What
Telemetry is the usage and performance data Claude Code sends back to Anthropic. Its timing data for a turn (one request and reply) now includes more detail.
- Attachment preparation (the extra context added to your message): time spent on setup, on each source of context, on starting and waiting for background context, on rendering, on token counts and on reading changed files, plus size bands for changed files.
- Remote text uploads: how many text posts were sent, how many came more than half a second apart, and how late the flush timer ran at worst.
The slowest-step measurement now counts from when its group last started.
Why
These numbers measure how long turns take and how smoothly text streams in. Nothing changes in how Claude Code behaves for you.