Anthropic reduced Claude Code’s prompt cache TTL from one hour to five minutes, causing higher token write costs and faster quota depletion for long coding sessions. Developers report frequent cache misses—especially with large context windows—hitting usage limits and degrading performance. Anthropic says it will tweak default context windows but won’t offer a global TTL setting.

• Anthropic quietly cut Claude Code's cache TTL from one hour to five minutes in early March, causing far more expensive cache misses on long sessions.
• Cache writes cost 25% more per token than hits, so Pro users ($20/mo) report exhausting quotas after just two prompts in five hours.
• Anthropic says TTL is auto-selected client-side with no global override, but is testing a smaller 400K default context window (up to 1M optional) to curb costs.
• Beyond cost, users report degraded model behavior—looping, repetition, and "overthinking"—since a late-March update, separate from the caching issue.