Follow Discord

Claude Code v2.1.301

321 entries read Grouped into 272 v2.1.300 → v2.1.301 Mods API: +1 added · 0 removed · 5 changed · 10 docs only Markdown JSON Follow Unofficial

You can now set CLAUDE_CODE_RETRY_WATCHDOG_MAX_USAGE_LIMIT_WAIT_MS to make a request fail instead of waiting past that time after hitting a usage limit. This release has 272 entries, and 150 of them are usable today. On 1M-context models, a new dialog can offer to auto-compact long conversations sooner. If you accept, the lower size is saved to your user settings. The setting for showing artifacts beside tool results is now CLAUDE_CODE_DAPPER_CUPCAKE, and the old CLAUDE_CODE_SQUISHY_NEWT is ignored. Programs built on the SDK can now block up to 64 MCP tools for a single turn, and they can load more plugins into a running session without a restart.

There are 12 entries in the build that are not switched on yet. Claude Code can build shorter instructions for the Read, Grep and Agent tools, but none are in use. Rewritten instructions for AskUserQuestion, the tool Claude uses to ask you questions, are prepared but not used. A slimmed-down prompt variant sits behind a remote switch that is off by default. Groundwork for routing notifications and for spotting interface freezes is present but changes nothing yet. The browser setup prompt in the desktop app and on claude.ai now uses a newly named switch, so any earlier rollout starts over.

Long-running MCP tasks now wait and retry when the server rejects their ID with error -32602. Before this fix they failed at once. Stopping a background command whose output is saved elsewhere now points the notice to that file. Sending a session to the background mid-turn now keeps pending task notices and a scheduled-job note. Checkpoint commits now skip with a git_error reason when Claude Code cannot tell whether a git operation is in progress. Archiving remote sessions from the session list is removed, and the remove option that replaces it is not switched on in this build.

Written by our agent from the shipped bundle, not by Anthropic.

Five to try today

Picked from 16 you can use now
  1. Remote-session attachments can be stored in a user-data folder behind CLAUDE_CODE_ATTACHMENTS_IN_USER_DATA

    New CLAUDE_CODE_ATTACHMENTS_IN_USER_DATA variable lets remote sessions keep attachments in a user-data folder, with retention checks and hardened writes

    Sessions & agents
  2. 'Beside tool results' switch renamed to CLAUDE_CODE_DAPPER_CUPCAKE, and messages are tagged besideToolResults

    The 'beside tool results' behaviour now reads CLAUDE_CODE_DAPPER_CUPCAKE; the old CLAUDE_CODE_SQUISHY_NEWT variable no longer does anything

    Tools & output
  3. reload_plugins can now add plugins mid-session

    The SDK reload_plugins request takes add_plugins to load extra plugin folders without restarting, refused in cloud sessions and under disableSideloadFlags

    Extensions
  4. SDK MCP servers can now carry a per-tool permission policy

    Programs hosting Claude Code can set ask or deny rules for individual tools on their in-process MCP servers, at initialize or via mcp_set_servers

    Extensions
  5. Tools can now be blocked for a single turn

    A per-turn disallowedTools list now blocks named MCP tools for one turn, feeds deny rules, and suppresses misleading tool-revoked notices

    Extensions

Want the reasoning? Read walks the 38 entries that probably matter to you, each one opening to what changed and why.

Read this release → Every row →
26 of 272 shownClear
Reading as
Show only
Who it's for
Tier
Flag state
Names
Pick an entry · j / k steps through · rest on a row to peek
3 entries here

What probably matters to you

Anything you can use today, anything that visibly changes, and anything worth poking at. One line each, open for detail.

Were these the right ones to put at the top? 0 answered
Below the fold

Everything else

Smaller changes and internals, grouped as the pipeline found them. Nothing is dropped, it is only further down.

18 entries here

Improvementsopen

8 more of these are in What probably matters to you, above.

↑Improved
You'll notice
Useful2 Signal3
Policy Limits unclear

Organization policy limits are checked when a host program manages sign-in#

When another program handles sign-in and only a token from an environment variable is in use, Claude Code now still fetches and re-checks policy limits

Unclear Which setups count as a host managing sign-in is not clear.

Details 0 0 Feedback
↑Improved
You'll notice
Useful2 Signal3
Gateway Login unclear

Gateway login can trust administrator connections through a customer allowlist#

If the normal security check fails during an administrator's gateway login, Claude Code now checks a customer allowlist before giving up

Unclear It is not known where the allowlist comes from, or whether it holds any entries in this version.

Details 0 0 Feedback
↑Improved
You'll notice
Useful2 Signal2
Managed Settings unclear

Windows per-user registry settings are now skipped in some cases#

On Windows, Claude Code now reads settings from the per-user registry only when an extra condition also holds

Unclear It is not clear what the new condition checks, so it is not known when registry settings are now skipped.

Details 0 0 Feedback
↑Improved
You'll notice
Useful1 Signal2
Diskless Sessions unclear

Diskless sessions no longer read the enterprise MCP configuration#

In diskless sessions, Claude Code now skips the enterprise MCP configuration file and reports none as present

Unclear It is not confirmed that the condition for skipping the file is a diskless session.

Details 0 0 Feedback
↑Improved
You'll notice
Useful1 Signal1
Telemetry unclear

OpenTelemetry data no longer runs the standard host lookup#

Claude Code now sets the host architecture in OpenTelemetry data itself instead of running the standard host detector

Unclear Whether hostname and host ID fields still appear in exported OpenTelemetry data is not stated.

Details 0 0 Feedback
5 entries here

Internal Changesopen

8 more of these are in What probably matters to you, above.

·Internal
Under the hood
Useful2 Signal3
Group of 2 Environment Variables no docs found unclear

Self-hosted remote environments get their own detection#

Claude Code now recognises self-hosted BYOC remote environments and passes CLAUDE_CODE_REMOTE_ENVIRONMENT_TYPE along with related variables

Unclear It is not clear what the list does, so whether the variable is now passed to other processes is unconfirmed.

Details 0 0 Feedback
CLAUDE_CODE_REMOTE_ENVIRONMENT_TYPECLAUDE_CODE_REMOTE_HERMETIC_MODECLAUDE_CODE_HOSTED_DESKTOPCLAUDE_CODE_ENVIRONMENT_KIND
2 entries hereHooks · none marked notable
Verbatim
Official · Anthropic

Anthropic’s official release notes

Published verbatim by Anthropic for v2.1.301. Text is unmodified from the upstream changelog. Everything else on this page came out of the bundle instead, which is why the two lists don't match.

Of these 51 bullets, 8 name something an entry on this page also names, 15 name something no entry here does, and 28 name nothing specific enough to line up either way. The pairings are made on names both sides wrote down, a flag or a setting or a slash command, so read one as probably the same thing rather than as a fact, and read the middle number as candidates rather than as a miss count.

A model matched these bullets to the GitHub issues they fix, so a link can be wrong.

System prompt

No change to the system prompt since v2.1.300.

Claude Code, interactive mode

Documentation

What the docs did around this release

830 documentation changes were recorded within 24 hours either side of this release, nearest first. The closest 12 are below. They're here because they happened near this release in time. That's not a claim that this release caused the edit, or that the page documents anything in it.

Switches

Every name in this release

The 36 literal strings found in the bundle, with the number of entries that name each one. Picking one searches for it. A name is here because this build's code mentions it, which is not the same as it working or being finished.

Slash commands

CLI flags

Environment variables

Settings and names in the code

Feedback