Claude Code model configuration

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.

1. Start Claude Code: claude

2. Type /model and choose your desired model from the interactive menu.

3. Your model change takes effect immediately.

Supported models

• Fable 5, claude-fable-5

• Opus 4.8, claude-opus-4-8

• Opus 4.7, claude-opus-4-7

• Sonnet 4.6, claude-sonnet-4-6

• Opus 4.6, claude-opus-4-6

• Opus 4.5, claude-opus-4-5-20251101

• Haiku 4.5, claude-haiku-4-5-20251001

• Sonnet 4.5, claude-sonnet-4-5-20250929

Change model for current session only

Use the --model flag when starting Claude Code.

1. Start a fresh Terminal session.

2. Enter the following commands (depending on the model you’d like to use for that session):

   • For Fable 5: claude --model claude-fable-5

   • For Opus 4.8: claude --model claude-opus-4-8

   • For Opus 4.7: claude --model claude-opus-4-7

   • For Sonnet 4.6: claude --model claude-sonnet-4-6

   • For Opus 4.6: claude --model claude-opus-4-6

   • For Opus 4.5: claude --model claude-opus-4-5-20251101

   • For Haiku 4.5: claude --model claude-haiku-4-5-20251001

   • For Sonnet 4.5: claude --model claude-sonnet-4-5-20250929

Change default model for all future sessions

Step 1) Check your shell type by running: echo $SHELL

• /bin/zsh → You're using zsh (macOS default)

• /bin/bash → You're using bash (Linux default)

Step 2) Add model setting to your shell config:

For ZSH users (macOS)

• Fable 5: echo 'export ANTHROPIC_MODEL="claude-fable-5"' >> ~/.zshrc

• Opus 4.8: echo 'export ANTHROPIC_MODEL="claude-opus-4-8"' >> ~/.zshrc

• Opus 4.7: echo 'export ANTHROPIC_MODEL="claude-opus-4-7"' >> ~/.zshrc

• Sonnet 4.6: echo 'export ANTHROPIC_MODEL="claude-sonnet-4-6"' >> ~/.zshrc

• Opus 4.6: echo 'export ANTHROPIC_MODEL="claude-opus-4-6"' >> ~/.zshrc

• Opus 4.5: echo 'export ANTHROPIC_MODEL="claude-opus-4-5-20251101"' >> ~/.zshrc

• Haiku 4.5: echo 'export ANTHROPIC_MODEL="claude-haiku-4-5-20251001"' >> ~/.zshrc

• Sonnet 4.5: echo 'export ANTHROPIC_MODEL="claude-sonnet-4-5-20250929"' >> ~/.zshrc

For BASH users (Linux)

• Fable 5: echo 'export ANTHROPIC_MODEL="claude-fable-5"' >> ~/.bashrc

• Opus 4.8: echo 'export ANTHROPIC_MODEL="claude-opus-4-8"' >> ~/.bashrc

• Opus 4.7: echo 'export ANTHROPIC_MODEL="claude-opus-4-7"' >> ~/.bashrc

• Sonnet 4.6: echo 'export ANTHROPIC_MODEL="claude-sonnet-4-6"' >> ~/.bashrc

• Opus 4.6: echo 'export ANTHROPIC_MODEL="claude-opus-4-6"' >> ~/.bashrc

• Opus 4.5: echo 'export ANTHROPIC_MODEL="claude-opus-4-5-20251101"' >> ~/.bashrc

• Haiku 4.5: echo 'export ANTHROPIC_MODEL="claude-haiku-4-5-20251001"' >> ~/.bashrc

• Sonnet 4.5: echo 'export ANTHROPIC_MODEL="claude-sonnet-4-5-20250929"' >> ~/.bashrc

Step 3) Apply the changes:

• For ZSH: source ~/.zshrc

• For BASH: source ~/.bashrc

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.