{"version":"2.1.281","anchor":"attachment-download-telemetry-expanded","canonical_anchor":"attachment-download-telemetry-expanded","heading":"Attachment download telemetry expanded","tier":"internal","area":"Telemetry","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.281\/e\/attachment-download-telemetry-expanded","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.281","markdown":"### Attachment download telemetry expanded\n\nAttachment download telemetry now records slowest wait times plus counts of reused, prefetched and shared downloads\n\n**Unclear.** The finding does not settle whether attachments are actually reused, prefetched or shared in this release, or only counted.\n\n**What**\n\nWhen Claude Code fetches attachments, it now records more telemetry, which is usage data sent back about how things performed:\n\n- `slowestTimeToHeadersMs`\n\n- `slowestJoinWaitMs`\n\n- `reusedFileCount`\n\n- `prefetchedFileCount`\n\n- `joinedInFlightCount`\n\n**Why**\n\nThese measure how long the slowest attachment took, and how many files were reused, fetched ahead of time, or shared between requests waiting for the same download.\n\n- Area: Telemetry\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 1\/5"}