Claude Code 2.1.45
**Claude Sonnet 4.6 support + SDK rate-limit observability.** Model expansion (new flagship) + SDK types for throttle-aware consumer code. Why it matters: agents and tools that respect rate limits can now signal backpressure programmatically.
New primitives
Claude Sonnet 4.6capabilityModel support for Claude Sonnet 4.6
--add-dir plugins/marketplacesflag-extensionExtended `--add-dir` to read `enabledPlugins` and `extraKnownMarketplaces` from directories
spinnerTipsOverridesettingCustomize spinner tips with custom tip array; optionally exclude default tips
SDKRateLimitInfo / SDKRateLimitEventSDK-typesSDK types enabling consumers to receive rate limit status updates including utilization, reset times, and overage information
Workflow recipes
Agents consuming the SDK can now observe rate-limit utilization and reset times in real time, enabling intelligent work-deferral and priority-based queueing strategies. Sonnet 4.6 as the model tier increases throughput ceiling, making observability more actionable.
Build an agent coordinator that consumes SDKRateLimitEvent types to track per-endpoint utilization (tokens, requests), calculates backoff windows dynamically, and routes high-priority work to Sonnet 4.6 when available while deferring or batching lower-priority tasks. Pluggable backends (Bedrock, Vertex, Foundry) propagate the same events, allowing cloud agents to share a unified backpressure model.
Agents can now bulk-load plugin catalogs and marketplace definitions from directories, enabling dynamic capability composition. spinnerTipsOverride makes long operations more agent-transparent (can be used to signal phase/status in feedback loops).
On startup, an orchestrator agent reads a curated --add-dir directory containing plugin manifests and marketplace definitions, auto-discovers available tools and commands, and builds a live capability graph. During multi-step workflows, spinner tips can be overridden to echo the current task context (e.g., "Scanning SAGO definitions", "Building draft offer"), making progress observable to downstream logs/monitoring without polling.
Agentic relevance
SDK rate-limit types enable agents to implement backpressure and throttle-aware work planning. Sonnet 4.6 support gives agents access to a new flagship model capability (if configured). Plugin/marketplace discovery via `--add-dir` expands agent composition surface for multi-tool orchestration.
Hardening & fixes (11)
- Fixed Agent Teams teammates failing on Bedrock, Vertex, and Foundry by propagating API provider environment variables to tmux-spawned processes (anthropics/claude-code#23561)
- Fixed sandbox "operation not permitted" errors when writing temporary files on macOS by using the correct per-user temp directory (anthropics/claude-code#21654)
- Fixed Task tool (backgrounded agents) crashing with a `ReferenceError` on completion (anthropics/claude-code#22087)
- Fixed autocomplete suggestions not being accepted on Enter when images are pasted in the input
- Fixed skills invoked by subagents incorrectly appearing in main session context after compaction
- Fixed excessive `.claude.json.backup` files accumulating on every startup
- Fixed plugin-provided commands, agents, and hooks not being available immediately after installation without requiring a restart
- Improved startup performance by removing eager loading of session history for stats caching
- Improved memory usage for shell commands that produce large output — RSS no longer grows unboundedly with command output size
- Improved collapsed read/search groups to show the current file or search pattern being processed beneath the summary line while active
- [VSCode] Improved permission destination choice (project/user/session) to persist across sessions
Raw changelog
## 2.1.45 - Added support for Claude Sonnet 4.6 - Added support for reading `enabledPlugins` and `extraKnownMarketplaces` from `--add-dir` directories - Added `spinnerTipsOverride` setting to customize spinner tips — configure `tips` with an array of custom tip strings, and optionally set `excludeDefault: true` to show only your custom tips instead of the built-in ones - Added `SDKRateLimitInfo` and `SDKRateLimitEvent` types to the SDK, enabling consumers to receive rate limit status updates including utilization, reset times, and overage information - Fixed Agent Teams teammates failing on Bedrock, Vertex, and Foundry by propagating API provider environment variables to tmux-spawned processes (anthropics/claude-code#23561) - Fixed sandbox "operation not permitted" errors when writing temporary files on macOS by using the correct per-user temp directory (anthropics/claude-code#21654) - Fixed Task tool (backgrounded agents) crashing with a `ReferenceError` on completion (anthropics/claude-code#22087) - Fixed autocomplete suggestions not being accepted on Enter when images are pasted in the input - Fixed skills invoked by subagents incorrectly appearing in main session context after compaction - Fixed excessive `.claude.json.backup` files accumulating on every startup - Fixed plugin-provided commands, agents, and hooks not being available immediately after installation without requiring a restart - Improved startup performance by removing eager loading of session history for stats caching - Improved memory usage for shell commands that produce large output — RSS no longer grows unboundedly with command output size - Improved collapsed read/search groups to show the current file or search pattern being processed beneath the summary line while active - [VSCode] Improved permission destination choice (project/user/session) to persist across sessions