user19493: I'd like to write a simple Bitcoin client that broadcast transactions. The model is pretty simple:

Alice wants to send 10 BTC to Bob. We only know Alice's private key and Bob's address.

For making the transaction, I need to collect enough Alice's previous transactions up to 10 BTC.
I've found the Blockchain Data API, that can be queried using Alice's address (which I can derive from Alice's private key, which is known by the client).
If I GET the API above using
$ curl -L http://blockchain.info/address/<Alice's address>?format=json&sort=<[01]>

I'll be returned with a JSON containing the whole list of transactions.
How should  I use this result for collecting all the Alice's transactions that can be used in a newer transaction?

user19036: You will want to use the listunspent call from the blockchain.info API
http://blockchain.info/unspent?active=$address
This will give you a list of all unspent outputs at that address which are available to be used in a transaction.
You will then need to build a raw transaction to spend those outputs.
https://en.bitcoin.it/wiki/Raw_Transactions

19493: <p>I'd like to write a simple Bitcoin client that broadcast transactions. The model is pretty simple:</p>

<blockquote>
  <p>Alice wants to send 10 BTC to Bob. We <strong>only</strong> know Alice's private key and Bob's address.</p>
</blockquote>

<p>For making the transaction, I need to collect enough Alice's previous transactions up to 10 BTC.</p>

<p>I've found the <a href="https://blockchain.info/api/blockchain_api" rel="nofollow">Blockchain Data API</a>, that can be queried using Alice's address (which I can derive from Alice's private key, which is known by the client).</p>

<p>If I <code>GET</code> the API above using</p>

<pre><code>$ curl -L http://blockchain.info/address/&lt;Alice's address&gt;?format=json&amp;sort=&lt;[01]&gt;
</code></pre>

<p>I'll be returned with a JSON containing the whole list of transactions.</p>

<p>How should  I use this result for collecting all the Alice's transactions that can be used in a newer transaction?</p>
 19036: <p>You will want to use the listunspent call from the blockchain.info API</p>

<p><a href="http://blockchain.info/unspent?active=" rel="nofollow">http://blockchain.info/unspent?active=</a>$address</p>

<p>This will give you a list of all unspent outputs at that address which are available to be used in a transaction.</p>

<p>You will then need to build a raw transaction to spend those outputs.</p>

<p><a href="https://en.bitcoin.it/wiki/Raw_Transactions" rel="nofollow">https://en.bitcoin.it/wiki/Raw_Transactions</a></p>
