Claude Code 2.1.306-2.1.308: safety events, API version

Claude Code 2.1.307 carries the real changes in this batch: a /claude-api api-version command, a new OpenTelemetry event for stopped tool calls, and a retry rule for broken tool calls. 2.1.306 is two bug fixes. 2.1.308 is one line in Anthropic's changelog: "Bug fixes and reliability improvements".

This brief picks up after the 2.1.305 notes. It covers the headline items, not every one of the 26 bug fixes listed for 2.1.307.

This site is independent and not affiliated with Anthropic. We read the changelog and two docs pages on 2026-10-22. We did not install or run 2.1.306, 2.1.307 or 2.1.308, so nothing below is a hands-on result. The entries we read show no release dates.

A command to move API code to a new API version

The 2.1.307 entry adds a subcommand to /claude-api:

Added /claude-api api-version to move Claude API code to API version 2026-10-21

Anthropic's commands page names api-version among the subcommands of /claude-api. It says the skill "Also activates automatically when your code imports anthropic or @anthropic-ai/sdk."

The entry does not say what the command edits. Run it on a clean git branch so you can read the diff before you keep anything.

A new event for every stopped tool call

This one is for admins who collect telemetry. The changelog says:

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

In plain terms, one event per tool call that a guardrail interrupted, whichever guardrail it was. The entry does not list the fields the event carries.

Telemetry has to be switched on first. Anthropic's monitoring page names CLAUDE_CODE_ENABLE_TELEMETRY as the setting that enables collection. If you rely on hooks as a control, see our guide on making hooks fail closed.

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Retries and forked subagents

Two reliability changes land in the "6 improvements" list. The first is a retry rule:

Improved recovery from unparseable tool calls: Claude Code now retries the call up to twice before ending the turn with an error

The second touches subagents started in a batch:

Improved fork subagents launched together: each is now told which launch is its own, so forks are much less likely to try to start each other's work

"Much less likely" is the changelog's wording, not a measured rate. We have no number for either change.

Runner, search and Code Review changes

Four smaller items matter only if you use the feature:

• Self-hosted runner: checkout hooks are now "stopped after 30 minutes by default, failing the session's setup". To change that, raise --checkout-hook-timeout-min or set it to 0.
• WebSearch: when the search budget runs out, Claude now also gets told "not to query search engines in a browser or through computer use".
• Code Review: @claude review stop (also off and pause) ends an @claude review always subscription on a pull request. Our Code Review launch brief explains the service.
• Screen readers: the axScreenReader setting now applies only from user, managed or --settings settings (the entry adds "since 2.1.305").

What 2.1.306 and 2.1.308 contain

2.1.306 lists two fixes. One stops claude -p inside cloud sessions from reporting "Not logged in" when it starts without the session's environment variables. The other stops an API error being replaced by "prompt is too long", with an unneeded compaction, in sessions with many MCP tools.

2.1.308 lists nothing else. Read it as a maintenance release until Anthropic says more. If your team tracks rate and retry behavior, our rate limits guide is the place to compare notes.

Upgrade readout

If you	Do this
Write code against the Claude API	Try /claude-api api-version on a branch and read the diff
Collect telemetry	Look for claude_code.safety_event in your pipeline
Run a self-hosted runner	Check whether a checkout hook runs longer than 30 minutes
Use @claude review always	Know that @claude review stop now ends it
Anyone else	Routine upgrade

What this brief does not cover

We did not run any command, setting or event named above. The 2.1.307 entry lists 26 bug fixes and we did not go through them one by one. The entries show no dates, so we cannot say when each version shipped. For admin controls, our managed settings guide shows where organization settings live.

What does /claude-api api-version do in Claude Code?

Per the 2.1.307 changelog, it moves Claude API code to API version 2026-10-21. The entry does not say which files it edits or how, so run it on a branch and review the diff before committing.

What is the claude_code.safety_event event?

It is an OpenTelemetry event that 2.1.307 sends for each tool call that a permission rule, auto mode, a safety check, a hook or the sandbox stopped, prompted or sent back. The changelog does not list its fields.

What changed in Claude Code 2.1.308?

The changelog entry for 2.1.308 reads "Bug fixes and reliability improvements" and lists nothing else. The notable changes in this batch are in 2.1.307, and 2.1.306 holds two bug fixes.

Sources (checked 2026-10-22)

• Claude Code changelog: the 2.1.306, 2.1.307 and 2.1.308 entries.
• Commands reference: the /claude-api bundled skill.
• Monitoring: how telemetry is enabled.