# Robustness Principle

> A design rule that a component is strict in what it sends and tolerant of harmless variation in what it receives.

Record: `architecture:robustness-principle`
Kind: principle
Layer: [Correctness Core](https://banes-lab.com/records/layer/correctness-core.md)
Severity: contextual
Scope: protocol, API, input processing
Canonical: https://banes-lab.com/ontology#architecture-robustness-principle

Listed in [Architecture principles](https://banes-lab.com/api/records/architecture.md), after [Resilience](https://banes-lab.com/records/architecture/resilience.md) and before [Error Handling](https://banes-lab.com/records/architecture/error-handling.md).

## Repair

- Refactored by: Normalize Input, Validate Semantics
- Detected by: parser brittleness
- Violated by: rejecting harmless compatible input variations
- Measured by: compatibility failure rate
- Enforced by: compatibility test suite

## Requires

- [Strict Output](https://banes-lab.com/records/lexicon/strict-output.md)
- [Tolerant Input](https://banes-lab.com/records/lexicon/tolerant-input.md)

## Reinforces

- [Compatibility](https://banes-lab.com/records/lexicon/compatibility.md)

## Enables

- [Interoperability](https://banes-lab.com/records/architecture/interoperability.md)

## Conflicts with

- [Fragile Parsing](https://banes-lab.com/records/lexicon/fragile-parsing.md)

## In tension with

- [Strict Validation](https://banes-lab.com/records/lexicon/strict-validation.md)

## Tensions

- [Robustness Principle / Strict Validation](https://banes-lab.com/records/tension/robustness-principle-strict-validation.md)

## Severity

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

## Category

- [Error Handling / Resilience](https://banes-lab.com/records/architecture-category/error-handling-resilience.md)

## Linked from

- [Contracts / Interfaces / Compatibility](https://banes-lab.com/ontology/principles/architecture-category-contracts-interfaces-compatibility.md)
- [Core Vocabulary](https://banes-lab.com/ontology/lexicon/lexicon-category-core-vocabulary.md)
- [Error Handling / Resilience](https://banes-lab.com/ontology/lexicon/lexicon-category-error-handling-resilience.md)
- [Severity levels](https://banes-lab.com/ontology/schema/the-vocabulary-severity.md)
- [The resolutions](https://banes-lab.com/ontology/schema/the-resolutions.md)