anthropics/claude-agent-sdk-python v0.2.82 on GitHub

Breaking: MCP servers now connect in the background by default; sessions start immediately and slow servers report status: "pending" in init until ready. Set MCP_CONNECTION_NONBLOCKING=0 to restore the old behavior of waiting up to 5s before the first query, or mark a server alwaysLoad: true to require it in turn 1.
Breaking: Headless and SDK sessions now use Task tools (TaskCreate / TaskUpdate / TaskGet / TaskList) instead of TodoWrite. Tool consumers should accumulate by task ID instead of replacing a snapshot list.

EffortLevel type export: Added a public EffortLevel type alias for Claude effort string levels ("low", "medium", "high", "max", "xhigh") and exported it from the package root, making it available for downstream SDK wrappers and type annotations (#951)

Stderr callback isolation: Fixed an issue where a user-provided stderr callback that raises an exception would silently terminate the stderr reader loop, dropping all subsequent stderr lines for the rest of the session. Exceptions are now caught per-line so a failing callback does not prevent delivery of later lines (#932)
CancelledError in eager-flush done callback: Fixed noisy Exception in callback log messages on shutdown when pending eager-flush tasks were cancelled. The done callback now gracefully handles CancelledError instead of unconditionally calling Task.exception() (#931)
Tighter permission_suggestions type: Replaced list[Any] | None with list[dict[str, Any]] | None on SDKControlPermissionRequest.permission_suggestions, enabling proper type-checking on consumers of that field (#955)

Clarified that hooks dispatch for a given event is concurrent (all matchers fire in parallel), not sequential, preventing incorrect assumptions about ordering-dependent hooks like rate limiters gating subsequent hooks (#956)

Bumped mcp dependency lower bound to >=1.23.0 to address GHSA-9h52-p55h-vw2f (CVE-2025-66416), which disables DNS rebinding protection by default in older versions (#927)
Stabilized eager-flush transcript mirror tests with deterministic wait helpers instead of fixed asyncio.sleep(0) yields (#933)
Updated bundled Claude CLI to version 2.1.142

PyPI: https://pypi.org/project/claude-agent-sdk/0.2.82/

pip install claude-agent-sdk==0.2.82