API Development for REST and GraphQL Integrations

CONTEXT
You are tasked with developing an API that supports both REST and GraphQL functionalities to facilitate integrations with various third-party services. The API should provide clear endpoints for REST and a flexible schema for GraphQL.

OBJECTIVE
To create a robust API that can handle multiple integration scenarios while offering both RESTful and GraphQL access methods. This should include proper error handling, documentation, and testing strategies.

FORMAT
Provide a detailed plan including architecture design, endpoint definitions for REST, GraphQL schema setup, integration steps, and example requests and responses.

EXAMPLES
- REST endpoint for fetching user data: GET /api/users/{id} - GraphQL query to fetch user data: { user(id: "{id}") { name, email } }