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.

All of v2.1.227 Home All releases olderv2.1.226 v2.1.228newer
Claude Code v2.1.227

Model roster flag can redirect refusal fallback

Under the hood
Useful1 Signal3
Model Fallback

The server can list models that should be routed differently when a refusal fallback happens.

A server-supplied model roster feeding refusal fallback is empty by default, so nothing changes.

Feature flag
tengu_loggia_roster Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.227: not a boolean we can read

These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.

Read once, for one account on one subscription tier, against v2.1.227. It isn't a statement about your account. What a flag value here can and cannot tell you

What

A new server-controlled list of model ids now feeds the logic that picks a replacement model after a refusal. Models on the list skip an early exit and are pushed down the fallback path. The list is empty unless the server supplies one, so this has no effect in a default build.

Details
  • Read from the tengu_loggia_roster flag as a JSON array of model ids; anything else logs "is not a JSON array of model ids; treating it as empty" and falls back to an empty list.
Evidence

tengu_loggia_roster

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 v2.1.227 →