Skills
Claude API Prompt Caching Workspace Isolation: 90% Input Cost Reduction Now Scoped Per-Workspace (February 2026)
Anthropic updated prompt caching on February 5, 2026 to enforce workspace-level cache isolation, replacing the prior organization-level sharing — meaning caches are now properly siloed between workspaces within the same org, enabling safer multi-tenant agent deployments. Cache read tokens cost 10% of base input price (90% reduction), while 1-hour cache writes cost 2x base — breaking even after two reads, making it net-positive for any agent that touches the same system prompt or file more than twice. The 1-hour cache duration is sufficient to cover the full lifespan of most coding agent sessions.
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