Async-GraphQL vs GraphQL Nexus: What are the differences?

<GraphQL is a query language for APIs that provides a powerful and flexible way to request data from a server. There are various tools and libraries available for working with GraphQL, two of which are Async-GraphQL and GraphQL Nexus.>

1. **Execution Model**: Async-GraphQL uses an asynchronous execution model, which means that resolvers can return promises or be asynchronous functions, allowing for non-blocking operations. In contrast, GraphQL Nexus follows a synchronous execution model, where resolvers are synchronous functions.
  
2. **Type Safety**: GraphQL Nexus provides strong type safety by leveraging TypeScript types for defining GraphQL schema, ensuring that the schema is fully typed at compile time. On the other hand, Async-GraphQL does not provide the same level of type safety out-of-the-box, requiring additional configuration or tools for achieving similar type safety.

3. **Code Generation**: GraphQL Nexus enables code generation for generating TypeScript types based on the defined GraphQL schema, reducing the chances of runtime errors due to schema inconsistencies. In comparison, Async-GraphQL does not have built-in support for code generation, requiring manual effort to ensure consistency between the schema and TypeScript types.

4. **Ease of Use**: Async-GraphQL focuses on providing a more approachable and flexible API for working with GraphQL, simplifying some aspects of schema definition and query execution. Conversely, GraphQL Nexus has a more opinionated API design that aims to reduce boilerplate code and guide developers towards best practices in schema construction.

5. **Extensibility**: Async-GraphQL allows for greater extensibility by providing hooks and middleware mechanisms to customize and extend the behavior of the GraphQL server. In contrast, GraphQL Nexus has a more structured approach, limiting the extent to which the server can be customized or extended beyond its predefined conventions.

6. **Community Support**: Both Async-GraphQL and GraphQL Nexus have active communities, but the level of community support and documentation may vary between the two. Depending on the specific requirements and preferences of developers, one library might have a more vibrant or helpful community ecosystem.

In Summary, Async-GraphQL and GraphQL Nexus differ in their execution model, type safety, code generation support, ease of use, extensibility, and community support, offering developers distinct approaches to working with GraphQL in their projects.