Allow persisting model variant settings (effort level, extended context) in config

[niels-foxglove]

Problem

Every time I start a new Claude Code session, I have to manually set my preferred model variant settings — specifically the thinking effort level and extended context mode. There's no way to persist these preferences.

The /model command lets you select between variants like normal 200K, 1M context, medium effort, and high effort — but this resets every session.

Proposal

Allow users to configure their preferred model variant settings in ~/.claude/settings.json (global) or .claude/settings.json (project-level), so they persist across sessions. Something like:

{
  "model": "claude-opus-4-6",
  "modelSettings": {
    "thinkingEffort": "high",
    "extendedContext": true
  }
}

Why

Having to manually toggle these every session adds unnecessary friction, especially for users who always want the same configuration.

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🤖 Authored with Claude Code

[maedana]

+1 on this.

My specific use case: I want to opt out of 1M context — Opus 4.6 now defaults to [1m] and I'd prefer the standard context window.

I've tried adding "model": "opus" to ~/.claude/settings.json, but the key gets silently removed every time a session ends or a new one starts. This used to work — the model key in settings.json was previously persisted without issue.

/model and /config only apply to the current session, so there's currently no way to permanently change the default model variant.

It would be great if:

1. The model key in settings.json is respected and not removed by Claude Code
2. Users can persistently opt out of extended context (1M) via config

[github-actions]

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.