# Dependencies

Nova uses the standard OpenStack dependency management model. Keep dependency changes in the file that matches how the dependency is used so that local development, packaging, and CI jobs install the same inputs.

## Python dependencies

Runtime Python dependencies belong in `requirements.txt`. These are packages needed when Nova services or libraries run.

Test-only Python dependencies belong in `test-requirements.txt`. These are packages needed by unit, functional, and validation jobs but not by a deployed Nova service.

Documentation-only Python dependencies belong in `doc/requirements.txt`. These are packages needed to build or validate the documentation, such as Sphinx extensions, documentation themes, release note tooling, and redirect test tools.

## System packages

Binary and operating-system package dependencies belong in `bindep.txt`. Use bindep profiles such as `test`, `doc`, or `pdf-docs` when a package is only needed by a specific class of jobs. For example, a library or command needed only when building documentation should be listed in `bindep.txt` with the `doc` profile rather than documented as a manual setup step.

## Packaging metadata

Nova uses `pbr` for Python packaging metadata. Do not introduce alternative version or dependency management systems such as `setuptools-scm`. Keep package dependencies in the requirement files above so OpenStack constraints and CI can manage them consistently.

`pyproject.toml` is present and records static package metadata per PEP 621, such as the project name, classifiers, and entry points. The version and main Python dependency list are dynamic and managed by `pbr`; they are not edited in the `dependencies` table.

Runtime, test, and documentation Python dependencies must continue to be declared in `requirements.txt`, `test-requirements.txt`, and `doc/requirements.txt` as described above.

Nova also defines a small set of setuptools extra groups in the `[project.optional-dependencies]` table (for example `osprofiler`, `zvm`, and `vmware`). Use those only for the same driver or tooling extras already represented there. Do not add new general runtime or test dependencies via `optional-dependencies`; add them to the appropriate requirement file instead.

this page last updated: 2026-08-20 01:33:50

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