API Development for REST and GraphQL Integrations

CONTEXT
You are tasked with developing an API that supports both REST and GraphQL standards to enhance integrations with multiple platforms. Your objective is to ensure that the API is well-documented, efficient, and easy to use for developers.

OBJECTIVE
Create an API specification that outlines the endpoints for RESTful services and the query/mutation structures for GraphQL. Make sure to address authentication, error handling, and versioning in your design.

FORMAT
Present the API documentation in a structured format, including sections for REST endpoints, GraphQL schema, authentication methods, and examples of requests and responses for both REST and GraphQL.

EXAMPLES
Example REST endpoint: GET /api/users, Example GraphQL query: { users { id, name } }. Provide error handling examples and authentication requirements for both approaches.