AI news from Anthropic: 27 updates. Every card links to the maker's own page.
Fast mode is out of research preview for Claude Opus 5.5 and no longer requires an access request or beta header.
Why it matters
Developers in the Start, Build and Scale usage tiers now receive a default fast mode rate limit for Claude Opus 5.5.
OpenTelemetry export is in beta for tracing Messages API requests and Claude Managed Agents sessions in an observability backend.
Why it matters
Claude API users can add an OpenTelemetry destination in the Claude Console to receive spans.
Scheduled deployments for Claude Managed Agents are now available on Claude Platform on AWS.
Why it matters
Claude Platform on AWS users can now schedule deployments for managed agents.
Claude Haiku 5.5 is designed for high-volume, cost-sensitive tasks.
Why it matters
Teams can use it for quick and repetitive work such as summaries, database queries, and classification requests.
Claude Haiku 5.5 is available through the Claude API and other listed platforms.
Why it matters
Code written for Haiku 4.5 can break, so founders using it should review the migration guide and test their integrations.
Claude Code now includes Claude Haiku 5.5 as the default Haiku model on the Anthropic API.
Why it matters
Teams that rely on Claude Code's default Haiku model on the Anthropic API now get Haiku 5.5, and status-line scripts can read the subagent type.
Claude's Models API now reports whether each model accepts web search and code execution tools.
Why it matters
Products can check these capabilities before choosing a model or enabling a tool workflow.
Anthropic combined its cyber access programs into a three-tier verification program for qualifying security professionals.
Why it matters
Eligible security teams can apply for access matched to their defensive or authorized testing work.
Claude Code added /claude-api managed-agents-onboard, which sets up the Managed Agents pattern a page describes as ant apply files.
Why it matters
Founders can go from reading an agent recipe to running it in fewer steps.
The Models API now returns the model line each model belongs to, such as opus. Apps can group models without parsing their IDs.
Why it matters
Apps that pick Claude models automatically can choose by line instead of matching model names.
Claude Code added Claude Mods: plugins may now modify deeper behavior.
Why it matters
Plugin makers get a deeper extension point to build on.
Anthropic announced the deprecation of Claude Sonnet 4.5, with retirement on the Claude API scheduled for . It recommends migrating to Claude Sonnet 5.5.
Why it matters
Products that pin Claude Sonnet 4.5 on the Claude API have a fixed date to migrate.
Claude Sonnet 5.5 is available on the Claude API, Amazon Bedrock and Google Cloud. Anthropic says code written for Claude Sonnet 5 can break on Claude Sonnet 5.5 in five ways.
Why it matters
Apps on the Claude API that move from Sonnet 5 should test against the migration changes before switching.
Cache diagnostics is out of beta on the Claude API and no longer needs a beta header. Requests opt in by including the diagnostics object.
Why it matters
Teams on the Claude API can see why a prompt missed the cache without depending on a beta feature.
On Claude Opus 5.5, requests that set thinking to disabled or enabled return a 400 error. Thinking depth is set with the effort parameter instead.
Why it matters
Integrations moving to Claude Opus 5.5 need to drop the thinking field before they switch.
Tools can now be defined inside a mid-conversation system message, in beta on the Claude API. A tool can be added or changed partway through a conversation.
Why it matters
Agents on the Claude API whose tools change as a task moves along can update them without starting over.
Claude Opus 5.5 is the first model in Anthropic's new Claude 5.5 family.
Why it matters
Vetted organizations can apply to use Opus 5.5 for biology research.
Claude Code now syncs the skills and plugins enabled on a claude.ai account to terminal sessions signed in with it. Users can opt out with a setting.
Why it matters
A skill or plugin enabled once on claude.ai now also reaches the same user in the terminal.
Claude Code can now fork a session started with Remote Control from the Claude app. The fork runs as a background session on the user's computer.
Why it matters
Work started from a phone can now split into parallel tasks on the desktop.
The Messages API can now compact a conversation on demand on the Claude API, in beta. The API returns a signed compaction block that summarizes earlier messages, and later requests send it in their place.
Why it matters
Long-running agents on the Claude API can keep sessions going without writing their own context trimming.
Claude Code added claude plugin eval, which runs a plugin's eval suite against Claude Code. It returns scored, reproducible results as a JSON and HTML report.
Why it matters
Plugin makers can test each release the same way and share the results.
Claude Managed Agents permission policies now include auto. The server evaluates each agent or MCP tool call and runs it, denies it, or pauses for approval.
Why it matters
Teams running hosted agents with MCP tools get a middle ground between approving every call and approving none.
Version 1.32.0 of the ant CLI adds ant beta:sessions connect. It lets you follow a Claude Managed Agents session live, send messages, and allow or deny tool calls waiting for approval.
Why it matters
Builders can supervise a hosted agent from the terminal without opening the Claude Console.
Claude Code added /skill-doctor, which shows which loaded skills go unused and what they cost in context. Users can then prune them.
Why it matters
Skill makers should keep skills small and clearly useful, since unused ones now show up as a cost.
Version 1.30.0 of the ant CLI adds ant apply, which creates and updates agents, environments, skills, memory stores and deployments from files in a repository. A lockfile it writes lets later runs in CI update the same resources.
Why it matters
Teams can review and version their Claude agent setups like code instead of editing them by hand in a console.
Claude Fable 5.1 is the successor to Claude Fable 5 for long-running agentic coding, knowledge work and research. Claude Mythos 5.1 launched alongside it for Project Glasswing participants.
Why it matters
Code that forces tool use breaks on Claude Fable 5.1, because the tool_choice types any and tool return an error.
Find dated assistant changes, one table per assistant, in the tracker.