# Claude Code v2.1.168

> Claude Code v2.1.168, released 6 Jun 2026 (2026-06-06). 3 entries read out of the shipped bundle. Unofficial, and not affiliated with Anthropic.

Web version: https://changelogs.core-directive.com/v/2.1.168

This is a small maintenance release built on June 6, 2026. The primary substantive change is the addition of extended thinking budget support for the `claude-mythos-preview` model family, along with infrastructure pre-registration for two upcoming model families ("fruitcake" and "macaroon"). All other changes are version number propagation across the codebase.

## Changes

### Extended Thinking Budget for claude-mythos-preview

Claude Code now enables extended thinking for models in the "mythos" family (such as `claude-mythos-preview`) where it was previously disabled. Two distinct thinking budget paths are updated:

- The always-disabled thinking path (`[false, 0]`) now returns `[undefined, 2048]` for mythos-family models, activating thinking with a 2048-token budget.
- The main thinking configuration path now checks for mythos-family models first and applies a dedicated 2048-token budget constant (`Cx4`) before falling through to the general thinking settings.

This means users who have `claude-mythos-preview` configured as their model will now benefit from extended reasoning where Claude thinks through problems more carefully before responding.

**Evidence**

Model family detection uses `ZW_ = ["fruitcake", "macaroon", "mythos"]` — search for `"mythos"` in the source; thinking budget is `Cx4 = 2048` (search for `"Cx4 = 2048"`).

### New Model Family Codenames Pre-Registered

Two new model family identifiers, `"fruitcake"` and `"macaroon"`, are pre-registered alongside `"mythos"` in the model-family detection array. These codenames are used by the same thinking-budget routing logic described above, meaning that when models with these internal names ship they will automatically inherit the same 2048-token thinking configuration without requiring a code change.

No user-facing `claude-fruitcake-*` or `claude-macaroon-*` models are available yet; this is infrastructure preparation.

**Evidence**

New array `ZW_ = ["fruitcake", "macaroon", "mythos"]` (search for `"fruitcake"`).

### Advisor Model Matching Improved

A new helper function was added that finds which advisor model family a given model name belongs to by doing a case-insensitive substring search against the list of valid advisor model families (`["opus", "sonnet"]`). This replaces ad-hoc string comparisons and makes error messages for invalid advisor choices more consistent.

**Evidence**

New function `DxA` performs `_sH.find((q) => $.includes(q))` where `_sH = ["opus", "sonnet"]` (search for `"cannot be used as an advisor. Valid options"`).