Pin Claude Code to Opus 4.6 (1M) for CLI + VS Code extension

set-claude-code-model.md

Pin Claude Code to Opus 4.6 (1M context) — CLI + VS Code

Set a default model for both the Claude Code CLI and the VS Code extension. They share the same global config, so one change covers both.

TL;DR

Add a model key to your global user settings at ~/.claude/settings.json:

{
  "model": "claude-opus-4-6[1m]"
}

The [1m] suffix selects the 1-million-token context variant of Opus 4.6.

Steps

1. Open (or create) ~/.claude/settings.json.

2. Add the model key, merging with whatever is already there — don't overwrite the file. Example of a file that already had other settings:

   {
     "model": "claude-opus-4-6[1m]",
     "skipDangerousModePermissionPrompt": true,
     "enabledPlugins": {
       "warp@claude-code-warp": true
     }
   }

3. Start a new session (restart the CLI, or reload the VS Code window). Already-open sessions won't switch mid-session.

4. Verify with /model in a fresh session — it should show Opus 4.6 (1M) as active.

Why this covers both surfaces

The CLI and the VS Code extension run the same Claude Code core and both read ~/.claude/settings.json. Setting the model there makes it the default everywhere.

Caveats / precedence

Settings load in order user → project → local → flag, where later wins. So this global default is overridden by:

• A project's .claude/settings.json or .claude/settings.local.json with its own model.
• A --model flag on the CLI.
• A manual pick via /model (CLI) or the VS Code model picker — that choice can take precedence for that session.

If /model doesn't show the expected model, check those higher-precedence sources.

Other ways to set it

• /config inside Claude Code — interactive settings UI.
• claude --model "claude-opus-4-6[1m]" — one-off per invocation.