bump-pydantic
Convert Pydantic from V1 to V2 ♻
Decision gist · record as of 2026-08-14
Yes, if you have a Pydantic V1 codebase to migrate and need to automate routine refactoring tasks. The tool handles the majority of straightforward patterns and is low-friction to install. However, be aware that the project is archived and no longer maintained—it will not adapt to new Pydantic V2 features or Python versions, and complex migrations may still require manual work. Use it as a starting point rather than a complete solution.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.8 or later; the tool operates on source files in place or via diff, so a version control system is recommended to review and revert changes if needed.
- Low install friction with a pure-Python wheel and four lightweight dependencies.
- However, the project is archived and has not been updated since late 2023, meaning it will not receive fixes for new Pydantic V2 patterns or Python versions beyond 3.12.
License · maintenance · safety
permissive license (permissive) — MIT license (permissive) allows free use, modification, and distribution with minimal restrictions, suitable for both open-source and commercial projects.
last release 2023-12-28 (960 days) · last repo commit 2026-05-27 · 351 stars · archived
0 known vulnerabilities (OSV.dev, 2026-08-14) · 229,283 downloads/mo, #9,134 on PyPI
Alternatives
Verify before relying
pip install bump-pydantic
bump-pydantic /path/to/my_package
# Or check diff first:
bump-pydantic --diff /path/to/my_package- Whether the tool correctly handles all edge cases in real-world Pydantic V1 codebases, given the project is no longer maintained.
- Performance and accuracy on large projects with complex validator chains or custom type definitions.
- Compatibility with Pydantic V2 minor versions released after the tool's last update in December 2023.
What it is and what it does
Bump Pydantic is a command-line tool that automates the migration of Pydantic V1 code to V2 by applying nine transformation rules (BP001–BP009). It handles common refactoring tasks such as replacing the Config class with model_config, updating Field parameters, converting validators to their V2 equivalents, and replacing deprecated constraint functions with Annotated types. The tool uses libcst for safe AST-based code transformation and provides a --diff flag to preview changes before applying them.
The tool is designed for developers maintaining Pydantic V1 projects who need to upgrade to V2 but face large codebases where manual refactoring is impractical. It covers the majority of straightforward migration patterns, though complex custom types and protocol functions may require manual follow-up (flagged with TODO comments). The project is archived and no longer actively maintained, so it will not evolve with future Pydantic V2 releases.
Use it for
- Bulk-migrate a Pydantic V1 codebase to V2 by running the tool on your package directory and reviewing the generated diff.
- Automate replacement of Config classes with model_config and Field parameter updates across multiple files.
- Convert V1 validators (@validator, @root_validator) to their V2 equivalents (@field_validator, @model_validator) in one pass.
- Replace constraint functions (constr, conint, etc.) with Annotated type hints across a large project.
- Identify and mark custom type methods (__get_validators__, __modify_schema__) that require manual V2 migration with TODO comments.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you have a Pydantic V1 codebase to migrate and need to automate routine refactoring tasks.
The tool handles the majority of straightforward patterns and is low-friction to install. However, be aware that the project is archived and no longer maintained—it will not adapt to new Pydantic V2 features or Python versions, and complex migrations may still require manual work. Use it as a starting point rather than a complete solution.
Install
bump-pydantic on PyPI
Before you install
Low install friction with a pure-Python wheel and four lightweight dependencies. However, the project is archived and has not been updated since late 2023, meaning it will not receive fixes for new Pydantic V2 patterns or Python versions beyond 3.12.
Requires Python 3.8 or later; the tool operates on source files in place or via diff, so a version control system is recommended to review and revert changes if needed.
License in practice
MIT license (permissive) allows free use, modification, and distribution with minimal restrictions, suitable for both open-source and commercial projects.
Quickstart
pip install bump-pydantic
bump-pydantic /path/to/my_package
# Or check diff first:
bump-pydantic --diff /path/to/my_packageVerify before relying
- Whether the tool correctly handles all edge cases in real-world Pydantic V1 codebases, given the project is no longer maintained.
- Performance and accuracy on large projects with complex validator chains or custom type definitions.
- Compatibility with Pydantic V2 minor versions released after the tool's last update in December 2023.
Package facts
| License | permissive license permissive |
| Python support | Supports the current Python release >=3.8 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 4 packageslibcstrichtypertyping-extensions |
| Maintenance | Abandoned 960 days since the last release |
| Last repo commit | repository archived |
| First released | |
| Downloads | 229,283 / month, #9,134 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 4 - BetaEnvironment :: ConsoleFramework :: PydanticLicense :: OSI Approved :: MIT LicenseProgramming Language :: PythonProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPyTopic :: Software Development :: Code Generators |
Evidence: bump_pydantic-0.8.0-py3-none-any.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “pydantic v1 to v2 migration”
- bump-pydanticA CLI tool that automatically refactors Pydantic V1 code to V2 by…
- pydantic-compatProvides compatibility mixins and adapters to use either pydantic v1…
- pydantic-function-modelsWraps Python functions to validate their arguments against type hints…
Give your agent the search over MCP, or paste the wish link into any chat.
More Code Generators packages
Proto Plus wraps protocol buffers to provide Python classes that behave like native Python types while maintaining protocol buffer serialization and schema validation.
Install it if you're working with protocol buffers in Python and want a more Pythonic interface, or if you're using Google Cloud libraries that depend on it.
Cython is a source code translator that compiles Python code to C, enabling optional static typing and direct C/C++ interoperability to generate efficient native extensions.
Install it if you need to optimize Python performance, wrap C/C++ libraries, or build fast native extensions.
Annotates Python abstract syntax trees with the positions of tokens and source code text, enabling tools to map AST nodes back to their originating code for refactoring, analysis, and transformation.
Beartype is a runtime type checker that validates Python type hints at function call time, catching type violations before they cause downstream bugs.
Install it if you want runtime type safety for your annotated code or need to validate type hints on third-party packages.
llvmlite provides a lightweight Python binding to LLVM's IR builder, optimizer, and JIT compiler APIs, enabling you to write JIT compilers and code generators without needing the full LLVM C++ API surface.
astor converts Python abstract syntax trees (ASTs) back to readable source code and provides tools for AST manipulation, inspection, and non-recursive tree traversal.
Install it if you need AST round-tripping or advanced tree inspection.
See also pydantic-compat · prime-pydantic-config · flask-pydantic-spec · Flask-Pydantic · pylint-pydantic · jsonschema-pydantic-converter · pydantic-to-typescript2 · pydantic_yaml · pydantic-to-typescript · clabe