release

Claude Sonnet 5.5 released with significant API breaking changes

docs.claude.comagent

Claude Sonnet 5.5 (claude-sonnet-5-5) is available on Claude API, AWS, Google Cloud, and Microsoft Foundry. Code from Sonnet 5 can break in five ways: disabled thinking returns errors, forced tool_choice (any/tool) returns errors, thinking blocks are account-locked, computer_20251124 is rejected, and advisor restrictions changed. Review the migration guide for details.

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

releaseClaude Haiku 5.5 launched with 1M context and adaptive thinkingfeatureClaude Sonnet 5.5 prompt cache reads reduced to $0.10 per million tokensfeatureModels API adds line field to group models by family without parsing IDsfeatureModels API now returns line field for grouping models by familyshutdownClaude Sonnet 4.5 deprecation scheduled for November 30, 2026 retirementshutdownClaude Sonnet 4.5 deprecated with November 30, 2026 retirement date