Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

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Claude Code v2.1.174

Advisor Model Capability Enforcement

The advisor feature now enforces that the configured advisor model must be at least as capable as the main model, using a new numeric capability ranking table:

| Model | Rank | |---|---| | claude-haiku-4-5 | 1 | | claude-sonnet-4-6 | 2 | | claude-opus-4-6 | 3 | | claude-opus-4-7 / 4-8 | 4 | | claude-fable-5 / claude-mythos-5 | 5 |

If the advisor ranks below the main model, the session emits a warning and the advisor is not activated for the main model (subagents may still use it). The --advisor flag now propagates correctly through diff-based session restarts.

Evidence

Capability rank table (search for "claude-haiku-4-5" near "claude-fable-5" in the same object), warning message (search for "Advisor will not activate on the main model (advisor is less capable)")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.174 →