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<li class="toctree-l4"><a class="reference internal" href="#infuraprovider-inherits-from-jsonrpcprovider">InfuraProvider <sup>( inherits from JsonRpcProvider )</sup></a></li>
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<div class="section" id="providers-api">
<span id="api-provider"></span><h1>Providers API<a class="headerlink" href="#providers-api" title="Permalink to this headline"></a></h1>
<p>A Provider abstracts a connection to the Ethereum blockchain, for issuing queries
and sending state changing transactions.</p>
<p>Unlike the Web3 provider, there is no concept of accounts or signing entities in
an Ethers Provider. It is simply a connection to the network, and cannot unlock
accounts or sign and is unaware of your Ethereum addresses.</p>
<p>To manage state changing operations, you must use a <a class="reference internal" href="api-wallet.html#api-wallet"><span class="std std-ref">Wallet</span></a>
to sign transactions. If you pass a wallet in as a signer to
a <a class="reference internal" href="api-contract.html#api-contract"><span class="std std-ref">Contract</span></a>, this is managed for you by the contract.</p>
<hr class="docutils" />
<div class="section" id="connecting-to-ethereum">
<h2>Connecting to Ethereum<a class="headerlink" href="#connecting-to-ethereum" title="Permalink to this headline"></a></h2>
<p>There are several ways to connect to the Ethereum blockchain:</p>
<dl class="docutils">
<dt>new <sup>ethers . providers</sup> . EtherscanProvider( [ network ] [ , apiToken ] )</dt>
<dd><p class="first">Connect to the <a class="reference external" href="https://etherscan.io/apis">Etherscan</a> blockchain <a class="reference external" href="https://etherscan.io/apis">web service API</a>.</p>
<p class="last"><strong>default:</strong> <em>network</em>=homestead, <em>apiToken</em>=null</p>
</dd>
<dt>new <sup>ethers . providers</sup> . JsonRpcProvider( [ url ] [ , network ] )</dt>
<dd><p class="first">Connect to the <a class="reference external" href="https://github.com/ethereum/wiki/wiki/JSON-RPC">JSON-RPC API</a> <em>url</em> of an Ethereum node, such as <a class="reference external" href="https://ethcore.io/parity.html">Parity</a> or <a class="reference external" href="https://geth.ethereum.org">Geth</a>.</p>
<p class="last"><strong>default:</strong> <em>url</em>=”<a class="reference external" href="http://localhost:8545/">http://localhost:8545/</a>”, <em>network</em>=homestead</p>
</dd>
<dt>new <sup>ethers . providers</sup> . InfuraProvider( [ network ] [ , apiAccessToken ] )</dt>
<dd><p class="first">Connect to the <a class="reference external" href="https://infura.io">INFURA</a> hosted network of Ethereum nodes.</p>
<p class="last"><strong>default:</strong> <em>network</em>=homestead, <em>apiAccessToken</em>=null</p>
</dd>
<dt>new <sup>ethers . providers</sup> . Web3Provider( web3Provider [ , network ] )</dt>
<dd><p class="first">Connect to an existing Web3 provider (e.g. <cite>web3Instance.currentProvider</cite>).</p>
<p class="last"><strong>default:</strong> <em>network</em>=homestead</p>
</dd>
<dt>new <sup>ethers . providers</sup> . FallbackProvider( providers )</dt>
<dd>Improves reliability by attempting each provider in turn, falling back to the
next in the list if an error was encountered.</dd>
<dt><sup>ethers . providers</sup> . getDefaultProvider( [ network ] )</dt>
<dd><p class="first">This automatically creates a FallbackProvider backed by INFURA and Etherscan; recommended</p>
<p class="last"><strong>default:</strong> <em>network</em>=homestead</p>
</dd>
</dl>
<div class="section" id="examples">
<h3><em>Examples</em><a class="headerlink" href="#examples" title="Permalink to this headline"></a></h3>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">providers</span> <span class="o">=</span> <span class="n">require</span><span class="p">(</span><span class="s1">&#39;ethers&#39;</span><span class="p">)</span><span class="o">.</span><span class="n">providers</span><span class="p">;</span>
<span class="o">//</span> <span class="n">Connect</span> <span class="n">to</span> <span class="n">Ropsten</span> <span class="p">(</span><span class="n">the</span> <span class="n">test</span> <span class="n">network</span><span class="p">)</span>
<span class="o">//</span> <span class="n">You</span> <span class="n">may</span> <span class="n">specify</span> <span class="nb">any</span> <span class="n">of</span><span class="p">:</span>
<span class="o">//</span> <span class="o">-</span> <span class="n">boolean</span><span class="p">;</span> <span class="n">true</span> <span class="o">=</span> <span class="n">ropsten</span><span class="p">,</span> <span class="n">false</span> <span class="o">=</span> <span class="n">homestead</span>
<span class="o">//</span> <span class="o">-</span> <span class="nb">object</span><span class="p">;</span> <span class="p">{</span> <span class="n">name</span><span class="p">:</span> <span class="s1">&#39;ropsten&#39;</span><span class="p">,</span> <span class="n">chainId</span><span class="p">:</span> <span class="mi">3</span> <span class="p">}</span> <span class="p">(</span><span class="n">see</span> <span class="n">ethers</span><span class="o">.</span><span class="n">networks</span><span class="p">);</span>
<span class="o">//</span> <span class="o">-</span> <span class="n">string</span><span class="p">;</span> <span class="n">e</span><span class="o">.</span><span class="n">g</span><span class="o">.</span> <span class="s1">&#39;homestead&#39;</span><span class="p">,</span> <span class="s1">&#39;ropsten&#39;</span><span class="p">,</span> <span class="s1">&#39;rinkeby&#39;</span><span class="p">,</span> <span class="s1">&#39;kovan&#39;</span>
<span class="n">var</span> <span class="n">network</span> <span class="o">=</span> <span class="n">providers</span><span class="o">.</span><span class="n">networks</span><span class="o">.</span><span class="n">ropsten</span><span class="p">;</span>
<span class="o">//</span> <span class="n">Connect</span> <span class="n">to</span> <span class="n">INFUA</span>
<span class="n">var</span> <span class="n">infuraProvider</span> <span class="o">=</span> <span class="n">new</span> <span class="n">providers</span><span class="o">.</span><span class="n">InfuraProvider</span><span class="p">(</span><span class="n">network</span><span class="p">);</span>
<span class="o">//</span> <span class="n">Connect</span> <span class="n">to</span> <span class="n">Etherscan</span>
<span class="n">var</span> <span class="n">etherscanProvider</span> <span class="o">=</span> <span class="n">new</span> <span class="n">providers</span><span class="o">.</span><span class="n">EtherscanProvider</span><span class="p">(</span><span class="n">network</span><span class="p">);</span>
<span class="o">//</span> <span class="n">Creating</span> <span class="n">a</span> <span class="n">provider</span> <span class="n">to</span> <span class="n">automatically</span> <span class="n">fallback</span> <span class="n">onto</span> <span class="n">Etherscan</span>
<span class="o">//</span> <span class="k">if</span> <span class="n">INFURA</span> <span class="ow">is</span> <span class="n">down</span>
<span class="n">var</span> <span class="n">fallbackProvider</span> <span class="o">=</span> <span class="n">new</span> <span class="n">providers</span><span class="o">.</span><span class="n">FallbackProvider</span><span class="p">([</span>
<span class="n">infuraProvider</span><span class="p">,</span>
<span class="n">etherscanProvider</span>
<span class="p">]);</span>
<span class="o">//</span> <span class="n">This</span> <span class="ow">is</span> <span class="n">equivalent</span> <span class="n">to</span> <span class="n">using</span> <span class="n">the</span> <span class="n">getDefaultProvider</span>
<span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">(</span><span class="n">network</span><span class="p">)</span>
<span class="o">//</span> <span class="n">Connect</span> <span class="n">to</span> <span class="n">a</span> <span class="n">local</span> <span class="n">Parity</span> <span class="n">instance</span>
<span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">new</span> <span class="n">providers</span><span class="o">.</span><span class="n">JsonRpcProvider</span><span class="p">(</span><span class="s1">&#39;http://localhost:8545&#39;</span><span class="p">,</span> <span class="n">network</span><span class="p">);</span>
<span class="o">//</span> <span class="n">Connect</span> <span class="n">to</span> <span class="n">an</span> <span class="n">injected</span> <span class="n">Web3</span><span class="s1">&#39;s provider (e.g. MetaMask)</span>
<span class="n">var</span> <span class="n">web3Provider</span> <span class="o">=</span> <span class="n">new</span> <span class="n">providers</span><span class="o">.</span><span class="n">Web3Provider</span><span class="p">(</span><span class="n">web3</span><span class="o">.</span><span class="n">currentProvider</span><span class="p">,</span> <span class="n">network</span><span class="p">);</span>
</pre></div>
</div>
</div>
</div>
<hr class="docutils" />
<div class="section" id="prototype">
<h2>Prototype<a class="headerlink" href="#prototype" title="Permalink to this headline"></a></h2>
<p>All properties are immutable, and reflect their default value if not specified, or if
indirectly populated by child Objects.</p>
<div class="section" id="provider">
<span id="id1"></span><h3>Provider<a class="headerlink" href="#provider" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . name</dt>
<dd>The name of the network the provider is connected to (e.g. homestead, ropsten, rinkeby, kovan)</dd>
<dt><sup>prototype</sup> . chainId</dt>
<dd>The chain ID (or network ID) this provider is connected as; this is used by
signers to prevent <a class="reference external" href="https://github.com/ethereum/EIPs/issues/155">replay attacks</a> across compatible networks</dd>
</dl>
</div>
<div class="section" id="fallbackprovider-inherits-from-provider">
<h3>FallbackProvider <sup>( inherits from Provider )</sup><a class="headerlink" href="#fallbackprovider-inherits-from-provider" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . providers</dt>
<dd>A <strong>copy</strong> of the array of providers (modifying this variable will not affect
the providers attached)</dd>
</dl>
</div>
<div class="section" id="jsonrpcprovider-inherits-from-provider">
<h3>JsonRpcProvider <sup>( inherits from Provider )</sup><a class="headerlink" href="#jsonrpcprovider-inherits-from-provider" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . url</dt>
<dd>The JSON-RPC URL the provider is connected to</dd>
<dt><sup>prototype</sup> . send ( method , params )</dt>
<dd>Send the JSON-RPC <em>method</em> with <em>params</em>. This is useful for calling
non-standard or less common JSON-RPC methods. A <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> is
returned which will resolve to the parsed JSON result.</dd>
</dl>
</div>
<div class="section" id="etherscanprovider-inherits-from-provider">
<h3>EtherscanProvider <sup>( inherits from Provider )</sup><a class="headerlink" href="#etherscanprovider-inherits-from-provider" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . apiToken</dt>
<dd>The Etherscan API Token (or null if not specified)</dd>
</dl>
</div>
<div class="section" id="infuraprovider-inherits-from-jsonrpcprovider">
<h3>InfuraProvider <sup>( inherits from JsonRpcProvider )</sup><a class="headerlink" href="#infuraprovider-inherits-from-jsonrpcprovider" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . apiAccessToken</dt>
<dd>The INFURA API Access Token (or null if not specified)</dd>
</dl>
</div>
<div class="section" id="web3provider-inherits-from-jsonrpcprovider">
<h3>Web3Provider <sup>( inherits from JsonRpcProvider )</sup><a class="headerlink" href="#web3provider-inherits-from-jsonrpcprovider" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . provider</dt>
<dd><p class="first">The underlying Web3-compatible provider from the Web3 library, for example
an <a class="reference external" href="https://github.com/ethereum/web3.js/blob/develop/lib/web3/httpprovider.js">HTTPProvider</a> or <a class="reference external" href="https://github.com/ethereum/web3.js/blob/develop/lib/web3/ipcprovider.js">IPCProvider</a>. The only required method on a Web3 provider
is:</p>
<p class="last"><em>sendAsync ( method , params , callback )</em></p>
</dd>
</dl>
</div>
</div>
<hr class="docutils" />
<div class="section" id="account-actions">
<h2>Account Actions<a class="headerlink" href="#account-actions" title="Permalink to this headline"></a></h2>
<dl class="docutils">
<dt><sup>prototype</sup> . getBalance ( addressOrName [ , blockTag ] )</dt>
<dd><p class="first">Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the balance (as a <a class="reference internal" href="api-utils.html#bignumber"><span class="std std-ref">BigNumber</span></a>) of
<em>addressOrName</em> at <em>blockTag</em>. (See: <a class="reference internal" href="#blocktag"><span class="std std-ref">Block Tags</span></a>)</p>
<p class="last"><strong>default:</strong> <em>blockTag</em>=”latest”</p>
</dd>
<dt><sup>prototype</sup> . getTransactionCount ( addressOrName [ , blockTag ] )</dt>
<dd><p class="first">Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the number of sent transactions (as a Number) from
<em>addressOrName</em> at <em>blockTag</em>. This is also the nonce required to send a new
transaction. (See: <a class="reference internal" href="#blocktag"><span class="std std-ref">Block Tags</span></a>)</p>
<p class="last"><strong>default:</strong> <em>blockTag</em>=”latest”</p>
</dd>
<dt><sup>prototype</sup> . lookupAddress ( address )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> which resolves to the ENS name (or null) that <em>address</em> resolves
to.</dd>
<dt><sup>prototype</sup> . resolveName ( ensName )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> which resolves to the address (or null) of that the <em>ensName</em>
resolves to.</dd>
</dl>
<div class="section" id="id2">
<h3><em>Examples</em><a class="headerlink" href="#id2" title="Permalink to this headline"></a></h3>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">ethers</span> <span class="o">=</span> <span class="n">require</span><span class="p">(</span><span class="s1">&#39;ethers&#39;</span><span class="p">);</span>
<span class="n">var</span> <span class="n">providers</span> <span class="o">=</span> <span class="n">ethers</span><span class="o">.</span><span class="n">providers</span><span class="p">;</span>
<span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">(</span><span class="s1">&#39;ropsten&#39;</span><span class="p">);</span>
<span class="n">var</span> <span class="n">address</span> <span class="o">=</span> <span class="s2">&quot;0x02F024e0882B310c6734703AB9066EdD3a10C6e0&quot;</span><span class="p">;</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getBalance</span><span class="p">(</span><span class="n">address</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">balance</span><span class="p">)</span> <span class="p">{</span>
<span class="o">//</span> <span class="n">balance</span> <span class="ow">is</span> <span class="n">a</span> <span class="n">BigNumber</span> <span class="p">(</span><span class="ow">in</span> <span class="n">wei</span><span class="p">);</span> <span class="nb">format</span> <span class="ow">is</span> <span class="k">as</span> <span class="n">a</span> <span class="n">sting</span> <span class="p">(</span><span class="ow">in</span> <span class="n">ether</span><span class="p">)</span>
<span class="n">var</span> <span class="n">etherString</span> <span class="o">=</span> <span class="n">ethers</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">formatEther</span><span class="p">(</span><span class="n">balance</span><span class="p">);</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s2">&quot;Balance: &quot;</span> <span class="o">+</span> <span class="n">etherString</span><span class="p">);</span>
<span class="p">});</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getTransactionCount</span><span class="p">(</span><span class="n">address</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">transactionCount</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s2">&quot;Total Transactions Ever Send: &quot;</span> <span class="o">+</span> <span class="n">transactionCount</span><span class="p">);</span>
<span class="p">});</span>
<span class="n">provider</span><span class="o">.</span><span class="n">resolveName</span><span class="p">(</span><span class="s2">&quot;test.ricmoose.eth&quot;</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">address</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s2">&quot;Address: &quot;</span> <span class="o">+</span> <span class="n">address</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
</div>
</div>
</div>
<hr class="docutils" />
<div class="section" id="blockchain-status">
<h2>Blockchain Status<a class="headerlink" href="#blockchain-status" title="Permalink to this headline"></a></h2>
<dl class="docutils">
<dt><sup>prototype</sup> . getBlockNumber ( )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the latest block number (as a Number).</dd>
<dt><sup>prototype</sup> . getGasPrice ( )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the current gas price (as a <a class="reference internal" href="api-utils.html#bignumber"><span class="std std-ref">BigNumber</span></a>).</dd>
<dt><sup>prototype</sup> . getBlock ( blockHashOrBlockNumber )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the block at <em>blockHashorBlockNumber</em>. (See: <a class="reference internal" href="#blockresponse"><span class="std std-ref">Block Responses</span></a>)</dd>
<dt><sup>prototype</sup> . getTransaction ( transactionHash )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the transaction with <em>transactionHash</em>. (See: <a class="reference internal" href="#transactionresponse"><span class="std std-ref">Transaction Responses</span></a>)</dd>
<dt><sup>prototype</sup> . getTransactionReceipt ( transactionHash )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the transaction receipt with <em>transactionHash</em>.
(See: <a class="reference internal" href="#transactionreceipt"><span class="std std-ref">Transaction Receipts</span></a>)</dd>
</dl>
<div class="section" id="id3">
<h3><em>Examples</em><a class="headerlink" href="#id3" title="Permalink to this headline"></a></h3>
<p><strong>Current State</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">();</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getBlockNumber</span><span class="p">()</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">blockNumber</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s2">&quot;Current block number: &quot;</span> <span class="o">+</span> <span class="n">blockNumber</span><span class="p">);</span>
<span class="p">});</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getGasPrice</span><span class="p">()</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">gasPrice</span><span class="p">)</span> <span class="p">{</span>
<span class="o">//</span> <span class="n">gasPrice</span> <span class="ow">is</span> <span class="n">a</span> <span class="n">BigNumber</span><span class="p">;</span> <span class="n">convert</span> <span class="n">it</span> <span class="n">to</span> <span class="n">a</span> <span class="n">decimal</span> <span class="n">string</span>
<span class="n">gasPriceString</span> <span class="o">=</span> <span class="n">gasPrice</span><span class="o">.</span><span class="n">toString</span><span class="p">();</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s2">&quot;Current gas price: &quot;</span> <span class="o">+</span> <span class="n">gasPriceString</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
</div>
<p><strong>Blocks</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">();</span>
<span class="o">//</span> <span class="n">Block</span> <span class="n">Number</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getBlock</span><span class="p">(</span><span class="mi">3346773</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">block</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">block</span><span class="p">);</span>
<span class="p">});</span>
<span class="o">//</span> <span class="n">Block</span> <span class="n">Hash</span>
<span class="n">var</span> <span class="n">blockHash</span> <span class="o">=</span> <span class="s2">&quot;0x7a1d0b010393c8d850200d0ec1e27c0c8a295366247b1bd6124d496cf59182ad&quot;</span><span class="p">;</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getBlock</span><span class="p">(</span><span class="n">blockHash</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">block</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">block</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
</div>
<p><strong>Transactions</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">();</span>
<span class="n">var</span> <span class="n">transactionHash</span> <span class="o">=</span> <span class="s2">&quot;0x7baea23e7d77bff455d94f0c81916f938c398252fb62fce2cdb43643134ce4ed&quot;</span><span class="p">;</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getTransaction</span><span class="p">(</span><span class="n">transactionHash</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">transaction</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">transaction</span><span class="p">);</span>
<span class="p">});</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getTransactionReceipt</span><span class="p">(</span><span class="n">transactionHash</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">transactionReceipt</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">transactionReceipt</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
</div>
</div>
</div>
<hr class="docutils" />
<div class="section" id="ethereum-name-resolution">
<h2>Ethereum Name Resolution<a class="headerlink" href="#ethereum-name-resolution" title="Permalink to this headline"></a></h2>
<p>The Ethereum Naming Service (ENS) allows easy to remember and use names to be
assigned to Ethereum addresses. Any provider operation which takes an address
may also take an ENS name.</p>
<p>It is often useful to resolve a name entered by a user or perform a reverse lookup
of an address to get a more human readbale name.</p>
<p><strong>Resolving Names</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">providers</span> <span class="o">=</span> <span class="n">require</span><span class="p">(</span><span class="s1">&#39;ethers&#39;</span><span class="p">)</span><span class="o">.</span><span class="n">providers</span><span class="p">;</span>
<span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">();</span>
<span class="n">provider</span><span class="o">.</span><span class="n">resolveName</span><span class="p">(</span><span class="s1">&#39;registrar.firefly.eth&#39;</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">address</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">address</span><span class="p">);</span>
<span class="o">//</span> <span class="s1">&#39;0x6fC21092DA55B392b045eD78F4732bff3C580e2c&#39;</span>
<span class="p">});</span>
</pre></div>
</div>
<p><strong>Looking up Addresses</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">provider</span><span class="o">.</span><span class="n">lookupAddress</span><span class="p">(</span><span class="s1">&#39;0x6fC21092DA55B392b045eD78F4732bff3C580e2c&#39;</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">name</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">name</span><span class="p">);</span>
<span class="o">//</span> <span class="s1">&#39;registrar.firefly.eth&#39;</span>
<span class="p">});</span>
</pre></div>
</div>
</div>
<hr class="docutils" />
<div class="section" id="contract-execution">
<h2>Contract Execution<a class="headerlink" href="#contract-execution" title="Permalink to this headline"></a></h2>
<p>These are relatively low-level calls. The <a class="reference internal" href="api-contract.html#api-contract"><span class="std std-ref">Contracts API</span></a> should
usually be used instead.</p>
<dl class="docutils">
<dt><sup>prototype</sup> . call ( transaction )</dt>
<dd><p class="first">Send the <strong>read-only</strong> (constant) <em>transaction</em> to a single Ethereum node and
return a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the result (as a <a class="reference internal" href="api-utils.html#hexstring"><span class="std std-ref">hex string</span></a>) of executing it.
(See <a class="reference internal" href="#transactionrequest"><span class="std std-ref">Transaction Requests</span></a>)</p>
<p class="last">This is free, since it does not change any state on the blockchain.</p>
</dd>
<dt><sup>prototype</sup> . estimateGas ( transaction )</dt>
<dd><p class="first">Send a <em>transaction</em> to a single Ethereum node and return a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the
estimated amount of gas required (as a <a class="reference internal" href="api-utils.html#bignumber"><span class="std std-ref">BigNumber</span></a>) to send it.
(See <a class="reference internal" href="#transactionrequest"><span class="std std-ref">Transaction Requests</span></a>)</p>
<p class="last">This is free, but only an estimate. Providing too little gas will result in a
transaction being rejected (while still consuming all provided gas).</p>
</dd>
<dt><sup>prototype</sup> . sendTransaction ( signedTransaction )</dt>
<dd><p class="first">Send the <em>signedTransaction</em> to the <strong>entire</strong> Ethereum network and returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a>
with the transaction hash.</p>
<p class="last"><strong>This will consume gas</strong> from the account that signed the transaction.</p>
</dd>
</dl>
<div class="section" id="id4">
<h3><em>Examples</em><a class="headerlink" href="#id4" title="Permalink to this headline"></a></h3>
<p><strong>Call (Constant) Functions</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">ethers</span> <span class="o">=</span> <span class="n">require</span><span class="p">(</span><span class="s1">&#39;ethers&#39;</span><span class="p">);</span>
<span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">ethers</span><span class="o">.</span><span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">();</span>
<span class="o">//</span> <span class="n">setup</span> <span class="n">a</span> <span class="n">transaction</span> <span class="n">to</span> <span class="n">call</span> <span class="n">the</span> <span class="n">CryptoKitties</span><span class="o">.</span><span class="n">symbol</span><span class="p">()</span> <span class="n">function</span>
<span class="o">//</span> <span class="n">CryptoKitties</span> <span class="n">contract</span> <span class="n">address</span>
<span class="n">var</span> <span class="n">address</span> <span class="o">=</span> <span class="s2">&quot;0x06012c8cf97BEaD5deAe237070F9587f8E7A266d&quot;</span><span class="p">;</span>
<span class="o">//</span> <span class="n">first</span> <span class="mi">8</span> <span class="n">nibbles</span> <span class="n">of</span> <span class="n">the</span> <span class="nb">hash</span> <span class="n">of</span> <span class="n">symbol</span><span class="p">()</span>
<span class="n">var</span> <span class="n">data</span> <span class="o">=</span> <span class="n">ethers</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">id</span><span class="p">(</span><span class="s1">&#39;symbol()&#39;</span><span class="p">)</span><span class="o">.</span><span class="n">substring</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span><span class="mi">10</span><span class="p">);</span>
<span class="n">var</span> <span class="n">transaction</span> <span class="o">=</span> <span class="p">{</span>
<span class="n">to</span><span class="p">:</span> <span class="n">address</span><span class="p">,</span>
<span class="n">data</span><span class="p">:</span> <span class="n">data</span>
<span class="p">}</span>
<span class="n">provider</span><span class="o">.</span><span class="n">call</span><span class="p">(</span><span class="n">transaction</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">result</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">result</span><span class="p">);</span>
<span class="o">//</span> <span class="s1">&#39;0x000000000000000000000000000000000000000000000000000000000000002&#39;</span><span class="o">+</span>
<span class="o">//</span> <span class="s1">&#39;00000000000000000000000000000000000000000000000000000000000000002&#39;</span><span class="o">+</span>
<span class="o">//</span> <span class="s1">&#39;434b000000000000000000000000000000000000000000000000000000000000&#39;</span>
<span class="p">});</span>
</pre></div>
</div>
<p><strong>sendTransaction</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">ethers</span> <span class="o">=</span> <span class="n">require</span><span class="p">(</span><span class="s1">&#39;ethers&#39;</span><span class="p">);</span>
<span class="n">var</span> <span class="n">privateKey</span> <span class="o">=</span> <span class="s1">&#39;0x0123456789012345678901234567890123456789012345678901234567890123&#39;</span><span class="p">;</span>
<span class="n">var</span> <span class="n">wallet</span> <span class="o">=</span> <span class="n">new</span> <span class="n">ethers</span><span class="o">.</span><span class="n">Wallet</span><span class="p">(</span><span class="n">privateKey</span><span class="p">);</span>
<span class="n">wallet</span><span class="o">.</span><span class="n">provider</span> <span class="o">=</span> <span class="n">ethers</span><span class="o">.</span><span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">(</span><span class="s1">&#39;ropsten&#39;</span><span class="p">);</span>
<span class="n">var</span> <span class="n">transaction</span> <span class="o">=</span> <span class="p">{</span>
<span class="n">to</span><span class="p">:</span> <span class="s2">&quot;0x88a5C2d9919e46F883EB62F7b8Dd9d0CC45bc290&quot;</span><span class="p">,</span>
<span class="n">value</span><span class="p">:</span> <span class="n">ethers</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">parseEther</span><span class="p">(</span><span class="s2">&quot;0.1&quot;</span><span class="p">)</span>
<span class="p">};</span>
<span class="n">var</span> <span class="n">estimateGasPromise</span> <span class="o">=</span> <span class="n">wallet</span><span class="o">.</span><span class="n">estimateGas</span><span class="p">(</span><span class="n">transaction</span><span class="p">);</span>
<span class="n">estimateGasPromise</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">gasEstimate</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">gasEstimate</span><span class="o">.</span><span class="n">toString</span><span class="p">());</span>
<span class="n">transaction</span><span class="o">.</span><span class="n">gasLimit</span> <span class="o">=</span> <span class="n">gasEstimate</span><span class="p">;</span>
<span class="o">//</span> <span class="n">Send</span> <span class="n">the</span> <span class="n">transaction</span>
<span class="n">var</span> <span class="n">sendTransactionPromise</span> <span class="o">=</span> <span class="n">wallet</span><span class="o">.</span><span class="n">sendTransaction</span><span class="p">(</span><span class="n">transaction</span><span class="p">);</span>
<span class="n">sendTransactionPromise</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">transactionHash</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">transactionHash</span><span class="p">);</span>
<span class="p">});</span>
<span class="p">});</span>
</pre></div>
</div>
</div>
</div>
<hr class="docutils" />
<div class="section" id="contract-state">
<h2>Contract State<a class="headerlink" href="#contract-state" title="Permalink to this headline"></a></h2>
<dl class="docutils">
<dt><sup>prototype</sup> . getCode ( addressOrName )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the bytecode (as a <a class="reference internal" href="api-utils.html#hexstring"><span class="std std-ref">hex string</span></a>)
at <em>addressOrName</em>.</dd>
<dt><sup>prototype</sup> . getStorageAt ( addressOrName , position [ , blockTag ] )</dt>
<dd><p class="first">Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the value (as a <a class="reference internal" href="api-utils.html#hexstring"><span class="std std-ref">hex string</span></a>) at
<em>addressOrName</em> in <em>position</em> at <em>blockTag</em>. (See <a class="reference internal" href="#blocktag"><span class="std std-ref">Block Tags</span></a>)</p>
<p class="last">default: <em>blockTag</em>= “latest”</p>
</dd>
<dt><sup>prototype</sup> . getLogs ( filter )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with an array (possibly empty) of the logs that
match the <em>filter</em>. (See <a class="reference internal" href="#filter"><span class="std std-ref">Filters</span></a>)</dd>
</dl>
<div class="section" id="id5">
<h3><em>Examples</em><a class="headerlink" href="#id5" title="Permalink to this headline"></a></h3>
<p><strong>getCode</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">ethers</span> <span class="o">=</span> <span class="n">require</span><span class="p">(</span><span class="s1">&#39;ethers&#39;</span><span class="p">);</span>
<span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">ethers</span><span class="o">.</span><span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">();</span>
<span class="n">var</span> <span class="n">contractAddress</span> <span class="o">=</span> <span class="s1">&#39;0x6fC21092DA55B392b045eD78F4732bff3C580e2c&#39;</span><span class="p">;</span>
<span class="n">var</span> <span class="n">contractEnsName</span> <span class="o">=</span> <span class="s1">&#39;registrar.firefly.eth&#39;</span><span class="p">;</span>
<span class="n">var</span> <span class="n">codePromise</span> <span class="o">=</span> <span class="n">provider</span><span class="o">.</span><span class="n">getCode</span><span class="p">(</span><span class="n">contractEnsName</span><span class="p">);</span>
<span class="n">codePromise</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">result</span><span class="p">){</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s1">&#39;getCode by ENS name:&#39;</span><span class="p">);</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">result</span><span class="p">);</span>
<span class="p">});</span>
<span class="n">var</span> <span class="n">codeByAddressPromise</span> <span class="o">=</span> <span class="n">provider</span><span class="o">.</span><span class="n">getCode</span><span class="p">(</span><span class="n">contractAddress</span><span class="p">);</span>
<span class="n">codeByAddressPromise</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">result</span><span class="p">){</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s1">&#39;getCode by contract address:&#39;</span><span class="p">);</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">result</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
</div>
<p><strong>getStorageAt</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">ethers</span> <span class="o">=</span> <span class="n">require</span><span class="p">(</span><span class="s1">&#39;ethers&#39;</span><span class="p">);</span>
<span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">ethers</span><span class="o">.</span><span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">();</span>
<span class="n">var</span> <span class="n">contractEnsName</span> <span class="o">=</span> <span class="s1">&#39;registrar.firefly.eth&#39;</span><span class="p">;</span>
<span class="n">var</span> <span class="n">storagePromise</span> <span class="o">=</span> <span class="n">provider</span><span class="o">.</span><span class="n">getStorageAt</span><span class="p">(</span><span class="n">contractEnsName</span><span class="p">,</span> <span class="mi">0</span><span class="p">);</span>
<span class="n">storagePromise</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">result</span><span class="p">){</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">result</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
</div>
<p><strong>getLogs</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">ethers</span> <span class="o">=</span> <span class="n">require</span><span class="p">(</span><span class="s1">&#39;ethers&#39;</span><span class="p">);</span>
<span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">ethers</span><span class="o">.</span><span class="n">providers</span><span class="o">.</span><span class="n">getDefaultProvider</span><span class="p">();</span>
<span class="n">var</span> <span class="n">cryptoKittiesContractAddress</span> <span class="o">=</span> <span class="s1">&#39;0x06012c8cf97BEaD5deAe237070F9587f8E7A266d&#39;</span><span class="p">;</span>
<span class="n">var</span> <span class="n">topic</span> <span class="o">=</span> <span class="s1">&#39;0x241ea03ca20251805084d27d4440371c34a0b85ff108f6bb5611248f73818b80&#39;</span><span class="p">;</span>
<span class="n">var</span> <span class="nb">filter</span> <span class="o">=</span> <span class="p">{</span>
<span class="n">fromBlock</span><span class="p">:</span> <span class="mi">5044502</span><span class="p">,</span>
<span class="n">address</span><span class="p">:</span> <span class="n">cryptoKittiesContractAddress</span><span class="p">,</span>
<span class="n">topics</span><span class="p">:</span> <span class="p">[</span> <span class="n">topic</span> <span class="p">]</span>
<span class="p">}</span>
<span class="n">var</span> <span class="n">filterPromise</span> <span class="o">=</span> <span class="n">provider</span><span class="o">.</span><span class="n">getLogs</span><span class="p">(</span><span class="nb">filter</span><span class="p">);</span>
<span class="n">filterPromise</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">result</span><span class="p">){</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">result</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
</div>
</div>
</div>
<hr class="docutils" />
<div class="section" id="events">
<h2>Events<a class="headerlink" href="#events" title="Permalink to this headline"></a></h2>
<p>These methods allow management of callbacks on certain events on the blockchain
and contracts. They are largely based on the <a class="reference external" href="https://nodejs.org/dist/latest-v6.x/docs/api/events.html">EventEmitter API</a>.</p>
<dl class="docutils">
<dt><sup>prototype</sup> . on ( eventType , callback )</dt>
<dd>Register a callback for any future <em>eventType</em>; see below for callback parameters</dd>
<dt><sup>prototype</sup> . once ( eventType , callback)</dt>
<dd>Register a callback for the next (and only next) <em>eventType</em>; see below for callback parameters</dd>
<dt><sup>prototype</sup> . removeListener ( eventType , callback )</dt>
<dd>Unregister the <em>callback</em> for <em>eventType</em>; if the same callback is registered
more than once, only the first registered instance is removed</dd>
<dt><sup>prototype</sup> . removeAllListeners ( eventType )</dt>
<dd>Unregister all callbacks for <em>eventType</em></dd>
<dt><sup>prototype</sup> . listenerCount ( [ eventType ] )</dt>
<dd>Return the number of callbacks registered for <em>eventType</em>, or if ommitted, the
total number of callbacks registered</dd>
<dt><sup>prototype</sup> . resetEventsBlock ( blockNumber )</dt>
<dd>Begin scanning for events from <em>blockNumber</em>. By default, events begin at the
block number that the provider began polling at.</dd>
</dl>
<div class="section" id="event-types">
<h3>Event Types<a class="headerlink" href="#event-types" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt>“block”</dt>
<dd><p class="first">Whenever a new block is mined</p>
<p class="last"><code class="docutils literal"><span class="pre">callback(</span> <span class="pre">blockNumber</span> <span class="pre">)</span></code></p>
</dd>
<dt>any address</dt>
<dd><p class="first">When the balance of the corresponding address changes</p>
<p class="last"><code class="docutils literal"><span class="pre">callback(</span> <span class="pre">balance</span> <span class="pre">)</span></code></p>
</dd>
<dt>any transaction hash</dt>
<dd><p class="first">When the corresponding transaction is mined; also see
<a class="reference internal" href="#waitfortransaction"><span class="std std-ref">Waiting for Transactions</span></a></p>
<p class="last"><code class="docutils literal"><span class="pre">callback(</span> <span class="pre">transaction</span> <span class="pre">)</span></code></p>
</dd>
<dt>an array of topics</dt>
<dd><p class="first">When any of the topics are triggered in a blocks logs; when using the
<a class="reference internal" href="api-contract.html#api-contract"><span class="std std-ref">Contract API</span></a>, this is automatically handled;</p>
<p class="last"><code class="docutils literal"><span class="pre">callback(</span> <span class="pre">log</span> <span class="pre">)</span></code></p>
</dd>
</dl>
</div>
<div class="section" id="waiting-for-transactions">
<span id="waitfortransaction"></span><h3>Waiting for Transactions<a class="headerlink" href="#waiting-for-transactions" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . waitForTransaction ( transactionHash [ , timeout ] )</dt>
<dd>Return a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> which returns the transaction once <em>transactionHash</em> is
mined, with an optional <em>timeout</em> (in milliseconds)</dd>
</dl>
</div>
<div class="section" id="id6">
<h3><em>Examples</em><a class="headerlink" href="#id6" title="Permalink to this headline"></a></h3>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="o">//</span> <span class="n">Get</span> <span class="n">notified</span> <span class="n">on</span> <span class="n">every</span> <span class="n">new</span> <span class="n">block</span>
<span class="n">provider</span><span class="o">.</span><span class="n">on</span><span class="p">(</span><span class="s1">&#39;block&#39;</span><span class="p">,</span> <span class="n">function</span><span class="p">(</span><span class="n">blockNumber</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s1">&#39;New Block: &#39;</span> <span class="o">+</span> <span class="n">blockNumber</span><span class="p">);</span>
<span class="p">});</span>
<span class="o">//</span> <span class="n">Get</span> <span class="n">notified</span> <span class="n">on</span> <span class="n">account</span> <span class="n">balance</span> <span class="n">change</span>
<span class="n">provider</span><span class="o">.</span><span class="n">on</span><span class="p">(</span><span class="s1">&#39;0x46Fa84b9355dB0708b6A57cd6ac222950478Be1d&#39;</span><span class="p">,</span> <span class="n">function</span><span class="p">(</span><span class="n">balance</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s1">&#39;New Balance: &#39;</span> <span class="o">+</span> <span class="n">balance</span><span class="p">);</span>
<span class="p">});</span>
<span class="o">//</span> <span class="n">Get</span> <span class="n">notified</span> <span class="n">when</span> <span class="n">a</span> <span class="n">transaction</span> <span class="ow">is</span> <span class="n">mined</span>
<span class="n">provider</span><span class="o">.</span><span class="n">once</span><span class="p">(</span><span class="n">transactionHash</span><span class="p">,</span> <span class="n">function</span><span class="p">(</span><span class="n">transaction</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s1">&#39;Transaction Minded: &#39;</span> <span class="o">+</span> <span class="n">transaction</span><span class="o">.</span><span class="n">hash</span><span class="p">);</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">transaction</span><span class="p">);</span>
<span class="p">);</span>
<span class="o">//</span> <span class="n">OR</span> <span class="n">equivalently</span> <span class="n">the</span> <span class="n">waitForTransaction</span><span class="p">()</span> <span class="n">returns</span> <span class="n">a</span> <span class="n">Promise</span>
<span class="n">provider</span><span class="o">.</span><span class="n">waitForTransaction</span><span class="p">(</span><span class="n">transactionHash</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">transaction</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s1">&#39;Transaction Mined: &#39;</span> <span class="o">+</span> <span class="n">transaction</span><span class="o">.</span><span class="n">hash</span><span class="p">);</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">transaction</span><span class="p">);</span>
<span class="p">});</span>
<span class="o">//</span> <span class="n">Get</span> <span class="n">notified</span> <span class="n">when</span> <span class="n">a</span> <span class="n">contract</span> <span class="n">event</span> <span class="ow">is</span> <span class="n">logged</span>
<span class="n">var</span> <span class="n">eventTopic</span> <span class="o">=</span> <span class="s1">&#39;0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef&#39;</span><span class="p">;</span>
<span class="n">provider</span><span class="o">.</span><span class="n">on</span><span class="p">([</span> <span class="n">eventTopic</span> <span class="p">],</span> <span class="n">function</span><span class="p">(</span><span class="n">log</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s1">&#39;Event Log&#39;</span><span class="p">);</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">log</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
</div>
</div>
</div>
<hr class="docutils" />
<div class="section" id="objects">
<h2>Objects<a class="headerlink" href="#objects" title="Permalink to this headline"></a></h2>
<p>There are several common objects and types that are commonly used as input parameters or
return types for various provider calls.</p>
<div class="section" id="block-tag">
<span id="blocktag"></span><h3>Block Tag<a class="headerlink" href="#block-tag" title="Permalink to this headline"></a></h3>
<p>A block tag is used to uniquely identify a blocks position in the blockchain:</p>
<dl class="docutils">
<dt>a Number or <a class="reference internal" href="api-utils.html#hexstring"><span class="std std-ref">hex string</span></a>:</dt>
<dd>Each block has a block number (eg. <code class="docutils literal"><span class="pre">42</span></code> or <code class="docutils literal"><span class="pre">&quot;0x2a</span></code>.</dd>
<dt>“latest”:</dt>
<dd>The most recently mined block.</dd>
<dt>“pending”:</dt>
<dd>The block that is currently being mined.</dd>
</dl>
</div>
<div class="section" id="block-responses">
<span id="blockresponse"></span><h3>Block Responses<a class="headerlink" href="#block-responses" title="Permalink to this headline"></a></h3>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="p">{</span>
<span class="n">parentHash</span><span class="p">:</span> <span class="s2">&quot;0x3d8182d27303d92a2c9efd294a36dac878e1a9f7cb0964fa0f789fa96b5d0667&quot;</span><span class="p">,</span>
<span class="nb">hash</span><span class="p">:</span> <span class="s2">&quot;0x7f20ef60e9f91896b7ebb0962a18b8defb5e9074e62e1b6cde992648fe78794b&quot;</span><span class="p">,</span>
<span class="n">number</span><span class="p">:</span> <span class="mi">3346463</span><span class="p">,</span>
<span class="n">difficulty</span><span class="p">:</span> <span class="mi">183765779077962</span><span class="p">,</span>
<span class="n">timestamp</span><span class="p">:</span> <span class="mi">1489440489</span><span class="p">,</span>
<span class="n">nonce</span><span class="p">:</span> <span class="s2">&quot;0x17060cb000d2c714&quot;</span><span class="p">,</span>
<span class="n">extraData</span><span class="p">:</span> <span class="s2">&quot;0x65746865726d696e65202d20555331&quot;</span><span class="p">,</span>
<span class="n">gasLimit</span><span class="p">:</span> <span class="n">utils</span><span class="o">.</span><span class="n">bigNumberify</span><span class="p">(</span><span class="s2">&quot;3993225&quot;</span><span class="p">),</span>
<span class="n">gasUsed</span><span class="p">:</span> <span class="n">utils</span><span class="o">.</span><span class="n">bigNuberify</span><span class="p">(</span><span class="s2">&quot;3254236&quot;</span><span class="p">),</span>
<span class="n">miner</span><span class="p">:</span> <span class="s2">&quot;0xEA674fdDe714fd979de3EdF0F56AA9716B898ec8&quot;</span><span class="p">,</span>
<span class="n">transactions</span><span class="p">:</span> <span class="p">[</span>
<span class="s2">&quot;0x125d2b846de85c4c74eafb6f1b49fdb2326e22400ae223d96a8a0b26ccb2a513&quot;</span><span class="p">,</span>
<span class="s2">&quot;0x948d6e8f6f8a4d30c0bd527becbe24d15b1aba796f9a9a09a758b622145fd963&quot;</span><span class="p">,</span>
<span class="o">...</span> <span class="p">[</span> <span class="mi">49</span> <span class="n">more</span> <span class="n">transaction</span> <span class="n">hashes</span> <span class="p">]</span> <span class="o">...</span>
<span class="s2">&quot;0xbd141969b164ed70388f95d780864210e045e7db83e71f171ab851b2fba6b730&quot;</span>
<span class="p">]</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="transaction-requests">
<span id="transactionrequest"></span><h3>Transaction Requests<a class="headerlink" href="#transaction-requests" title="Permalink to this headline"></a></h3>
<p>Any property which accepts a number may also be specified as a <a class="reference internal" href="api-utils.html#bignumber"><span class="std std-ref">BigNumber</span></a>
or <a class="reference internal" href="api-utils.html#hexstring"><span class="std std-ref">hex string</span></a>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="o">//</span> <span class="n">Example</span><span class="p">:</span>
<span class="p">{</span>
<span class="o">//</span> <span class="n">Required</span> <span class="n">unless</span> <span class="n">deploying</span> <span class="n">a</span> <span class="n">contract</span> <span class="p">(</span><span class="ow">in</span> <span class="n">which</span> <span class="n">case</span> <span class="n">omit</span><span class="p">)</span>
<span class="n">to</span><span class="p">:</span> <span class="n">addressOrName</span><span class="p">,</span> <span class="o">//</span> <span class="n">the</span> <span class="n">target</span> <span class="n">address</span> <span class="ow">or</span> <span class="n">ENS</span> <span class="n">name</span>
<span class="o">//</span> <span class="n">These</span> <span class="n">are</span> <span class="n">optional</span><span class="o">/</span><span class="n">meaningless</span> <span class="k">for</span> <span class="n">call</span> <span class="ow">and</span> <span class="n">estimateGas</span>
<span class="n">nonce</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="o">//</span> <span class="n">the</span> <span class="n">transaction</span> <span class="n">nonce</span>
<span class="n">gasLimit</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="o">//</span> <span class="n">the</span> <span class="n">maximum</span> <span class="n">gas</span> <span class="n">this</span> <span class="n">transaction</span> <span class="n">may</span> <span class="n">spend</span>
<span class="n">gasPrice</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="o">//</span> <span class="n">the</span> <span class="n">price</span> <span class="p">(</span><span class="ow">in</span> <span class="n">wei</span><span class="p">)</span> <span class="n">per</span> <span class="n">unit</span> <span class="n">of</span> <span class="n">gas</span>
<span class="o">//</span> <span class="n">These</span> <span class="n">are</span> <span class="n">always</span> <span class="n">optional</span> <span class="p">(</span><span class="n">but</span> <span class="k">for</span> <span class="n">call</span><span class="p">,</span> <span class="n">data</span> <span class="ow">is</span> <span class="n">usually</span> <span class="n">specified</span><span class="p">)</span>
<span class="n">data</span><span class="p">:</span> <span class="s2">&quot;0x&quot;</span><span class="p">,</span> <span class="o">//</span> <span class="n">extra</span> <span class="n">data</span> <span class="k">for</span> <span class="n">the</span> <span class="n">transaction</span><span class="p">,</span> <span class="ow">or</span> <span class="nb">input</span> <span class="k">for</span> <span class="n">call</span>
<span class="n">value</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="o">//</span> <span class="n">the</span> <span class="n">amount</span> <span class="p">(</span><span class="ow">in</span> <span class="n">wei</span><span class="p">)</span> <span class="n">this</span> <span class="n">transaction</span> <span class="ow">is</span> <span class="n">sending</span>
<span class="n">chainId</span><span class="p">:</span> <span class="mi">3</span> <span class="o">//</span> <span class="n">the</span> <span class="n">network</span> <span class="n">ID</span><span class="p">;</span> <span class="n">usually</span> <span class="n">added</span> <span class="n">by</span> <span class="n">a</span> <span class="n">signer</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="transaction-response">
<span id="transactionresponse"></span><h3>Transaction Response<a class="headerlink" href="#transaction-response" title="Permalink to this headline"></a></h3>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="o">//</span> <span class="n">Example</span><span class="p">:</span>
<span class="p">{</span>
<span class="o">//</span> <span class="n">Only</span> <span class="n">available</span> <span class="k">for</span> <span class="n">mined</span> <span class="n">transactions</span>
<span class="n">blockHash</span><span class="p">:</span> <span class="s2">&quot;0x7f20ef60e9f91896b7ebb0962a18b8defb5e9074e62e1b6cde992648fe78794b&quot;</span><span class="p">,</span>
<span class="n">blockNumber</span><span class="p">:</span> <span class="mi">3346463</span><span class="p">,</span>
<span class="n">transactionIndex</span><span class="p">:</span> <span class="mi">51</span><span class="p">,</span>
<span class="o">//</span> <span class="n">Exactly</span> <span class="n">one</span> <span class="n">of</span> <span class="n">these</span> <span class="n">will</span> <span class="n">be</span> <span class="n">present</span> <span class="p">(</span><span class="n">send</span> <span class="n">vs</span><span class="o">.</span> <span class="n">deploy</span> <span class="n">contract</span><span class="p">)</span>
<span class="n">creates</span><span class="p">:</span> <span class="n">null</span><span class="p">,</span>
<span class="n">to</span><span class="p">:</span> <span class="s2">&quot;0xc149Be1bcDFa69a94384b46A1F91350E5f81c1AB&quot;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">The</span> <span class="n">transaction</span> <span class="nb">hash</span>
<span class="nb">hash</span><span class="p">:</span> <span class="s2">&quot;0xf517872f3c466c2e1520e35ad943d833fdca5a6739cfea9e686c4c1b3ab1022e&quot;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">See</span> <span class="n">above</span> <span class="p">(</span><span class="n">Transaction</span> <span class="n">Requests</span><span class="p">)</span> <span class="k">for</span> <span class="n">these</span> <span class="n">explained</span>
<span class="n">data</span><span class="p">:</span> <span class="s2">&quot;0x&quot;</span><span class="p">,</span>
<span class="n">from</span><span class="p">:</span> <span class="s2">&quot;0xEA674fdDe714fd979de3EdF0F56AA9716B898ec8&quot;</span><span class="p">,</span>
<span class="n">gasLimit</span><span class="p">:</span> <span class="n">utils</span><span class="o">.</span><span class="n">bigNumberify</span><span class="p">(</span><span class="s2">&quot;90000&quot;</span><span class="p">),</span>
<span class="n">gasPrice</span><span class="p">:</span> <span class="n">utils</span><span class="o">.</span><span class="n">bigNumberify</span><span class="p">(</span><span class="s2">&quot;21488430592&quot;</span><span class="p">),</span>
<span class="n">nonce</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="p">:</span> <span class="n">utils</span><span class="o">.</span><span class="n">parseEther</span><span class="p">(</span><span class="mf">1.0017071732629267</span><span class="p">),</span>
<span class="o">//</span> <span class="n">The</span> <span class="n">network</span> <span class="n">ID</span> <span class="p">(</span><span class="ow">or</span> <span class="n">chain</span> <span class="n">ID</span><span class="p">);</span> <span class="mi">0</span> <span class="n">indicates</span> <span class="n">replay</span><span class="o">-</span><span class="n">attack</span> <span class="n">vulnerable</span>
<span class="o">//</span> <span class="p">(</span><span class="n">eg</span><span class="o">.</span> <span class="mi">1</span> <span class="o">=</span> <span class="n">Homestead</span> <span class="n">mainnet</span><span class="p">,</span> <span class="mi">3</span> <span class="o">=</span> <span class="n">Ropsten</span> <span class="n">testnet</span><span class="p">)</span>
<span class="n">networkId</span><span class="p">:</span> <span class="mi">1</span><span class="p">,</span>
<span class="o">//</span> <span class="n">The</span> <span class="n">signature</span> <span class="n">of</span> <span class="n">the</span> <span class="n">transaction</span>
<span class="n">r</span><span class="p">:</span> <span class="s2">&quot;0x5b13ef45ce3faf69d1f40f9d15b0070cc9e2c92f3df79ad46d5b3226d7f3d1e8&quot;</span><span class="p">,</span>
<span class="n">s</span><span class="p">:</span> <span class="s2">&quot;0x535236e497c59e3fba93b78e124305c7c9b20db0f8531b015066725e4bb31de6&quot;</span><span class="p">,</span>
<span class="n">v</span><span class="p">:</span> <span class="mi">37</span><span class="p">,</span>
<span class="o">//</span> <span class="n">The</span> <span class="n">raw</span> <span class="n">transaction</span>
<span class="n">raw</span><span class="p">:</span> <span class="s2">&quot;0xf87083154262850500cf6e0083015f9094c149be1bcdfa69a94384b46a1f913&quot;</span> <span class="o">+</span>
<span class="s2">&quot;50e5f81c1ab880de6c75de74c236c8025a05b13ef45ce3faf69d1f40f9d15b0&quot;</span> <span class="o">+</span>
<span class="s2">&quot;070cc9e2c92f3df79ad46d5b3226d7f3d1e8a0535236e497c59e3fba93b78e1&quot;</span> <span class="o">+</span>
<span class="s2">&quot;24305c7c9b20db0f8531b015066725e4bb31de6&quot;</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="transaction-receipts">
<span id="transactionreceipt"></span><h3>Transaction Receipts<a class="headerlink" href="#transaction-receipts" title="Permalink to this headline"></a></h3>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="o">//</span> <span class="n">Example</span>
<span class="p">{</span>
<span class="n">transactionHash</span><span class="p">:</span> <span class="s2">&quot;0x7dec07531aae8178e9d0b0abbd317ac3bb6e8e0fd37c2733b4e0d382ba34c5d2&quot;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">The</span> <span class="n">block</span> <span class="n">this</span> <span class="n">transaction</span> <span class="n">was</span> <span class="n">mined</span> <span class="n">into</span>
<span class="n">blockHash</span><span class="p">:</span> <span class="s2">&quot;0xca1d4d9c4ac0b903a64cf3ae3be55cc31f25f81bf29933dd23c13e51c3711840&quot;</span><span class="p">,</span>
<span class="n">blockNumber</span><span class="p">:</span> <span class="mi">3346629</span><span class="p">,</span>
<span class="o">//</span> <span class="n">The</span> <span class="n">index</span> <span class="n">into</span> <span class="n">this</span> <span class="n">block</span> <span class="n">of</span> <span class="n">the</span> <span class="n">transaction</span>
<span class="n">transactionIndex</span><span class="p">:</span> <span class="mi">1</span><span class="p">,</span>
<span class="o">//</span> <span class="n">The</span> <span class="n">address</span> <span class="n">of</span> <span class="n">the</span> <span class="n">contract</span> <span class="p">(</span><span class="k">if</span> <span class="n">one</span> <span class="n">was</span> <span class="n">created</span><span class="p">)</span>
<span class="n">contractAddress</span><span class="p">:</span> <span class="n">null</span><span class="p">,</span>
<span class="o">//</span> <span class="n">Gas</span>
<span class="n">cumulativeGasUsed</span><span class="p">:</span> <span class="n">utils</span><span class="o">.</span><span class="n">bigNumberify</span><span class="p">(</span><span class="s2">&quot;42000&quot;</span><span class="p">),</span>
<span class="n">gasUsed</span><span class="p">:</span> <span class="n">utils</span><span class="o">.</span><span class="n">bigNumberify</span><span class="p">(</span><span class="s2">&quot;21000&quot;</span><span class="p">),</span>
<span class="o">//</span> <span class="n">Logs</span>
<span class="n">log</span><span class="p">:</span> <span class="p">[</span> <span class="p">],</span>
<span class="n">logsBloom</span><span class="p">:</span> <span class="s2">&quot;0x00&quot;</span> <span class="o">...</span> <span class="p">[</span> <span class="mi">256</span> <span class="nb">bytes</span> <span class="n">of</span> <span class="mi">0</span> <span class="p">]</span> <span class="o">...</span> <span class="s2">&quot;00&quot;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">Post</span><span class="o">-</span><span class="n">Byzantium</span> <span class="n">hard</span><span class="o">-</span><span class="n">fork</span>
<span class="n">byzantium</span><span class="p">:</span> <span class="n">false</span>
<span class="o">////////////</span>
<span class="o">//</span> <span class="n">Pre</span><span class="o">-</span><span class="n">byzantium</span> <span class="n">blocks</span> <span class="n">will</span> <span class="n">have</span> <span class="n">a</span> <span class="n">state</span> <span class="n">root</span><span class="p">:</span>
<span class="n">root</span><span class="p">:</span> <span class="s2">&quot;0x8a27e1f7d3e92ae1a01db5cce3e4718e04954a34e9b17c1942011a5f3a942bf4&quot;</span><span class="p">,</span>
<span class="o">////////////</span>
<span class="o">//</span> <span class="n">Post</span><span class="o">-</span><span class="n">byzantium</span> <span class="n">blocks</span> <span class="n">will</span> <span class="n">have</span> <span class="n">a</span> <span class="n">status</span> <span class="p">(</span><span class="mi">0</span> <span class="n">indicated</span> <span class="n">failure</span> <span class="n">during</span> <span class="n">execution</span><span class="p">)</span>
<span class="o">//</span> <span class="n">status</span><span class="p">:</span> <span class="mi">1</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="filters">
<span id="filter"></span><h3>Filters<a class="headerlink" href="#filters" title="Permalink to this headline"></a></h3>
<p>Filtering on topics supports a <a class="reference external" href="https://github.com/ethereum/wiki/wiki/JSON-RPC#a-note-on-specifying-topic-filters">somewhat complicated</a> specification, however,
for the vast majority of filters, a single topic is usually sufficient (see the example below).</p>
<p>The <em>EtherscanProvider</em> only supports a single topic.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="o">//</span> <span class="n">Example</span>
<span class="p">{</span>
<span class="o">//</span> <span class="n">Optional</span><span class="p">;</span> <span class="n">The</span> <span class="nb">range</span> <span class="n">of</span> <span class="n">blocks</span> <span class="n">to</span> <span class="n">limit</span> <span class="n">querying</span> <span class="p">(</span><span class="n">See</span><span class="p">:</span> <span class="n">Block</span> <span class="n">Tags</span> <span class="n">above</span><span class="p">)</span>
<span class="n">fromBlock</span><span class="p">:</span> <span class="s2">&quot;latest&quot;</span><span class="p">,</span>
<span class="n">toBlock</span><span class="p">:</span> <span class="s2">&quot;latest&quot;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">Optional</span><span class="p">;</span> <span class="n">An</span> <span class="n">address</span> <span class="p">(</span><span class="ow">or</span> <span class="n">ENS</span> <span class="n">name</span><span class="p">)</span> <span class="n">to</span> <span class="nb">filter</span> <span class="n">by</span>
<span class="n">address</span><span class="p">:</span> <span class="n">addressOrName</span><span class="p">,</span>
<span class="o">//</span> <span class="n">Optional</span><span class="p">;</span> <span class="n">A</span> <span class="p">(</span><span class="n">possibly</span> <span class="n">nested</span><span class="p">)</span> <span class="nb">list</span> <span class="n">of</span> <span class="n">topics</span>
<span class="n">topics</span><span class="p">:</span> <span class="p">[</span> <span class="n">topic1</span> <span class="p">]</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
</div>
<hr class="docutils" />
<div class="section" id="provider-specific-extra-api-calls">
<h2>Provider Specific Extra API Calls<a class="headerlink" href="#provider-specific-extra-api-calls" title="Permalink to this headline"></a></h2>
<div class="section" id="etherscan">
<h3>Etherscan<a class="headerlink" href="#etherscan" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . getEtherPrice ( )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with the price of ether in USD.</dd>
<dt><sup>prototype</sup> . getHistory ( addressOrName [ , startBlock [ , endBlock ] ] )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with an array of <a class="reference internal" href="#transactionresponse"><span class="std std-ref">Transaction Responses</span></a>
for each transaction to or from <em>addressOrName</em> between <em>startBlock</em> and <em>endBlock</em> (inclusive).</dd>
</dl>
<p><strong>Examples</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">var</span> <span class="n">provider</span> <span class="o">=</span> <span class="n">new</span> <span class="n">ethers</span><span class="o">.</span><span class="n">providers</span><span class="o">.</span><span class="n">EtherscanProvider</span><span class="p">();</span>
<span class="o">//</span> <span class="n">Getting</span> <span class="n">the</span> <span class="n">current</span> <span class="n">Ethereum</span> <span class="n">price</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getEtherPrice</span><span class="p">()</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">price</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s2">&quot;Ether price in USD: &quot;</span> <span class="o">+</span> <span class="n">price</span><span class="p">);</span>
<span class="p">});</span>
<span class="o">//</span> <span class="n">Getting</span> <span class="n">the</span> <span class="n">transaction</span> <span class="n">history</span> <span class="n">of</span> <span class="n">an</span> <span class="n">address</span>
<span class="n">var</span> <span class="n">address</span> <span class="o">=</span> <span class="s1">&#39;0xb2682160c482eB985EC9F3e364eEc0a904C44C23&#39;</span><span class="p">;</span>
<span class="n">var</span> <span class="n">startBlock</span> <span class="o">=</span> <span class="mi">3135808</span><span class="p">;</span>
<span class="n">var</span> <span class="n">endBlock</span> <span class="o">=</span> <span class="mi">5091477</span><span class="p">;</span>
<span class="n">provider</span><span class="o">.</span><span class="n">getHistory</span><span class="p">(</span><span class="n">address</span><span class="p">,</span> <span class="n">startBlock</span><span class="p">,</span> <span class="n">endBlock</span><span class="p">)</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">history</span><span class="p">)</span> <span class="p">{</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">history</span><span class="p">);</span>
<span class="o">//</span> <span class="p">[</span>
<span class="o">//</span> <span class="p">{</span>
<span class="o">//</span> <span class="nb">hash</span><span class="p">:</span> <span class="s1">&#39;0x327632ccb6d7bb47b455383e936b2f14e6dc50dbefdc214870b446603b468675&#39;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">blockHash</span><span class="p">:</span> <span class="s1">&#39;0x0415f0d2741de45fb748166c7dc2aad9b3ff66bcf7d0a127f42a71d3e286c36d&#39;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">blockNumber</span><span class="p">:</span> <span class="mi">3135808</span><span class="p">,</span>
<span class="o">//</span> <span class="n">transactionIndex</span><span class="p">:</span> <span class="mi">1</span><span class="p">,</span>
<span class="o">//</span> <span class="n">from</span><span class="p">:</span> <span class="s1">&#39;0xb2682160c482eB985EC9F3e364eEc0a904C44C23&#39;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">gasPrice</span><span class="p">:</span> <span class="n">ethers</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">bigNumberify</span><span class="p">(</span><span class="s1">&#39;0x4a817c800&#39;</span><span class="p">),</span>
<span class="o">//</span> <span class="n">gasLimit</span><span class="p">:</span> <span class="n">ethers</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">bigNumberify</span><span class="p">(</span><span class="s1">&#39;0x493e0&#39;</span><span class="p">),</span>
<span class="o">//</span> <span class="n">to</span><span class="p">:</span> <span class="s1">&#39;0xAe572713CfE65cd7033774170F029B7219Ee7f70&#39;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">value</span><span class="p">:</span> <span class="n">ethers</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">bigNumberify</span><span class="p">(</span><span class="s1">&#39;0xd2f13f7789f0000&#39;</span><span class="p">),</span>
<span class="o">//</span> <span class="n">nonce</span><span class="p">:</span> <span class="mi">25</span><span class="p">,</span>
<span class="o">//</span> <span class="n">data</span><span class="p">:</span> <span class="s1">&#39;0x&#39;</span><span class="p">,</span>
<span class="o">//</span> <span class="n">creates</span><span class="p">:</span> <span class="n">null</span><span class="p">,</span>
<span class="o">//</span> <span class="n">networkId</span><span class="p">:</span> <span class="mi">0</span>
<span class="o">//</span> <span class="p">},</span>
<span class="o">//</span> <span class="p">{</span>
<span class="o">//</span> <span class="nb">hash</span><span class="p">:</span> <span class="s1">&#39;0x7c10f2e7125a1fa5e37b54f5fac5465e8d594f89ff97916806ca56a5744812d9&#39;</span><span class="p">,</span>
<span class="o">//</span> <span class="o">...</span>
<span class="o">//</span> <span class="p">}</span>
<span class="o">//</span> <span class="p">]</span>
<span class="p">});</span>
</pre></div>
</div>
</div>
<div class="section" id="web3provider">
<h3>Web3Provider<a class="headerlink" href="#web3provider" title="Permalink to this headline"></a></h3>
<dl class="docutils">
<dt><sup>prototype</sup> . listAccounts ( )</dt>
<dd>Returns a <a class="reference internal" href="notes.html#promise"><span class="std std-ref">Promise</span></a> with a list of all accounts the node connected
to this Web3 controls.</dd>
<dt><sup>prototype</sup> . getSigner( [ address ] )</dt>
<dd>Returns a <a class="reference internal" href="api-contract.html#custom-signer"><span class="std std-ref">Signer</span></a> that uses an account on the node
the Web3 object is connected to. If no address is specified, the first
account on the node is used.</dd>
</dl>
<p><strong>Examples</strong></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">web3Provider</span><span class="o">.</span><span class="n">listAccounts</span><span class="p">()</span><span class="o">.</span><span class="n">then</span><span class="p">(</span><span class="n">function</span><span class="p">(</span><span class="n">accounts</span><span class="p">)</span> <span class="p">{</span>
<span class="n">var</span> <span class="n">signer</span> <span class="o">=</span> <span class="n">web3Provider</span><span class="o">.</span><span class="n">getSigner</span><span class="p">(</span><span class="n">accounts</span><span class="p">[</span><span class="mi">1</span><span class="p">]);</span>
<span class="n">console</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="n">signer</span><span class="p">);</span>
<span class="p">});</span>
</pre></div>
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