release

Claude Fable 5.1 and Claude Mythos 5.1 launched for agentic coding with improved reasoning

docs.claude.comagent

Claude Fable 5.1 succeeds Claude Fable 5 with a 1M token context window, 128k max output tokens, always-on adaptive thinking, and significantly reduced cache read costs ($0.25 per million tokens, down from 0.1x). Both models are available on Claude API, Amazon Bedrock, Google Cloud, and Microsoft Foundry at $10/$50 per million tokens.

Stacks this affects

Claude ships in 34 tested stacks here.

Full-stack with Lovable
Code · Builder
$70/mo
Cloud IDE with Replit
Code · Builder
$40/mo
UI-first with v0
Code · Builder
$60/mo
AI newsletter
Writing · Newsletter
$80/mo
AI newsletter (Substack)
Writing · Newsletter
$53/mo
AI thumbnails + ad creative
Marketing · Visual
$50/mo
Android app with AI
Code · Mobile
$42/mo
Autonomous research agent
Research · Intelligence
$59/mo
Cheap bulk LLM automation
Code · Backend
$140/mo
Cold outbound
Sales · Outbound
$342/mo
Cold outbound (solo)
Sales · Outbound
$75/mo
iOS + Android with Expo
Code · Mobile
$67/mo
Faceless YouTube
Video · Creator
$92/mo
Faceless YouTube (budget)
Video · Creator
$6/mo
Inbox triage
Productivity · Inbox
$51/mo
Inbox triage (free)
Productivity · Inbox
$26/mo
Indie SaaS
Code · Builder
$75/mo
Indie SaaS (Gemini long-context)
Code · Builder
$75/mo
iOS app with AI
Code · Mobile
$48/mo
LinkedIn ghostwriting
Writing · Agency
$129/mo
LinkedIn (for yourself)
Writing · Personal
$33/mo
Live trend research
Research · Intelligence
$70/mo
Multilingual content factory
Writing · Content
$60/mo
Open-weight LLM stack
Code · Backend
$170/mo
SEO content engine
Writing · SEO
$118/mo
Antigravity (Google)
Code · Workflow
$40/mo
Codex (CLI + cloud)
Code · Workflow
$40/mo
Ship code with AI
Code · Workflow
$50/mo
Cross-platform short-form
Marketing · Distribution
$49/mo
Self-hosted scheduler
Marketing · Distribution
$25/mo
TikTok character
Video · Creator
$92/mo
TikTok character (audio + text)
Video · Creator
$42/mo
UGC ad creative
Marketing · Ads
$67/mo
UGC ads (CapCut-only)
Marketing · Ads
$24/mo
All Claude changes and pricing

More Claude

featureCache diagnostics graduated from beta on Claude APIfeatureCache diagnostics exits beta on the Claude APIfeatureCache diagnostics exits beta on Claude APIreleaseClaude Opus 5.5 launched with 1M context and always-on adaptive thinkingreleaseClaude Opus 5.5 released for long-running agentic workfeatureTools can be added or modified mid-conversation without cache invalidation