a href="index.html#type-service2">service2</a></span> <span>&#45;&gt;</span> <span class="type-var">'arg1</span> <span>&#45;&gt;</span> <span class="type-var">'arg2</span> <span>&#45;&gt;</span> <span><span><span>(<span class="type-var">'output</span>, <span class="type-var">'error</span>)</span> <a href="index.html#type-api_result">api_result</a></span> Lwt.t</span></code></dt><dt class="spec value" id="val-post0"><a href="#val-post0" class="anchor"></a><code><span class="keyword">val</span> post0 : <span