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.

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Claude Code v2.0.63

Increased Startup Performance Telemetry Sampling

What: Startup performance telemetry sampling rate increased from 0.1% to 0.5% of CLI invocations.

Details:

  • Constant changed from OP9 = 0.001 to Xa2 = 0.005
  • Provides 5x more data points for analyzing real-world startup performance
  • Can still be forced on with CLAUDE_CODE_PROFILE_STARTUP=1 environment variable
  • Evidence: Xa2 = 0.005 at line 2661, sampling logic at line 2674

See this entry in the whole of v2.0.63 →