
| [[getwork]] || [data] || If [data] is not specified, returns formatted hash data to work on:
* "midstate" : precomputed hash state after hashing the first half of the data
* "data" : block data
* "hash1" : formatted hash buffer for second hash
* "target" : little endian hash target
If [data] is specified, tries to solve the block and returns true if it was successful.
|| N
|-
| help || [command] || List commands, or get help for a command. || N
|-
| importprivkey || <bitcoinprivkey> [label] [rescan=true]|| Adds a private key (as returned by dumpprivkey) to your wallet. This may take a while, as a [[How_to_import_private_keys#Import_Private_key.28s.29|rescan]] is done, looking for existing transactions. '''Optional [rescan] parameter added in 0.8.0.''' Note: There's no need to import public key, as in [[Elliptic_Curve_Digital_Signature_Algorithm|ECDSA]] (unlike RSA) this can be computed from private key. || Y
|-
| keypoolrefill || || Fills the keypool, requires wallet passphrase to be set. || Y
|-
| listaccounts || [minconf=1] || Returns Object that has account names as keys, account balances as values. || N
|-
| listaddressgroupings || || '''version 0.7''' Returns all addresses in the wallet and info used for coincontrol. || N
|-
| listreceivedbyaccount || [minconf=1] [includeempty=false] || Returns an array of objects containing:
* "account" : the account of the receiving addresses
* "amount" : total amount received by addresses with this account
* "confirmations" : number of confirmations of the most recent transaction included
|| N
|-
| listreceivedbyaddress || [minconf=1] [includeempty=false] || Returns an array of objects containing:
* "address" : receiving address
* "account" : the account of the receiving address
* "amount" : total amount received by the address
* "confirmations" : number of confirmations of the most recent transaction included
To get a list of accounts on the system, execute bitcoind listreceivedbyaddress 0 true
|| N
|-
| listsinceblock|| [blockhash] [target-confirmations] || Get all transactions in blocks since block [blockhash], or all transactions if omitted. [target-confirmations] intentionally '''does not''' affect the list of returned transactions, but only affects the returned "lastblock" value.[https://github.com/bitcoin/bitcoin/pull/199#issuecomment-1514952] || N
|-
| listtransactions || [account] [count=10] [from=0] || Returns up to [count] most recent transactions skipping the first [from] transactions for account [account]. If [account] not provided it'll return recent transactions from all accounts.
|| N
|-
| listunspent || [minconf=1] [maxconf=999999] || '''version 0.7''' Returns array of unspent transaction inputs in the wallet. || N
|-
| listlockunspent || || '''version 0.8''' Returns list of temporarily unspendable outputs
|-
| lockunspent || <unlock?> [array-of-objects] || '''version 0.8''' Updates list of temporarily unspendable outputs
|-
| move || <fromaccount> <toaccount> <amount> [minconf=1] [comment] || Move from one account in your wallet to another || N
|-
| sendfrom || <fromaccount> <tobitcoinaddress> <amount> [minconf=1] [comment] [comment-to] || <amount> is a real and is rounded to 8 decimal places. Will send the given amount to the given address, ensuring the account has a valid balance using [minconf] confirmations. Returns the transaction ID if successful (not in JSON object). || Y
|-
| sendmany || <fromaccount> {address:amount,...} [minconf=1] [comment] || amounts are double-precision floating point numbers || Y
|-
| sendrawtransaction || <hexstring> || '''version 0.7''' Submits [[Raw Transactions|raw transaction]] (serialized, hex-encoded) to local node and network. || N
|-
| sendtoaddress || <bitcoinaddress> <amount> [comment] [comment-to] || <amount> is a real and is rounded to 8 decimal places. Returns the transaction ID <txid> if successful. || Y
|-
| setaccount || <bitcoinaddress> <account> || Sets the account associated with the given address. Assigning address that is already assigned to the same account will create a new address associated with that account. || N
|-
| setgenerate || <generate> [genproclimit] || <generate> is true or false to turn generation on or off.<br/>Generation is limited to [genproclimit] processors, -1 is unlimited. || N
|-
| settxfee || <amount> || <amount> is a real and is rounded to the nearest 0.00000001 || N
|-
| signmessage || <bitcoinaddress> <message> || Sign a message with the private key of an address. || Y
|-
| signrawtransaction || <hexstring> [{"txid":txid,"vout":n,"scriptPubKey":hex},...] [<privatekey1>,...] || '''version 0.7''' Adds signatures to a [[Raw Transactions|raw transaction]] and returns the resulting raw transaction. || Y/N
|-
| stop || || Stop bitcoin server. || N
|-
| submitblock || <hex data> [optional-params-obj] || Attempts to submit new block to network. || N
|-
| validateaddress || <bitcoinaddress> || Return information about <bitcoinaddress>. || N
|-
| verifymessage || <bitcoinaddress> <signature> <message> || Verify a signed message. || N
|-
| walletlock || || Removes the wallet encryption key from memory, locking the wallet. After calling this method, you will need to call walletpassphrase again before being able to call any methods which require the wallet to be unlocked. || N
|-
| walletpassphrase || <passphrase> <timeout> || Stores the wallet decryption key in memory for <timeout> seconds. || N
|-
| walletpassphrasechange || <oldpassphrase> <newpassphrase> || Changes the wallet passphrase from <oldpassphrase> to <newpassphrase>. || N

|}

==Error Codes==

See [https://github.com/bitcoin/bitcoin/blob/master/src/rpcprotocol.h#L34 rpcprotocol.h] for the list of error codes and their meanings.

==See Also==

* [[Original Bitcoin client]]
* [[Running Bitcoin]]
* [[Protocol specification]]
* [[API reference (JSON-RPC)]]
* [[Lazy_API]]
* [[Elis-API]] - A more detailed version of this page - for developers!
* [http://code.gogulski.com/bitcoin-php/class_bitcoin_client.html PHP BitcoinClient Class Reference]

==References==
<references />

[[Category:Technical]]
[[Category:Developer]]

Original Bitcoin client/API calls list

2015-06-29T18:17:06Z

Anduck: added importaddress

Bitcoin API call list (as of version 0.8.0)

Note: up-to-date API reference can be [https://bitcoin.org/en/developer-reference#bitcoin-core-apis found here].

== Common operations ==

=== Listing my bitcoin addresses ===

Listing the bitcoin [[address|addresses]] in your wallet is easily done via ''listreceivedbyaddress''. It normally lists only addresses which already have received transactions, however you can list all the addresses by setting the first argument to 0, and the second one to true.

[[accounts explained|Accounts]] are used to organize addresses.

== Full list ==

Required arguments are denoted inside < and > Optional arguments are inside [ and ].

{|class="wikitable"
! Command !! Parameters !! Description !! Requires unlocked wallet? (v0.4.0+)
|-
| addmultisigaddress || <nrequired> <'["key","key"]'> [account] || Add a nrequired-to-sign multisignature address to the wallet. Each key is a bitcoin address or hex-encoded public key. If [account] is specified, assign address to [account]. Returns a string containing the address. || N
|-
| addnode || <node> <add/remove/onetry> || '''version 0.8''' Attempts add or remove <node> from the addnode list or try a connection to <node> once. || N
|-
| backupwallet || <destination> || Safely copies wallet.dat to destination, which can be a directory or a path with filename. || N
|-
| createmultisig || <nrequired> <'["key,"key"]'> || Creates a multi-signature address and returns a json object ||
|-
| createrawtransaction || [{"txid":txid,"vout":n},...] {address:amount,...} || '''version 0.7''' Creates a [[Raw Transactions|raw transaction]] spending given inputs. || N
|-
| decoderawtransaction || <hex string> || '''version 0.7''' Produces a human-readable JSON object for a [[Raw Transactions|raw transaction]]. || N
|-
| dumpprivkey || <bitcoinaddress> || Reveals the private key corresponding to <bitcoinaddress> || Y
|-
| encryptwallet || <passphrase> || Encrypts the wallet with <passphrase>. || N
|-
| getaccount || <bitcoinaddress> || Returns the account associated with the given address. || N
|-
| getaccountaddress || <account> || Returns the current bitcoin address for receiving payments to this account. If <account> does not exist, it will be created along with an associated new address that will be returned. || N
|-
| getaddednodeinfo || <dns> [node] || '''version 0.8''' Returns information about the given added node, or all added nodes
(note that onetry addnodes are not listed here)
If dns is false, only a list of added nodes will be provided,
otherwise connected information will also be available.
|-
| getaddressesbyaccount || <account> || Returns the list of addresses for the given account. || N
|-
| getbalance || [account] [minconf=1] || If [account] is not specified, returns the server's total available balance.<br/>If [account] is specified, returns the balance in the account. || N
|-
| getbestblockhash || || '''version 0.9''' Returns the hash of the best (tip) block in the longest block chain. || N
|-
| getblock || <hash> || Returns information about the block with the given hash. || N
|-
| getblockcount || || Returns the number of blocks in the longest block chain. || N
|-
| getblockhash || <index> || Returns hash of block in best-block-chain at <index>; index 0 is the [[genesis block]] || N
|-
| getblocknumber || || '''Deprecated'''. '''Removed in version 0.7'''. Use getblockcount. || N
|-
| getblocktemplate || [params] || Returns data needed to construct a block to work on. See [[ BIP_0022]] for more info on params.|| N
|-
| getconnectioncount || || Returns the number of connections to other nodes. || N
|-
| getdifficulty || || Returns the proof-of-work difficulty as a multiple of the minimum difficulty. || N
|-
| getgenerate || || Returns true or false whether bitcoind is currently generating hashes || N
|-
| gethashespersec || || Returns a recent hashes per second performance measurement while generating. || N
|-
| getinfo || || Returns an object containing various state info. || N
|-
| getmemorypool || [data] || '''Replaced in v0.7.0 with getblocktemplate, submitblock, getrawmempool''' || N
|-
| getmininginfo || || Returns an object containing mining-related information:
* blocks
* currentblocksize
* currentblocktx
* difficulty
* errors
* generate
* genproclimit
* hashespersec
* pooledtx
* testnet
|| N
|-
| getnewaddress || [account] || Returns a new bitcoin address for receiving payments. If [account] is specified payments received with the address will be credited to [account]. || N
|-
| getpeerinfo || || '''version 0.7''' Returns data about each connected node. || N
|-
| getrawchangeaddress || [account]|| '''version 0.9''' Returns a new Bitcoin address, for receiving change. This is for use with raw transactions, NOT normal use. || N
|-
| getrawmempool || || '''version 0.7''' Returns all transaction ids in memory pool || N
|-
| getrawtransaction || <txid> [verbose=0] || '''version 0.7''' Returns [[Raw Transactions|raw transaction]] representation for given transaction id. || N
|-
| getreceivedbyaccount || [account] [minconf=1] || Returns the total amount received by addresses with [account] in transactions with at least [minconf] confirmations. If [account] not provided return will include all transactions to all accounts. (version 0.3.24) || N
|-
| getreceivedbyaddress || <bitcoinaddress> [minconf=1] || Returns the amount received by <bitcoinaddress> in transactions with at least [minconf] confirmations. It correctly handles the case where someone has sent to the address in multiple transactions. Keep in mind that addresses are only ever used for receiving transactions. Works only for addresses in the local wallet, external addresses will always show 0. || N
|-
| gettransaction || <txid> || Returns an object about the given transaction containing:
* "amount" : total amount of the transaction
* "confirmations" : number of confirmations of the transaction
* "txid" : the transaction ID
* "time" : time associated with the transaction<ref>From block timestamp, unless transaction was already in memory pool then the local time when the client added the transaction to its memory pool</ref>.
* "details" - An array of objects containing:
** "account"
** "address"
** "category"
** "amount"
** "fee"
|| N
|-
| gettxout || <txid> <n> [includemempool=true] || Returns details about an unspent transaction output (UTXO) || N
|-
| gettxoutsetinfo || || Returns statistics about the unspent transaction output (UTXO) set || N
|-
| [[getwork]] || [data] || If [data] is not specified, returns formatted hash data to work on:
* "midstate" : precomputed hash state after hashing the first half of the data
* "data" : block data
* "hash1" : formatted hash buffer for second hash
* "target" : little endian hash target
If [data] is specified, tries to solve the block and returns true if it was successful.
|| N
|-
| help || [command] || List commands, or get help for a command. || N
|-
| importaddress || <address> [label] [rescan=true]|| Adds an address or script (in hex) that can be watched as if it were in your wallet but cannot be used to spend. || Y
|-
| importprivkey || <bitcoinprivkey> [label] [rescan=true]|| Adds a private key (as returned by dumpprivkey) to your wallet. This may take a while, as a [[How_to_import_private_keys#Import_Private_key.28s.29|rescan]] is done, looking for existing transactions. '''Optional [rescan] parameter added in 0.8.0.''' Note: There's no need to import public key, as in [[Elliptic_Curve_Digital_Signature_Algorithm|ECDSA]] (unlike RSA) this can be computed from private key. || Y
|-
| keypoolrefill || || Fills the keypool, requires wallet passphrase to be set. || Y
|-
| listaccounts || [minconf=1] || Returns Object that has account names as keys, account balances as values. || N
|-
| listaddressgroupings || || '''version 0.7''' Returns all addresses in the wallet and info used for coincontrol. || N
|-
| listreceivedbyaccount || [minconf=1] [includeempty=false] || Returns an array of objects containing:
* "account" : the account of the receiving addresses
* "amount" : total amount received by addresses with this account
* "confirmations" : number of confirmations of the most recent transaction included
|| N
|-
| listreceivedbyaddress || [minconf=1] [includeempty=false] || Returns an array of objects containing:
* "address" : receiving address
* "account" : the account of the receiving address
* "amount" : total amount received by the address
* "confirmations" : number of confirmations of the most recent transaction included
To get a list of accounts on the system, execute bitcoind listreceivedbyaddress 0 true
|| N
|-
| listsinceblock|| [blockhash] [target-confirmations] || Get all transactions in blocks since block [blockhash], or all transactions if omitted. [target-confirmations] intentionally '''does not''' affect the list of returned transactions, but only affects the returned "lastblock" value.[https://github.com/bitcoin/bitcoin/pull/199#issuecomment-1514952] || N
|-
| listtransactions || [account] [count=10] [from=0] || Returns up to [count] most recent transactions skipping the first [from] transactions for account [account]. If [account] not provided it'll return recent transactions from all accounts.
|| N
|-
| listunspent || [minconf=1] [maxconf=999999] || '''version 0.7''' Returns array of unspent transaction inputs in the wallet. || N
|-
| listlockunspent || || '''version 0.8''' Returns list of temporarily unspendable outputs
|-
| lockunspent || <unlock?> [array-of-objects] || '''version 0.8''' Updates list of temporarily unspendable outputs
|-
| move || <fromaccount> <toaccount> <amount> [minconf=1] [comment] || Move from one account in your wallet to another || N
|-
| sendfrom || <fromaccount> <tobitcoinaddress> <amount> [minconf=1] [comment] [comment-to] || <amount> is a real and is rounded to 8 decimal places. Will send the given amount to the given address, ensuring the account has a valid balance using [minconf] confirmations. Returns the transaction ID if successful (not in JSON object). || Y
|-
| sendmany || <fromaccount> {address:amount,...} [minconf=1] [comment] || amounts are double-precision floating point numbers || Y
|-
| sendrawtransaction || <hexstring> || '''version 0.7''' Submits [[Raw Transactions|raw transaction]] (serialized, hex-encoded) to local node and network. || N
|-
| sendtoaddress || <bitcoinaddress> <amount> [comment] [comment-to] || <amount> is a real and is rounded to 8 decimal places. Returns the transaction ID <txid> if successful. || Y
|-
| setaccount || <bitcoinaddress> <account> || Sets the account associated with the given address. Assigning address that is already assigned to the same account will create a new address associated with that account. || N
|-
| setgenerate || <generate> [genproclimit] || <generate> is true or false to turn generation on or off.<br/>Generation is limited to [genproclimit] processors, -1 is unlimited. || N
|-
| settxfee || <amount> || <amount> is a real and is rounded to the nearest 0.00000001 || N
|-
| signmessage || <bitcoinaddress> <message> || Sign a message with the private key of an address. || Y
|-
| signrawtransaction || <hexstring> [{"txid":txid,"vout":n,"scriptPubKey":hex},...] [<privatekey1>,...] || '''version 0.7''' Adds signatures to a [[Raw Transactions|raw transaction]] and returns the resulting raw transaction. || Y/N
|-
| stop || || Stop bitcoin server. || N
|-
| submitblock || <hex data> [optional-params-obj] || Attempts to submit new block to network. || N
|-
| validateaddress || <bitcoinaddress> || Return information about <bitcoinaddress>. || N
|-
| verifymessage || <bitcoinaddress> <signature> <message> || Verify a signed message. || N
|-
| walletlock || || Removes the wallet encryption key from memory, locking the wallet. After calling this method, you will need to call walletpassphrase again before being able to call any methods which require the wallet to be unlocked. || N
|-
| walletpassphrase || <passphrase> <timeout> || Stores the wallet decryption key in memory for <timeout> seconds. || N
|-
| walletpassphrasechange || <oldpassphrase> <newpassphrase> || Changes the wallet passphrase from <oldpassphrase> to <newpassphrase>. || N

|}

==Error Codes==

See [https://github.com/bitcoin/bitcoin/blob/master/src/rpcprotocol.h#L34 rpcprotocol.h] for the list of error codes and their meanings.

==See Also==

* [[Original Bitcoin client]]
* [[Running Bitcoin]]
* [[Protocol specification]]
* [[API reference (JSON-RPC)]]
* [[Lazy_API]]
* [[Elis-API]] - A more detailed version of this page - for developers!
* [http://code.gogulski.com/bitcoin-php/class_bitcoin_client.html PHP BitcoinClient Class Reference]

==References==
<references />

[[Category:Technical]]
[[Category:Developer]]

Units

2015-03-01T11:20:01Z

Anduck:

While units in Bitcoin follow the Standard Metric Notation system, this page lists the most commonly used units. These can be written/typed/expressed in any number of ways. From using some form of the prefix, to an abbreviation of both the prefix and adding bit/bitcoin. Bitcoin as a unit of account is commonly written without capitalization.

{| class="wikitable sortable"
|-
! Unit !! Abbreviation !! Decimal (BTC) !! Alternate names !! Info
|-
| bitcoin || BTC || 1 || coin || one bitcoin
|-
| millibitcoin || mBTC || 0.001 || millibit, millicoin, and millie || thousandth of a bitcoin
|-
| microbitcoin || μBTC || 0.000001 || bit || millionth of a bitcoin
|-
| satoshi || sat || 0.00000001 || ''none'' || 100 millionth of a bitcoin, the smallest unit currently possible to represent, named after the inventor
|}

Alternate systems for representing Bitcoin units exist, such as [[Tonal Bitcoin|Tonal Bitcoin (TBC)]].

Units

2015-03-01T11:18:55Z

Anduck: note about bitcoin units commonly being without capitalization

While units in Bitcoin follow the Standard Metric Notation system, this page lists the most commonly used units. These can be written/typed/expressed in any number of ways. From using some form of the prefix, to an abbreviation of both the prefix and adding bit/bitcoin. Bitcoin as a unit of account is commonly written without capitalization.

{| class="wikitable sortable"
|-
! Unit !! Abbreviation !! Decimal (BTC) !! Alternate names !! Info
|-
| bitcoin || BTC || 1 || coin || One bitcoin
|-
| millibitcoin || mBTC || 0.001 || millibit, millicoin, and millie || thousandth of a bitcoin
|-
| microbitcoin || μBTC || 0.000001 || bit || millionth of a bitcoin
|-
| satoshi || sat || 0.00000001 || ''none'' || 100 millionth of a bitcoin, the smallest unit currently possible to represent, named after the inventor
|}

Alternate systems for representing Bitcoin units exist, such as [[Tonal Bitcoin|Tonal Bitcoin (TBC)]].