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Anthropic Release notes and new features

San Francisco, US · 106 releases · 36 this month

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Also onAcquisitions(2 acquisitions)·Paydays(Pay schedule)·TechConf(3 conferences)

Anthropic releases

September 2026 digest
DateRelease
Sep 23Claude Code 2.1.281unverified
Claude CodeUpdate
Sep 22Claude Opus 5.5 launched, first model in the Claude 5.5 family
Claude appsGA
Sep 22Claude API beta lets tools be defined inside mid-conversation system messages
Claude PlatformBeta
Sep 22Fast mode research preview available for Claude Opus 5.5 on the Claude API
Claude PlatformPreview
Sep 22Claude Code 2.1.280
Claude CodeUpdate
Sep 22Claude Opus 5.5 breaking changes: thinking can't be disabled, forced tool_choice removed
Claude PlatformUpdate
Sep 22Claude Opus 5.5 launches with a 1M token context window and 128k output
Claude PlatformGA
Sep 19Claude Code 2.1.278
Claude CodeUpdate
Sep 18Claude Code 2.1.276
Claude CodeUpdate
Sep 18Claude Code 2.1.277
Claude CodeUpdate
Sep 18Compliance API adds Claude in Chrome session transcripts in beta
Claude PlatformBeta
Sep 17Claude Code 2.1.274
Claude CodeUpdate
Sep 17Claude Code 2.1.275
Claude CodeUpdate
Sep 15Salesforce in Claude plugin (beta) with 37 pre-built sales skills
Claude appsBeta
Sep 15Claude Code 2.1.272
Claude CodeUpdate
Sep 15Claude Code 2.1.273
Claude CodeUpdate
Sep 14Claude Code 2.1.271
Claude CodeUpdate
Sep 14Claude API input_transformations adds thinking_mismatch_allowed entries in beta
Claude PlatformBeta
Sep 14Messages API adds on-demand conversation compaction in beta
Claude PlatformBeta
Sep 12Claude Code 2.1.270
Claude CodeUpdate
Sep 10Smart reports (beta) on Claude Enterprise analyze team usage and costs
Claude appsBeta
Sep 10Claude Managed Agents permission policies add an auto mode
Claude PlatformUpdate
Sep 10ant CLI 1.32.0 adds sessions connect for live Managed Agents sessions
Claude PlatformBeta
Sep 3Per-message effort changes beta expands to Claude on Google Cloud
Claude PlatformBeta
Sep 3ant CLI 1.30.0 adds ant apply to manage agents and resources as code
Claude PlatformUpdate
Sep 1Claude Fable 5.1 and Claude Mythos 5.1 launched
Claude appsGA
Sep 1Claude API adds turn-scoped system messages in beta
Claude PlatformBeta
Sep 1Claude API thinking.display adds an updates mode in beta
Claude PlatformBeta
Sep 1Claude Enterprise Admin, Analytics and Compliance API guides add anthropic-version
Claude PlatformUpdate
Sep 1Claude Fable 5.1 and Mythos 5.1 require 30-day data retention
Claude PlatformUpdate
Sep 1Claude Fable 5.1 output carries text watermarks and C2PA Content Credentials
Claude PlatformUpdate
Sep 1Per-message effort changes enter beta on the Claude API
Claude PlatformBeta
Sep 1Claude Fable 5.1 and Mythos 5.1 reject tool_choice any and tool
Claude PlatformUpdate
Sep 1Claude Fable 5.1 launches alongside Claude Mythos 5.1 with 1M token context
Claude PlatformGA
Sep 1Claude Fable 5.1 thinking blocks only replay to the same or newer models
Claude PlatformUpdate
Sep 1Prompt cache reads on Claude Fable 5.1 and Mythos 5.1 drop to $0.25 per MTok
Claude PlatformPricing
Aug 27Claude Console adds personal and service account API keys
Claude PlatformUpdate
Aug 27Claude SDKs stop sending beta headers for Files and Skills clients
Claude PlatformUpdate
Aug 26Admin API comes to the ant CLI and Claude SDKs under client.beta.organization
Claude PlatformBeta
Aug 26Compliance API adds Claude Science and Microsoft 365 session transcripts in beta
Claude PlatformBeta
Aug 26Compliance API session endpoints are out of beta for Cowork and Claude Code
Claude CodeGA
Aug 25Memory in Claude Cowork, editable memory topics, and sensitive topics setting
Claude appsUpdate
Aug 20Claude Python SDK v1.0 moves to httpx2 and requires Python 3.10
Claude PlatformUpdate
Aug 20Claude computer use and browser use toolsets arrive on Google Cloud
Claude PlatformUpdate
Aug 19Claude Console session viewer redesigned with timeline and Inspector panel
Claude PlatformUpdate
Aug 19Claude Managed Agents self-hosted sandboxes can attach memory stores
Claude PlatformUpdate
Aug 19Agent Skills and the Skills API are out of beta on the Claude API
Claude PlatformGA
Aug 19Claude API launches browser_toolset_20260801 browser use tool
Claude PlatformUpdate
Aug 19Claude Enterprise Admin API user-management endpoints are out of beta
Claude PlatformGA
Aug 19Claude Managed Agents can restrict domains for web_search and web_fetch
Claude PlatformUpdate
Aug 19Computer and browser use toolsets support Claude Fable 5, Opus 5 and Sonnet 5
Claude PlatformUpdate
Aug 19Files API is out of beta on the Claude API
Claude PlatformGA
Aug 19Claude computer use tool is out of beta as computer_toolset_20260801
Claude PlatformGA
Aug 18Claude Console Workbench is renamed playground
Claude PlatformUpdate
Aug 11Claude API adds the anthropic-workspace-id response header
Claude PlatformUpdate
Aug 11Compliance API returns local Cowork and Claude Code session transcripts in beta
Claude CodeBeta
Aug 10Claude Sonnet 5 introductory pricing of $2 / $10 per MTok becomes permanent
Claude PlatformPricing
Aug 7Claude Managed Agents adds inference_geo to control where inference runs
Claude PlatformUpdate
Aug 7Claude Managed Agents sessions can consult an advisor model
Claude PlatformUpdate
Aug 7Claude Managed Agents sessions load skills from GitHub repositories
Claude PlatformUpdate

Summaries of vendors' own notes. Product names and logos belong to their owners; logos via logo.dev.

About and activity

Anthropic, PBC is an American artificial intelligence (AI) public benefit corporation headquartered in San Francisco, California. Its flagship product is Claude, a series of proprietary large language models (LLMs).

Company profile
Releases per month
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Official release-notes pages 10
Claude apps release notes
support.claude.com
Claude Code changelog
github.com
Claude Code changelog (docs)
code.claude.com
Claude Code releases
github.com
RSS
Claude Platform release notes
platform.claude.com
Claude Agent SDK (Python) releases
github.com
RSS
Claude Agent SDK (TS) releases
github.com
RSS
Python SDK releases
github.com
RSS
System prompts release notes
platform.claude.com
TypeScript SDK releases
github.com
RSS

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