# Anthropic cuts cache-reading fees by 75% in Claude Fable 5.1

Digest AI · Generative AI & Models · published 2026-10-05T20:02:00Z

Canonical: https://digestai.news/story/anthropic-cuts-cache-reading-fees-by-75-in-claude-fable-5-1

## Summary

Anthropic announced on September 1, 2026, that its top-tier model, **Claude Fable 5.1**, will be up to 45% cheaper for certain use cases, though the base price remains unchanged. The cost reduction stems from a 75% drop in the **cache-reading fee**, which applies when the model re-reads previously processed input—such as rereading a PDF or intermediate steps in an agent task. Anthropic compared this to bookmarking a page in a long document, reducing redundant processing costs.

The savings vary by usage: general tasks see about a **25% discount**, while delegated tasks (e.g., AI agents handling long workflows) can save up to **45%**, based on August 2026 data. Additionally, the model’s safety filters now block **basic biology and medical questions 85% less frequently** than in Fable 5, though complex or sensitive queries may still trigger Claude Opus 5 for handling. Anthropic’s CTO, Ogiso, emphasized that **Claude Opus 5.5**—released September 22—offers comparable capabilities at under half the price of Fable 5.1, suggesting users weigh cost against performance for their needs.

## Key points

- Cache-reading fees dropped 75%, cutting costs for repeated input processing in Claude Fable 5.1
- General use sees ~25% savings; delegated tasks (agents) save up to 45% based on August 2026 data
- Safety filters now block biology/medical queries 85% less often than in Fable 5

## Why it matters

The fee cut targets high-cost AI workflows like agents, making long-term automation more affordable for businesses. The relaxed safety filters could expand use cases but may introduce risks for sensitive queries.

## Sources

1. [What is the cost of Claude Fable 5.1? Up to 45% cheaper with no price cuts EeeeAI](https://note.com/eeeemo_japan/n/n5739ceff9f9b?hl=en) (note.com, 2026-10-05)

Part of the developing story: [Claude Outage and Reset Token Saga](https://digestai.news/thread/anthropic-s-claude-reportedly-down-for-thousands-of-users-on-september-21) (3 stories)

## Cite

Digest AI, "Anthropic cuts cache-reading fees by 75% in Claude Fable 5.1", 5 October 2026, https://digestai.news/story/anthropic-cuts-cache-reading-fees-by-75-in-claude-fable-5-1

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