# What changed in pgvector

> 14 changes in pgvector 0.4 to 0.5 from its official release notes, upgrade guides and advisories: 8 breaking, 1 new APIs and options. Each one cited. Sources checked 2026-10-28. HTML: https://unstale.sh/pypi/pgvector/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## pgvector 0.5

### Breaking changes

- For Django, SQLAlchemy, SQLModel, and Peewee, halfvec now returns a list. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)
- The dependency on NumPy was removed. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)
- Support for Python versions earlier than 3.10 was dropped. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)
- Re-exported classes were removed; use the top-level pgvector package instead. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)
- Support for SQLAlchemy versions earlier than 2 was dropped. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)
- The utils package was removed; use the top-level pgvector package instead. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)
- For Django, SQLAlchemy, SQLModel, and Peewee, vector now returns a list. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)
- For Psycopg 3, Psycopg 2, asyncpg, and pg8000, vector now returns a Vector object. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)

### New APIs and options

- Added experimental support for type hints. (0.5.0) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#050-2026-07-06)

### Fixes and other changes

- Fixed an error with the Bit constructor for NumPy 1.24–1.26. (0.5.1) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#051-2026-10-08)
- Fixed an error with non-canonical SciPy sparse arrays. (0.5.1) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#051-2026-10-08)
- Fixed an error with SciPy sparse arrays that contain explicit zeros. (0.5.1) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#051-2026-10-08)

## pgvector 0.4

### Fixes and other changes

- SQLAlchemy support for bit types now accepts str objects. (0.4.2) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#042-2025-12-04)
- Added support for Django 6. (0.4.2) — [release notes](https://github.com/pgvector/pgvector-python/blob/97e9fefe23fdc787e3bea96f06b1d2686f8b6d5d/CHANGELOG.md#042-2025-12-04)