starlette-middleware-collection 0.1.0

Collection of middleware for Starlette applications

starlette-middleware-collection

A small collection of Starlette-compatible middleware, with FastAPI compatibility and examples.

Included Middleware

• SizeLimit: Rejects requests with bodies larger than a configured byte limit.
• RequestUUID: Adds a per-request UUID to request.state.id.

Installation

Install from source:

pip install -e .

SizeLimit

The SizeLimit middleware checks the incoming content-length header and returns 413 Content Too Large when the request body exceeds the configured limit.

• Constructor argument: limit (bytes)
• Environment variable: MW_REQUEST_BODY_LIMIT
• Default: 10 * 1024 * 1024 (10 MB)

Basic Usage

from fastapi import FastAPI
from starlette_middleware_collection import SizeLimit

app = FastAPI()
app.add_middleware(SizeLimit)

With a Custom Limit

from fastapi import FastAPI
from starlette_middleware_collection import SizeLimit

app = FastAPI()
app.add_middleware(SizeLimit, limit=5 * 1024 * 1024)  # 5 MB

Using Environment Variable (SizeLimit)

import os
from fastapi import FastAPI
from starlette_middleware_collection import SizeLimit

os.environ["MW_REQUEST_BODY_LIMIT"] = str(1024 * 1024)  # 1 MB

app = FastAPI()
app.add_middleware(SizeLimit)

[!NOTE] The constructor argument takes precedence over the environment variable.

RequestUUID

The RequestUUID middleware sets request.state.id for every request.

• Constructor argument: uuid_version
• Environment variable: MW_UUID_VERSION
• Supported versions: 4, 7
• Default: 7

Basic Usage (Default UUIDv7)

from fastapi import FastAPI, Request
from starlette_middleware_collection import RequestUUID

app = FastAPI()
app.add_middleware(RequestUUID)


@app.post("/")
async def read_root(request: Request):
    return {"uuid": str(request.state.id)}

With a Custom UUID Version

from fastapi import FastAPI
from starlette_middleware_collection import RequestUUID

app = FastAPI()
app.add_middleware(RequestUUID, uuid_version=4)

Using Environment Variable (RequestUUID)

import os
from fastapi import FastAPI
from starlette_middleware_collection import RequestUUID

os.environ["MW_UUID_VERSION"] = "4"

app = FastAPI()
app.add_middleware(RequestUUID)

[!NOTE] The constructor argument takes precedence over the environment variable.

If an unsupported uuid_version is provided, a ValueError is raised.

Combined Example

from fastapi import FastAPI, Request
from starlette_middleware_collection import RequestUUID, SizeLimit

app = FastAPI()
app.add_middleware(SizeLimit, limit=2 * 1024 * 1024)  # 2 MB
app.add_middleware(RequestUUID, uuid_version=7)


@app.post("/upload")
async def upload(request: Request):
    return {"request_id": str(request.state.id)}

Running Tests

pytest