# Application Programming Interface [API | Wikipedia](https://en.wikipedia.org/wiki/API) ## Styles - The old-fashioned: [[rpc|RPC]] - Modern approach: [[rest|RESTful]] ## Standards - [OpenAPI Specification](https://spec.openapis.org/oas/latest.html) - [Stoplight API Stylebook](https://apistylebook.stoplight.io/) - This style guide somehow prefers snake case for query params and path params? - [GitLab API Style Guide](https://docs.gitlab.com/development/api_styleguide/) - [Google APIs Design Guide](https://cloud.google.com/apis/design/) - [[microsoft|Microsoft]] - [Graph REST API Guidelines](https://github.com/microsoft/api-guidelines/blob/vNext/graph/GuidelinesGraph.md) - [Azure REST API Guidelines](https://github.com/microsoft/api-guidelines/blob/vNext/azure/Guidelines.md), recommends camelCase for query params. - [Atlassian REST API Design Guidelines version 1](https://developer.atlassian.com/server/framework/atlassian-sdk/atlassian-rest-api-design-guidelines-version-1/#AtlassianRESTAPIDesignGuidelinesversion1-RESTResources)