Anthropic · Frontier
Claude Fable 5
Anthropic's most capable widely released model, aimed at the most demanding reasoning and long-horizon agentic work. Thinking is always on and cannot be disabled, and the raw chain of thought is never returned. You get a summary or nothing.
Model ID: claude-fable-5
What that means
A worked example
Per-token pricing is hard to feel. Take a moderately chatty production workload: 100 calls a day, roughly 10,000 tokens in and 2,000 out each time. On Claude Fable 5 that comes to about:
$600 / month
Before caching, batching or volume discounts, all of which move this number a long way. Illustrative only.
Strong at
- -Long-horizon agentic work
- -Hard reasoning
- -Autonomous coding runs
Typical use
- -Multi-hour agent runs
- -Complex research synthesis
- -Large refactors
Watch out for
- -Requires 30-day data retention, not available under zero data retention
- -No assistant prefill; sampling parameters removed
Same tier
What else to look at
| Model | Developer | Context | In / 1M | Out / 1M |
|---|---|---|---|---|
| Claude Opus 5 | Anthropic | 1M | $5 | $25 |
| Claude Opus 4.8 | Anthropic | 1M | $5 | $25 |
| GPT-5.6 Sol | OpenAI | 1M | $5 | $30 |
| GPT-5.5 | OpenAI | 1M | $5 | $30 |
| Gemini 3.1 Pro | 2M | $2 | $12 |
Verified 2026-08-07.