v2.40.1

2.40.1 (2026-06-09)

Full Changelog: v2.40.0...v2.40.1

Bug Fixes

• api: add frontier_llm refusal category (1627fd3)

v2.40.0

2.40.0 (2026-06-09)

Full Changelog: v2.39.0...v2.40.0

Features

• api: add support for Managed Agents deployments and environment variable credentials (628720b)

v2.39.0

2.39.0 (2026-06-09)

Full Changelog: v2.38.0...v2.39.0

Features

• api: add support for claude-mythos-5 and claude-fable-5, with support for server-side fallbacks on refusal (835fb42)
• client: adds client-side fallbacks middleware for API providers that do not support server-side fallbacks (835fb42)

Bug Fixes

• 3p middleware ordering (#34) (d01da3a)
• streaming: merge message_delta usage without dropping or rejecting iterations (#39) (e3af118)

v2.38.0

2.38.0 (2026-06-06)

Full Changelog: v2.37.0...v2.38.0

Features

• api: small updates to Managed Agents types (c7b08d8)

v2.37.0

2.37.0 (2026-06-05)

Full Changelog: v2.36.0...v2.37.0

Features

• api: mark Claude Opus 4.1 as deprecated (693cbb4)

v2.36.0

2.36.0 (2026-06-04)

Full Changelog: v2.35.0...v2.36.0

Features

• client: add interceptors support (565ab77)

Bug Fixes

• client: allow .addX methods on .toBuilder() (5255700)
• streaming: accumulate citations_delta without crashing on absent citations (#8) (ea1647e)
• streaming: carry encrypted_content through beta compaction accumulator (#1248) (ec42069)
• streaming: keep missing citations when accumulating text deltas (#20) (e912eba)

Chores

• fix build error in test (#23) (fa53392)
• internal: build local repo before minting jwt in workflow (226c529)
• internal: fix branch names (b66a5d2)
• internal: fix printed pkg url (c738596)
• internal: update private repo name (fc11324)

Documentation

• point security reports to Anthropic's HackerOne program (#10) (57040fd)

v2.35.0

2.35.0 (2026-05-28)

Full Changelog: v2.34.1...v2.35.0

Features

• api: Add support for claude-opus-4-8, mid-conversation system blocks, and usage.output_tokens_details (3e4621e)

v2.34.1

2.34.1 (2026-05-27)

Full Changelog: v2.34.0...v2.34.1

Bug Fixes

• structured-outputs: support all nullability annotations (#1254) (95e4391)

Documentation

• replace literal newlines (c5573d9)

v2.34.0

2.34.0 (2026-05-21)

Full Changelog: v2.33.0...v2.34.0

Features

• api: Add support for thinking-token-count beta for estimated tokens in thinking block deltas when streaming (c814c7a)

Bug Fixes

• test: set required estimatedTokens on BetaThinkingDelta in BetaMessageAccumulatorTest (04aedf3)

v2.33.0

2.33.0 (2026-05-19)

Full Changelog: v2.32.0...v2.33.0

Features

• client: Add support for self-hosted sandboxes in CMA with sandbox helpers (d519362)