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AI release notes

Anthropic's official release notes. Claude apps: the website, desktop and phone apps. Claude Code: Claude's coding assistant. Claude API: what developers use to build Claude into their own products.

Compiled by the Toolstash team · Updated

  1. Claude Code

    Claude Code 2.1.312

    4 new22 fixes13 other

    Added oidc.user_id_claim to the Claude apps gateway, to identify people by an id_token claim other than sub, such as Microsoft Entra ID's oid. Added click to send: in fullscreen, clicking the "to send now" hint under a queued message sends it right away, as its key does.

  2. Claude Code

    Claude Code 2.1.311

    5 new55 fixes32 other

    Added --hold-idle-file and --max-hold-min to self-hosted-runner, to keep an idle session while your host reports processes it left running. Added a tip for the Explanatory output style, shown when you ask Claude for explanations.

  3. Claude Code

    Claude Code 2.1.310

    3 new14 fixes9 other

    Added the Monitor tool and plugin monitors on Bedrock, Vertex, and Foundry, and when telemetry or nonessential traffic is disabled; long foreground sleeps are now blocked there too. [Cloud sessions] Added Claude Code cloud sessions and Remote Control permissions to Enterprise custom roles, so Owners can control access to each by role.

  4. Claude API

    The Claude Tag API is available in beta for Claude Enterprise organizations with the…

    Its /v1/organizations/claude_tag/ endpoints read and change Claude Tag settings on Slack channels and Slack workspaces, show which settings apply in a channel and where each comes from, and attach Access bundles. Call it with an Admin API key that your primary owner creates in claude.ai with the read:claude_tag or write:claude_tag scope. It is not available to Claude Platform (Claude Console) organizations.

  5. Claude Code

    Claude Code 2.1.309

    1 new61 fixes17 other

    [VSCode] Added a log warning that says what to do when dictation or the extension's own requests fail certificate verification, such as behind a TLS-inspecting proxy.

  6. Claude Code

    Claude Code 2.1.308

    1 other

    Bug fixes and reliability improvements.

  7. Claude API

    We’ve launched Claude Models on Google Cloud, the Claude API operated by Anthropic and reached through your…

    Google Cloud IAM controls access. Google Cloud Marketplace handles billing. Fast mode is available for Claude Opus 5.5 on Claude Models on Google Cloud (Anthropic managed).

  8. Claude Code

    Claude Code 2.1.307

    4 new24 fixes15 other

    Added /claude-api api-version to move Claude API code to API version 2026-10-21. Added the claude_code.safety_event OpenTelemetry event for each tool call a permission rule, auto mode, a safety check, a hook or the sandbox stopped, prompted or sent back.

  9. Claude Code

    Claude Code 2.1.306

    2 fixes

    Fixed claude -p inside cloud sessions reporting "Not logged in" when started without the session's environment variables. Fixed an API error being replaced by "prompt is too long", and an unneeded compaction, in sessions with many MCP tools.

  10. Claude API

    We’ve released API version 2026-10-21

    Migrating to API version 2026-10-21 shows how to upgrade. We’ve released new versions of the client SDKs and the ant CLI that send API version 2026-10-21 by default: Python SDK 2.0.0, TypeScript SDK 1.0.0, C# SDK 13.0.0, Go SDK 2.0.0, Java SDK 3.0.0, PHP SDK 1.0.0, Ruby SDK 2.0.0, and ant CLI 2.0.0. The new SDK and CLI versions also have breaking changes that don’t depend on the API version, and they are licensed under Apache 2.0 instead of the MIT License. We’ve added the enforcement_status and enforcement_actions fields to user profiles, so you can see whether Anthropic has restricted or banned one of your end customers.

  11. Claude appsAnnouncement

    Claude Duet research preview for Pro and Max plans

    We just opened a research preview for users on Pro and Max plans: Claude Duet, a new app where Claude works as a proactive agent.

  12. Claude Code

    Claude Code 2.1.305

    4 new19 fixes15 other

    Added sandbox.allowNestedUserNamespaces so sandboxed commands on Linux can create user namespaces (Chromium, rootless podman); this lets them get around the sandbox's file protections. Added CLAUDE_CODE_RETRY_WATCHDOG_USAGE_LIMIT_RECHECK_MS so unattended retry mode (CLAUDE_CODE_RETRY_WATCHDOG) notices a usage limit that was lifted before its reset.

  13. Claude API

    Inference hooks are out of beta for Claude Enterprise organizations

    We’ve launched user profiles, so you can tell Anthropic which of your end customers each API request is for. We’ve added organization webhooks to the Admin API, in beta with the webhooks-2026-10-07 beta header. Organization admins can now turn off web fetch for their organization on the Capabilities page of the Claude Console. In Claude Managed Agents, the web_fetch tool now follows your organization’s web fetch domain restrictions set on the Capabilities page of the Claude Console. In Claude Managed Agents, sessions follow your organization’s web search settings on the Capabilities page of the Claude Console: the Allow web search setting since October 6, and its web search domain restrictions since October 14.

  14. Claude Code

    Claude Code 2.1.304

    10 new43 fixes23 other

    Added a transcript line when a plugin that runs first skips one of your mod's hooks, naming the event and the plugin. Added decider: "person" to a mod's tool.check answer: only the permission dialog or a host's callback can approve the ask, and it is refused with the mod's reason where nobody can be asked.

  15. Claude Code

    Claude Code 2.1.303

    1 other

    Bug fixes and reliability improvements.

  16. Claude Code

    Claude Code 2.1.302

    4 new42 fixes17 other

    Added CLAUDE_CODE_AUTO_MODE_MODEL to choose the model the client-side auto mode classifier uses; it does not change the model for server-side auto mode. Added an Idle compaction row to /config for turning idle compaction off or back on; the notices shown after an idle compaction now say how to turn it off.

  17. Claude Code

    Claude Code 2.1.301

    8 new33 fixes10 other

    Added CLAUDE_CODE_RETRY_WATCHDOG_MAX_USAGE_LIMIT_WAIT_MS so unattended retry mode (CLAUDE_CODE_RETRY_WATCHDOG) ends a request at a usage limit that resets too far away instead of waiting. Added OpenTelemetry tracing guidance to the claude-api skill, including setting up trace destinations with the ant CLI.

  18. Claude API

    We’ve added capabilities.thinking.types.between_tools to the Models API

    GET /v1/models and GET /v1/models/{model_id} now report whether each model accepts thinking: {type: "between_tools"}, which turns off up-front thinking. The Compliance API now returns the text each organization member saved as Instructions for Claude in claude.ai and as Global instructions in Cowork, in beta for Claude Enterprise organizations. Fast mode is out of research preview for Claude Opus 5.5, and you no longer need to request access. Fast mode for Claude Opus 5.5 is now available on Claude in Microsoft Foundry for deployments hosted on Azure.

  19. Claude Code

    Claude Code 2.1.300

    12 new58 fixes18 other

    Added virtualText to a mod's prompt decorations: text drawn in the prompt box that never enters the draft or the submitted prompt. Added cache_creation_5m_tokens and cache_creation_1h_tokens to the OpenTelemetry api_request event, splitting cache writes by lifetime.

  20. Claude Code

    Claude Code 2.1.299

    18 new130 fixes42 other

    Added CLAUDE_CODE_DISABLE_FILE_MENTIONS environment variable: Claude gets the paths of @ file mentions to read with its file tools, not the files' contents. Added idle compaction in the terminal: a 200K+ token conversation left idle for about 54 minutes is compacted before its one-hour prompt cache expires, so your next message doesn't reprocess it all.

  21. Claude API

    We’ve launched OpenTelemetry export in beta, so you can trace Messages API requests and Claude Managed…

    The Claude SDK emits spans in Python, TypeScript, C#, Go, Java, PHP, and Ruby. To get spans from the API, add an OpenTelemetry destination in the Claude Console. Claude Managed Agents scheduled deployments are now available on Claude Platform on AWS.

  22. Claude Code

    Claude Code 2.1.296

    8 new56 fixes15 other

    Added a code key to the Claude apps gateway's managed.policies[]: the same settings as cli, also applied in Claude Desktop's Code tab; beside desktop, it turns on Claude Desktop's gateway mode. Added autoCompactWindow to subagent frontmatter and --agents definitions, so a subagent can auto-compact earlier than the main conversation's window.

  23. Claude API

    You can now let a Claude Managed Agents agent use dynamic workflows, in beta with the…

    For work with many pieces, such as reviewing hundreds of documents, the agent can write a workflow. A workflow is a program that runs many agents in phases and combines their results. The server runs it in the background as a workflow run. To turn dynamic workflows on, set the agent’s multiagent field to {"type": "multiagent_20261001", "workflows": {"type": "enabled"}}. To guide the agent, tell it in its system prompt when to start a run. Follow each run through workflow_run.* events on the session’s event stream.

  24. Claude Code

    Claude Code 2.1.295

    17 new96 fixes30 other

    Added onFailure: "block" for command and HTTP hooks: a hook that can't start, times out, or exits with an unexpected code blocks the action instead of letting it through. Added Program Status Protocol (OSC 7501) support: terminals that implement it can show whether Claude Code is working, waiting on you, or done.

  25. Claude Code

    Claude Code 2.1.294

    1 fix1 other

    Fixed prompt and agent hooks written as instructions (such as "Block commands that...") allowing what they should block. Improved how prompt hooks on Stop and SubagentStop written as instructions (such as "Carry on if the build is broken") are judged, so Claude is less likely to stop early.

  26. Claude API

    The Compliance API chat endpoints now also return chats from the unified Claude experience, in beta for…

    The Compliance API can now download Claude Docs documents as Word files, in beta.

  27. Claude Code

    Claude Code 2.1.293

    3 new38 fixes15 other

    Added Claude Haiku 5.5 (claude-haiku-5-5), now the default Haiku model on the Anthropic API — 1M context, $0.10/$0.50 per Mtok ($0.50/$2.50 for prompts over 100K). Added agentType to the subagentStatusLine payload, so scripts can tell custom subagent types apart.

  28. Claude API

    We’ve lowered the price of prompt cache reads on Claude Sonnet 5.5 from $0.20 USD to $0.10 USD per million…

    Cache writes and all other prices are unchanged. Code written for Claude Haiku 4.5 can break on Claude Haiku 5.5. The Python and TypeScript SDKs now include classes, in beta, for the browser use tool and the computer use tool. Claude Max and Team plans now include monthly API credits. In Claude Managed Agents, a cloud environment with limited networking now also applies its allowed_hosts to the web_search and web_fetch tools. With limited networking, creating a session fails with a 400 error when an enabled web tool’s allowed_domains has an entry not within allowed_hosts. In Claude Managed Agents, the web_fetch tool now fetches only URLs that have already appeared in the session, for example in the text of a user message, in a web_search result, or in a page that web_fetch returned earlier.

  29. Claude appsAnnouncement

    Claude Haiku 5.5 launch, plus 1 more change

    We just launched Claude Haiku 5.5, the cheapest, fastest, and most capable small model we’ve released, designed for high-volume, cost-sensitive tasks. Max and Team plans now include monthly API credits for running your own apps and agents on the Claude Platform. They roll out over a few days. Claim them by linking a Claude Console organization in Settings > Billing (Max) or Organization settings > Billing (Team). Learn more about monthly API credits for Max and Team plans.

  30. New modelAnnouncement

    New model: Claude Haiku 5.5

    We’ve launched Claude Haiku 5.5 (claude-haiku-5-5), our most capable model tuned for high-volume and latency-sensitive work. It has a 1M token context window, 128k max output tokens, and adaptive thinking with the effort parameter. It’s available on the Claude API, Claude in Amazon Bedrock, Claude Platform on AWS, Claude on Google Cloud, and Claude in Microsoft Foundry.