Client: Commands

Use client.command(...) to send a request to the server and receive a response. This is a core mechanism for client-server interaction.

Sending commands

const result = await client.command("echo", "Hello!");
console.log(result); // "echo: Hello!"
 
const sum = await client.command("math:add", { a: 5, b: 3 });
console.log(sum); // 8

The method returns a Promise that resolves with the response or rejects if the server throws or times out.

Error handling

If the server throws an error or a guard fails, the client receives it:

try {
  const result = await client.command("divide", { a: 10, b: 0 });
} catch (err) {
  console.error(err.message); // e.g. "Cannot divide by zero"
  console.error(err.code); // e.g. "ESERVER" or your custom code
}

You can inspect .message, .code, and .name on the error object.

Timeouts

The third argument to client.command(...) is a timeout in milliseconds (not an object):

await client.command("slow-op", {}, 5000); // 5s timeout

If the command takes too long to respond, it rejects with a CodeError:

{
  message: "Command timed out after 5000ms.",
  code: "ETIMEOUT",
  name: "TimeoutError"
}

Best practices

• Wrap command calls in try/catch
• Use descriptive command names like "user:update" or "chat:send"
• Handle command timeouts explicitly
• Validate inputs on the client before sending