Claude Fable 5:
Every Way to Use It in the Claude Ecosystem
Fable 5 is live in claude.ai and Claude Code — but it's only included in Pro/Max plans through June 22. Here's how to enable it, how usage is counted, and how to keep it after the window closes.
⏰ The timeline
June 9–22: included on Pro / Max / Team / seat-based Enterprise at no extra cost, counting as 2× usage.
June 23: removed from those plans; continued use requires usage credits (Anthropic may extend "if capacity allows" — don't bet your workflow on it).
👉 Set up your fallback now
What is Fable Claude?
"Fable Claude," "Claude Fable," and "Fable 5" all refer to the same thing: Claude Fable 5, the new Claude model Anthropic released on June 9, 2026 (API model ID claude-fable-5) — the most capable Claude available to the public, and no relation to the Fable video game. For benchmarks, pricing, and the Mythos 5 backstory, see our sister site fable5ai.net; this site covers one thing: actually using it in the Claude ecosystem (claude.ai / Claude Code).
Option 1: claude.ai web / apps
- You need Pro / Max / Team / seat-based Enterprise (not the free tier).
- Pick Fable 5 in the model selector.
- Chat normally — but remember every Fable 5 message burns 2× usage. Save it for hard problems; use Opus 4.8 for everything else.
Worth switching for: long-document analysis (1M context), complex multi-step reasoning, and reading data off charts and figures (it's the vision SOTA).
Option 2: Claude Code (where it shines brightest)
Fable 5's headline strength is long-horizon autonomous work — planning across stages, delegating to sub-agents, checking its own output for days at a time. That's exactly Claude Code's shape. To switch:
# In-session (recommended; saved as your default)
/model
# then pick Fable 5
# Or at launch
claude --model claude-fable-5- Still 2× usage on subscriptions: use Fable 5 for big refactors, migrations, and hard bugs; flip back to Opus/Sonnet for small edits.
- Give it bigger chunks of work. Its edge over other models grows with task length (reference point: a 50M-line codebase migration done in a day).
How to keep using Fable 5 after June 23
① Buy official usage credits
Stay in the official apps; credits track API pricing ($10/$50), so heavy use adds up fast.
② Go direct to the API
Get a key and use it in Claude Code or your own apps — quickstart at fableapi.app.
③ Use a compatible API endpoint ⭐
Claude Code officially supports custom endpoints. Configure once and everything keeps working:
export ANTHROPIC_BASE_URL="https://api.omniakey.com"
export ANTHROPIC_API_KEY="YOUR_API_KEY"
claude --model claude-fable-5Set up your fallback before the deadline
OmniaKey: Fable 5 at $3/$15 (limited-time, ~70% off) · pay as you go · no card required
FAQ
What does "2× usage" mean?
Subscription quota is a consumption pool; a Fable 5 message draws twice the quota of the equivalent Opus 4.8 message. Route hard tasks to Fable 5 and routine ones to Opus to stretch your plan.
Why does Fable 5 sometimes feel "dumber"?
Queries touching cybersecurity, biology, or chemistry get answered by Opus 4.8 via the safety-classifier fallback (you're notified). It's official behavior — details at fable5ai.net, and see the Mythos 5 deep dive for where the unguarded version lives.
Is pointing Claude Code at a third-party endpoint safe?
ANTHROPIC_BASE_URL is an officially supported setting, but your code and conversations transit that endpoint — vet the provider and think twice for sensitive repos.
Will the free window be extended?
Anthropic's wording is "may extend if capacity allows." Plan around the June 22 cutoff and treat any extension as a bonus.