Under the hoodTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Headless ModeArea: what it touches
Internal ChangesKind: in v2.1.246,
Internal ChangesSection of the release
What
On starting a print/headless run, Claude Code now writes a debug line naming which of its two turn loops is active, which makes headless behaviour easier to triage.
Details
Selected by the environment variable CLAUDE_CODE_PRINT_ENGINE_LOOP; the accessor returns its value when set and false otherwise, so the legacy per-turn path is the default.
Evidence
[print] turns run on the engine session (createHeadlessSession)
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
