AnthropicClaude Code

Claude Code 2.1.51

Tuesday, 24 February 20263 new4 fixes5 other

AI summary

Written by AI from the official notes. Check them for exact details.

Claude Code 2.1.51 introduces new features for plugin management and improves performance and security.

Added claude remote-control for external builds and local serving.
Updated plugin marketplace git timeout to 120s.
Support for custom npm registries and version pinning added.
BashTool skips login shell by default for better performance.
Tool results larger than 50K characters are now persisted to disk.

Why it matters: Developers and users of Claude tools should care for enhanced functionality and improved security.

Official notes on github.com

Full release notes12 changes

What's changed

Added claude remote-control subcommand for external builds, enabling local environment serving for all users.
Updated plugin marketplace default git timeout from 30s to 120s and added CLAUDE_CODE_PLUGIN_GIT_TIMEOUT_MS to configure.
Added support for custom npm registries and specific version pinning when installing plugins from npm sources
BashTool now skips login shell (-l flag) by default when a shell snapshot is available, improving command execution performance. Previously this required setting CLAUDE_BASH_NO_LOGIN=true.
Fixed a security issue where statusLine and fileSuggestion hook commands could execute without workspace trust acceptance in interactive mode.
Tool results larger than 50K characters are now persisted to disk (previously 100K). This reduces context window usage and improves conversation longevity.
Fixed a security issue where HTTP hooks could interpolate arbitrary environment variables from header values. Env var interpolation now requires an explicit allowedEnvVars list in the hook configuration.
Fixed a bug where duplicate control_response messages (e.g. from WebSocket reconnects) could cause API 400 errors by pushing duplicate assistant messages into the conversation.
Added CLAUDE_CODE_ACCOUNT_UUID, CLAUDE_CODE_USER_EMAIL, and CLAUDE_CODE_ORGANIZATION_UUID environment variables for SDK callers to provide account info synchronously, eliminating a race condition where early telemetry events lacked account metadata.
Fixed slash command autocomplete crashing when a plugin's SKILL.md description is a YAML array or other non-string type
HTTP hooks are now routed through the sandbox network proxy when sandboxing is enabled, enforcing the domain allowlist. HTTP hooks are not supported for SessionStart/Setup events.
The /model picker now shows human-readable labels (e.g., "Sonnet 4.5") instead of raw model IDs for pinned model versions, with an upgrade hint when a newer version is available.

Full release notes12 changes

What's changed

Added claude remote-control subcommand for external builds, enabling local environment serving for all users.
Updated plugin marketplace default git timeout from 30s to 120s and added CLAUDE_CODE_PLUGIN_GIT_TIMEOUT_MS to configure.
Added support for custom npm registries and specific version pinning when installing plugins from npm sources
BashTool now skips login shell (-l flag) by default when a shell snapshot is available, improving command execution performance. Previously this required setting CLAUDE_BASH_NO_LOGIN=true.
Fixed a security issue where statusLine and fileSuggestion hook commands could execute without workspace trust acceptance in interactive mode.
Tool results larger than 50K characters are now persisted to disk (previously 100K). This reduces context window usage and improves conversation longevity.
Fixed a security issue where HTTP hooks could interpolate arbitrary environment variables from header values. Env var interpolation now requires an explicit allowedEnvVars list in the hook configuration.
Fixed a bug where duplicate control_response messages (e.g. from WebSocket reconnects) could cause API 400 errors by pushing duplicate assistant messages into the conversation.
Added CLAUDE_CODE_ACCOUNT_UUID, CLAUDE_CODE_USER_EMAIL, and CLAUDE_CODE_ORGANIZATION_UUID environment variables for SDK callers to provide account info synchronously, eliminating a race condition where early telemetry events lacked account metadata.
Fixed slash command autocomplete crashing when a plugin's SKILL.md description is a YAML array or other non-string type
HTTP hooks are now routed through the sandbox network proxy when sandboxing is enabled, enforcing the domain allowlist. HTTP hooks are not supported for SessionStart/Setup events.
The /model picker now shows human-readable labels (e.g., "Sonnet 4.5") instead of raw model IDs for pinned model versions, with an upgrade hint when a newer version is available.