28 zed integration

Module 28: Zed Integration

Run your Java ACP agent inside the Zed editor.

What You’ll Learn

• Building an agent JAR for editor integration
• Configuring Zed to launch your agent
• The stdio transport mechanism editors use to communicate with agents

Prerequisites

• Zed editor installed
• Java 17+
• Agent JAR built (see below)

The Agent

The agent is the same sync builder pattern from Module 12, with conversational responses:

var transport = new StdioAcpAgentTransport();

AcpSyncAgent agent = AcpAgent.sync(transport)
    .initializeHandler(req -> {
        System.err.println("[ZedAgent] Received initialize request");
        return InitializeResponse.ok();
    })

    .newSessionHandler(req -> {
        System.err.println("[ZedAgent] Creating session for cwd: " + req.cwd());
        return new NewSessionResponse(
            UUID.randomUUID().toString(), null, null);
    })

    .promptHandler((req, context) -> {
        String promptText = req.text();

        context.sendThought("Processing your request...");

        String response = generateResponse(promptText);
        context.sendMessage(response);

        return PromptResponse.endTurn();
    })
    .build();

agent.run();

Logging goes to stderr because Zed captures stdout for the JSON-RPC protocol.

Build and Configure

1. Build the JAR

./mvnw package -pl module-28-zed-integration -q

2. Get the absolute path

realpath module-28-zed-integration/target/zed-agent.jar

3. Configure Zed

Open Zed settings (Ctrl+, on Linux, Cmd+, on Mac) and add:

{
  "agent_servers": {
    "Java Tutorial Agent": {
      "type": "custom",
      "command": "java",
      "args": ["-jar", "/absolute/path/to/zed-agent.jar"]
    }
  }
}

4. Use in Zed

Open the Agent Panel (Ctrl+?), click +, select Java Tutorial Agent, and start chatting.

How It Works

Zed launches your agent as a subprocess and communicates via JSON-RPC over stdio. This is the same mechanism used by LSP language servers. Your agent receives initialize, session/new, and session/prompt requests, and responds with JSON-RPC responses and notifications.

No code changes are needed for different editors. The same JAR works in Zed, JetBrains, and VS Code.

Source Code

View on GitHub

Running the Example

./mvnw package -pl module-28-zed-integration -q
./mvnw exec:java -pl module-28-zed-integration

Next Module

Module 29: JetBrains Integration — configure the same agent for IntelliJ, PyCharm, and other JetBrains IDEs.