Claude Fable 5
A new tier above Opus — Anthropic's most capable model yet
Anthropic's most capable tier above Opus — native 1M context, 128K max output, $10/$50 per MTok. After a month-long regulatory suspension, Fable 5 was restored on July 15, 2026 and is live on QCode for all plans.
On June 12, 2026, Fable 5 (and Mythos 5) were suspended worldwide under a US export-control directive. Access was restored in mid-July and QCode re-enabled Fable 5 for all plans on July 15, 2026 — selecting claude-fable-5 works again, no action needed. See the availability tracker for the full dated history.
Key Highlights
Fable 5 is Anthropic's most powerful, most intelligent model to date — a brand-new flagship tier above the Opus line
Same-class 1M context window as Opus 4.8 — whole-repo analysis and long documents in one shot
Up to 128K output tokens per response (streaming required for large outputs) — big refactors and long reports in one pass
$10 input / $50 output per MTok — 2× Opus 4.8, matching the stronger capability tier
Positioning: Built for the Hardest Tasks
Anthropic positions Fable 5 as the flagship for the most demanding work — long-horizon agentic execution, deep reasoning and knowledge work beyond the Opus line
Stronger long-horizon agentic execution
More reliable than Opus 4.8 on long autonomous runs — hand it complex multi-step engineering tasks end to end
Deeper reasoning
A new ceiling for reasoning depth, tunable via effort levels (high / xhigh / max) to balance depth and cost
Code generation & refactoring
Carries forward Opus 4.8's high-reliability codegen, with stronger results on hard cross-file refactors and architecture-level tasks
Knowledge work & long documents
The flagship pick for research, analysis and writing — stays coherent across long chains within the 1M context
Multimodal understanding
Image input supported — screenshots, charts and document parsing on par with the Opus line
⭐ Benchmarks: official numbers only
Anthropic positions Fable 5 as its 'most powerful, most intelligent model'; per-benchmark scores will follow official publication — this page does not invent numbers
Specs & API Surface
Fable 5 shares the same API surface as Opus 4.7/4.8 — existing code migrates at near-zero cost
1M context / 128K output
Native 1M context plus 128K max output (streaming required for large outputs) — specs aligned with Opus 4.8
Adaptive thinking
Adaptive thinking only: thinking={type:"adaptive"}; note an explicit disabled returns 400 — simply omit the param when thinking isn't needed
Full effort range
All effort levels supported — low / medium / high / xhigh / max; high / xhigh recommended for coding and agentic work
Caching & tooling unchanged
Prompt caching, structured outputs and tool use behave as on Opus 4.8 — no changes to your cache or tool chain
Ecosystem & Tooling
xhigh effort level
Full support for the xhigh level between high and max — the recommended setting for coding and agentic tasks
/ultrareview deep code review
Claude Code ecosystem commands carry over — an independent review session with a stronger model pushes production risk even lower
Task Budgets
task_budget (beta) supports Fable 5 — long agentic loops see their token budget and self-moderate
Available in Claude Code
Select claude-fable-5 directly in Claude Code and other tools — seamless with existing workflows
Migration Guide (⭐ key section)
When access is restored, Opus 4.8 → Fable 5 is just a model-ID swap — same API surface, with two things to watch (the thinking param and budget).
1. One-line upgrade
Change the model ID to claude-fable-5 — same API surface as Opus 4.7/4.8, a drop-in replacement
2. Re-budget at 2×
$10 input / $50 output per MTok is 2× Opus 4.8 — run high-value tasks on Fable 5 and keep routine work on Opus 4.8
3. No explicit thinking-disabled
thinking={type:"disabled"} returns 400 on Fable 5 (still accepted on Opus 4.8); omit the thinking param instead, or just use adaptive
4. Sampling params removed
As on Opus 4.7/4.8: temperature / top_p / top_k are removed and return 400 — steer with prompting and effort
client.messages.create(
model="claude-fable-5",
thinking={"type": "disabled"} # 400 on Fable 5
)
client.messages.create(
model="claude-fable-5",
thinking={"type": "adaptive"},
effort="xhigh" # low / medium / high / xhigh / max
)
Fable 5 vs Opus 4.8 vs Sonnet 4.6
Three Claude tiers side by side: when to reach for Fable 5, and when Opus 4.8 / Sonnet 4.6 is the better deal
| Metric | Fable 5 | Opus 4.8 | Sonnet 4.6 |
|---|---|---|---|
| Positioning | Top flagship (above Opus) | Opus flagship, value workhorse | Speed-intelligence balance |
| Input $ / MTok | $10 | $5 | $3 |
| Output $ / MTok | $50 | $25 | $15 |
| Context window | Native 1M | Native 1M | 1M |
| Max output | 128K | 128K | 64K |
How QCode will get you on Fable 5 when it returns
Fable 5 is live again. Register today and run it alongside Opus 4.8 and Sonnet 5 — one balance, one API, no migration needed.
Billed at official-price ratio
Charged proportionally to Anthropic's official $10/$50 pricing — same rate system as every other Claude model on the platform
effort / thinking passthrough
Full passthrough of xhigh / max effort, adaptive thinking and other Fable 5 parameters
Opus 4.8 today, Fable 5 on return
When Fable 5 returns, selecting claude-fable-5 is all it takes — until then, Opus 4.8 is the drop-in flagship you can use right now.
Direct China access, low latency
Multi-node smart routing with circuit-breaker fallback — avoids the instability of reaching the official API from China
Use Opus 4.8 now — get Fable 5 the day it returns
Register at QCode for a stable Claude developer platform: Opus 4.8 today, Fable 5 re-enabled the moment access is restored.
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