---
id: molecule
version: "26.8.0"
license: MIT
license_treatment: permissive
maintenance: active
---

# molecule — Molecule aids in the development and testing of Ansible roles

License: permissive · Maintenance: active · Downloads: 2.4M/mo

## What it is and what it does

Molecule is a testing framework built on top of Ansible that helps developers validate Ansible roles, playbooks, and collections. It uses standard Ansible features—inventory, playbooks, and collections—to run test scenarios against any infrastructure Ansible can reach: containers, VMs, cloud services, APIs, databases, and network devices. The framework encourages consistent, well-written Ansible content by automating the testing workflow.

The package is actively maintained by the Ansible community and requires Python 3.10 or later, supporting only the two most recent major versions of Ansible. It ships as a pure-Python wheel with 11 runtime dependencies including ansible-core, click for CLI handling, and rich for terminal output formatting. Installation is straightforward and friction-free.

Use it for:

- Test Ansible roles across multiple OS distributions and container images in a single scenario.
- Validate playbook logic and variable handling before deploying to production infrastructure.
- Verify Ansible collection functionality and compatibility across supported Ansible versions.
- Automate inventory configuration validation and dynamic inventory source testing.
- Run integration tests for Ansible content in CI/CD pipelines targeting cloud or on-premises systems.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Molecule is an Ansible testing framework for developing and testing Ansible collections, playbooks, and roles across containers, virtual machines, cloud infrastructure, and other systems reachable from Ansible.

Yes. Molecule is production-stable, actively maintained, permissively licensed, and has low install friction. It is the standard testing framework for Ansible content development. Install it if you develop or maintain Ansible roles, playbooks, or collections and want to automate testing across diverse infrastructure targets.

## Install

pip install molecule
uv add molecule
poetry add molecule

## Installing molecule

Before you install: Low install friction with a pure-Python wheel distribution. Actively maintained with a release 2 days ago and recent commits. Requires Python 3.10 or later and depends on 11 runtime packages including ansible-core, click, and rich for CLI functionality.

License in practice: MIT license is permissive, allowing commercial and private use with minimal restrictions—you may use, modify, and distribute Molecule freely as long as you include the license notice.

Quickstart:

pip install molecule
molecule --version
molecule init scenario --scenario-name default

Requires Python 3.10 or later and Ansible installed (via ansible-core dependency). Molecule supports only the latest two major versions of Ansible (N/N-1).

Verify before relying:

- Whether Molecule's test scenarios can run in CI/CD pipelines without additional setup beyond the listed dependencies.
- Support for specific container runtimes or orchestration platforms beyond the general 'any system reachable from Ansible' claim.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 2.4M/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

ansible role testing framework, ansible playbook testing, ansible collection testing, molecule test automation, ansible infrastructure testing, ansible scenario testing, ansible configuration validation, ansible, testing, infrastructure-as-code

[View on SkillFed](https://skillfed.io/packages/molecule) · [View on PyPI](https://pypi.org/project/molecule/)