user1878: I have an arbitrary address.  How can I get the current balance of the account through a Web API? ... how do I get it for a local API?
I'm also interested in all transaction history for that address.  Let me know if the API can offer that as well.

user628: You can query the unspent outputs of an address with this:
 http://blockchain.info/unspent?active=$bitcoin_address

You can get the transaction history for an address with this:
 http://blockchain.info/address/$bitcoin_address?format=json

For more information see http://blockchain.info/api/blockchain_api

1878: <p>I have an arbitrary address.  How can I get the current balance of the account through a Web API? ... how do I get it for a local API?</p>

<p>I'm also interested in all transaction history for that address.  Let me know if the API can offer that as well.</p>
 628: <p>You can query the unspent outputs of an address with this:</p>

<pre><code> http://blockchain.info/unspent?active=$bitcoin_address
</code></pre>

<p>You can get the transaction history for an address with this:</p>

<pre><code> http://blockchain.info/address/$bitcoin_address?format=json
</code></pre>

<p>For more information see <a href="http://blockchain.info/api/blockchain_api" rel="nofollow">http://blockchain.info/api/blockchain_api</a></p>
