Follow Discord
Sweep 25 Sep 2026 · 19:33Z Build v2.1.283 504 read Stable v2.1.274 Latest v2.1.283 Next v2.1.283 Feeds RSS JSON llms.txt llms-full.txt Unofficial
HomeReleasesv2.1.280entry #327

Claude Code v2.1.280 ·

New Opus 5.5 prompt bundle and capability gate

Opus 5.5 gets its own tailored system prompt bundle, gated by a new opus_5_5_prompt_bundle capability check

Group of 2 Under the hood No documentation found Internal Changes
JSON All of v2.1.280
Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
ModelsArea: what it touches
Internal ChangesKind: in v2.1.280,
Internal ChangesSection of the release

What

  • A new named prompt bundle, opus_5_5_prompt_bundle, was added alongside the existing opus_5_prompt_bundle and fable_5_1_prompt_bundle entries, giving Opus 5.5 its own tailored system prompt bundle.
  • A capability-check set (including silent_turn_reminder and quizzical_shore) now also returns true when the opus_5_5_prompt_bundle remote-config flag is enabled (and a separate condition is false), so this capability turns on when the new bundle is active.

Why

This lets Claude Code apply Opus-5.5-specific prompt behavior in a controlled way, tied to a remote-config flag rather than being always on.

Read from
Names in the bundleopus_5_5_prompt_bundle
Feature flag
tengu_tool_pear Off in both readings

The flag server returned off for the account this site reads and for the anonymous baseline. A reading of off cannot rule out a rollout these two readings sit outside of.

This account: off · anonymous baseline: off · compiled default in v2.1.280: off

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 v2.1.280. It isn't a statement about your account. What a flag value here can and cannot tell you

See this entry in the whole of v2.1.280 →

Feedback