# Summary

* [Introduction](README.md)
* [Core Principles](core-principles/README.md)
  * [API First](core-principles/api-first.md)
  * [OpenAPI Specification](core-principles/openapi-specification.md)
  * [Apiary](core-principles/apiary.md)
  * [Version Control System](core-principles/version-control-system.md)
  * [Contract](core-principles/contract.md)
  * [Testing](core-principles/testing.md)