Todo API

The same CRUD REST API, built from scratch in many languages — a polyglot learning project.

One fixed API contract (a TodoMVC-style todo list), re-implemented across languages and frameworks to see what each layer of abstraction does, and hides. The low-level versions (C, C++) implement everything by hand — HTTP parsing, JSON, routing, memory. The higher-level ones (Node, Laravel) lean on their frameworks. Side by side, the differences are the lesson.

The contract

Every implementation exposes the identical API:

Method	Path	Description	Success
GET	/todos	List all todos	200
POST	/todos	Create a todo	201
GET	/todos/{id}	Fetch a single todo	200
PATCH	/todos/{id}	Partial update	200
PUT	/todos/{id}	Full replace (strict)	200
DELETE	/todos/{id}	Delete a todo	204

Errors: 400 (malformed / invalid id), 404 (not found), 500 (server error).

Todo schema

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "title": "Buy milk",
  "completed": false
}

• id — a UUIDv4, assigned by the server
• title — string, required on create
• completed — boolean, defaults to false

PATCH is a partial update (send only what changes); PUT is a strict full replace (all fields required).

Implementations

Language / Stack	Status	Folder
C (POSIX sockets)	✅ Done	c/
C++	⬜ Planned	cpp/
Rust	⬜ Planned	rust/
Go	⬜ Planned	go/
Node (http)	⬜ Planned	node/
Express	⬜ Planned	express/
NestJS	⬜ Planned	nest/
PHP	⬜ Planned	php/
Laravel	⬜ Planned	laravel/

Goal

Each version targets the same contract, so the interesting part is the implementation, not the feature set. Building the hardest version first (C, from raw sockets) makes it clear exactly what every framework automates — by the time the same API is a handful of lines in Express or Laravel, you know what those lines are doing underneath.

Structure

todo-api/
├── README.md        # this file
├── c/               # the C implementation (done)
│   ├── main.c
│   ├── openapi.json
│   └── README.md
└── …                # one folder per language, added over time

Each language folder has its own README with build and run instructions.

License

MIT