🏗️ FastAPI Mini-Blog API

A small FastAPI backend API for a mini-blog, with JWT authentication, posts, comments, tests, and configurable SQLite/PostgreSQL database support.

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🚀 Features

• JWT authentication using /register (user creation + token) and /token (OAuth2 form login)
• Protected write endpoints /post and /comment
• Nested read via GET /posts/{id} returning a post with its comments
• Clean responses hiding internal database fields
• Configurable SQLite/PostgreSQL database support using SQLAlchemy Core tables

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📦 Setup

pip install -r requirements.txt
cp .env.example .env
uvicorn main:app --reload --env-file .env

DATABASE_URL controls the database backend. SQLite is used by default when DATABASE_URL is not set. PostgreSQL can be used by setting DATABASE_URL to a PostgreSQL connection string.

python-multipart (included in requirements.txt) is required for the OAuth2 form at /token.

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🔐 Authentication

1. Register

POST /register
Content-Type: application/json

{
  "username": "blue_caterpillar",
  "password": "mushroom42"
}

201 Created → returns an access token.

2. Log in through Swagger

• Open /docs
• Click Authorize
• Enter username and password
  Swagger will attach the token automatically to subsequent requests.

3. Direct token request (optional)

POST /token
Content-Type: application/x-www-form-urlencoded

username=blue_caterpillar&password=mushroom42

200 OK → returns an access token.

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🧱 Endpoints

Posts

Method	Path	Auth	Response
POST	/post	✅	201 → UserPost
GET	/posts	❌	List[UserPost]
GET	/posts/{id}	❌	UserPostWithComments

Example

{
  "id": 1,
  "body": "My first post",
  "comments": [
    { "id": 1, "body": "Nice work!" }
  ]
}

Comments

Method	Path	Auth	Response
POST	/comment	✅	201 → CommentOut
GET	/post/{id}/comments	❌	List[CommentOut]

Example

{ "id": 1, "body": "Nice work!" }

Foreign-key validation
POST /comment verifies that post_id exists in the posts table:

HTTP/1.1 404 Not Found
{ "detail": "Post not found" }

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Health

GET /health
Returns a simple liveness probe:

{ "status": "ok" }

Dev Maintenance (local use only)

POST /_dev/reset → 204 No Content
Clears comments, then posts (guarded; requires maintainer account).
Use only on local/dev databases.

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🧩 Models (summary)

• UserPost: { id, body }
• CommentOut: { id, body }
• UserPostWithComments: { id, body, comments: CommentOut[] }

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🛠️ Future Extensions

• Pagination: GET /posts?limit=&skip= and GET /post/{id}/comments?limit=&skip=

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✅ Quick Verification

1. Open /docs and Authorize with your credentials.
2. Create a post → POST /post (201 Created).
3. Create a comment for that post → POST /comment (201 Created).
4. Retrieve nested data → GET /posts/{id} to see comments embedded.

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Originally inspired by the Teclado FastAPI course.
Extended, debugged, and documented independently.