Short model names such as opus and sonnet now work beyond Anthropic's own API. Fable is now recognised as a short model name too. A new Claude Test panel in the terminal shows each test's pass, fail or blocked mark, with a progress bar and time left. It builds on the groundwork for that panel in v2.1.309. On Vertex and Bedrock, default models can now come from a published model document. Setting CLAUDE_CODE_RETRY_WATCHDOG_SCOPE=capacity limits the automatic retry waiting to capacity errors only.
Several features are in this build but not switched on yet. A /claude-api check that scans your project for retiring Claude model names is built and stays off. Sending a project's documents to Claude as plain text is also off unless switched on remotely. The tool that writes project documents gains a safety check that is off by default. When switched on, it refuses to replace a document whose text differs from what Claude last saw. Groundwork for picking up background agents left behind after a resume is present but hidden.
Starting a cloud session now recovers when this computer is not yet a trusted device. Claude Code re-enrolls the computer and retries, or tells you to run /login. Saving incoming attachments no longer overwrites files that have the same name. Inline images inside tmux now stay in place when the pane moves, resizes or regains focus. A NODE_EXTRA_CA_CERTS file with one blocked certificate no longer causes the whole file to be ignored. The bundled claude-code.d.ts type definitions file is removed.
Written by our agent from the shipped bundle, not by Anthropic.
Short model names such as opus and sonnet are no longer limited to Anthropic's own API, and fable is now recognised as one
Sessions & agentsMCP server settings accept a new connectorId field, stdio servers keep their original configuredCommand, and mcp_call refuses some servers' tools
ExtensionsIn proxied sessions, the built-in gh now refuses to run outside the session's proxy, and a new standalone-proxy mode sets up git and gh
Tools & outputOn Windows, strict sandbox mode now explains why a command was refused, and the CLAUDE_CODE_NANKEEN_KESTREL switch remembers it was on
Interface
CLAUDE_CODE_RETRY_WATCHDOG_SCOPE limits the retry watchdog to capacity waitsSet CLAUDE_CODE_RETRY_WATCHDOG_SCOPE=capacity to keep the retry watchdog waiting through capacity errors without its other retry changes
Want the reasoning? Read walks the 22 entries that probably matter to you, each one opening to what changed and why.
Read this release → Every row →Anything you can use today, anything that visibly changes, and anything worth poking at. One line each, open for detail.
Short model names such as opus and sonnet are no longer limited to Anthropic's own API, and fable is now recognised as one
Unclear Whether you can choose fable as a model is not stated.
In proxied sessions, the built-in gh now refuses to run outside the session's proxy, and a new standalone-proxy mode sets up git and gh
Unclear Nothing shown passes "standalone-proxy" to the stand-in, so whether this path is reachable in normal use is unclear.
On Vertex and Bedrock, default models can now come from a published document per tier, falling back to models mapped in modelOverrides
Project settings files may set CLAUDE_CODE_MODEL_CATALOG only to "off"; any other value is ignored with a warning
What would fix it?
Smaller changes and internals, grouped as the pipeline found them. Nothing is dropped, it is only further down.
9 more of these are in What probably matters to you, above.
The default model behind each family alias can now come from a document, with modelOverrides and Bedrock and Vertex checks adjusted to match
Unclear Which models have a published-document target is not stated.
Managed git and gh access can now go through a standalone proxy URL, and a new message tells Claude not to bypass TLS checks when setup fails
Self-hosted runners now send and log a list of capabilities when they register, and can prepare repositories at the same time
Anthropic-managed git sessions can now run through a self-hosted agent proxy, except on Windows and in a few other cases
Unclear It is not clear whether the server ever asks for the new kind of governed git that this mode now accepts.
Permission rules that deny or ask before the artifact REPL tool runs code now also match a second tool name
Unclear The second tool name the rules now cover is not stated.
When sending OpenTelemetry data, Claude Code now builds its connection from your own certificate and proxy settings, not the shared setup
Unclear It is not clear which of your certificate and proxy settings now apply to the telemetry connection, or when the strict connection is chosen.
The check that picks out a custom host from ANTHROPIC_BASE_URL now reads the variable directly and returns nothing in some modes
Unclear Which modes cause Claude Code to ignore ANTHROPIC_BASE_URL here is not stated.
Self-hosted runners now prepare repositories through a scheduler with separate hook and git slots, replacing a simple one-after-another loop
Unclear Whether more than one repository is actually prepared at the same time in practice.
A deny or ask permission rule matched against an MCP tool now also checks your other deny and ask rules and a related parent rule, so it can cover more tools
Unclear Exactly which additional MCP tools a given deny or ask rule now covers is not spelled out.
Settings env is now tracked by whether it came from the repository, and telemetry variables are put back if no settings source still sets them
A NODE_EXTRA_CA_CERTS file holding a blocked or damaged certificate now keeps its readable certificates, with new warnings explaining what was dropped
MCP servers that reach the Artifacts server are now left out of self-hosted runner child sessions where artifacts are disabled or the tool is denied
Model allowlist matching now also tries the part of a model id after its last slash, and matches through catalog names and families
Gateway model discovery and gateway host checks now pass extra connection and certificate options, likely for custom certificate setups
Unclear It is not clear whether custom certificate settings now fully apply to gateway model discovery and managed settings requests.
For some kinds of configuration, the allow and deny lists for MCP servers now match against a second worked-out form of the command or URL
Unclear It is not clear which kinds of server configuration get the second check or how the second form differs from the first.
The failure message for the self-hosted agent proxy now says "your self-hosted agent proxy" instead of an internal mode name
When Claude Code checks a gateway and looks up its models, it now trusts the extra CA certificates you have configured
6 more of these are in What probably matters to you, above.
Self-hosted runners now send a capabilities list when they register and a capabilities header when fetching session settings; the orchestrator client sends an empty list
Telemetry records of tool use and permission decisions now include the API request_id, and a few other usage records gain extra fields
For header helper commands supplied by an organization, Claude Code now prepares the command's environment only when it is needed instead of upfront
Organization settings merging, gateway sign-in handling and cloud session flushing were adjusted internally
When setting up remote managed settings at startup, Claude Code now reads signature details alongside the policy and settings
When Claude Code checks your Google Cloud credentials, it now hands a set of client options to Google's authentication library
Unclear It is not clear which options are passed, so it is unclear whether this changes proxy or certificate handling for the credential check.
When Claude Code starts an MCP server, it now records whether that server came from an organization
Claude Code now records whether your default model was chosen by your organization or account, or is just the global default
Unclear Nothing shows what Claude Code does differently with this information, so its effect on which model you see or use is unclear.
Hooks set by your organization now start without the environment variables from a repository's settings, and a debug line says so
Before launching a session, a self-hosted runner's config check now also learns whether git config is on and whether the launched program's version is known
Unclear What the check does differently with these new details.
Sessions started by a self-hosted runner are no longer handled like other remote sessions when Claude Code sets up the artifacts MCP laptop entry
Unclear Whether self-hosted runner sessions now get the artifacts laptop entry or still go without it is not shown.
Anthropic has not published official notes for v2.1.310 yet. This section updates automatically when the entry appears in the upstream changelog. Everything else on this page came out of the bundle instead, which is why the two lists don't match.
3 of 30 tool descriptions changed. 1 of 28 tool schemas changed. The appended system-reminder blocks moved: 1 line added.
Claude Code, interactive mode
15 prompt changes in this release could not be quoted from the build, so no entry on this page describes them.
640 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.
The 29 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.
What's wrong with this entry?