System Chat

Play 0x79, server → client.

play · 0x79 · clientbound (server → client)

Sends an unsigned system message. The server uses it for command feedback, join and leave messages, and other server-generated text. If isActionBar is set the client shows it above the hotbar instead of in chat.

Sent by the server, read by the client. Listen for it with client.on("SystemChat", (data) => …) on the receiving side.

Fields

Field	Type	Notes
`content`	NBT
`isActionBar`	Boolean

Send it

await client.sendPacket("SystemChat", {
  content: { text: "Welcome!", color: "green" },
  isActionBar: false,
});

// Action bar: short text above the hotbar.
await client.sendPacket("SystemChat", {
  content: "Saved.",
  isActionBar: true,
});

content is a text component as NBT; a plain string works too. This is the easy way to show a message: no chat session, no signatures. For player chat use PlayerChat.

Field aliases listed under Notes are accepted as alternative keys when writing.

Source: src/Core/Versions/776/Packets/play/clientbound/SystemChat.ts