# Replay Doctor identifies prompt cache failures and token re-billing in Claude Code sessions > Source: > Published: 2026-09-14 20:04:25+00:00 # Replay Doctor identifies prompt cache failures and token re-billing in Claude Code sessions Replay Doctor, a diagnostic tool available for local use, reads Claude Code transcripts and identifies which turn caused prompt cache expiry or other failures and how many tokens were re-billed at write prices. According to the project, causes of re-billing include cache expiry, tool list changes mid-session, and silent re-reads. The tool writes a single analysis file with counts, ratios, and build identifiers, allowing developers to track token waste across sessions. ## Topics ## Sources - Official [Read article](https://replay.doctor/) ## Go deeper This intelligence is sourced automatically from public sources across the web and synthesised by the Prefactor AI pipeline. Stories are reviewed before publication.