TL;DR
- Fast mode now auto-restores after switching models. If you toggle away from a fast-mode-capable model and back, fast mode re-enables itself instead of staying off. No more manual re-toggle.
- Scientific notation in env vars was silently truncated.
CLAUDE_CODE_MAX_OUTPUT_TOKENS=1e6was read as1, not 1,000,000. If you use exponential notation in anyCLAUDE_CODE_*env var, verify your values are landing correctly. /release-notes "Show all"was leaking the entire changelog into context. Every subsequent request carried the full changelog, silently burning your context window. If you noticed degraded responses after viewing release notes, this was why.- Six memory leaks fixed, three performance bottlenecks removed (more below). Long sessions should be meaningfully more stable, especially with many MCP servers or edit-heavy workflows.
New in 2.1.208
2.1.208 (July 14, 2026)
- Added screen reader mode: opt-in plain-text rendering for screen reader users. Run
claude --ax-screen-reader, setCLAUDE_AX_SCREEN_READER=1, or add"axScreenReader": trueto settings. - Added
vimInsertModeRemapssetting: map two-key insert-mode sequences likejjto Escape in vim mode - Added
CLAUDE_CODE_PROCESS_WRAPPER: agent view and the background service now honor a corporate launcher by running every Claude Code self-spawn through a required wrapper executable - Added mouse-click support for multi-select menus and "Other" input rows in fullscreen mode
- Fixed fast mode staying off after switching back to a model that supports it; it now restores automatically when enabled in settings
- Fixed replies typed to a background agent being lost when delivery fails; the text is now saved and delivered when the session restarts
- Fixed background-session attach failing permanently ("Couldn't start the background daemon") after an update replaced the binary a running
claude agentsprocess was launched from - Fixed the context window (and auto-compact indicator) briefly resetting to 200k after the CLI auto-updates, causing a false "100% context used" when resuming long-context sessions
- Fixed supervised and background sessions crashing when a server closed an HTTP/2 connection with a GOAWAY while requests were in flight
- Fixed truncated stream-json/JSON output and missing result message when piping large responses from
claude -p - Fixed
CLAUDE_CODE_MAX_OUTPUT_TOKENSand similar env vars silently using the mantissa of scientific-notation values (1e6became1) - Fixed very large markdown tables stalling rendering or using excessive memory; tables over 200 rows show the first 200 with a "... N more rows" notice
- Fixed the Edit tool failing on files modified after reading when the target text still matches uniquely
- Fixed Read reporting empty files as "shorter than offset", Grep silently returning "No files found" for invalid regex patterns, Grep count mode under-reporting totals when paginated, and Glob crashing with an unclear error when the pattern, path, or working directory contained a null byte
- Fixed
apiKeyHelperscript failures being hidden behind a generic 401 after ~10 silent retries; the script's own error is now shown within 3 attempts - Fixed Bedrock streaming requests failing with a misleading "Truncated event message received" when a gateway transforms the response; the error now names the content-type and points at the proxy
- Fixed
/upgradeshowing a login flow instead of the upgrade URL when the browser fails to open - Fixed stream-json input killing the session on blank CRLF or whitespace-only lines from Windows-style SDK hosts
- Fixed headless stream-json sessions hanging permanently when a
control_requestcarried a non-stringset_modelpayload; the CLI now answers with an error response - Fixed repeated "No completion record was found" notices on session resume; orphaned background tasks now collapse into a single summary
- Fixed Remote Control clients attaching to a terminal-hosted session not seeing background agents and workflow progress until a task started or stopped
- Fixed the Agent tool launching with no tools when a subagent's
toolslist resolves to nothing; it now returns a clear error naming the unrecognized entries - Fixed
/usageshowing stale cached bars over fresher data, and/mcpnot reclassifying placeholder servers after config edits - Fixed "Change directory" in SDK hosts (e.g. Claude Desktop) failing with "A turn is in progress" on idle sessions that have a running background task
- Fixed the workflow save dialog showing
~/.claude/workflows/instead of theCLAUDE_CONFIG_DIRlocation for user-scope saves - Fixed
/release-notesadding the viewed notes to the model's context; "Show all" previously injected the entire changelog into every subsequent request - Fixed a memory leak in the agent view where pasted images were retained for the screen's lifetime after sending peek replies
- Fixed SDK sessions losing agents defined via the initialize request when a plugin refresh ran before the client attached
- Fixed several memory leaks in long sessions: MCP stdio server stderr accumulating up to 64 MB per server, LSP documents staying open indefinitely (now LRU with 50-doc cap), async hook output retained after backgrounding, and unbounded growth in headless/SDK sessions from large tool-result payloads
- Fixed a memory blowup when reading files with extremely long single lines using offset/limit; the read now returns a clean error instead of loading the whole line
- Fixed multi-second per-turn slowdowns in sessions with many permission deny/ask rules; rule matchers are now compiled once and cached
- Improved input responsiveness while agent task lists update; task updates no longer re-render the entire UI
- Reduced per-tool-call CPU overhead in print/SDK sessions with many MCP tools by caching tool-pool assembly (up to 7x faster tool rounds at high tool counts)
- Reduced memory usage by bounding the file edit read cache to 16 MB instead of pinning up to 1,000 full files
- Reduced session transcript size (up to 79x in edit-heavy sessions) and bounded checkpoint disk usage by pruning superseded file-history backups
- Reduced memory usage when resuming sessions with background agents or forks spawned from large conversations
- Completed background agents now stay listed in
/tasksuntil cleanup instead of vanishing the moment they finish - Attaching to a stopped background agent now shows its transcript immediately while the session warms up, instead of a blank "Session is starting" screen
- Background sessions: an older daemon no longer silently restarts workers spawned by a newer version onto the older binary
- Agent view: Ctrl+X now deletes renamed-branch worktrees, never destroys unpushed commits, keeps the session row when a worktree is kept, and reused worktree names reset to the current base
- Catastrophic removals (e.g.
rm -rf ~) in commands containing$()/backticks/<()now prompt in--dangerously-skip-permissionsand auto mode, matching the plain form /install-github-appand the/mcpsettings menu no longer open in background sessions- MCP servers configured with an empty URL now show as "not configured" in
/mcpinstead of a config error /usagenow shows your last-known usage bars with an "as of" note when the usage endpoint is rate-limited, instead of an error screen- Fixed Bedrock auth failing with "Session token not found or invalid" for AWS SSO profiles whose sso_region differs from the Bedrock region (2.1.207 regression)
Notes
Memory and performance: the most comprehensive cleanup in weeks
This release addresses more memory and performance issues than any single release since the 2.1.19x series. Six distinct memory leaks are fixed: MCP stdio server stderr could accumulate up to 64 MB per server in long sessions, LSP documents stayed open indefinitely (now capped at 50 via LRU), async hook output was retained after backgrounding, headless/SDK sessions grew unboundedly from large tool-result payloads, the file edit read cache pinned up to 1,000 full files (now capped at 16 MB), and pasted images in the agent view were never released.
On the performance side, three bottlenecks are removed. Permission deny/ask rule matching, which caused multi-second per-turn slowdowns in repos with many rules, is now compiled once and cached. Tool-pool assembly for sessions with many MCP tools is cached, yielding up to 7x faster tool rounds. Session transcript size in edit-heavy sessions is reduced up to 79x by pruning superseded file-history backups.