Claude Code 2.1.241

• [new] Built-in Mcp tool is available again in the core tool set.
• [new] Read results can record when a read completed a saved Artifact source (slug + version), so later turns know which artifact version counts as viewed.
• [new] Document reads can surface extracted page images (with firstPage labeling) in the model-facing tool result for page-range workflows.
• [new] Nested/agent reads report omission and failure notes when images, failed pages, or PDFs are dropped by per-result caps—so the model sees why content is missing.
• [new] Dynamic loop ticks can mark noop: true when nothing changed; consecutive no-ops collapse in the terminal view and count as a streak (unless stop ends the loop).
• [new] Agent tool results carry optional hand-back provenance fields (harness section counts/hash, handoff-review-skipped) so delivery framing stays correct across rewrites.
• [new] Remote trigger / scheduler status payloads can include extra detail and server_message text for failures and run state.
• [changed] Feedback/bug report field copy tightened (punctuation-only clarification on evidence, failure mode, and task category descriptions).
• [changed] Artifact publish force guidance clarified: force discards the newer published version only when the user explicitly opts to, and still won’t override some in-page saves.
• [changed] SDK wrapper compatibility matrix updated (adds 0.3.225; drops older 0.3.204–0.3.206 from the tested list).
• [changed] Native binaries are larger across platforms, reflecting the expanded embedded agent surface.

Models & prompts

• [changed] Plan-mode / Ultraplan rejection handling still recognizes local teleport markers and tells the user to return to their terminal; wording aligned so a broken handoff does not follow the error’s “retry” advice blindly.
• [changed] Computer-use access guidance refined: applications (including Finder for desktop/Dock/Finder UI) must be granted via request_access before use; menu bar input remains allowed when the frontmost app is already approved.
• [changed] Migration and API skill text updated for current Opus/Sonnet lines—including fast-mode retirement notes (do not leave callers on retired -fast model strings; prefer current fast-mode guidance), code-review harness tuning when models follow “be conservative” instructions more literally, and clearer scope-asking before broad Write/Edit migrations.
• [changed] Cloud/worktree session prompts better explain file-sync lag, cleared worktree isolation, and cancelled bash (command may have started—don’t blindly retry non-idempotent work).
• [removed] API beta header forth-2025-04-20 is no longer bundled.

Under the hood

• Background/bridge session stack expanded (attach/reattach, daemon/worker lifecycle, roster and handoff metadata) with matching telemetry gates.
• Directory-sync paths advanced (engine/fast-forward style sync, git worker arming, reachability and first-turn hold behavior).
• Device-side hook forwarding/consent and device bash outcome events added for sandboxed or companion-device runs.
• Cloud plugin admission, consent, reload, and create-checklist flows instrumented; related session/cloud ID env plumbing refreshed.
• Early gates for Android emulator and iOS simulator targets appear in the build.
• Prompt-cache TTL controls (including subagent-specific) and resume behavior that tolerates context appends.
• Fork-subagent, bundled-skills disable, hooks-same-thread, workflow launch provenance, and tmux session env hooks for specialized runners.
• GitHub npm registry endpoint included for package resolution paths that need it.
• Internal settings and env surface reorganized (many CLAUDE_CODE_* / ANTHROPIC_* keys renamed or replaced); treat undocumented keys as unstable.

Upgrade notes

• If you parse Agent, Read, or loop tool_result payloads in wrappers or hooks, allow the new optional fields (artifactRead, page image metadata, omission counts, noop, harness provenance). Older clients can ignore unknown keys.
• Confirm any automation that depended on retired fast-mode model IDs is pointed at supported models; silent fallback vs hard error differs by ID.
• Custom builds pinning old SDK wrapper versions should move onto the currently tested 0.3.207+ range (including 0.3.225).
• Binary size increased on all platforms; ensure installers and update channels allow the larger artifacts.