python 38 lines · 8 steps

Building a REST article resource in FastAPI

A router pairs a create endpoint that returns a Location header with a fetch endpoint, wired to SQLAlchemy through dependency injection.

Explained by highlit
FastAPI Intermediate dependency injection rest api orm response models http headers
1from fastapi import APIRouter, Depends, Response, status
2from sqlalchemy.orm import Session
3 
4from .database import get_db
5from .schemas import ArticleCreate, ArticleRead
6from . import models
7 
8router = APIRouter(prefix="/articles", tags=["articles"])
9 
10 
11@router.post(
12 "",
13 response_model=ArticleRead,
14 status_code=status.HTTP_201_CREATED,
15)
16def create_article(
17 payload: ArticleCreate,
18 response: Response,
19 db: Session = Depends(get_db),
20) -> models.Article:
21 article = models.Article(
22 title=payload.title,
23 slug=payload.slug,
24 body=payload.body,
25 )
26 db.add(article)
27 db.commit()
28 db.refresh(article)
29 
30 response.headers["Location"] = router.url_path_for(
31 "get_article", article_id=article.id
32 )
33 return article
34 
35 
36@router.get("/{article_id}", response_model=ArticleRead)
37def get_article(article_id: int, db: Session = Depends(get_db)) -> models.Article:
38 return db.query(models.Article).get(article_id)
01 / 01
STEP 01

Walkthrough

Space play ←→ step click any line
Three takeaways
  1. 1Declaring dependencies as parameters lets FastAPI supply and clean up resources like DB sessions per request.
  2. 2A 201 response should point clients to the new resource via a Location header built from named routes.
  3. 3Separate request and response schemas keep input validation and output shape independent from the ORM model.

Related explainers

python 
from flask import Blueprint, jsonify, request, abort
 
v1 = Blueprint("users_v1", __name__)
v2 = Blueprint("users_v2", __name__)

Versioning a Flask API with Blueprints

api versioning blueprints rest
Intermediate 7 steps
python 
import time
import threading
from enum import Enum
from functools import wraps

Building a circuit breaker in Python

circuit-breaker resilience decorators
Advanced 7 steps
python 
from django.contrib.postgres.search import SearchQuery, SearchRank, SearchVector
from django.core.cache import cache
from django.db.models import F
from django.http import JsonResponse

Ranked full-text search in Django

full-text-search debouncing caching
Advanced 9 steps
python 
import os
from datetime import timedelta
 
 

Class-based config in a Flask app factory

configuration app-factory inheritance
Intermediate 7 steps
python 
import time
 
from flask import Flask, g, request
 

Timing requests with Flask hooks

middleware request-lifecycle instrumentation
Intermediate 5 steps
python 
from pathlib import Path
 
from PIL import Image, ImageOps
 

Batch image resizing with Pillow

image-processing batch-jobs error-handling
Intermediate 8 steps

Share this explainer

Here's the card — post it anywhere.

Building a REST article resource in FastAPI — share card
Made with highlit — turn any snippet into a walkthrough like this in about a minute.
Explain your code