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

Debug logging rebuilt around a single logger instance

Under the hood
Useful3 Signal2
Debug Logging not in their notes

Debug logging now runs through one logger that keeps queued lines when it restarts.

CLAUDE_CODE_DEBUG_LOG_LEVEL--debug-to-stderr--debug-fileCLAUDE_CODE_DEBUG_LOGS_DIR
What

Debug log settings that were separate cached lookups (CLAUDE_CODE_DEBUG_LOG_LEVEL, --debug=, --debug-to-stderr, --debug-file, CLAUDE_CODE_DEBUG_LOGS_DIR) now live on one object. Lines are tagged with their session and grouped before flushing, and can be written through the storage layer when one is installed, falling back to plain rotated log files otherwise. A newly started logger takes over the previous one's queued lines instead of losing them.

Evidence

CLAUDE_CODE_DEBUG_LOGS_DIR

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

See this entry in the whole of v2.1.227 →