Flask-RESTPlus

0.13.0 verified Mon Apr 27 auth: no python maintenance

Flask-RESTPlus is a Flask extension for building REST APIs with automatic Swagger documentation. Version 0.13.0 is the final release; the project is effectively in maintenance mode and superseded by Flask-RESTx. It offers request parsing, serialization, and Swagger UI generation.

pip install flask-restplus==0.13.0

Common errors

error No module named 'flask_restplus' ↓

cause Package not installed or misspelled.

fix

Run 'pip install flask-restplus' or use 'flask_restx' for maintained version.

error AttributeError: module 'flask_restplus' has no attribute 'Api' ↓

cause Import from wrong submodule or incorrect package version.

fix

Use 'from flask_restplus import Api' (top-level) and ensure flask-restplus is installed.

error TypeError: Object of type 'Response' is not JSON serializable ↓

cause Returning raw Flask response objects from resource methods.

fix

Return a dictionary or use api.marshal_with instead of manual JSON serialization.

Warnings

breaking Flask-RESTPlus is no longer maintained. The successor is Flask-RESTx, which has breaking API changes (e.g., different decorators for Swagger). ↓

fix Migrate to flask-restx: replace imports from flask_restplus to flask_restx.

deprecated The @api.param decorator is deprecated in later versions; use @api.expect with a parser. ↓

fix Define a RequestParser and use @api.expect(parser).

gotcha Automatic Swagger documentation relies on decorator order. Applying @api.response before @api.route can break docs. ↓

fix Always place @api.response after @api.route and the Resource class definition.

Imports

Api
wrong
```
from flask_restplus.api import Api
```
correct
```
from flask_restplus import Api
```
Direct import from submodule not guaranteed to work, use top-level import.

fields

wrong

from flask_restplus.fields import String

correct

from flask_restplus import fields

Fields class is accessed via top-level import, not submodule.

Quickstart

Basic setup with Flask-RESTPlus exposing a simple GET endpoint.

from flask import Flask
from flask_restplus import Api, Resource

app = Flask(__name__)
api = Api(app)

@api.route('/hello')
class HelloWorld(Resource):
    def get(self):
        return {'hello': 'world'}

if __name__ == '__main__':
    app.run(debug=True)