# Consumer-Driven Contracts

> A rule or precondition that a provider verifies each change against the expectations its consumers have recorded.

Record: `architecture:consumer-driven-contracts`
Kind: constraint
Layer: [Contracts Core](https://banes-lab.com/records/layer/contracts-core.md)
Severity: recommended
Scope: API, service, integration
Canonical: https://banes-lab.com/ontology#architecture-consumer-driven-contracts

Listed in [Architecture principles](https://banes-lab.com/api/records/architecture.md), after [Uniform Interface](https://banes-lab.com/records/architecture/uniform-interface.md) and before [Control Plane](https://banes-lab.com/records/architecture/control-plane.md).

## Repair

- Refactored by: Introduce Consumer-Driven Contract tests
- Detected by: integration breaks discovered only in production
- Violated by: providers changing responses with no consumer expectation check
- Measured by: consumer-break incident rate
- Enforced by: contract test gate

## Requires

- [Explicit Contracts](https://banes-lab.com/records/architecture/explicit-contracts.md)

## Reinforces

- [Backward Compatibility](https://banes-lab.com/records/architecture/backward-compatibility.md)
- [Contract-First Design](https://banes-lab.com/records/architecture/contract-first-design.md)

## Enables

- [Provider Change Safety](https://banes-lab.com/records/lexicon/provider-change-safety.md)
- [Consumer-Verified Compatibility](https://banes-lab.com/records/lexicon/consumer-verified-compatibility.md)

## Conflicts with

- [Unversioned Breaking Change](https://banes-lab.com/records/architecture/unversioned-breaking-change.md)

## In tension with

- [Provider Autonomy](https://banes-lab.com/records/lexicon/provider-autonomy.md)

## Tensions

- [Consumer-Driven Contracts / Provider Autonomy](https://banes-lab.com/records/tension/consumer-driven-contracts-provider-autonomy.md)

## Severity

- [recommended](https://banes-lab.com/records/vocabulary/severity-recommended.md)

## Category

- [Contracts / Interfaces / Compatibility](https://banes-lab.com/records/architecture-category/contracts-interfaces-compatibility.md)

## Linked from

- [Anti-patterns](https://banes-lab.com/ontology/principles/architecture-category-anti-patterns.md)
- [Contracts / Interfaces / Compatibility](https://banes-lab.com/ontology/principles/architecture-category-contracts-interfaces-compatibility.md)
- [Contracts / Interfaces / Compatibility](https://banes-lab.com/ontology/lexicon/lexicon-category-contracts-interfaces-compatibility.md)
- [Severity levels](https://banes-lab.com/ontology/schema/the-vocabulary-severity.md)
- [The resolutions](https://banes-lab.com/ontology/schema/the-resolutions.md)