Claude Code 2.1.238

• [changed] Artifact sessions handle live updates more carefully: viewers are notified when another session republishes an artifact; when a session leaves, page events stop and room_send reports not connected instead of silently retrying; runtime diagnostics stay owner-only.
• [changed] Cross-session inbox delivery is stricter about drops and refusals — undelivered or rate-limited messages are treated as unsent (not something to retry in a loop), and sessions that decline cross-session traffic are reported clearly rather than waited on.
• [changed] First SIGTERM/SIGINT no longer drains in-flight work: the runner stops taking new work and resumes on the user’s next message instead of tearing the session down aggressively.
• [changed] PR/review thread handling: resolve only threads activated for Claude; never resolve a thread marked not activated even if you replied elsewhere — leave those for the commenter.
• [changed] Claude in Chrome: if the user declines the extension install, Claude stops re-prompting for the rest of the session and continues with read-only web tools or manual browser steps (/chrome remains available later).
• [changed] SDK / host reconnects during PreToolUse no longer look like denials — the same tool call can be retried when the host reconnects before the hook answers.
• [new] Filesystem MCP surface gains read_file (mcp__filesystem__read_file).
• [changed] Computer-use MCP guidance is wired in so desktop screenshot/click/keyboard tools are used with explicit tab/context checks when available.
• [changed] Subagent defaults remain background-first, with clearer rules on when to force foreground (run_in_background: false only when the next step truly depends on the result) and never fabricating pending agent results.
• [changed] Correction → memory timing is stricter: durable preferences from a correction should be written in the same turn that engages the fix, not deferred until later.
• [changed] Focus mode copy reinforces that only the final text message is user-visible — skip mid-turn progress chatter and put everything needed in the closing message.
• [changed] Plugin install/update path can fetch plugin archives through a headers helper on explicit /plugin updates; marketplace name/URL knobs are present for configured marketplaces.
• [changed] SDK compatibility matrix drops older wrapper test pins (0.3.199–0.3.200) and adds 0.3.223.

Models & prompts

• Plan mode, auto-mode classifier, and permission-denied tool feedback wording stay aligned with “block on the side of caution” and full-effect judgment, without applying user ALLOW exceptions in the first stage.
• Git stash guidance still requires tagged, SHA-addressed stash apply (never bare pop) when multiple sessions/worktrees share a stash stack.
• Onboarding-guide and high-effort review prompts remain available for teammate walkthroughs and recall-oriented reviews.
• Document/artifact page chrome guidance clarifies TITLE vs PURPOSE so titles stay short and distinctive.

Under the hood

• Artifact verify / republish gates and related env controls (CLAUDE_CODE_ARTIFACT_*, including verify and sync base URL) support the live artifact path; frame diagnostics expose /api/frame/diag.
• Bridge and Chrome connection telemetry expands (host declined end, signed-out neutral, token-absence classification, extension/bridge connected, tools added/disconnected).
• MCP discovery cache is re-gated under an enable flag; optional gzip of request bodies and SDK malformed-input tracking land behind internal gates.
• Task-list and experimental observer-agent / workflow-size controls continue to evolve via feature flags; several older one-off env knobs (plan-artifacts, effort-level, gateway model discovery, SDK file checkpointing, tmux truecolor, and assorted internal codenames) were removed or replaced.
• Plugin sync stall/install timeouts and websocket auth file-descriptor options are available for tuning install and auth edge cases.
• Home-directory trust remains session-only without an interactive accept; room_send still requires an interactive approval surface and will not retry in headless/no-card sessions.
• Cowork “live room” events that need an approval card are not retried in sessions that cannot show one; org wake-subscription absence is reported as non-retriable while disabled.

Upgrade notes

• If you pin the Claude Code SDK wrapper, note tested compatibility now includes 0.3.223 and no longer lists 0.3.199 / 0.3.200.
• Sessions that previously relied on aggressive drain-on-signal behaviour should expect the first interrupt to pause new work and resume on the next user message.
• Users who dismissed Claude in Chrome will not see install nudges again until a later session (or /chrome).