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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 2.1.275

    13 new61 fixes22 other

    Added the signed-in account to Claude apps gateway sign-in: when the gateway names it, you confirm it before the credential is saved, and /status shows it. Added a send-now key (ctrl+enter, or ctrl+x ctrl+s) that interrupts the current turn and sends all queued messages at once; sent and queued messages show in gray until the model receives them.

  2. Claude Code

    Claude Code 2.1.274

    13 new71 fixes24 other

    Added a visible warning when memory usage is critical, with steps to free memory or restart safely. Added CLAUDE_CODE_MCP_STARTUP_WAIT_MS to bound how long the first non-interactive turn waits for connecting MCP servers (0 = don't wait).

  3. Claude apps

    Claude Cowork comes to every conversation, plus 1 more change

    We're rolling out a new Claude experience that makes everything Claude Cowork does available from any conversation. Ask a quick question or hand Claude a bigger task, like a report, spreadsheet, or presentation, without choosing a mode first. Your chats, Cowork tasks, projects, connectors, and skills carry over. The new experience is rolling out gradually to Pro and Max plans on web, desktop, and mobile. Learn more in Claude Cowork and chat are one Claude. You can now ask for a design, deck, or document in any conversation with Claude, including in Claude Code and the Artifacts tab, and edit it with Claude or directly as you work. Claude Design works inside your conversations with all of its features, including on-canvas editing and importing your design system. Claude Slides gives presentations their own starting point, and Claude Docs is a new way to write living documents with Claude and your team. Artifacts, including Claude Design, Claude Slides, and Claude Docs, are available on every plan, including Free. On Enterprise plans, Claude Design, Claude Slides, and Claude Docs are in beta and off by default until an owner turns them on. Learn more in What are artifacts and how do I use them? and Get started with Claude Docs.

  4. Claude Code

    Claude Code 2.1.273

    4 new35 fixes25 other

    Added x-claude-code-request-class, x-claude-code-agent-type, x-claude-code-prev-tool-durations, x-claude-code-compaction and x-claude-code-context-compacted request headers for LLM gateways; opt in with CLAUDE_CODE_GATEWAY_HINT_HEADERS=1. Added a notification when an MCP server disconnects mid-session and automatic reconnection gives up, pointing at /mcp.

  5. Claude Code

    Claude Code 2.1.272

    1 other

    Bug fixes and reliability improvements.

  6. Claude appsAnnouncement

    Launching Salesforce in Claude (beta)

    We've launched Salesforce in Claude, a plugin that brings a seller’s accounts, opportunities, and pipeline into Claude with 37 pre-built sales skills. Prep a call, review a deal, create a pipeline dashboard, and send your forecast all from Claude. It’s now available in beta on all paid plans for organizations Salesforce approves through its beta sign-up.

  7. Claude Code

    Claude Code 2.1.271

    10 new59 fixes27 other

    Added fast mode in Claude Code Remote sessions (cloud and self-hosted runners): the host's fast-mode setting or /fast typed in the session applies where your organization allows it. Added mouse support to the /config panel in fullscreen mode: the wheel scrolls the settings list, a click on a setting's value changes it, and the row under the pointer is highlighted.

  8. Claude API

    The Messages API can now compact a conversation on demand on the Claude API, in beta with the…

    Send the top-level compaction parameter, and the API returns a signed compaction block that summarizes the messages you sent. On later requests, send that block first, in place of those messages. You choose when to compact, the request can run in the background, and you can keep recent turns word for word after the summary. On models with preserved thinking, the thinking in those kept turns can stay valid. With the thinking-binding-controls-2026-08-01 beta header, the input_transformations response field gains a second entry type, thinking_mismatch_allowed.

  9. Claude Code

    Claude Code 2.1.270

    1 fix

    Fixed read-only git commands in Bash unexpectedly asking for permission after a session had been running for a while (regression in 2.1.269).

  10. Claude Code

    Claude Code 2.1.269

    14 new66 fixes18 other

    Added claude plugin eval: run a plugin's eval suite against Claude Code and get scored, reproducible results (JSON + HTML report); see claude plugin eval --help. Added /output-style [name] to list and switch output styles, including over Remote Control and in cloud and other headless sessions.

  11. Claude Code

    Claude Code 2.1.268

    11 new59 fixes26 other

    Added to the Claude apps gateway: with pricing: set in gateway.yaml, signed-in Claude Code clients receive the same rates through managed settings, so /cost and telemetry match the spend meter. Added a startup warning for gateways when access_control.allow_cidrs is empty, and a one-time warning the first time a request arrives from a public address.

  12. Claude API

    Claude Managed Agents permission policies now include auto: the server evaluates each agent or MCP tool call…

    Version 1.32.0 of the ant CLI adds ant beta:sessions connect, which attaches your terminal to a Claude Managed Agents session.

  13. Claude apps

    Smart reports (beta)

    We’ve launched smart reports, which analyze how a team uses Claude and report on the work getting done, what it costs, where sessions run into friction, and which repeated patterns are worth packaging as shared skills. Smart reports are available in beta on Claude Enterprise plans. Learn more in Get started with smart reports.

  14. Claude Code

    Claude Code 2.1.267

    3 new41 fixes9 other

    Added maxEffortLevel setting (top-level or per model under modelSettings): caps the effort level on every provider, including Bedrock, Vertex and Foundry; users can still pick a lower level. Added --system-prompt-snapshot off to render the system prompt fresh on every request instead of reusing the conversation's recorded prompt (for iterating on prompt text).

  15. Claude API

    For cache diagnostics, the API now stores a request’s fingerprint only when the request includes the…

    A request that sends only the cache-diagnosis-2026-04-07 beta header is still accepted, but no fingerprint is stored. A later turn that points previous_message_id at it reports previous_message_not_found. Include diagnostics on every turn, with "previous_message_id": null on the first.

  16. Claude Code

    Claude Code 2.1.266

    1 fix

    Fixed a 2.1.265 regression affecting LLM-gateway and proxy setups: the undocumented CLAUDE_CODE_USE_GATEWAY environment variable, previously ignored unless ANTHROPIC_BASE_URL and ANTHROPIC_AUTH_TOKEN were both set, began forcing Cloud-gateway sign-in on its own in 2.1.265, so configurations that set it alongside an API key, apiKeyHelper, or custom auth headers failed every request with "Not signed in to the Cloud gateway". The variable on its own is ignored again; no configuration change is needed.

  17. Claude Code

    Claude Code 2.1.265

    4 new34 fixes12 other

    Added user.email and user.groups to the telemetry Claude Desktop and Cowork send through a Claude apps gateway, matching terminal sessions. Added support for pointing --plugin-dir at a folder of plugins: each child folder with a manifest loads, and children added or removed while running are picked up.

  18. Claude Code

    Claude Code 2.1.263

    1 other

    Bug fixes and reliability improvements.

  19. Claude Code

    Claude Code 2.1.261

    9 new47 fixes11 other

    Added an "Organization policy" line to /status and claude doctor that says why your organization's policy could not be loaded, such as a proxy not passing the endpoint through. Added bashOutputMaxChars and taskOutputMaxChars settings to raise how much command and background-task output Claude receives inline before it is saved to a file, up to 128K characters.

  20. Claude Code

    Claude Code 2.1.260

    8 new37 fixes21 other

    Added a diff panel that opens beside the conversation in fullscreen mode and shows your uncommitted changes as Claude edits; toggle it with /diff. Added a likely cause for prompt-cache misses (e.g. tool definitions or system prompt changed, idle past the TTL) to /cost and the status line's prompt_cache field.

  21. Claude API

    Version 1.30.0 of the ant CLI adds ant apply, which creates and updates agents, environments, skills, memory…

    Describe each resource in a file, run ant apply, and approve the plan it prints. Commit the claude-lock.json lockfile it writes so that later runs, on your machine or in CI, update the same resources instead of creating new ones. Per-message effort changes, in beta, are also available on Google Cloud for Claude Fable 5.1, Claude Mythos 5.1, and Claude Opus 5, with the same mid-conversation-output-config-2026-07-01 beta header.

  22. Claude Code

    Claude Code 2.1.259

    5 new26 fixes6 other

    Added managedMcpServers managed setting: organizations can provide HTTP/SSE MCP servers to every user (same entry shape as .mcp.json); entries that name a command to run are skipped. Added --permission-prompts none for unattended headless hosts: anything that would prompt is denied automatically while the active permission mode (including auto mode) keeps deciding.

  23. Claude Code

    Claude Code 2.1.258

    2 fixes

    Fixed Claude Code failing to launch on macOS 12 (Monterey), a regression introduced in 2.1.255. Fixed remote and scheduled sessions failing with "user messages must have non-empty content" after a re-sent permission approval could not be applied.

  24. Claude Code

    Claude Code 2.1.257

    12 new67 fixes25 other

    Added Claude Fable 5.1 (claude-fable-5-1), now the default Fable model — 1M context, $10/$50 per Mtok with $0.25/Mtok cache reads. Added "Time format" (timeFormat) and timeZone settings: 12-hour, 24-hour, 24-hour UTC, or a strftime pattern for the turn-end clock and transcript-view timestamps.

  25. Claude API

    Prompt cache reads on Claude Fable 5.1 and Claude Mythos 5.1 cost $0.25 USD per million tokens: 0.025x the…

    Cache writes are unchanged. On Claude Fable 5.1 and Claude Mythos 5.1, tool_choice types any and tool aren’t supported and return a 400 error. auto and none are unchanged. Thinking blocks produced by Claude Fable 5.1 and Claude Mythos 5.1 are preserved only for the model that produced them or a newer one: earlier models can’t read them, and the API drops one replayed to an earlier model. Per-message effort changes are in beta on Claude Fable 5.1, Claude Mythos 5.1, and Claude Opus 5 on the Claude API. Turn-scoped system messages are in beta (mid-conversation-system-clear-at-2026-08-21 header). thinking.display accepts a third value, "updates", in beta (thinking-display-updates-2026-08-18 header). Text generated by Claude Fable 5.1 and Claude Mythos 5.1 carries Anthropic’s text watermark, and supported image, video, and audio files that Claude produces through the code execution tool carry C2PA Content Credentials when you retrieve them through the Files API on the Claude API. Like Claude Fable 5, both models require 30-day data retention and aren’t available under zero data retention unless expressly authorized by Anthropic. The guides for the Claude Enterprise endpoints of the Admin API (user management and spend limits), the Claude Enterprise Analytics API, and the Compliance API now show the anthropic-version header; send it on every request to these endpoints, as in the rest of the Claude API.

  26. Claude appsAnnouncement

    Claude Fable 5.1 and Claude Mythos 5.1 launch

    We just launched Claude Fable 5.1 and Claude Mythos 5.1, the world’s most advanced models for coding and knowledge work.

  27. New modelAnnouncement

    New models: Claude Fable 5.1 and Claude Mythos 5.1

    We’ve launched Claude Fable 5.1 (claude-fable-5-1), the successor to Claude Fable 5 for long-running agentic coding, knowledge work, and research, alongside Claude Mythos 5.1 (claude-mythos-5-1) for Project Glasswing participants. Both models support a 1M token context window by default, 128k max output tokens, and always-on adaptive thinking, at $10 / $50 USD per MTok, the same as Claude Fable 5, with cache reads cut to $0.25 USD per MTok. Claude Fable 5.1 is available on the Claude API, Claude in Amazon Bedrock, Claude Platform on AWS, Claude on Google Cloud, and Claude in Microsoft Foundry.

  28. Claude Code

    Claude Code 2.1.252

    4 fixes

    Fixed Bash commands failing with "task output swap refused (tasks dir moved or linked)" on some Macs. Fixed "always allow" not saving in a project that has no.claude/settings.local.json yet.

  29. Claude Code

    Claude Code 2.1.251

    5 new41 fixes25 other

    Added PreModelSwitch and PostModelSwitch hook events (block, confirm, or annotate a model switch); SessionStart resume hooks now receive session staleness and the estimated re-cache cost. Added live streaming of a foreground subagent's tool calls and results to Remote Control clients (background subagents, the default, still show status only).

  30. Claude Code

    Claude Code 2.1.250

    1 other

    Bug fixes and reliability improvements.