Claude Code v2.1.89 · 31 Mar 2026
Entry Kind: in v2.1.89, 31 Mar 26
Changes Section of the release
The changelog for version 2.1.89 is complete. Here's a summary of the key changes I identified:
Major new features:
Configurable auto-compact window with /autocompact Terminal tab status showing Idle/Working/Waiting stateFull mouse text selection and clipboard system with copy-on-select, new scroll keybindings, and tmux integrationMCP OAuth authentication tool allowing the model to trigger auth flows mid-conversation/buddy coding companionRecently denied commands view for auto-mode denialsSession resume with summary optiondefer permission typePermissionDenied eventKey improvements:
Shell security migrated from shell-quote to tree-sitter (more accurate bash analysis) Better file edit error messages (stale content, too large, not read yet) Improved 1M context messaging and extra usage guidance Message rating system PowerShell edition detection New CLI flags: --include-hook-events --mcp-config servers--server-option
How sure we are
One source agrees One thing we can check says the same as this entry.
Anthropic's release notes agree Added MCP_CONNECTION_NONBLOCKING=true for -p mode to skip the MCP connection wait entirely, and bounded --mcp-config server connections at…
See this entry in the whole of v2.1.89 →
Names in this entry
slash /autocompact Set the auto-compact window: how full the context window gets before Claude Code compacts automatically. Pass a size such as 500k, or auto to return to the window tuned for your model. Claude Code saves the value to user settings and applies it to the current session. See Set the auto-compact window for accepted values and what overrides it. Without an argument, opens a dialog that shows the current window. Requires Claude Code v2.1.221 or later
cli auto-mode A safety rule in the auto-mode prompt got a wrapper tag; the rule text is unchanged.
hook PermissionDenied When auto mode denies a tool call, including denials without a classifier verdict. Use JSON hookSpecificOutput.retry: true to tell the model it may retry the denied tool call. Claude Code ignores retry when the classifier produced no verdict
cli --include-hook-events Include hook lifecycle events in the output stream. SessionStart and Setup hook events are always included and don't need this flag. Some hook events, such as Notification, SessionEnd, PreCompact, and PostCompact, never produce a hook_started event, even with this flag. For those events, Claude Code still emits hook_progress while a command hook that runs for more than a second produces output, and emits hook_response only when a hook that runs in the background finishes. Requires --output-format stream-json
cli --mcp-config Load MCP servers from JSON files or strings (space-separated). When you pass this flag with -p, Claude Code waits for still-pending servers to connect before running the first turn, up to the MCP_TIMEOUTcached tool list skips the wait and connects on first use. The wait requires Claude Code v2.1.221 or later
Anthropic's notes
Upstream's own release notes for v2.1.89 name something this entry names, so the two are probably about the same change. Probably: the pairing is made on a shared name rather than on the words around it.
Added MCP_CONNECTION_NONBLOCKING =true-p mode to skip the MCP connection wait entirely, and bounded --mcp-config
/buddy is here for April 1st — hatch a small creature that watches you code
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Hard to understand Too vague Looks wrong Not relevant to me Too long Missing the detail I wanted Duplicate of another card
Clear Learned something new I can act on this Good catch
