Contract Testing Python Packages

pact-python

Python version of Pact. Enables consumer driven contract testing, providing a mock service and DSL for the consumer project, and interaction playback and verification for the service provider project.

pact-python-ffi

Python version of Pact. Enables consumer driven contract testing, providing a mock service and DSL for the consumer project, and interaction playback and verification for the service provider project.

pact-python-cli

Python version of Pact. Enables consumer driven contract testing, providing a mock service and DSL for the consumer project, and interaction playback and verification for the service provider project.

django-contract-tester

Test utility for validating Django APIs against their OpenAPI specification

specfact-cli

AI-bloat defense CLI for Python teams: deterministic code review, cleanup forecasts, and spec/contract evidence for AI-assisted and brownfield delivery.

surety

A Python framework for contract testing in CI/CD pipelines. Validates communication boundaries between services without requiring a shared environment.

assertpy2

Fluent, fully typed assertion library for Python: your type checker sees only the assertions that fit the value, and every failure carries a structured diff. Soft assertions, polling, inline snapshots, OpenAPI contracts.

zft

ZFT (Zero-Friction Traceability) — contract-grounded verification and trace matrix gates for multi-agent work

prauga-flexdoc

Backend-native API workbench that detects when your running implementation disagrees with OpenAPI.

bowline-agent

Write once, typed everywhere. API clients generated from plain Go functions.

bowline-client

Write once, typed everywhere. API clients generated from plain Go functions.

specsentinel

CLI that checks a live API against its OpenAPI spec. Exit code 0 if it matches, 1 on drift, 2 if the check could not run.

excelalchemy

Schema-driven Python library for typed Excel import/export workflows with Pydantic, locale-aware workbooks, pluggable storage, and contract-tested architecture.

a2a-proof

Black-box contract tests for A2A agents

boundver

A Git-aware lockfile and CI check for contracts shared across components

ai-prompt-runner

Deterministic stateless multi-provider AI prompt runner for CLI, scripts, and CI workflows with contract-driven structured outputs.

jev-oas-sentinel

Catch breaking API behavior hidden in OpenAPI prose with deterministic checks and TypeSafe JEV System One semantic review.

bergendy

Runtime schemas, drafted from your live traffic.

narrative-contracts

MateProbe by Mate4B — mutation testing for your validators. Audit missed faults, wrong-reason rejections and valid controls with pytest.

covenant-mcp

Contract linter and drift firewall for MCP servers: snapshot tool schemas, classify drift, quarantine drifted tools, enforce fleet-wide with a Kubernetes operator.

pytest-narrative-contracts

MateProbe by Mate4B — mutation testing for your validators. Audit missed faults, wrong-reason rejections and valid controls with pytest.

resultseal

Deterministic observation-integrity contracts for AI-agent tool results. HTTP 200 is not an observation.

fild

[DEPRECATED] Migrated to surety — https://github.com/elenakulgavaya/surety

breakproof

No-spec API break gate: fail PRs only on deleted routes, with caller proof. pipx install, 10s demo, GitHub Action included.