I’m not trying to hate on Anthropic. I’m raising this because Claude Code is positioned as a professional development tool, Max 20x is expensive, and prompt caching directly affects usage, latency and cost. I previously posted that I suspected Claude Code was not yet properly optimized for orchestrator-style workflows with many subagents, tools, hooks and long-running context, because the usage consumption was extreme. Since the Fable 5.1 rollout, we started looking much more closely at the cache behavior. And the official Claude Code changelog now confirms multiple serious prompt-cache bugs. Confirmed fixes include:
- v2.1.260: Fable 5.1 context added after tool results was not covered by prompt caching and was re-sent as uncached input on EVERY tool-call turn.
- v2.1.260: changing Fable 5.1 effort mid-session invalidated the prompt cache.
- v2.1.261: agent-team teammates re-sent tool/skill announcements on the second turn, changing the request prefix and causing cache misses.
- v2.1.265: resuming a subagent changed its tool list and system-prompt prefix, breaking prompt-cache reuse.
- v2.1.265: teammates and resumed subagents moved SubagentStart hook context and preloaded skills out of the cached prefix on later turns, again breaking cache reuse. There are also detailed open reports in Anthropic’s own GitHub tracker describing full cache rewrites involving hundreds of thousands of tokens, including #91514, #91706 and #92090. One report documents 2.9 million tokens being re-cached by eight parallel Fable 5.1 subagents in about 40 minutes. Some of these are Fable-specific; others are general Claude Code orchestration/cache bugs. But the common result is the same: context that should have been reused can instead be processed again as uncached input. This matters especially for orchestrator-heavy setups like ours with many subagents, hooks, skills, tools and large contexts. We cannot prove exactly how much of our Claude Max usage was consumed because of these bugs because Anthropic does not expose the subscription accounting at that level. But we did observe extremely high usage, and several confirmed fixes directly address mechanisms capable of causing unnecessary token processing. We haven’t yet tested the newest 2.1.265/2.1.266 versions thoroughly in our orchestrator setup. Usage has gradually improved, and I’m genuinely interested to see whether these fixes finally make a significant difference. My concern is broader: How did this many cache-related regressions reach production in a product where prompt caching is fundamental to the economics? And more importantly: what happens to the usage already consumed because of confirmed Anthropic bugs? If a Max subscriber loses a meaningful part of their allowance because Claude Code repeatedly sends context uncached due to a software defect, should Anthropic restore that usage or provide credits? I think Anthropic should address this transparently. Not because Claude or Fable are bad models — quite the opposite. But if you market one of the strongest coding systems in the world at premium subscription prices, the surrounding software and usage accounting need to meet the same professional standard. Official references:
- Claude Code changelog: v2.1.260, v2.1.261, v2.1.265
- Anthropic GitHub issues: #91514, #91706, #92090 I’m interested in experiences from other heavy Claude Code / Max users: did your usage noticeably improve after these cache fixes? submitted by /u/AironParsMan
Originally posted by u/AironParsMan on r/ClaudeCode
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