Babel Shelf

A CRUD bookshelf app built in every language. Same API, same database, different implementations.

Architecture

babel-shelf/
├── db/                  # Shared Postgres schema
│   └── init.sql
├── go-bookshelf/        # Go (port 8080)
├── ts-bookshelf/        # TypeScript/Bun (port 8081)
├── docker-compose.yml   # Orchestrates apps + Postgres
└── README.md

Each language gets its own directory (<lang>-bookshelf/) with a Dockerfile and devcontainer config. They all share the same Postgres database and expose the same REST API.

API

Method	Endpoint	Description	Status
POST	/books	Create a book	201
GET	/books	List all books	200
GET	/books/{id}	Get one book	200
PUT	/books/{id}	Update a book	200
DELETE	/books/{id}	Delete a book	204

Book object

{
  "id": 1,
  "title": "Dune",
  "author": "Frank Herbert",
  "status": "want to read"
}

Status must be one of: want to read, reading, finished.

Running

docker compose up --build

Implementation	URL
Go	http://localhost:8080
TypeScript	http://localhost:8081

Testing

Tests are integration tests that hit a real Postgres database (no mocks).

# Go — from inside devcontainer or with Go installed:
cd go-bookshelf
DATABASE_URL="postgres://shelf:shelf@db:5432/bookshelf?sslmode=disable" go test -v

# TypeScript — from inside devcontainer or with Bun installed:
cd ts-bookshelf
DATABASE_URL="postgres://shelf:shelf@db:5432/bookshelf?sslmode=disable" bun test

Implementations

• Go
• TypeScript (Bun + Hono + pg)