I am attempting to set up the PHP bitwasp library from the github repository:


The installing instructions suggest I simply execute:

$ composer require bitwasp/bitcoin

I do have composer installed but I am getting the following error message:

Problem 1 - Installation request for bitwasp/bitcoin dev-master -> satisfiable by bitwasp/bitcoin[dev-master]. - Can only install one of: bitwasp/bitcoin[v0.0.29.1, dev-master]. - Installation request for bitwasp/bitcoin v0.0.29.1 -> satisfiable by bitwasp/bitcoin[v0.0.29.1].

I do not practice PHP full time so I lack the experience of installing packages in that language and using composer. I would be grateful if someone could point me in the right direction.

EDIT The suggestion has been made that the package is already installed. However, the following code sample which I got from another thread:

// failing to install bitwasp
use BitWasp\Bitcoin\Bitcoin;
use BitWasp\Bitcoin\Address;
use BitWasp\Bitcoin\Key\PrivateKeyFactory;

$network = Bitcoin::getNetwork();

$privateKey = PrivateKeyFactory::create(true);
$publicKey = $privateKey->getPublicKey();
$address = $publicKey->getAddress();


is giving me PHP Fatal error: Class 'BitWasp\Bitcoin\Bitcoin' not found.

  • 1
    Did you include the vendor/autoload.php file? It's missing from your snippet, so as suggested below, it might already be on your system.
    – karimkorun
    Aug 25, 2016 at 20:25
  • 2
    You have made me very happy !!! First of all I had to type composer install instead of composer require bitswap/bitcoin and this triggered a proper installation, and in particular this created a vendor directory with an autoload.php file in it. Then I created a symbolic link from my working directory to this vendor directory. Then I added the line require 'vendor/autoload.php'; in my snippet as you suggested. And voila the thing ran :) Thank you very much !!. If you want to explain the answer for the record (better than I can do, I am no PHP specialist) I will gladly upvote it. . Aug 25, 2016 at 21:49
  • Oh, please be careful :P someone published bitswap/bitcoin on composer and I'm not sure if they're typo-squatting! If you can, @Sven could you update your comment if this wasn't what you meant?
    – karimkorun
    Jan 14, 2018 at 22:27
  • 1
    require 'vendor/autoload.php'; For those having similar issues.
    – Sydwell
    Nov 1, 2018 at 10:10

1 Answer 1


You have it installed already. That's why it's saying you have the requirements met and don't need to download it again.

  • Thank you very much ! I am guessing something else is wrong too. I have updated my question to explain. Aug 24, 2016 at 21:16
  • I think I know why. Did you use "bitcoin" instead of "bitcoin-php"? Aug 24, 2016 at 21:18
  • I typed composer require bitwasp/bitcoin to install and the code is exactly as I have stated it. Using the indicated repository. I am on Debian 8. Aug 24, 2016 at 21:22
  • Oh, im not familiar with Debian. What php version are you using? Aug 24, 2016 at 21:23
  • PHP 5.6.24. Zend Engine v2.6.0 with Zend OPcache v7.0.6-dev. This is pure PHP, run as a script (no browser involed), if this matters. Aug 24, 2016 at 21:25

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