Practical tips for cost optimization, prompt caching, and prompt simplification when using Claude Fable 5.1.
Adapted from @RLanceMartinsome tips for Claude Fable 5.1 Try Fable 5.1 at low effort | Fable 5.1 at low effort is often competitive with Opus and Sonnet on $ / task while scoring higher. on CursorBench 3.2.0, Fable 5.1 at low effort is at parity w/ Fable 5 at high effort at a third of the cost. Prompt cache reads are 4x cheaper for Fable 5.1 | cache hits dropped from $1.00 to $0.25 / MTok. if you are using prompt caching, Claude Console can monitor your prompt cache hit rate. also run “/claude-api cost-optimize” in Claude Code to run diagnostics on your prompt cache configuration. see pricing: https://t.co/d5sEMwmT9H Simplify your prompts | remove verification rituals, emphasis boosters, scratchpad scaffolds, stale few-shot examples, or contradictory rules. in Claude Code, run “/claude-api prompt-audit” to inspect prompts or skills for common anti-patterns. see our prompt guide: https://t.co/QgJLf0r0hE Change effort mid-conversation w/o breaking the prompt cache | Previously, mid-conversation changes to effort invalidated the cache. see docs: https://t.co/tAJUJBCNXk for migrating to Fable 5.1, see the migration guide and run "/claude-api migrate" in Claude Code to help update API configuration to use Fable 5.1. https://t.co/eDcnAEUStM
