Discord error 4005: Already authenticated

Your client sent a second Identify (op 2) on a connection that was already identified. A gateway connection authenticates once; if you need a new session you open a new socket. Sending Identify again on the live socket is treated as a protocol violation and the connection is closed.

In libraries this typically comes from calling login() / run() / start() twice, for example once at module load and once in a main function, or from a hot-reload setup that re-executes the bot entry point without tearing down the old client. Custom clients produce it when their reconnect logic sends Identify on the existing socket instead of opening a new one, or when a resume failure handler falls through into an identify path while the socket is still open.

// WebSocket close frame
code: 4005
reason: "Already authenticated."

Construct and start the client in one place guarded against re-entry. For development, use a process manager that restarts the whole process on change rather than re-requiring modules inside a live process.

Double-identify is almost always a lifecycle bug in your process management rather than in protocol code. One client instance, one entry point, explicit teardown on reload. The identify concurrency and session budgets a duplicate login also drains are on the Discord limits page; sending before identifying is the mirror-image bug, 4003.