anthropic breaking changes

**client:** run formatter ([2e4ff86](https://github.com/anthropics/anthropic-sdk-python/commit/2e4ff86d7b8bef8fe5c4b7e62bf47dfff79f0577))

**structured outputs:** avoid including beta header if `output_format` is missing ([#1121](https://github.com/anthropics/anthropic-sdk-python/issues/1121)) ([062077e](https://github.com/anthropics/anthropic-sdk-python/commit/062077e50d182719637403576f59761999b3b2f5))

**ci:** upgrade `actions/github-script` ([34df616](https://github.com/anthropics/anthropic-sdk-python/commit/34df6160ad386a7e8848e3435b22bd18bd726702))

**client:** add custom JSON encoder for extended type support ([7780e90](https://github.com/anthropics/anthropic-sdk-python/commit/7780e90bd2fe4c1116d59bc0ad543aa609fc643d))

use output_config for structured outputs ([82d669d](https://github.com/anthropics/anthropic-sdk-python/commit/82d669db652ed3d9aede61fd500fabb291b8f035))

**internal:** update `actions/checkout` version ([ea50de9](https://github.com/anthropics/anthropic-sdk-python/commit/ea50de95bd1e43b8f00a45ef472330a3c8b396c8))

remove class causing breaking change ([#1333](https://github.com/anthropics/anthropic-sdk-python/issues/1333)) ([81ee953](https://github.com/anthropics/anthropic-sdk-python/commit/81ee9533d14f9dc3753a4a1320ea744825b17e92))

**client:** adds support for code-execution-2025-08-26 tool ([fe92af0](https://github.com/anthropics/anthropic-sdk-python/commit/fe92af02a2fa2d1bc626bb238ee54886bc701829))

**types:** replace List[str] with SequenceNotStr in params ([f542b54](https://github.com/anthropics/anthropic-sdk-python/commit/f542b541ba1e70b65704e9b96a87733cb1d9d77f))

avoid newer type syntax ([c6d1cf5](https://github.com/anthropics/anthropic-sdk-python/commit/c6d1cf5895f15d5fc526af9a34a6b53a514bf28e))

**client:** sync SequenceNotStr over to custom stream methods ([dd16483](https://github.com/anthropics/anthropic-sdk-python/commit/dd16483da5900a9c02519617d52d951f429d4685))

**internal:** add Sequence related utils ([d523f29](https://github.com/anthropics/anthropic-sdk-python/commit/d523f295541c23de43d3b51512327265d243ac35))

**internal:** bump uv version ([aab5bc6](https://github.com/anthropics/anthropic-sdk-python/commit/aab5bc667e5aa1144dc45650cd4c6a63f1be6051))

**internal:** change ci workflow machines ([5383431](https://github.com/anthropics/anthropic-sdk-python/commit/5383431a31c7368c45f7cc42b358798a2f2c8a7f))

**internal:** codegen related update ([eb8b19f](https://github.com/anthropics/anthropic-sdk-python/commit/eb8b19f5d7e6e4af3cfbf4cc6f02a9e5ce50f1b8))

**internal:** improve breaking change detection ([6c8afa9](https://github.com/anthropics/anthropic-sdk-python/commit/6c8afa9c9fb667d824d0630de22c1662e85d7bd3))

**internal:** refactor pydantic v1 test setup ([cb5444b](https://github.com/anthropics/anthropic-sdk-python/commit/cb5444be33dd798748fc5d0709ce1d47d5d4c012))

**internal:** run tests in an isolated environment ([9adb089](https://github.com/anthropics/anthropic-sdk-python/commit/9adb089e2fb0d67b23b389128e2375a134564ef5))

**internal:** update pyright exclude list ([85961ef](https://github.com/anthropics/anthropic-sdk-python/commit/85961ef1d4cec5243c2e74160df65aef3090a59a))

update github action ([1e6a135](https://github.com/anthropics/anthropic-sdk-python/commit/1e6a1353d045b26cea766fc6bcf7331159522fa5))

**client:** remove unused import ([712c6d8](https://github.com/anthropics/anthropic-sdk-python/commit/712c6d8b1c47eb663d2fc06b97b8c0630d4579cf))

update @stainless-api/prism-cli to v5.15.0 ([55cb0a1](https://github.com/anthropics/anthropic-sdk-python/commit/55cb0a1d1f42f6bcae74c6d1946f927534e30276))

**betas:** add context-1m-2025-08-07 ([57a80e7](https://github.com/anthropics/anthropic-sdk-python/commit/57a80e7a2cf6813db6633516dbb5bb65a6e85122))

**internal:** update comment in script ([9e9d69c](https://github.com/anthropics/anthropic-sdk-python/commit/9e9d69cdd98a838adac734a0748e1f52ccd4faa4))

**internal:** update test skipping reason ([b18a3d5](https://github.com/anthropics/anthropic-sdk-python/commit/b18a3d55a8f75ba3257ec83283d31bcb82548713))

**internal:** detect breaking changes when removing endpoints ([5c62d7b](https://github.com/anthropics/anthropic-sdk-python/commit/5c62d7bdaf8a180dcb6bc30c17a6bdf13d976ab2))

**tests:** run tests with min and max supported Python versions by default ([0ad8534](https://github.com/anthropics/anthropic-sdk-python/commit/0ad85343fbe4d2934aa826fde36c7927f7b57803))

**internal:** codegen related update ([a385cb9](https://github.com/anthropics/anthropic-sdk-python/commit/a385cb9270f8214907ce1f4923e16537ac10cdab))

**bedrock:** automatically infer AWS Region ([#974](https://github.com/anthropics/anthropic-sdk-python/issues/974)) ([f648e09](https://github.com/anthropics/anthropic-sdk-python/commit/f648e09c43ea227a7a388cbdd21e8ddb762963e4))

**vertex:** support global region endpoint ([1fd1adf](https://github.com/anthropics/anthropic-sdk-python/commit/1fd1adf736e4e5a3e16819c052903dfe4a436132))

**ci:** correct conditional ([18e625a](https://github.com/anthropics/anthropic-sdk-python/commit/18e625a1a6de15ff7729149c19b8c22191ed8622))

**ci:** release-doctor — report correct token name ([c91f50d](https://github.com/anthropics/anthropic-sdk-python/commit/c91f50dbd7057ea465b9d71795488cdae8c1a13a))

**ci:** only run for pushes and fork pull requests ([447b793](https://github.com/anthropics/anthropic-sdk-python/commit/447b793baf8ba4df63a8fcfcd870a85dd2d07f07))

**internal:** add breaking change detection ([e6d0eca](https://github.com/anthropics/anthropic-sdk-python/commit/e6d0eca3fc5c918b56e42fbe46fcf9bedd26ca4d))

**internal:** codegen related update ([f88517b](https://github.com/anthropics/anthropic-sdk-python/commit/f88517bfb56969674b82193b788d2043806e5a39))

**internal:** codegen related update ([9d4b537](https://github.com/anthropics/anthropic-sdk-python/commit/9d4b537be3e248f2ce0d98721f9bbbdc32b75575))

**internal:** codegen related update ([6a3a6fe](https://github.com/anthropics/anthropic-sdk-python/commit/6a3a6fe3743ee448a83f294d394c5bf9b214176f))

**internal:** codegen related update ([28704a6](https://github.com/anthropics/anthropic-sdk-python/commit/28704a63eb20f6ed78f13b424190cac14aca8a0f))

**tests:** skip some failing tests on the latest python versions ([f63a2d2](https://github.com/anthropics/anthropic-sdk-python/commit/f63a2d29d5c56175078eaf5c67a142aec0937174))

**tests:** avoid deprecation warnings ([71b432f](https://github.com/anthropics/anthropic-sdk-python/commit/71b432f2d22d72f6763d7042677cb43122302ded))

This functionality has been replaced by the `client.beta.messages.count_tokens()` API which supports newer models and all content functionality, such as images and PDFs.

**client:** remove legacy `client.count_tokens()` & `client.get_tokenizer()` methods ([#726](https://github.com/anthropics/anthropic-sdk-python/issues/726))

**client:** don't error by default for unexpected content types ([#161](https://github.com/anthropics/anthropic-sdk-python/issues/161)) ([76cfcf9](https://github.com/anthropics/anthropic-sdk-python/commit/76cfcf91172f9804056a7d5c1ec99666ad5991a2))

update readme ([#172](https://github.com/anthropics/anthropic-sdk-python/issues/172)) ([351095b](https://github.com/anthropics/anthropic-sdk-python/commit/351095b189b111a74e9e1825ce5b6da6673a1635))

**client:** add forwards-compatible pydantic methods ([#171](https://github.com/anthropics/anthropic-sdk-python/issues/171)) ([4c5289e](https://github.com/anthropics/anthropic-sdk-python/commit/4c5289eb8519ca9a53e9483422237aa25944f8d8))

**client:** add support for passing in a httpx client ([#173](https://github.com/anthropics/anthropic-sdk-python/issues/173)) ([25046c4](https://github.com/anthropics/anthropic-sdk-python/commit/25046c4fbc6f9d343e3b1f21024cf3982ac48c35))

**client:** handle retry-after header with a date format ([#168](https://github.com/anthropics/anthropic-sdk-python/issues/168)) ([afeabf1](https://github.com/anthropics/anthropic-sdk-python/commit/afeabf13aa5795a7fadd141e53ec81eadbce099a))

**client:** retry on 408 Request Timeout ([#155](https://github.com/anthropics/anthropic-sdk-python/issues/155)) ([46386f8](https://github.com/anthropics/anthropic-sdk-python/commit/46386f8f60223f45bc133ddfcfda8d9ca9da26a8))

**package:** export a root error type ([#163](https://github.com/anthropics/anthropic-sdk-python/issues/163)) ([e7aa3e7](https://github.com/anthropics/anthropic-sdk-python/commit/e7aa3e7785ae511fa35a68ac72079a6230ca84f3))

**types:** improve params type names ([#160](https://github.com/anthropics/anthropic-sdk-python/issues/160)) ([43544a6](https://github.com/anthropics/anthropic-sdk-python/commit/43544a62c8410061c1a50282f4c45d029db7779b))

**client:** properly configure model set fields ([#154](https://github.com/anthropics/anthropic-sdk-python/issues/154)) ([da6ccb1](https://github.com/anthropics/anthropic-sdk-python/commit/da6ccb10a38e862153871a540cb75af0afdaefb3))

**internal:** add helpers ([#156](https://github.com/anthropics/anthropic-sdk-python/issues/156)) ([00f5a19](https://github.com/anthropics/anthropic-sdk-python/commit/00f5a19c9393f6238759faea40405e60b2054da3))

**internal:** move error classes from _base_exceptions to _exceptions (⚠️ breaking) ([#162](https://github.com/anthropics/anthropic-sdk-python/issues/162)) ([329b307](https://github.com/anthropics/anthropic-sdk-python/commit/329b307c205435d367c0d4b29b252be807c61c68))

**tests:** improve raw response test ([#166](https://github.com/anthropics/anthropic-sdk-python/issues/166)) ([8042473](https://github.com/anthropics/anthropic-sdk-python/commit/8042473bd73faa0b819c27a68bfc19b918361461))

add some missing inline documentation ([#151](https://github.com/anthropics/anthropic-sdk-python/issues/151)) ([1f98257](https://github.com/anthropics/anthropic-sdk-python/commit/1f9825775d58ed8a62b000caaddd622ed4ba3fd2))

**streaming:** remove old event_handler API ([#532](https://github.com/anthropics/anthropic-sdk-python/issues/532))

**api:** add Raw prefix to API stream event type names ([#529](https://github.com/anthropics/anthropic-sdk-python/issues/529)) ([bb62980](https://github.com/anthropics/anthropic-sdk-python/commit/bb629806887de6cd3e5d517af4d9615f40076542))

**api:** tool use is GA and available on 3P ([#530](https://github.com/anthropics/anthropic-sdk-python/issues/530)) ([ad7adbd](https://github.com/anthropics/anthropic-sdk-python/commit/ad7adbd2a732db98665333c27065ff4f4c946f15))

**streaming/tools:** refactor to event iterator structure ([bdcc283](https://github.com/anthropics/anthropic-sdk-python/commit/bdcc28303206fde2da01296cdae553c1e8efb60a))

**streaming:** add tools support ([9f00950](https://github.com/anthropics/anthropic-sdk-python/commit/9f00950b81d388f14027c48aca1ca3c044b93a03))

**beta:** streaming breakage due to breaking change in dependency ([afe3c87](https://github.com/anthropics/anthropic-sdk-python/commit/afe3c8726576cdc7e0503707f53fa9a80caed962))

add missing __all__ definitions ([#526](https://github.com/anthropics/anthropic-sdk-python/issues/526)) ([5021787](https://github.com/anthropics/anthropic-sdk-python/commit/5021787caeda8a38775c69449a5794b1072dbfe5))

**examples:** update tools ([56edecc](https://github.com/anthropics/anthropic-sdk-python/commit/56edecc2de1e943d6ca09a788c4fabac5978ea2d))

**formatting:** misc fixups ([fbad5a0](https://github.com/anthropics/anthropic-sdk-python/commit/fbad5a0e0d7f4dbeeffa8a038600c9acb88002fc))

**internal:** fix lint issues in tests ([d857640](https://github.com/anthropics/anthropic-sdk-python/commit/d857640c1e30b580e7e94e034a1fbc07f655acc6))

**internal:** update bootstrap script ([#527](https://github.com/anthropics/anthropic-sdk-python/issues/527)) ([93ae152](https://github.com/anthropics/anthropic-sdk-python/commit/93ae1528c0404631f32c49341032ca0d11314b80))

**internal:** update some references to rye-up.com ([00e34e7](https://github.com/anthropics/anthropic-sdk-python/commit/00e34e7fbbb3a797d55bb94c07d551ad083dc7d9))

**helpers:** mention input json event ([02d482c](https://github.com/anthropics/anthropic-sdk-python/commit/02d482c03c039bc635c4d35e04cebe4670e1762c))

**tests:** ensure messages.create() and messages.stream() stay in sync ([52bd67b](https://github.com/anthropics/anthropic-sdk-python/commit/52bd67b041283adeee662355d8df297ca4b1d560))

**helpers:** update for new event iterator ([26f9533](https://github.com/anthropics/anthropic-sdk-python/commit/26f9533df19ee3da55c590238eba745051cccf6c))

**streaming/messages:** refactor to event iterator structure ([997af69](https://github.com/anthropics/anthropic-sdk-python/commit/997af696a713a604d4146f36caf91397ba488e33))