Anthropic SDK v0.121.0

v0.121.0 (2026-08-07) adds the `mid-conversation-tool-changes-2026-07-01` beta and expands the API with session budgets, an advisor tool, pinned inference location, and skills auto-loading from GitHub. It also removes retired Claude Opus 4.1 models and tightens dependency version constraints, which signals both new workflow controls and cleanup of deprecated support.

0.121.0 (2026-08-07) Full Changelog: v0.120.2...v0.121.0 Features api: add mid-conversation-tool-changes-2026-07-01 beta ( c7d1531 ) api: add support for session budgets, advisor tool, pinned inference location and skills auto-loading from GitHub ( 193bae0 ) Chores api: remove retired Claude Opus 4.1 models ( 5352a33 ) docs: small updates to descriptions ( b8d4176 ) docs: updates to a few documentation strings ( 3a5dd69 ) ensure all dependencies have major version constraints ( #274 ) ( d52999b )