<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Async on Yarang's Tech Lair</title><link>https://blog.agentthread.dev/tags/async/</link><description>Recent content in Async on Yarang's Tech Lair</description><generator>Hugo -- gohugo.io</generator><language>en</language><lastBuildDate>Fri, 26 Jun 2026 09:01:09 +0900</lastBuildDate><atom:link href="https://blog.agentthread.dev/tags/async/index.xml" rel="self" type="application/rss+xml"/><item><title>ZeroClaw Agent Runtime: Implementing a TCP/IP Architecture for High-Performance Multi-Agent Communication</title><link>https://blog.agentthread.dev/post/zeroclaw-agent-runtime-implementing-a-tcp/ip-architecture-for-high-performance-multi-agent-communication/</link><pubDate>Fri, 26 Jun 2026 09:01:09 +0900</pubDate><guid>https://blog.agentthread.dev/post/zeroclaw-agent-runtime-implementing-a-tcp/ip-architecture-for-high-performance-multi-agent-communication/</guid><description>&lt;p&gt;Hello! As the open-source AI and agent ecosystem rapidly expands, there&amp;rsquo;s a growing interest in &amp;ldquo;multi-agent systems&amp;rdquo; where multiple agents collaborate beyond a single LLM. In a previous post, we covered the architectural design of the ZeroClaw project. This time, we aim to introduce the specific implementation details of how the actual ZeroClaw runtime internally handles inter-agent communication and achieves high performance by leveraging Rust&amp;rsquo;s powerful asynchronous runtime.&lt;/p&gt;
&lt;h2 id="challenges-with-existing-communication-and-zeroclaws-approach"&gt;Challenges with Existing Communication and ZeroClaw&amp;rsquo;s Approach
&lt;/h2&gt;&lt;p&gt;Typical MCP (Model Context Protocol) or basic agent systems primarily handle communication through in-memory sharing within a single process or simple local function calls. However, as systems become more complex and agents become distributed, the following problems arise:&lt;/p&gt;
&lt;ol&gt;
&lt;li&gt;&lt;strong&gt;Scalability Limitations:&lt;/strong&gt; Single-process memory buffers are finite, and bottlenecks occur when hundreds of agents send and receive messages simultaneously.&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Increased Coupling:&lt;/strong&gt; Communication between agents is tightly coupled with logic, making it difficult to replace or update specific agents.&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Network Separation:&lt;/strong&gt; If the communication methods differ between local development environments and cloud deployment environments, code modifications are required.&lt;/li&gt;
&lt;/ol&gt;
&lt;p&gt;To address these issues, ZeroClaw adopts a hybrid approach that combines &lt;strong&gt;&amp;ldquo;file-based architecture design&amp;rdquo;&lt;/strong&gt; with a &lt;strong&gt;&amp;ldquo;TCP/IP networking layer.&amp;rdquo;&lt;/strong&gt; Agents declaratively record their state in the file system, and actual message transmission is handled via asynchronous TCP sockets.&lt;/p&gt;
&lt;h2 id="asynchronous-server-structure-using-rust-tokio"&gt;Asynchronous Server Structure Using Rust Tokio
&lt;/h2&gt;&lt;p&gt;The core of ZeroClaw is its high-performance networking layer built on Rust&amp;rsquo;s &lt;code&gt;tokio&lt;/code&gt; runtime. Each agent runs as an independent task, and messages are exchanged safely through channels.&lt;/p&gt;
&lt;p&gt;Here&amp;rsquo;s a simplified example of the message broker, which is central to the ZeroClaw runtime.&lt;/p&gt;
&lt;h3 id="1-defining-basic-message-structures"&gt;1. Defining Basic Message Structures
&lt;/h3&gt;&lt;p&gt;First, we define the data structures for messages exchanged between agents. &lt;code&gt;serde&lt;/code&gt; is used to automate serialization.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; serde::{Deserialize, Serialize};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; std::collections::HashMap;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[derive(Debug, Clone, Serialize, Deserialize)]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;struct&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;AgentMessage&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; source: String, &lt;span style="color:#75715e"&gt;// Sender agent ID
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; target: String, &lt;span style="color:#75715e"&gt;// Receiver agent ID (or &amp;#34;broadcast&amp;#34;)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; payload: &lt;span style="color:#a6e22e"&gt;PayloadType&lt;/span&gt;,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[derive(Debug, Clone, Serialize, Deserialize)]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;enum&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;PayloadType&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Text(String),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Data(HashMap&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;String, String&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt;), &lt;span style="color:#75715e"&gt;// Map for flexible data transfer
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Control(ControlSignal),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[derive(Debug, Clone, Serialize, Deserialize)]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;enum&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;ControlSignal&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Start,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Stop,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; HeartBeat,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id="2-implementing-asynchronous-tcp-handlers"&gt;2. Implementing Asynchronous TCP Handlers
&lt;/h3&gt;&lt;p&gt;Actual communication occurs through &lt;code&gt;tokio::net::TcpListener&lt;/code&gt;. Each connection is handled as a separate task, so the slow response of one agent does not bring down the entire system.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; tokio::net::{TcpListener, TcpStream};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; tokio::io::{AsyncReadExt, AsyncWriteExt};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; tokio::sync::mpsc;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[derive(Clone)]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;struct&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;AgentConfig&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; id: String,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;run_agent_server&lt;/span&gt;(config: &lt;span style="color:#a6e22e"&gt;AgentConfig&lt;/span&gt;) -&amp;gt; Result&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;(), Box&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;dyn&lt;/span&gt; std::error::Error&lt;span style="color:#f92672"&gt;&amp;gt;&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; listener &lt;span style="color:#f92672"&gt;=&lt;/span&gt; TcpListener::bind(&lt;span style="color:#e6db74"&gt;&amp;#34;127.0.0.1:8080&amp;#34;&lt;/span&gt;).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;&lt;span style="color:#f92672"&gt;?&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;[&lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;] Agent Server listening on 127.0.0.1:8080&amp;#34;&lt;/span&gt;, config.id);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Channel for message routing (a more complex router would be used in actual implementation)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; (tx, &lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; rx) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; mpsc::channel::&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;AgentMessage&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt;(&lt;span style="color:#ae81ff"&gt;1000&lt;/span&gt;);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Receiving task (spawned)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; config_clone &lt;span style="color:#f92672"&gt;=&lt;/span&gt; config.clone();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; tokio::spawn(&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;move&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;while&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; Ok((&lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; socket, addr)) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; listener.accept().&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;[&lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;] Connection from &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, config_clone.id, addr);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; tx_clone &lt;span style="color:#f92672"&gt;=&lt;/span&gt; tx.clone();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; tokio::spawn(&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;move&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; buf &lt;span style="color:#f92672"&gt;=&lt;/span&gt; [&lt;span style="color:#ae81ff"&gt;0&lt;/span&gt;; &lt;span style="color:#ae81ff"&gt;1024&lt;/span&gt;];
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;loop&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; n &lt;span style="color:#f92672"&gt;=&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;match&lt;/span&gt; socket.read(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; buf).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(n) &lt;span style="color:#66d9ef"&gt;if&lt;/span&gt; n &lt;span style="color:#f92672"&gt;==&lt;/span&gt; &lt;span style="color:#ae81ff"&gt;0&lt;/span&gt; &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;return&lt;/span&gt;, &lt;span style="color:#75715e"&gt;// Connection closed
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(n) &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; n,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Err(e) &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;eprintln!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Failed to read from socket; err = &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{:?}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, e);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;return&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; };
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Message parsing (simplified logic)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; received_data &lt;span style="color:#f92672"&gt;=&lt;/span&gt; &lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;buf[&lt;span style="color:#f92672"&gt;..&lt;/span&gt;n];
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Deserialization would be performed here in reality
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Received: &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{:?}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, String::from_utf8_lossy(received_data));
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// ... (Business logic processing) ...
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; });
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; });
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Example sending task (periodic heartbeat)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; tokio::spawn(&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;move&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; interval &lt;span style="color:#f92672"&gt;=&lt;/span&gt; tokio::time::interval(tokio::time::Duration::from_secs(&lt;span style="color:#ae81ff"&gt;5&lt;/span&gt;));
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;loop&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; interval.tick().&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; hb &lt;span style="color:#f92672"&gt;=&lt;/span&gt; AgentMessage {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; source: &lt;span style="color:#a6e22e"&gt;config&lt;/span&gt;.id.clone(),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; target: &lt;span style="color:#e6db74"&gt;&amp;#34;broadcast&amp;#34;&lt;/span&gt;.to_string(),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; payload: &lt;span style="color:#a6e22e"&gt;PayloadType&lt;/span&gt;::Control(ControlSignal::HeartBeat),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; };
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Would actually write to a socket or send externally
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;[&lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;] Sending Heartbeat...&amp;#34;&lt;/span&gt;, config.id);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; });
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(())
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;This code demonstrates the basic framework for a ZeroClaw agent to asynchronously receive requests from other agents and periodically report its status. Since each connection is executed independently via &lt;code&gt;tokio::spawn&lt;/code&gt;, thousands of concurrent connections can be handled efficiently.&lt;/p&gt;
&lt;h2 id="team-agent-communication-and-protocol-design"&gt;Team Agent Communication and Protocol Design
&lt;/h2&gt;&lt;p&gt;Beyond simple 1:1 communication, ZeroClaw aims for &lt;strong&gt;team-level communication&lt;/strong&gt;. This connects with the previously discussed &amp;ldquo;Team Agent Communication Architecture.&amp;rdquo;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;Pub/Sub Pattern:&lt;/strong&gt; Messages are delivered in bulk to a group of agents subscribed to a specific topic.&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Peer-to-Peer (P2P):&lt;/strong&gt; Minimizes latency by enabling direct communication between agents without going through a central server.&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;ZeroClaw&amp;rsquo;s protocol is encapsulated and transmitted over the TCP layer using JSON or binary formats (like MessagePack for performance-critical scenarios). This forms a Network Abstraction Layer, allowing higher-level business logic to be written without worrying whether communication is local or remote.&lt;/p&gt;
&lt;h2 id="conclusion-towards-scalable-agent-systems"&gt;Conclusion: Towards Scalable Agent Systems
&lt;/h2&gt;&lt;p&gt;ZeroClaw is being designed as a true distributed system, going beyond a simple LLM wrapper. By combining Rust&amp;rsquo;s memory safety and zero-cost abstractions with &lt;code&gt;tokio&lt;/code&gt;&amp;rsquo;s powerful asynchronous processing capabilities, we are building a stable and fast agent runtime.&lt;/p&gt;
&lt;p&gt;In the next post, we will debug the flow of how an LLM makes decisions and performs actual actions through MCP tools on top of this communication architecture.&lt;/p&gt;
&lt;h2 id="reference-code-and-resources"&gt;Reference Code and Resources
&lt;/h2&gt;&lt;ul&gt;
&lt;li&gt;ZeroClaw GitHub Repository (preparing for open-source)&lt;/li&gt;
&lt;li&gt;&lt;a class="link" href="https://www.elsevier.com/books/the-garbage-collection-handbook/jones/978-0-12-812720-5" target="_blank" rel="noopener"
 &gt;The Garbage Collection Handbook: The Art of Automatic Memory Management (2nd Ed)&lt;/a&gt; - A classic and authoritative text on memory management, recently mentioned in the news.&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;Thank you for reading!&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-fallback" data-lang="fallback"&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;</description></item><item><title>[ZeroClaw] Rust Channel-Based IPC Design for Asynchronous Agent Runtime</title><link>https://blog.agentthread.dev/post/zeroclaw-rust-channel-based-ipc-design-for-asynchronous-agent-runtime/</link><pubDate>Thu, 11 Jun 2026 09:00:42 +0900</pubDate><guid>https://blog.agentthread.dev/post/zeroclaw-rust-channel-based-ipc-design-for-asynchronous-agent-runtime/</guid><description>&lt;h1 id="zeroclaw-rust-channel-based-ipc-design-for-asynchronous-agent-runtime"&gt;[ZeroClaw] Rust Channel-Based IPC Design for Asynchronous Agent Runtime
&lt;/h1&gt;&lt;p&gt;Hello. Recently, while enhancing the &amp;lsquo;Multi-Agent Architecture&amp;rsquo;, the core of the &lt;strong&gt;ZeroClaw&lt;/strong&gt; project, I would like to share my experience building a &lt;strong&gt;high-performance asynchronous communication (IPC, Inter-Process Communication)&lt;/strong&gt; environment that goes beyond simple message passing.&lt;/p&gt;
&lt;p&gt;The previous synchronous communication method increased coupling between agents and became a bottleneck (Single Point of Failure) that could halt the entire system due to the failure of one agent. To address this, we designed an event-driven, loosely coupled architecture using Rust&amp;rsquo;s powerful concurrency feature, the &lt;strong&gt;&lt;code&gt;tokio&lt;/code&gt; runtime&lt;/strong&gt;, and &lt;strong&gt;MPSC (Multi-Producer, Single-Consumer) channels&lt;/strong&gt;.&lt;/p&gt;
&lt;p&gt;In this post, we will examine how channels were designed and implemented to maximize the efficiency of the agent runtime, along with actual code.&lt;/p&gt;
&lt;h2 id="1-problems-with-the-existing-architecture-and-the-need-for-asynchronous-design"&gt;1. Problems with the Existing Architecture and the Need for Asynchronous Design
&lt;/h2&gt;&lt;p&gt;Until now, ZeroClaw agents primarily used the &lt;strong&gt;synchronous RPC&lt;/strong&gt; pattern, requesting messages and waiting for responses. However, as the number of agents increased to dozens and they began performing complex tasks (e.g., analyzing file-based architectures, processing large-scale logs), the following problems arose:&lt;/p&gt;
&lt;ol&gt;
&lt;li&gt;&lt;strong&gt;Blocking Issue:&lt;/strong&gt; While Agent A waits for a response from Agent B, Agent A cannot perform other tasks.&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Complex Error Propagation:&lt;/strong&gt; When a specific agent crashed or timed out, it was complicated to propagate the error to agents higher up the call chain.&lt;/li&gt;
&lt;/ol&gt;
&lt;p&gt;To solve this, we adopted an asynchronous pattern: &lt;strong&gt;&amp;ldquo;An agent sends a message and immediately performs other tasks. The processed result is received as an event.&amp;rdquo;&lt;/strong&gt;&lt;/p&gt;
&lt;h2 id="2-event-loop-structure-using-rusts-tokiosyncmpsc"&gt;2. Event Loop Structure Using Rust&amp;rsquo;s &lt;code&gt;tokio::sync::mpsc&lt;/code&gt;
&lt;/h2&gt;&lt;p&gt;The MPSC channel provided by Rust&amp;rsquo;s &lt;code&gt;tokio&lt;/code&gt; crate ensures high throughput and low latency, making it ideal for agent runtimes. Each agent has its own &lt;strong&gt;Task (unit of work)&lt;/strong&gt;, which executes independently via &lt;code&gt;tokio::spawn&lt;/code&gt;.&lt;/p&gt;
&lt;h3 id="core-design-points"&gt;Core Design Points
&lt;/h3&gt;&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;Message Bus:&lt;/strong&gt; Each agent holds a sender (&lt;code&gt;tx&lt;/code&gt;) and a receiver (&lt;code&gt;rx&lt;/code&gt;).&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Event Loop:&lt;/strong&gt; The receiver (&lt;code&gt;rx&lt;/code&gt;) runs in an infinite loop (&lt;code&gt;loop&lt;/code&gt;), asynchronously waiting (&lt;code&gt;recv()&lt;/code&gt;) until a message arrives.&lt;/li&gt;
&lt;/ul&gt;
&lt;h2 id="3-practical-code-a-concrete-implementation-example"&gt;3. Practical Code: A Concrete Implementation Example
&lt;/h2&gt;&lt;p&gt;Now, let&amp;rsquo;s write code that demonstrates how agents communicate within the ZeroClaw runtime.&lt;/p&gt;
&lt;h3 id="step-1-define-the-message-protocol"&gt;Step 1: Define the Message Protocol
&lt;/h3&gt;&lt;p&gt;First, we need to define the data structures that will be exchanged between agents. It is recommended to use an &lt;code&gt;Enum&lt;/code&gt; to manage message types safely.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// Cargo.toml dependencies
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// [dependencies]
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// tokio = { version = &amp;#34;1&amp;#34;, features = [&amp;#34;full&amp;#34;] }
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// serde = { version = &amp;#34;1&amp;#34;, features = [&amp;#34;derive&amp;#34;] }
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; tokio::sync::mpsc;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; serde::{Serialize, Deserialize};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[derive(Debug, Serialize, Deserialize)]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;enum&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;AgentMessage&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; TaskAssigned { task_id: String, description: String },
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; TaskCompleted { task_id: String, result: String },
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; StatusCheck,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id="step-2-implement-agent-struct-and-runner"&gt;Step 2: Implement Agent Struct and Runner
&lt;/h3&gt;&lt;p&gt;Each agent has a unique ID and a receiver (&lt;code&gt;rx&lt;/code&gt;). The &lt;code&gt;run&lt;/code&gt; method is the core function that manages the agent&amp;rsquo;s lifecycle.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;struct&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;Agent&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; id: String,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; rx: &lt;span style="color:#a6e22e"&gt;mpsc&lt;/span&gt;::Receiver&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;AgentMessage&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt;,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;impl&lt;/span&gt; Agent {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;new&lt;/span&gt;(id: String, rx: &lt;span style="color:#a6e22e"&gt;mpsc&lt;/span&gt;::Receiver&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;AgentMessage&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt;) -&amp;gt; &lt;span style="color:#a6e22e"&gt;Self&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Self { id, rx }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;run&lt;/span&gt;(&lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; self) {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;[&lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;] Agent started. Listening for messages...&amp;#34;&lt;/span&gt;, self.id);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Asynchronously wait for message reception
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;while&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; Some(msg) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; self.rx.recv().&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;match&lt;/span&gt; msg {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; AgentMessage::TaskAssigned { task_id, description } &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;[&lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;] Received task: &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt; - &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, self.id, task_id, description);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Actual logic processing (e.g., file analysis, external API calls)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Here, for example, we assume it takes 1 second and then sends a completion message.
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; AgentMessage::StatusCheck &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;[&lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;] Status: Active&amp;#34;&lt;/span&gt;, self.id);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; _ &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; {}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;[&lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;] Agent shutting down.&amp;#34;&lt;/span&gt;, self.id);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id="step-3-main-runtime-and-channel-connection"&gt;Step 3: Main Runtime and Channel Connection
&lt;/h3&gt;&lt;p&gt;In the main function, we create multiple agents, connect the channels, and then execute them in parallel using &lt;code&gt;tokio::spawn&lt;/code&gt;.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[tokio::main]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;main&lt;/span&gt;() -&amp;gt; Result&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;(), Box&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;dyn&lt;/span&gt; std::error::Error&lt;span style="color:#f92672"&gt;&amp;gt;&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// 1. Create channel (capacity 32)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; (tx, rx) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; mpsc::channel::&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;AgentMessage&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt;(&lt;span style="color:#ae81ff"&gt;32&lt;/span&gt;);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// 2. Create and run agent (separated into asynchronous tasks)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; agent_handle &lt;span style="color:#f92672"&gt;=&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; agent &lt;span style="color:#f92672"&gt;=&lt;/span&gt; Agent::new(&lt;span style="color:#e6db74"&gt;&amp;#34;Agent-A&amp;#34;&lt;/span&gt;.to_string(), rx);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; tokio::spawn(&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;move&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; agent.run().&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; })
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; };
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// 3. Send messages from the main runtime
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Other agents or API servers can use this tx to send messages.
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Assign task
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; _ &lt;span style="color:#f92672"&gt;=&lt;/span&gt; tx.send(AgentMessage::TaskAssigned {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; task_id: &lt;span style="color:#e6db74"&gt;&amp;#34;T-101&amp;#34;&lt;/span&gt;.to_string(),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; description: &lt;span style="color:#e6db74"&gt;&amp;#34;Analyze server logs&amp;#34;&lt;/span&gt;.to_string(),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Check status
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; _ &lt;span style="color:#f92672"&gt;=&lt;/span&gt; tx.send(AgentMessage::StatusCheck).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// 4. Wait for the agent to complete its task (in a real environment, it would continue running)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; drop(tx); &lt;span style="color:#75715e"&gt;// Sender drops -&amp;gt; channel closes -&amp;gt; agent loop termination condition met
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; agent_handle.&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;&lt;span style="color:#f92672"&gt;?&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(())
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h2 id="4-zeroclaw-project-application-effects"&gt;4. ZeroClaw Project Application Effects
&lt;/h2&gt;&lt;p&gt;As a result of applying the structure above to the ZeroClaw runtime, we achieved the following benefits:&lt;/p&gt;
&lt;ol&gt;
&lt;li&gt;&lt;strong&gt;Improved Parallel Processing Performance:&lt;/strong&gt; Since agents run within their own &lt;code&gt;tokio&lt;/code&gt; tasks, we were able to efficiently utilize CPU cores.&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Reduced Coupling:&lt;/strong&gt; The main logic doesn&amp;rsquo;t need to know the internal implementation of a specific agent; it simply calls &lt;code&gt;tx.send&lt;/code&gt;.&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Graceful Shutdown:&lt;/strong&gt; By dropping &lt;code&gt;tx&lt;/code&gt;, the channel closes, and the agent detects that no more messages will arrive, naturally exiting the &lt;code&gt;while let&lt;/code&gt; loop and shutting down.&lt;/li&gt;
&lt;/ol&gt;
&lt;h2 id="conclusion"&gt;Conclusion
&lt;/h2&gt;&lt;p&gt;Rust&amp;rsquo;s ownership system and &lt;code&gt;tokio&lt;/code&gt;&amp;rsquo;s asynchronous abstractions become powerful weapons in building multi-agent systems. In the next post, we will cover how these agents persist state when combined with a &lt;strong&gt;file-based architecture&lt;/strong&gt;.&lt;/p&gt;
&lt;p&gt;The development of ZeroClaw&amp;rsquo;s high-performance agent runtime continues.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-fallback" data-lang="fallback"&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;</description></item><item><title>MCP Server Performance Optimization: Building Ultra-Fast Processing Pipelines with Rust</title><link>https://blog.agentthread.dev/post/mcp-server-performance-optimization-building-ultra-fast-processing-pipelines-with-rust/</link><pubDate>Wed, 03 Jun 2026 09:00:50 +0900</pubDate><guid>https://blog.agentthread.dev/post/mcp-server-performance-optimization-building-ultra-fast-processing-pipelines-with-rust/</guid><description>&lt;h1 id="mcp-server-performance-optimization-building-ultra-fast-processing-pipelines-with-rust"&gt;MCP Server Performance Optimization: Building Ultra-Fast Processing Pipelines with Rust
&lt;/h1&gt;&lt;p&gt;As agent systems utilizing LLMs (Large Language Models) have become a hot topic in the development ecosystem, the importance of the supporting infrastructure, MCP (Model Context Protocol) servers, is growing. In a previous post, we discussed multi-agent architectures, mentioning high-performance runtimes like &lt;strong&gt;ZeroClaw&lt;/strong&gt;. Today, we will focus on Rust-based optimization techniques to dramatically improve the &lt;strong&gt;Throughput and Latency&lt;/strong&gt; of the MCP server itself.&lt;/p&gt;
&lt;p&gt;Simply saying &amp;ldquo;it&amp;rsquo;s fast&amp;rdquo; is not enough. The key is how efficiently the server manages resources when thousands of Tool Calls arrive simultaneously. In particular, as the current trend of AI agents collects RSS feeds or real-time data, I/O bound operations often become a bottleneck.&lt;/p&gt;
&lt;p&gt;This article will introduce concrete methods for eliminating bottlenecks and writing safe yet fast code by leveraging Tokio, Rust&amp;rsquo;s powerful asynchronous runtime.&lt;/p&gt;
&lt;h2 id="1-problem-definition-single-threaded-bottleneck"&gt;1. Problem Definition: Single-Threaded Bottleneck
&lt;/h2&gt;&lt;p&gt;Basically, simple MCP servers written in Python or Node.js often rely on a single-threaded event loop. This is advantageous for I/O-heavy tasks, but it has clear limitations when processing MCP tools that involve data manipulation or complex logic, as it only utilizes one CPU core.&lt;/p&gt;
&lt;p&gt;For example, when building an automated blog system, if CPU usage reaches 100% during the processing of large amounts of images or log parsing, other requests will pile up in the queue. We need to solve this with &lt;strong&gt;multi-threaded asynchronous processing&lt;/strong&gt;.&lt;/p&gt;
&lt;h2 id="2-asynchronous-processing-with-rust-and-tokio"&gt;2. Asynchronous Processing with Rust and Tokio
&lt;/h2&gt;&lt;p&gt;Rust can achieve both safety and performance through &amp;lsquo;Zero-cost abstractions&amp;rsquo;. Let&amp;rsquo;s parallelize the core logic of the MCP server, tool execution, using &lt;code&gt;tokio::spawn&lt;/code&gt;.&lt;/p&gt;
&lt;h3 id="basic-setup-cargotoml"&gt;Basic Setup (Cargo.toml)
&lt;/h3&gt;&lt;p&gt;First, add Tokio to your dependencies file.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-toml" data-lang="toml"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;[&lt;span style="color:#a6e22e"&gt;dependencies&lt;/span&gt;]
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#a6e22e"&gt;tokio&lt;/span&gt; = { &lt;span style="color:#a6e22e"&gt;version&lt;/span&gt; = &lt;span style="color:#e6db74"&gt;&amp;#34;1&amp;#34;&lt;/span&gt;, &lt;span style="color:#a6e22e"&gt;features&lt;/span&gt; = [&lt;span style="color:#e6db74"&gt;&amp;#34;full&amp;#34;&lt;/span&gt;] }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#a6e22e"&gt;serde&lt;/span&gt; = { &lt;span style="color:#a6e22e"&gt;version&lt;/span&gt; = &lt;span style="color:#e6db74"&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;, &lt;span style="color:#a6e22e"&gt;features&lt;/span&gt; = [&lt;span style="color:#e6db74"&gt;&amp;#34;derive&amp;#34;&lt;/span&gt;] }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#a6e22e"&gt;serde_json&lt;/span&gt; = &lt;span style="color:#e6db74"&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id="asynchronous-handler-implementation-example"&gt;Asynchronous Handler Implementation Example
&lt;/h3&gt;&lt;p&gt;The following code shows a simple MCP server handler structure that processes incoming requests by separating them into distinct tasks.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; tokio::net::TcpListener;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; tokio::io::{AsyncReadExt, AsyncWriteExt};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; serde::{Deserialize, Serialize};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; std::sync::Arc;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// Define the MCP request message structure
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[derive(Debug, Deserialize)]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;struct&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;McpRequest&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; id: String,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; method: String,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; params: &lt;span style="color:#a6e22e"&gt;serde_json&lt;/span&gt;::Value,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[derive(Debug, Serialize)]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;struct&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;McpResponse&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; id: String,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; result: &lt;span style="color:#a6e22e"&gt;serde_json&lt;/span&gt;::Value,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// Function to simulate heavy processing
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;process_heavy_tool&lt;/span&gt;(params: &lt;span style="color:#a6e22e"&gt;serde_json&lt;/span&gt;::Value) -&amp;gt; Result&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;String, String&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// In a real environment, this would involve database lookups or file I/O
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Simulate asynchronous waiting with tokio::time::sleep
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; tokio::time::sleep(tokio::time::Duration::from_secs(&lt;span style="color:#ae81ff"&gt;2&lt;/span&gt;)).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(&lt;span style="color:#a6e22e"&gt;format!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Processed: &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, params))
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[tokio::main]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;main&lt;/span&gt;() -&amp;gt; Result&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;(), Box&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;dyn&lt;/span&gt; std::error::Error&lt;span style="color:#f92672"&gt;&amp;gt;&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; listener &lt;span style="color:#f92672"&gt;=&lt;/span&gt; TcpListener::bind(&lt;span style="color:#e6db74"&gt;&amp;#34;127.0.0.1:8080&amp;#34;&lt;/span&gt;).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;&lt;span style="color:#f92672"&gt;?&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;MCP Server listening on &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, listener.local_addr()&lt;span style="color:#f92672"&gt;?&lt;/span&gt;);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;loop&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; (&lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; socket, _) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; listener.accept().&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;&lt;span style="color:#f92672"&gt;?&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Create a new task for each incoming connection (parallel processing)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; tokio::spawn(&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;move&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; buf &lt;span style="color:#f92672"&gt;=&lt;/span&gt; [&lt;span style="color:#ae81ff"&gt;0&lt;/span&gt;; &lt;span style="color:#ae81ff"&gt;1024&lt;/span&gt;];
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;loop&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; n &lt;span style="color:#f92672"&gt;=&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;match&lt;/span&gt; socket.read(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; buf).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(n) &lt;span style="color:#66d9ef"&gt;if&lt;/span&gt; n &lt;span style="color:#f92672"&gt;==&lt;/span&gt; &lt;span style="color:#ae81ff"&gt;0&lt;/span&gt; &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;return&lt;/span&gt;, &lt;span style="color:#75715e"&gt;// Connection closed
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(n) &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; n,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Err(e) &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;eprintln!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Failed to read from socket; err = &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{:?}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, e);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;return&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; };
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; req_str &lt;span style="color:#f92672"&gt;=&lt;/span&gt; String::from_utf8_lossy(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;buf[&lt;span style="color:#ae81ff"&gt;0&lt;/span&gt;&lt;span style="color:#f92672"&gt;..&lt;/span&gt;n]);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// JSON parsing and processing logic (error handling omitted)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;if&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; Ok(req) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; serde_json::from_str::&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;McpRequest&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt;(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;req_str) {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; req_id &lt;span style="color:#f92672"&gt;=&lt;/span&gt; req.id.clone();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Core logic: spawn an asynchronous function for non-blocking processing
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; handle &lt;span style="color:#f92672"&gt;=&lt;/span&gt; tokio::spawn(&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;move&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; process_heavy_tool(req.params).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; });
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Wait for the result and respond (using channels is recommended in actual implementations)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;if&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; Ok(Ok(result)) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; handle.&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; resp &lt;span style="color:#f92672"&gt;=&lt;/span&gt; McpResponse {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; id: &lt;span style="color:#a6e22e"&gt;req_id&lt;/span&gt;,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; result: &lt;span style="color:#a6e22e"&gt;serde_json&lt;/span&gt;::&lt;span style="color:#a6e22e"&gt;json!&lt;/span&gt;(result),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; };
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;if&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; Ok(serialized) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; serde_json::to_string(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;resp) {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; _ &lt;span style="color:#f92672"&gt;=&lt;/span&gt; socket.write_all(serialized.as_bytes()).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; });
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;The core of this code is that &lt;code&gt;tokio::spawn&lt;/code&gt; allows each request to execute independently without blocking the main loop.&lt;/p&gt;
&lt;h2 id="3-memory-optimization-through-streaming"&gt;3. Memory Optimization through Streaming
&lt;/h2&gt;&lt;p&gt;When processing large files or transferring logs, loading all data into memory (RAM) is fatal. Using Rust&amp;rsquo;s &lt;code&gt;Stream&lt;/code&gt; allows you to process data in chunks, maintaining consistent memory usage.&lt;/p&gt;
&lt;p&gt;This can be particularly useful in tasks like &lt;strong&gt;[blog-api-server] logging improvements&lt;/strong&gt; or &lt;strong&gt;Cloud Monitor&lt;/strong&gt; operations.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; futures::stream::{Stream, StreamExt};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; std::pin::Pin;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// Stream for generating virtual log data
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;log_stream&lt;/span&gt;() -&amp;gt; &lt;span style="color:#a6e22e"&gt;Pin&lt;/span&gt;&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;Box&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;dyn&lt;/span&gt; Stream&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;Item &lt;span style="color:#f92672"&gt;=&lt;/span&gt; String&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt; &lt;span style="color:#f92672"&gt;+&lt;/span&gt; Send&lt;span style="color:#f92672"&gt;&amp;gt;&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Box::pin(async_stream::&lt;span style="color:#a6e22e"&gt;stream!&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;for&lt;/span&gt; i &lt;span style="color:#66d9ef"&gt;in&lt;/span&gt; &lt;span style="color:#ae81ff"&gt;0&lt;/span&gt;&lt;span style="color:#f92672"&gt;..&lt;/span&gt;&lt;span style="color:#ae81ff"&gt;1000&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;yield&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;format!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Log entry #&lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#ae81ff"&gt;\n&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, i);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; tokio::time::sleep(tokio::time::Duration::from_millis(&lt;span style="color:#ae81ff"&gt;10&lt;/span&gt;)).&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; })
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// Stream processing example
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;async&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;process_logs&lt;/span&gt;() {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; stream &lt;span style="color:#f92672"&gt;=&lt;/span&gt; log_stream();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;while&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; Some(log_entry) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; stream.next().&lt;span style="color:#66d9ef"&gt;await&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Process line by line in real-time (write to file or send)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Processing: &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, log_entry);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h2 id="4-conclusion-towards-zeroclaw"&gt;4. Conclusion: Towards ZeroClaw
&lt;/h2&gt;&lt;p&gt;The &lt;strong&gt;ZeroClaw&lt;/strong&gt; runtime we aim for must provide asynchronous processing and memory safety as its core features. We need to go beyond simply porting existing Python scripts to Rust and actively leverage &lt;strong&gt;Tokio&amp;rsquo;s scheduling&lt;/strong&gt; and &lt;strong&gt;Zero-copy serialization&lt;/strong&gt; to withstand an environment where thousands of agents communicate concurrently.&lt;/p&gt;
&lt;p&gt;In the next post, we will discuss how to design &lt;strong&gt;agent-to-agent communication protocols&lt;/strong&gt; that operate on these high-performance servers.&lt;/p&gt;</description></item><item><title>High-Performance MCP Server Implemented with Rust: Asynchronous Messaging Using ZeroMQ</title><link>https://blog.agentthread.dev/post/high-performance-mcp-server-implemented-with-rust-asynchronous-messaging-using-zeromq/</link><pubDate>Sun, 10 May 2026 09:01:24 +0900</pubDate><guid>https://blog.agentthread.dev/post/high-performance-mcp-server-implemented-with-rust-asynchronous-messaging-using-zeromq/</guid><description>&lt;h1 id="high-performance-mcp-server-implemented-with-rust-asynchronous-messaging-using-zeromq"&gt;High-Performance MCP Server Implemented with Rust: Asynchronous Messaging Using ZeroMQ
&lt;/h1&gt;&lt;p&gt;Recently, while working on the &lt;code&gt;ZeroClaw&lt;/code&gt; project, we identified a need to overcome the performance limitations of MCP (Model Context Protocol) servers. Traditional HTTP-based communication struggles to move beyond a single request-response pattern, and real-time communication between numerous LLM agents is prone to bottlenecks. In this post, we will cover the process of building an ultra-lightweight, ultra-fast MCP server by leveraging Rust&amp;rsquo;s powerful asynchronous processing capabilities and ZeroMQ (ØMQ).&lt;/p&gt;
&lt;h2 id="why-zeromq-comparison-with-tcp-socket-limitations"&gt;Why ZeroMQ? (Comparison with TCP Socket Limitations)
&lt;/h2&gt;&lt;p&gt;In the previous &lt;code&gt;blog-api-server&lt;/code&gt; architecture, we defined and used protocols directly using standard TCP streams. However, in a multi-agent environment, the following issues arise:&lt;/p&gt;
&lt;ol&gt;
&lt;li&gt;&lt;strong&gt;Connection Management Complexity&lt;/strong&gt;: As the number of agents grows into the dozens, managing the &lt;code&gt;Accept&lt;/code&gt; loop and socket states requires &lt;code&gt;unsafe&lt;/code&gt; code or complex state machines.&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Message Enveloping&lt;/strong&gt;: TCP is a byte stream. We must implement Length-Prefixing directly to demarcate message boundaries, which is a common source of bugs.&lt;/li&gt;
&lt;/ol&gt;
&lt;p&gt;ZeroMQ abstracts away the complexity of this lower socket layer while providing a faster &amp;ldquo;User Space&amp;rdquo; transport layer than TCP. Notably, using the &lt;code&gt;ipc&lt;/code&gt; (Inter-Process Communication) protocol can completely eliminate network stack overhead for localhost communication.&lt;/p&gt;
&lt;h2 id="architecture-design-zeromq-pubsub-pattern"&gt;Architecture Design: ZeroMQ PUB/SUB Pattern
&lt;/h2&gt;&lt;p&gt;For this implementation, we will use the &lt;strong&gt;Publish/Subscribe (PUB/SUB)&lt;/strong&gt; pattern for loose coupling between agents. When one agent changes its state (Publishes), a message is immediately broadcast to other agents subscribing to that topic.&lt;/p&gt;
&lt;h3 id="key-dependencies-cargotoml"&gt;Key Dependencies (Cargo.toml)
&lt;/h3&gt;&lt;p&gt;In the Rust ecosystem, ZeroMQ is available through the &lt;code&gt;zmq&lt;/code&gt; crate. While &lt;code&gt;tokio-zmq&lt;/code&gt; can be used for integration with asynchronous runtimes, for pure performance, leveraging ZeroMQ&amp;rsquo;s &lt;code&gt;poll&lt;/code&gt; functionality is often more stable.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-toml" data-lang="toml"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;[&lt;span style="color:#a6e22e"&gt;dependencies&lt;/span&gt;]
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#a6e22e"&gt;zmq&lt;/span&gt; = &lt;span style="color:#e6db74"&gt;&amp;#34;0.10&amp;#34;&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#a6e22e"&gt;serde&lt;/span&gt; = { &lt;span style="color:#a6e22e"&gt;version&lt;/span&gt; = &lt;span style="color:#e6db74"&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;, &lt;span style="color:#a6e22e"&gt;features&lt;/span&gt; = [&lt;span style="color:#e6db74"&gt;&amp;#34;derive&amp;#34;&lt;/span&gt;] }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#a6e22e"&gt;serde_json&lt;/span&gt; = &lt;span style="color:#e6db74"&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#a6e22e"&gt;tokio&lt;/span&gt; = { &lt;span style="color:#a6e22e"&gt;version&lt;/span&gt; = &lt;span style="color:#e6db74"&gt;&amp;#34;1&amp;#34;&lt;/span&gt;, &lt;span style="color:#a6e22e"&gt;features&lt;/span&gt; = [&lt;span style="color:#e6db74"&gt;&amp;#34;full&amp;#34;&lt;/span&gt;] }
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h2 id="implementation-high-performance-mcp-router"&gt;Implementation: High-Performance MCP Router
&lt;/h2&gt;&lt;p&gt;The code below is an example implementation of an MCP Router that acts as a simple message broker. It serves as a central hub for multiple LLM agents (teams) to communicate with each other.&lt;/p&gt;
&lt;h3 id="1-define-message-protocol"&gt;1. Define Message Protocol
&lt;/h3&gt;&lt;p&gt;First, let&amp;rsquo;s define the format of messages exchanged between agents. We ensure compatibility by using JSON serialization.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; serde::{Deserialize, Serialize};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;#[derive(Debug, Serialize, Deserialize)]&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;struct&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;McpMessage&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; source_id: String,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; target_topic: String,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; payload: String,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;pub&lt;/span&gt; timestamp: &lt;span style="color:#66d9ef"&gt;i64&lt;/span&gt;,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id="2-asynchronous-zeromq-context-and-socket-setup"&gt;2. Asynchronous ZeroMQ Context and Socket Setup
&lt;/h3&gt;&lt;p&gt;ZeroMQ&amp;rsquo;s Context is thread-safe, so it&amp;rsquo;s common practice to create and share a single instance globally throughout the application.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; std::time::SystemTime;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; zmq::{Context, Socket, SocketType};
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;struct&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;McpRouter&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; context: &lt;span style="color:#a6e22e"&gt;Context&lt;/span&gt;,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; frontend: &lt;span style="color:#a6e22e"&gt;Socket&lt;/span&gt;, &lt;span style="color:#75715e"&gt;// Agents connect here
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Can add sockets for other patterns if needed
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;impl&lt;/span&gt; McpRouter {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;new&lt;/span&gt;() -&amp;gt; Result&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;Self, zmq::Error&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; context &lt;span style="color:#f92672"&gt;=&lt;/span&gt; Context::new();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; frontend &lt;span style="color:#f92672"&gt;=&lt;/span&gt; context.socket(SocketType::&lt;span style="color:#66d9ef"&gt;SUB&lt;/span&gt;)&lt;span style="color:#f92672"&gt;?&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Set to receive all messages (no filtering)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; frontend.set_subscribe(&lt;span style="color:#e6db74"&gt;b&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&amp;#34;&lt;/span&gt;)&lt;span style="color:#f92672"&gt;?&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(McpRouter { context, frontend })
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;start&lt;/span&gt;(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;self, endpoint: &lt;span style="color:#66d9ef"&gt;&amp;amp;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;str&lt;/span&gt;) -&amp;gt; Result&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;(), zmq::Error&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; self.frontend.bind(endpoint)&lt;span style="color:#f92672"&gt;?&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;[ZeroClaw Router] Listening on &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, endpoint);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; msg &lt;span style="color:#f92672"&gt;=&lt;/span&gt; zmq::Message::new();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;loop&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Can use poll for non-blocking receive
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Here, a simple blocking receive example
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;match&lt;/span&gt; self.frontend.recv(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;mut&lt;/span&gt; msg) {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Ok(_) &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; data &lt;span style="color:#f92672"&gt;=&lt;/span&gt; msg.as_str().unwrap();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Message parsing and routing logic
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;if&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; Ok(mcp_msg) &lt;span style="color:#f92672"&gt;=&lt;/span&gt; serde_json::from_str::&lt;span style="color:#f92672"&gt;&amp;lt;&lt;/span&gt;McpMessage&lt;span style="color:#f92672"&gt;&amp;gt;&lt;/span&gt;(data) {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; self.route_message(mcp_msg);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; Err(e) &lt;span style="color:#f92672"&gt;=&amp;gt;&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;eprintln!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Receive Error: &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, e);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;route_message&lt;/span&gt;(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;self, msg: &lt;span style="color:#a6e22e"&gt;McpMessage&lt;/span&gt;) {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Implement actual routing logic
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#a6e22e"&gt;println!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Routing from &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt; on topic &lt;/span&gt;&lt;span style="color:#e6db74"&gt;{}&lt;/span&gt;&lt;span style="color:#e6db74"&gt;&amp;#34;&lt;/span&gt;, msg.source_id, msg.target_topic);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// e.g., save to database, forward to another socket, etc.
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id="3-agent-publisher-implementation"&gt;3. Agent Publisher Implementation
&lt;/h3&gt;&lt;p&gt;Now, let&amp;rsquo;s write the code for individual agents to send messages. When using &lt;code&gt;tokio&lt;/code&gt;, you need to execute ZeroMQ&amp;rsquo;s blocking functions in a separate thread to avoid blocking the asynchronous runtime.&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;use&lt;/span&gt; std::thread;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;fn&lt;/span&gt; &lt;span style="color:#a6e22e"&gt;spawn_publisher_agent&lt;/span&gt;(id: &lt;span style="color:#66d9ef"&gt;&amp;amp;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;str&lt;/span&gt;, endpoint: &lt;span style="color:#66d9ef"&gt;&amp;amp;&lt;/span&gt;&lt;span style="color:#66d9ef"&gt;str&lt;/span&gt;) {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; context &lt;span style="color:#f92672"&gt;=&lt;/span&gt; Context::new();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; sender &lt;span style="color:#f92672"&gt;=&lt;/span&gt; context.socket(SocketType::&lt;span style="color:#66d9ef"&gt;PUB&lt;/span&gt;).expect(&lt;span style="color:#e6db74"&gt;&amp;#34;Failed to create PUB socket&amp;#34;&lt;/span&gt;);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; sender.connect(endpoint).expect(&lt;span style="color:#e6db74"&gt;&amp;#34;Failed to connect to Router&amp;#34;&lt;/span&gt;);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// Run in a separate thread to isolate from the Tokio runtime
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; thread::spawn(&lt;span style="color:#66d9ef"&gt;move&lt;/span&gt; &lt;span style="color:#f92672"&gt;||&lt;/span&gt; {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; counter &lt;span style="color:#f92672"&gt;=&lt;/span&gt; &lt;span style="color:#ae81ff"&gt;0&lt;/span&gt;&lt;span style="color:#f92672"&gt;..&lt;/span&gt;&lt;span style="color:#ae81ff"&gt;100&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;for&lt;/span&gt; i &lt;span style="color:#66d9ef"&gt;in&lt;/span&gt; counter {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; msg &lt;span style="color:#f92672"&gt;=&lt;/span&gt; McpMessage {
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; source_id: &lt;span style="color:#a6e22e"&gt;id&lt;/span&gt;.to_string(),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; target_topic: &lt;span style="color:#e6db74"&gt;&amp;#34;general&amp;#34;&lt;/span&gt;.to_string(),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; payload: &lt;span style="color:#a6e22e"&gt;format&lt;/span&gt;&lt;span style="color:#f92672"&gt;!&lt;/span&gt;(&lt;span style="color:#e6db74"&gt;&amp;#34;Message #{} from agent {}&amp;#34;&lt;/span&gt;, i, id),
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; timestamp: &lt;span style="color:#a6e22e"&gt;SystemTime&lt;/span&gt;::now().duration_since(SystemTime::&lt;span style="color:#66d9ef"&gt;UNIX_EPOCH&lt;/span&gt;).unwrap().as_secs() &lt;span style="color:#66d9ef"&gt;as&lt;/span&gt; &lt;span style="color:#66d9ef"&gt;i64&lt;/span&gt;,
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; };
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; json_str &lt;span style="color:#f92672"&gt;=&lt;/span&gt; serde_json::to_string(&lt;span style="color:#f92672"&gt;&amp;amp;&lt;/span&gt;msg).unwrap();
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#75715e"&gt;// ZeroMQ automatically retries or queues sending if it fails (set High-water mark if needed)
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; sender.send(json_str.as_bytes(), &lt;span style="color:#ae81ff"&gt;0&lt;/span&gt;).expect(&lt;span style="color:#e6db74"&gt;&amp;#34;Failed to send&amp;#34;&lt;/span&gt;);
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; 
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; thread::sleep(std::time::Duration::from_millis(&lt;span style="color:#ae81ff"&gt;100&lt;/span&gt;));
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; }
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; });
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;}
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h2 id="performance-optimization-and-ipc-utilization"&gt;Performance Optimization and IPC Utilization
&lt;/h2&gt;&lt;p&gt;The true power of a Rust ZeroMQ server is unleashed when using the &lt;strong&gt;IPC (Inter-Process Communication)&lt;/strong&gt; transport. While TCP involves packets traversing the network stack and looping back, IPC uses Unix Domain Sockets or Windows Named Pipes for communication at a level close to memory copying.&lt;/p&gt;
&lt;p&gt;To use the &lt;code&gt;ipc&lt;/code&gt; protocol, change the endpoint as follows:&lt;/p&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#75715e"&gt;// Use IPC instead of TCP
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#66d9ef"&gt;let&lt;/span&gt; endpoint &lt;span style="color:#f92672"&gt;=&lt;/span&gt; &lt;span style="color:#e6db74"&gt;&amp;#34;ipc:///tmp/mcp_router.ipc&amp;#34;&lt;/span&gt;;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;router.start(endpoint);
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;Just as modern languages like Bun and Zig gain attention for their system-level optimizations, the combination of Rust and ZeroMQ is one of the most powerful tools for building the &amp;ldquo;system bus&amp;rdquo; for LLM applications.&lt;/p&gt;
&lt;h2 id="conclusion"&gt;Conclusion
&lt;/h2&gt;&lt;p&gt;In this post, as part of the &lt;code&gt;ZeroClaw&lt;/code&gt; project, we explored how to build a high-performance MCP server using Rust and ZeroMQ. Beyond simple HTTP requests, this architecture offers significant advantages in scalability and performance for environments requiring real-time messaging between agents.&lt;/p&gt;
&lt;p&gt;In the next post, we will discuss the Circuit Breaker pattern and error handling strategies to add reliability to this messaging system.&lt;/p&gt;
&lt;h3 id="references"&gt;References
&lt;/h3&gt;&lt;ul&gt;
&lt;li&gt;&lt;a class="link" href="https://zeromq.org/get-started/" target="_blank" rel="noopener"
 &gt;ZeroMQ Guide - The Framework&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;&lt;a class="link" href="https://github.com/zeromq/tokio-zmq" target="_blank" rel="noopener"
 &gt;Tokio Zmq&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;&lt;a class="link" href="https://github.com/your-org/zeroclaw" target="_blank" rel="noopener"
 &gt;ZeroClaw GitHub&lt;/a&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;div class="highlight"&gt;&lt;pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-fallback" data-lang="fallback"&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;</description></item></channel></rss>