To create backend APIs with ORM in Go without relying on full-fledged frameworks, you can take a modular approach by using libraries that provide routing, database connections, and ORM functionalities while retaining flexibility. Here's a stack that could work well:

1. Routing

• Chi: A lightweight and idiomatic router that is compatible with Go's net/http. It provides minimalistic and expressive routing without adding too much overhead.
  • GitHub: go-chi/chi
• Mux: Part of the Gorilla toolkit, it's a simple HTTP router and URL matcher, perfect for handling HTTP requests.
  • GitHub: gorilla/mux

2. ORM

• GORM: A popular ORM for Go that provides a full-featured ORM with support for querying, relationships, hooks, transactions, etc. You can use only the parts you need and avoid others.
  • GitHub: go-gorm/gorm
• SQLx: A minimal extension to Go's database/sql that provides easier handling of named parameters, struct scanning, and simple queries. It gives you more control over your SQL while abstracting some boilerplate.
  • GitHub: jmoiron/sqlx

3. Database Connection

• Database/sql: The standard Go library for SQL database interactions. Using this with a library like SQLx will provide low-level control over your queries and connection handling.
• PGX: A pure Go PostgreSQL driver and toolkit, which offers better performance for PostgreSQL compared to database/sql. It can be used as a replacement for Postgres-based backends.
  • GitHub: jackc/pgx

4. Middleware (Optional)

• Negroni: A tiny middleware handler that adds flexibility to your API by making it easier to manage middleware layers like logging, recovery, and authorization.
  • GitHub: urfave/negroni

5. Validation

• Go-playground/validator: A library for validating Go structs and fields. It’s useful for validating API request payloads.
  • GitHub: go-playground/validator

6. Authentication/Authorization

• JWT-Go: A library for working with JSON Web Tokens, useful for token-based authentication.
  • GitHub: dgrijalva/jwt-go

By combining these libraries, you can create a modular API backend in Go, where you control the architecture while making use of specialized tools for routing, ORM, and validation.