Pact Python

Fast, easy and reliable testing for your APIs and microservices.

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Pact is the de-facto API contract testing tool. Replace expensive and brittle end-to-end integration tests with fast, reliable and easy to debug unit tests.

⚡ Lightning fast
🎈 Effortless full-stack integration testing - from the front-end to the back-end
🔌 Supports HTTP/REST and event-driven systems
🛠️ Configurable mock server
😌 Powerful matching rules prevents brittle tests
🤝 Integrates with Pact Broker / PactFlow for powerful CI/CD workflows
🔡 Supports 12+ languages

Why use Pact? Contract testing with Pact lets you:

⚡ Test locally
🚀 Deploy faster
⬇️ Reduce the lead time for change
💰 Reduce the cost of API integration testing
💥 Prevent breaking changes
🔎 Understand your system usage
📃 Document your APIs for free
🗄 Remove the need for complex data fixtures
🤷‍♂️ Reduce the reliance on complex test environments

Watch our series on the problems with end-to-end integrated tests, and how contract testing can help.

Documentation

This readme provides a high-level overview of the Pact Python library. For detailed documentation, please refer to the full Pact Python documentation. For a more general overview of Pact and the rest of the ecosystem, please refer to the Pact documentation.

Documentation for the API is generated from the docstrings in the code which you can view at pact-foundation.github.io/pact-python/pact.

Need Help

Join our community slack workspace.
Stack Overflow is a great place to ask questions.
Say 👋 on Twitter: @pact_up
Join a discussion 💬 on GitHub Discussions
Raise an issue on GitHub

Installation

The latest version of Pact Python can be installed from PyPi:

pip install pact-python
# 🚀 now write some tests!

Requirements

Pact Python tries to support all versions of Python that are still supported by the Python Software Foundation. Older version of Python may work, but are not officially supported.

In order to support the broadest range of use cases, Pact Python tries to impose the least restrictions on the versions of libraries that it uses.

Telemetry

In order to get better statistics as to who is using Pact, we collect some anonymous telemetry. The only things we record are your type of OS, and the version information for the package. No personally identifiable information is sent as part of this request. You can disable telemetry by setting the environment variable PACT_DO_NOT_TRACK=1:

Contributing

We welcome contributions to the Pact Python library in many forms. There are many ways to help, from writing code, to providing new examples, to writing documentation, to testing the library and providing feedback. For more information, see the contributing guide.

Release files for pact-python 3.4.1

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for pact-python 3.4.1
File	Size	Uploaded
pact_python-3.4.1.tar.gz	83.4 kB	Sep 17, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for pact-python 3.4.1
File	Interpreter	ABI	Platform	Reset
pact_python-3.4.1-py3-none-any.whl 99.2 kB Sep 17, 2026	Python 3	none	any	Details

Total release size: 182.6 kB

Release files / pact_python-3.4.1.tar.gz

Download URL	pact_python-3.4.1.tar.gz
Size	83.4 kB
Tags	Source
SHA-256 checksum How to use checksums	`4dff5c3966509e08081e5eb7e2aeeb68b93c3174c4436c23ac8e0a524f9a961b`
BLAKE2b-256 checksum How to use checksums	`6760dc7f8339fb1bbe5a1bad8024582c6400b92c288db1c6c4b8be0dd9888d32`
Upload date	Sep 17, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	Yes
Uploaded via	`twine/7.0.0 CPython/3.13.14`

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

Identity

Publishing platform: GitHub Actions
Publishing repository: github.com/pact-foundation/pact-python
Publishing commit: github.com/pact-foundation/pact-python/tree/21b35c6007bd52bc2373101f87cfed6554a548da

Workflow

Publishing configuration: github.com/pact-foundation/pact-python/blob/21b35c6007bd52bc2373101f87cfed6554a548da/.github/workflows/release-core.yml
Publishing logs: github.com/pact-foundation/pact-python/actions/runs/35212471368/attempts/1

Artifact

Subject: pact_python-3.4.1.tar.gz
SHA-256 checksum: 4dff5c3966509e08081e5eb7e2aeeb68b93c3174c4436c23ac8e0a524f9a961b Verifying attestations

Release files / pact_python-3.4.1-py3-none-any.whl

Download URL	pact_python-3.4.1-py3-none-any.whl
Size	99.2 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`5db3f69e827ca8788c92655821f7de8f8dbedfe4c245ac6bbf5ff2164395ecfe`
BLAKE2b-256 checksum How to use checksums	`186ca4a625bca3c1d5674d08667c2ec9001ed5896230cbce2871926e3625dea2`
Upload date	Sep 17, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	Yes
Uploaded via	`twine/7.0.0 CPython/3.13.14`

Provenance

Identity

Publishing platform: GitHub Actions
Publishing repository: github.com/pact-foundation/pact-python
Publishing commit: github.com/pact-foundation/pact-python/tree/21b35c6007bd52bc2373101f87cfed6554a548da

Workflow

Publishing configuration: github.com/pact-foundation/pact-python/blob/21b35c6007bd52bc2373101f87cfed6554a548da/.github/workflows/release-core.yml
Publishing logs: github.com/pact-foundation/pact-python/actions/runs/35212471368/attempts/1

Artifact

Subject: pact_python-3.4.1-py3-none-any.whl
SHA-256 checksum: 5db3f69e827ca8788c92655821f7de8f8dbedfe4c245ac6bbf5ff2164395ecfe Verifying attestations