Cloud sessions sample how much processor time each part of Claude Code uses

In some cloud sessions, Claude Code now measures how much processor time each of its threads (parallel strands of work inside the program) uses, such as the main thread, memory clean-up, code compilation, network requests and worker pools. It also measures time spent waiting to run and time taken by the host machine. A spare process started ahead of time is measured separately.

The results are added to the timing data Claude Code reports for each turn, both during a turn and between turns. Sampling happens only when all of these hold:

• CLAUDE_CODE_REMOTE is true
• no CLAUDE_CODE_ENVIRONMENT_KIND is set
• the environment is not self-hosted
• the session is picked at random, one in a number of sessions set by CLAUDE_CODE_THREAD_CPU_ONE_IN or by a built-in default