--- title: "pyo3 Breaking Changes on crates.io | Since.dev" description: "What each pyo3 release removed, renamed or changed: 189 breaking changes in 5 versions on crates.io, each with its source." canonical_url: https://since.dev/packages/crates/pyo3 last_updated: 2026-10-14 --- # pyo3 breaking changes Every breaking API change we have recorded in pyo3 on crates.io: 189 breaking changes in 5 versions. Below are its newest 5 versions, removals and renames first, each with its source. Newest change October 14, 2026 ## 0.30.1 59 breaking changes, first published October 14, 2026. - **Removed** `pyo3::prelude::Py::from_borrowed_ptr` Use Borrowed::from_borrowed_ptr instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::prelude::Py::from_borrowed_ptr_or_err` Use Borrowed::from_borrowed_ptr_or_err instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::prelude::Py::from_borrowed_ptr_or_opt` Use Borrowed::from_borrowed_ptr_or_opt instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::prelude::Py::from_owned_ptr` Use Bound::from_owned_ptr instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::prelude::Py::from_owned_ptr_or_err` Use Bound::from_owned_ptr_or_err instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::prelude::Py::from_owned_ptr_or_opt` Use Bound::from_owned_ptr_or_opt instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::Py::from_borrowed_ptr` Use Borrowed::from_borrowed_ptr instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::Py::from_borrowed_ptr_or_err` Use Borrowed::from_borrowed_ptr_or_err instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::Py::from_borrowed_ptr_or_opt` Use Borrowed::from_borrowed_ptr_or_opt instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) - **Removed** `pyo3::Py::from_owned_ptr` Use Bound::from_owned_ptr instead. [crates.io](https://crates.io/crates/pyo3/0.30.1) And 49 more in this version. ## 0.29.0 65 breaking changes, first published June 11, 2026. - **Removed** PyO3 0.29 no longer supports the experimental free-threaded Python 3.13t build; use Python 3.14t instead. [github.com](https://github.com/PyO3/pyo3/releases/tag/v0.29.0) - **Removed** PyO3 0.29 no longer supports Python 3.7, so projects on Python 3.7 must stay on PyO3 0.28 or move to a newer Python. [github.com](https://github.com/PyO3/pyo3/releases/tag/v0.29.0) - **Removed** Private CPython APIs with the \_Py underscore prefix have been removed from pyo3-ffi's public API, so code that uses them must change. [github.com](https://github.com/PyO3/pyo3/releases/tag/v0.29.0) - **Removed** `From for PyErr` Build a UnicodeDecodeError manually with PyUnicodeDecodeError::new_err instead. [pyo3.rs](https://pyo3.rs/v0.29.0/migration.html) - **Removed** `pyo3::conversion::FromPyObject::type_input` pyo3::conversion::FromPyObject::type_input was removed in pyo3 0.29.0 [crates.io](https://crates.io/crates/pyo3/0.29.0) - **Removed** `pyo3::conversion::IntoPyObject::type_output` pyo3::conversion::IntoPyObject::type_output was removed in pyo3 0.29.0 [crates.io](https://crates.io/crates/pyo3/0.29.0) - **Removed** `pyo3::DowncastError` Use CastError instead. [crates.io](https://crates.io/crates/pyo3/0.29.0) - **Removed** `pyo3::DowncastIntoError` Use CastIntoError instead. [crates.io](https://crates.io/crates/pyo3/0.29.0) - **Removed** `pyo3::FromPyObject::type_input` pyo3::FromPyObject::type_input was removed in pyo3 0.29.0 [crates.io](https://crates.io/crates/pyo3/0.29.0) - **Removed** `pyo3::import_exception_bound!` pyo3::import_exception_bound! was removed in pyo3 0.29.0 [crates.io](https://crates.io/crates/pyo3/0.29.0) And 55 more in this version. ## 0.28.2 61 breaking changes, first published February 18, 2026. - **Removed** `PyClassInitializer` The From> and From> conversions into PyClassInitializer were removed. Use clone or clone_ref on the existing object instead. [pyo3.rs](https://pyo3.rs/v0.28.0/migration.html) - **Removed** `pyo3::buffer::PyBuffer::buf_ptr` pyo3::buffer::PyBuffer::buf_ptr was removed in pyo3 0.28.2 [crates.io](https://crates.io/crates/pyo3/0.28.2) - **Removed** `pyo3::buffer::PyBuffer::dimensions` pyo3::buffer::PyBuffer::dimensions was removed in pyo3 0.28.2 [crates.io](https://crates.io/crates/pyo3/0.28.2) - **Removed** `pyo3::buffer::PyBuffer::format` Methods such as format moved from PyBuffer to PyUntypedBuffer. Method call syntax still works through dereferencing, but direct references to the moved functions need updating. [crates.io](https://crates.io/crates/pyo3/0.28.2) - **Removed** `pyo3::buffer::PyBuffer::get_ptr` pyo3::buffer::PyBuffer::get_ptr was removed in pyo3 0.28.2 [crates.io](https://crates.io/crates/pyo3/0.28.2) - **Removed** `pyo3::buffer::PyBuffer::is_c_contiguous` pyo3::buffer::PyBuffer::is_c_contiguous was removed in pyo3 0.28.2 [crates.io](https://crates.io/crates/pyo3/0.28.2) - **Removed** `pyo3::buffer::PyBuffer::is_fortran_contiguous` pyo3::buffer::PyBuffer::is_fortran_contiguous was removed in pyo3 0.28.2 [crates.io](https://crates.io/crates/pyo3/0.28.2) - **Removed** `pyo3::buffer::PyBuffer::item_count` pyo3::buffer::PyBuffer::item_count was removed in pyo3 0.28.2 [crates.io](https://crates.io/crates/pyo3/0.28.2) - **Removed** `pyo3::buffer::PyBuffer::item_size` pyo3::buffer::PyBuffer::item_size was removed in pyo3 0.28.2 [crates.io](https://crates.io/crates/pyo3/0.28.2) - **Removed** `pyo3::buffer::PyBuffer::len_bytes` pyo3::buffer::PyBuffer::len_bytes was removed in pyo3 0.28.2 [crates.io](https://crates.io/crates/pyo3/0.28.2) And 51 more in this version. ## 0.28.0 2 breaking changes, first published February 18, 2026. - **Removed** Code that relied on these private FFI definitions from pyo3::ffi will no longer compile. [github.com](https://github.com/PyO3/pyo3/releases/tag/v0.28.0) - **Configuration changed** Projects building PyO3 must use Rust 1.83 or later. [github.com](https://github.com/PyO3/pyo3/releases/tag/v0.28.0) ## 0.30.0 2 breaking changes, first published October 14, 2026. - **Removed** Python 3.8 is no longer supported, so projects on it must move to a newer Python version before upgrading. [github.com](https://github.com/PyO3/pyo3/releases/tag/v0.30.0) - **Configuration changed** Projects must build with Rust 1.85 or newer to use this release. [github.com](https://github.com/PyO3/pyo3/releases/tag/v0.30.0) ## Check your code These are the changes. To see which of them reach your code, [scan a public repository](https://since.dev/scan.md), or have your coding agent call `check_code` with your manifest or lockfile over [MCP](https://since.dev/docs.md#mcp). [The API](https://since.dev/docs.md#api) reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys. ## Put your code on continuous management. Scan a public repository now, or give your agent one line. ### See how out of date your code is. [Scan a repository](https://since.dev/scan.md). Any public GitHub repository. No sign-in. ### Tell your agent what changed since it was trained. `claude mcp add --transport http since https://api.since.dev/mcp` --- Every page on this site as Markdown: https://since.dev/sitemap.md. For agents: https://since.dev/llms.txt.