News

The project released v1.0.0 on 2026-08-20, with a breaking client upgrade to httpx2 plus minor breaking changes and a MIGRATION.md guide. It also fixes a beta warning around output_format on parse/stream/tool_runner helpers and updates documentation examples to use adaptive thinking.

v0.125.0 (2026-08-19) adds API support for managed agents web search configuration and self-hosted sandbox memory in commit b75afd6. These changes expand agent capabilities and deployment flexibility by letting teams tune search behavior and persist memory in their own sandbox setups.

v0.124.0 (2026-08-19) makes the Files and Skills APIs generally available and adds computer use and browser use toolsets. The GA status and new toolsets expand the platform’s core capabilities for file handling and agentic interaction with apps and web browsers.

v3.3.1 (2026-08-19) is a maintenance release that updates dependencies with published security fixes, migrates the build to uv, removes jsonschema and other unused fixture-validation dependencies, and locks the repository Pyright toolchain and mock server tooling. It also replaces an external README metadata hook and uses the standard library for platform detection, reducing supply-chain and build complexity.

v0.123.0, released on 2026-08-18, adds API updates for files, memory stores, skill, and user profiles, plus client helpers for reading workspace ID response headers. Notable fixes include removing unsupported mid-conversation system content blocks, avoiding subprocesses when computing platform headers, exporting several errors at the package root, and making session-tool execution and tool-result retries more robust.

v3.3.0, released on 2026-08-18, adds support for named data-residency endpoints, requires patched optional networking dependencies, removes unused dependencies, pins build tooling, and tightens Python SDK security contribution guidance. The main change is the new data-residency endpoint support, while the dependency and documentation updates suggest a security and maintenance-focused release.

Version 3.2.0 adds Bedrock Runtime endpoint support plus shell call streaming events and new service/image types. The update extends the API surface for Amazon Bedrock integrations and richer streaming/service handling.

v3.1.0 (2026-08-14) adds WebSocket stream IDs, workload identity access token issued events, Ultrafast tier support, structured MCP and WebSocket errors, and separate WebSocket events, while also deprecating the Sora video APIs. It also removes Stainless attribution and infrastructure, signaling a cleanup of the API surface alongside the new streaming and auth-related features.

Version 0.122.0 adds `output_behavior` to `dream` creation, letting callers either create a new memory store or update the input store in place, and exposes `beta.messages.parse`, `stream`, and `tool_runner` for Bedrock and Vertex. It also fixes async SigV4 signing, streaming message accumulation, and several client edge cases like empty Anthropic API credentials being treated as unset and symlink loops being rejected in tool paths.

Version 3.0.0 (2026-08-12) makes HTTPX2 the default HTTP client and stops installing httpx automatically, with a temporary runtime-only legacy HTTPX escape hatch for compatibility. The breaking change matters because apps using custom clients, transports, or config objects must migrate to HTTPX2 equivalents, making this a required API update rather than a simple dependency bump.

Version 2.54.0, dated 2026-08-11, adds new Responses model identifiers in the API and clarifies audio upload metadata requirements. It also updates generated-file header attribution to Castiron, a minor maintenance change that may matter for downstream tooling and compliance.

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.

Version 2.53.0, released 2026-08-03, adds gpt-5.5 and tool name/namespace fields to Responses types. It also fixes CI by avoiding NumPy source builds and duplicate HTTPX coverage, which mainly affects build reliability and SDK type coverage.

v2.52.1 was released on 2026-07-31 with a single chore change in CI: setup-uv v5 was pinned to its underlying commit in PR #3560. This is a small maintenance update that improves build reproducibility by avoiding changes from the moving v5 tag.

v2.52.0, released on 2026-07-31, adds API content provenance checks and documentation for API-key mTLS HTTP client recipes. It also changes the client to honor Retry-After delays for up to two minutes, which affects how rate-limited requests are retried.

v2.51.0, released 2026-07-30, adds an API fast tier and updates helper methods to include support for it. The change is notable because it extends a new tier across both the core API and helper methods, suggesting a broader rollout rather than a one-off endpoint update.

v2.50.0, released 2026-07-28, updates the transcription API model and restores the transcription keyword overload in audio. The change is notable because it affects both model behavior and a previously broken overload, which should improve compatibility for users of transcription workflows.

v0.120.2, released 2026-07-28, fixes MCP support to work with MCP SDK v2 alongside v1 in addition to the existing v1 integration. This matters because it preserves compatibility across MCP SDK versions, reducing breakage for users upgrading to v2.

v0.120.1, released on 2026-07-28, is a bug-fix update that pins the `mcp` extra to `<2` in response to issue #1783. This matters because it prevents the package from pulling in incompatible MCP v2 dependencies.

v2.49.0 was released on 2026-07-27, with features now requiring Python 3.10 and version reviews automated in PR #3537. The Python 3.10 requirement is a breaking change for older environments, while automated version reviews should reduce release friction and manual oversight.

v0.120.0, released on 2026-07-24, adds the Claude Opus 5 model, tool addition/removal blocks with tool_change events, and expanded client-side fallback credit token types plus a new server-side fallbacks default option. These API changes broaden model support and make tool orchestration and fallback behavior more explicit for client and server integrations.

v2.48.0, released on 2026-07-23, adds API support for accepting `None` for `prompt_cache_key` and `safety_identifier`, and introduces spend limit admin APIs. It matters because it expands administrative controls and makes those API fields more flexible for callers.

v0.119.0, released on 2026-07-23, adds a new API stop reason, `model_context_window_exceeded`, and fixes agent toolset read/edit handling for binary files. The new stop reason makes context-limit failures explicit, while the binary-file fix improves tool reliability when agents inspect or modify non-text content.

v2.47.0, released 2026-07-21, adds experimental runtime support for HTTPX2 clients in the client package and updates stlc workflow templates with configurable CI runners and private-production-repo support. It also fixes dependencies by requiring a patched aiohttp on Python 3.10+, which matters for keeping affected deployments secure and compatible.

v0.118.0 adds API support for Managed Agents model effort, initial session events, and threads delta streaming. These changes expand event and streaming capabilities for agent workflows, which can improve responsiveness and integration fidelity.

v0.117.1, released 2026-07-21, fixes AWS credential handling in `AnthropicAWS.copy()`, adds support for a new refusal category in the API, and includes documentation and dependency updates such as `http-snapshot` 0.1.9 and a pinned `httpx_aiohttp` major version. The refusal-category change is the most notable API-facing update, since it affects how clients interpret model outputs while the AWS fix addresses a correctness issue in copied client instances.

v2.46.0, dated 2026-07-17, adds the `/organization/projects/{project_id}/service_accounts/{service_account_id}/api_keys` endpoint and an `owner_project_access` field to `APIKeyListParams`, alongside several API manual updates. It also fixes generated type compatibility and removes beta-annotation compatibility aliases, signaling a cleanup of the API surface for downstream clients.

v0.117.0, dated 2026-07-16, adds API support for dreaming and MCP Tunnels, with bug fixes and documentation updates in the same release. The notable technical change is that credential material is kept out of traceback frame locals via `SecretStr`, improving secret handling during exceptions.

v2.45.0 was released on 2026-07-09 with a feature update for `gpt-5.6-sol`, a bug fix to restore beta resource accessors, and a release automation retrigger. The change is minor but notable for API users because it touches both model-related behavior and beta client compatibility.

v0.116.0, released on 2026-07-02, adds the `agent-memory-2026-07-22` beta header in the API. The new header suggests support for a forthcoming agent memory feature, which could affect how state is persisted across calls.

v0.115.1, released on 2026-07-01, removes some nonfunctional types from the SDKs in a chores/api change. It is a small cleanup release, with no new model or feature additions noted in the changelog.

v0.115.0, released on 2026-06-30, adds API support for Managed Agents event delta streaming, agent overrides, reverse pagination, vault credential injection scoping, and agent and deployment webhook events. These changes expand the platform’s agent orchestration and integration capabilities, especially for real-time event handling and more fine-grained deployment control.

v0.114.0, released on 2026-06-30, adds API support for Claude Sonnet 5 and fixes agent_toolset so absolute paths are allowed when they resolve inside the workdir. The model addition expands available Claude options, while the path fix removes a restriction that could break workflows using absolute paths.

v0.113.0, released on 2026-06-29, adds support for the 20260318 web fetch API and tools. It also fixes async token counting to merge `output_format` and `output_config`, and lets the API accept user profile IDs when counting tokens.

v2.44.0 was released on 2026-06-24 with a bug fix in auth to prioritize the first auth header. This matters because header precedence can affect which credentials are used when multiple auth headers are present, reducing ambiguity and unexpected authentication behavior.

v0.112.0, released on 2026-06-24, adds client support for streaming `system.message` events and includes API updates for a new refusal category and sending a User Profile ID in request headers. The release also fixes the memory tool so it creates parent directories with the correct permissions, a small but important filesystem-safety change.

v0.111.0, released on 2026-06-18, adds a helpers feature that tags refusal-fallback middleware requests with `fallback-refusal-middleware` (#96). This makes it easier to identify and trace fallback refusal handling in middleware flows.

v0.110.0, released on 2026-06-18, adds support for the new `code_execution_20260120` tool in the API and includes bug fixes for header merging, Bedrock stream event type preservation, and `x-stainless-helper` key handling. The notable detail is the new tool integration plus a cleanup of helper/header behavior, which should improve compatibility and reduce subtle request/streaming bugs.

v2.43.0 was released on 2026-06-17, with the only listed feature being an API update to the OpenAPI spec or Stainless config. The change is narrowly scoped and likely affects generated client or schema definitions rather than end-user functionality.

v2.42.0 was released on 2026-06-16 with new features for admin spend_alerts and manual updates, plus an updated OpenAPI spec/Stainless config and build-system changes including release workflow permission fixes and CI environment API keys for examples. The notable detail is that this is a fairly small maintenance-oriented release, but it adds admin spending controls and surfaces infrastructure hardening that can reduce deployment friction and security risk.

v0.109.2, released 2026-06-15, is a maintenance update whose only listed change is a chore to remove retired models from the API and SDKs. This matters because it keeps the surface area clean and prevents clients from relying on deprecated model names.

v2.41.1, released on 2026-06-05, updates the build system by removing the scheduled release workflow trigger in commit 2a91011, via issue #3366. This is a small maintenance change, but it alters release automation and could affect how future releases are triggered.

v0.109.1 (2026-06-09) adds a bug fix to the API by introducing a `frontier_llm` refusal category. This matters because it gives the API a more specific way to classify model refusals, which can improve downstream handling and reporting.

v0.109.0 was released on 2026-06-09, adding API support for Managed Agents deployments and environment variable credentials. This matters because it expands deployment options and makes authentication easier to configure in environment-based setups.

v0.108.0, released on 2026-06-09, adds API support for claude-mythos-5 and claude-fable-5, plus server-side fallbacks on refusal. It also introduces client-side fallbacks middleware for API providers that do not support server-side fallbacks, improving reliability across providers.

v0.107.1 was released on 2026-06-07 with a bug fix in foundry to send the `x-api-key` header when using API-key authentication. This matters because it restores compatibility with endpoints that require that specific header, closing issue #1661.

v0.107.0 was released on 2026-06-06, with the only listed feature being small updates to the Managed Agents API types. It matters mainly as a minor typed API refinement, indicating incremental changes rather than a major functional release.

v0.106.0, released 2026-06-05, marks Claude Opus 4.1 as deprecated and fixes Foundry client `copy()`/`with_options()` behavior plus schema handling so `$defs` are preserved when the root is a `$ref`. That matters because it signals a model lifecycle change while also tightening client and schema tooling used for integrations and code generation.

v2.41.0, released on 2026-06-03, adds `responses.moderation` and `chat_completions.moderation` features in the API. This matters because it extends moderation support to both the Responses and Chat Completions endpoints, making it easier to enforce safety checks across request types.

2.40.0 (2026-06-01) Full Changelog: v2.39.0...v2.40.0 Features api: Add Amazon Bedrock Responses support Bug Fixes api: allow setting bedrock api keys on the client directly (4d5bfde)