Nim Game API

Flask backend for a web implementation of the Nim game.

The API stores independent game sessions per user, exposes endpoints for game state and moves, validates player actions server-side, and implements the computer move logic using a Nim/XOR-based strategy with fallback random moves.

Companion frontend:

https://github.com/abenjas7/nimgame

Live API:

https://api-nim.onrender.com

Main Features

• REST API for starting games, reading state, applying player moves, and applying computer moves.
• Server-side validation for invalid, out-of-bounds, non-adjacent, or already removed sticks.
• Per-user sessions through the X-User-ID request header.
• Computer move selection based on game-state analysis and XOR-style Nim strategy.
• CORS enabled for frontend integration.

Stack

• Python
• Flask
• Flask-CORS
• Gunicorn

API Endpoints

Method	Endpoint	Purpose
GET	/	Health/status message
POST	/novo-jogo	Start a new game for the current user
GET	/estado	Return current game state
POST	/jogada	Apply a player move
POST	/jogada-computador	Apply a computer move

Player move payload:

{
  "linha": 2,
  "inicio": 1,
  "quantidade": 2
}

Example state response:

{
  "rows": [1, 2, 3, 4, 5],
  "available_paus": [[true], [true, true], [true, true, true], [true, true, true, true], [true, true, true, true, true]],
  "xor_total": 1,
  "jogo_terminado": false
}

Computer Strategy

The computer move logic evaluates possible moves and searches for favourable game states. It prioritizes positions with isolated sticks that match winning odd-count patterns, then falls back to moves that reduce the computed Nim/XOR state to zero. If no strategic move is found, it selects a valid random move.

This makes the project more than a CRUD API: it includes state modelling, rule validation, search over legal moves, and algorithmic decision-making.

Local Setup

Install dependencies:

pip install -r requirements.txt

Run locally:

python app.py

The application listens on:

0.0.0.0:10000

Portfolio Note

This project demonstrates backend API design, game-state modelling, input validation, algorithmic decision-making, and frontend/backend integration.