Claude Pro: Opus model will only be available if extra usage is enabled

Source: Hacker News

This guide shows you three ways to change which Claude model you’re using with Claude Code: the quick /model command for instant changes, the --model flag for one-time session changes, and environment variables to set your preferred model as the permanent default.

Easiest method: Use /model command

The simplest way to change models is to use the /model command directly within Claude Code. This works immediately without restarting your terminal.

Supported models

(list of supported models can be added here)

Change model for current session only

Use the --model flag when starting Claude Code.

claude --model 

Change default model for all future sessions

Step 1: Check your shell type.

echo $SHELL

Step 2: Add the model setting to your shell configuration file.

For ZSH users (macOS)

(add the appropriate export line to ~/.zshrc)

For BASH users (Linux)

(add the appropriate export line to ~/.bashrc)

Step 3: Apply the changes.

source ~/.zshrc   # for ZSH
# or
source ~/.bashrc  # for BASH

Step 4: Close Terminal completely, then reopen it.

Step 5: Start Claude Code in a fresh Terminal session.

claude

Now your chosen model will be the default for all future Claude Code sessions.

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