Ipregistry FastAPI

Official Ipregistry integration for FastAPI: dependency-driven IP geolocation and threat detection for every request, built on the asynchronous Ipregistry Python client.

from fastapi import FastAPI
from ipregistry_fastapi import IpInfoDep, ipregistry_lifespan

app = FastAPI(lifespan=ipregistry_lifespan)

@app.get("/")
async def index(info: IpInfoDep):
    return {"country": info.location.country.name if info else None}

Features

• Async-first: non-blocking lookups through the official asynchronous Ipregistry client, with connection reuse managed by the application lifespan.
• Idiomatic dependencies: IpInfoDep, IpregistryDep and ClientIpDep annotated types plug straight into path operations — HTTP and WebSocket alike; one cached lookup per request, shared by every consumer. All dependencies are coroutines: no threadpool dispatch on the request path.
• Guards: block countries (HTTP 451) and threats (HTTP 403) per route, per router, or app-wide.
• Middleware: optional pure-ASGI middleware for global enrichment and blocking, with static asset and bot skipping to save credits.
• Safe by default: fails open, never sends private or reserved addresses to the API, validates proxy headers, and never logs full client IPs.
• Configuration via environment: IPREGISTRY_* variables parsed with pydantic-settings.
• Typed responses: lookups return the client's Pydantic v2 models, ready to embed in your own response models.
• First-class testing: IpregistryFake swaps in canned responses with call assertions — no network, no API key.

Getting started

Requirements

• Python 3.10+
• FastAPI 0.115+
• An Ipregistry API key — the free tier includes 100,000 lookups

Installation

pip install ipregistry-fastapi

or with uv:

uv add ipregistry-fastapi

Quick start

Set your API key:

export IPREGISTRY_API_KEY=YOUR_API_KEY

Wire the lifespan and use the dependency:

from fastapi import FastAPI
from ipregistry_fastapi import IpInfoDep, ipregistry_lifespan

app = FastAPI(lifespan=ipregistry_lifespan)

@app.get("/whoami")
async def whoami(info: IpInfoDep):
    if info is None:
        return {"detail": "No IP intelligence available"}
    return {
        "ip": info.ip,
        "country": info.location.country.name,
        "city": info.location.city,
        "threat": info.security.is_threat,
    }

IpInfoDep resolves to an IpInfo model — or None when the client IP is private (e.g. on localhost) or the lookup failed. One lookup runs per request no matter how many dependencies, guards or middleware consume it, and responses are cached in memory across requests.

To configure programmatically instead of via the environment:

from ipregistry_fastapi import IpregistrySettings, add_ipregistry, ipregistry_lifespan

app = FastAPI(lifespan=ipregistry_lifespan)
add_ipregistry(app, IpregistrySettings(api_key="...", base_url="eu", fields="location,security"))

Blocking countries

block_countries returns a dependency enforcing an ISO 3166-1 alpha-2 country list. Blocked visitors receive 451 Unavailable For Legal Reasons by default. Invalid codes fail at declaration time, not at request time.

from fastapi import APIRouter, Depends
from ipregistry_fastapi import block_countries

router = APIRouter(dependencies=[Depends(block_countries("KP", "SY"))])

# Allowlist mode: only serve the EU single market
checkout = APIRouter(dependencies=[Depends(block_countries(EU_COUNTRIES, mode="allow"))])

Requests whose country cannot be determined are allowed unless you pass unknown="block".

Blocking threats

block_threats blocks IPs flagged as threats, attackers or abusers, and responds with 403. Anonymization signals are opt-in — a VPN user is not necessarily hostile:

from fastapi import Depends, FastAPI
from ipregistry_fastapi import block_threats

app = FastAPI(dependencies=[Depends(block_threats())])

# Stricter variant for sensitive routes:
admin = APIRouter(dependencies=[Depends(block_threats(proxy=True, tor=True, vpn=True, relay=True))])

Requests without security data are allowed (fail open), so an Ipregistry outage never locks users out of your API.

Middleware

Prefer dependencies for per-route rules. Reach for the middleware to enforce app-wide policies or eagerly enrich every request — including ones that never match a route:

from ipregistry_fastapi import IpregistryMiddleware, block_countries, block_threats

app.add_middleware(
    IpregistryMiddleware,
    actions=[block_countries("KP"), block_threats(tor=True)],
    skip_bots=True,          # skip lookups for crawler user agents
    skip_static_assets=True, # default: skip .css/.js/images/fonts
    skip=lambda request: request.url.path.startswith("/health"),
)

The middleware stores the lookup on request.state.ipregistry, so IpInfoDep and route guards reuse it for free.

Fail open or closed

By default a failed lookup lets the request proceed with info = None (fail open). To refuse requests instead when IP intelligence is unavailable:

• set IPREGISTRY_FAIL_OPEN=false — IpInfoDep and blocking dependencies respond with 503;
• or pass fail_closed=True (or a custom status code) to IpregistryMiddleware.

GDPR & EU detection

from ipregistry_fastapi import IpInfoDep, is_eu

@app.get("/consent")
async def consent(info: IpInfoDep):
    return {"show_banner": is_eu(info, assume_eu=True)}

is_eu reads location.in_eu; assume_eu=True errs on the side of showing a consent banner when the location is unknown. For EU data residency, set IPREGISTRY_BASE_URL=eu to route all API requests to https://eu.api.ipregistry.co.

Related helpers: is_threat(info, vpn=True, ...) and is_bot(request) (heuristic, no API call).

Configuration

All settings load from the environment via pydantic-settings, or can be passed programmatically with IpregistrySettings:

Environment variable	Default	Description
IPREGISTRY_API_KEY	—	Required. Your Ipregistry API key.
IPREGISTRY_BASE_URL	default	API endpoint; eu selects the EU-only endpoint; full URLs verbatim.
IPREGISTRY_FIELDS	all	Default field selection, e.g. location,security.
IPREGISTRY_HOSTNAME	false	Resolve the hostname of looked up IPs.
IPREGISTRY_TIMEOUT	5.0	Request timeout in seconds.
IPREGISTRY_RETRIES	1	Retry attempts after a failed request.
IPREGISTRY_RETRY_INTERVAL	0.5	Base delay between retries (exponential backoff).
IPREGISTRY_RETRY_ON_SERVER_ERROR	true	Retry on 5xx responses.
IPREGISTRY_RETRY_ON_TOO_MANY_REQUESTS	false	Retry on 429 responses (honors Retry-After).
IPREGISTRY_CACHE_ENABLED	true	Cache lookups in memory.
IPREGISTRY_CACHE_MAX_SIZE	2048	Maximum cached lookups.
IPREGISTRY_CACHE_TTL	600	Cache time-to-live in seconds.
IPREGISTRY_DEVELOPMENT_IP	—	Fallback IP when the client IP is private (e.g. localhost).
IPREGISTRY_FAIL_OPEN	true	Proceed without data when a lookup fails.
IPREGISTRY_IP_SOURCE	client	How to resolve the client IP (see below).

Selecting only the fields you need (e.g. IPREGISTRY_FIELDS=location,security) reduces latency and response size.

IP extraction behind proxies

By default (client) the library uses the ASGI client address — the right choice when uvicorn runs with --proxy-headers --forwarded-allow-ips or behind ProxyHeadersMiddleware, which already resolve the real client IP.

If your server does not rewrite the client address, pick the header set by a proxy you trust:

IPREGISTRY_IP_SOURCE	Headers consulted (in order)
client (default)	none — ASGI client address
auto	X-Real-IP, X-Forwarded-For
cloudflare	CF-Connecting-IP
nginx	X-Real-IP, X-Forwarded-For
forwarded-for	X-Forwarded-For (first entry)
header:<name>	the named header

A callable ip_extractor can also be passed to Ipregistry/add_ipregistry for full control. Values are sanitized (ports, IPv6 brackets and zone IDs stripped) and validated; only configure headers your proxy overwrites — client-supplied headers are trivially spoofable. Private, loopback and carrier-grade NAT addresses are never sent to the API; set IPREGISTRY_DEVELOPMENT_IP to test with a fixed address on localhost.

Caching and credits

Lookups are cached in memory (2048 entries, 10 minutes by default), so repeated requests from the same address consume a single credit. On top of that:

• one lookup per request, however many consumers;
• static asset and bot skipping in the middleware;
• private/reserved IPs short-circuit before reaching the API.

Multi-worker deployments (uvicorn --workers, gunicorn) hold one cache per process.

Testing your app

IpregistryFake is a drop-in service with canned responses and no network access:

from fastapi.testclient import TestClient
from ipregistry_fastapi import add_ipregistry
from ipregistry_fastapi.testing import IpregistryFake

fake = IpregistryFake({
    "66.165.2.7": {"location": {"country": {"code": "US"}}},
    "*": {"security": {"is_threat": False}},   # any other address
})
add_ipregistry(app, service=fake)

client = TestClient(app)
response = client.get("/whoami", headers={"x-real-ip": "66.165.2.7"})

fake.assert_looked_up("66.165.2.7")

Stubs are API-shaped dicts, IpInfo instances, or exceptions to raise. Unlike the real service, the fake accepts private addresses so requests made through TestClient resolve out of the box. Assertions: assert_looked_up, assert_not_looked_up, assert_looked_up_times, assert_nothing_looked_up, assert_origin_looked_up, assert_user_agents_parsed.

FastAPI's standard dependency_overrides mechanism works too, and propagates to IpInfoDep and the blocking guards:

from ipregistry_fastapi import get_ipregistry

app.dependency_overrides[get_ipregistry] = lambda: fake

Errors

Request-aware helpers (IpInfoDep, guards, middleware) never raise on lookup failure — they fail open and record the exception on request.state.ipregistry_error. Explicit lookups raise the client's exceptions:

from ipregistry_fastapi import ApiError, ClientError, ErrorCode, IpregistryDep

@app.get("/lookup/{ip}")
async def lookup(ip: str, ipregistry: IpregistryDep):
    try:
        return await ipregistry.lookup(ip)
    except ApiError as error:
        if error.error_code == ErrorCode.INVALID_IP_ADDRESS:
            raise HTTPException(status_code=400, detail=error.message)
        raise HTTPException(status_code=502, detail="Lookup failed")
    except ClientError:
        raise HTTPException(status_code=504, detail="Ipregistry unreachable")

Beyond IP lookups

The full asynchronous client remains available for batch lookups, ASN data, user-agent parsing and credits introspection:

@app.post("/enrich")
async def enrich(ips: list[str], ipregistry: IpregistryDep):
    results = await ipregistry.lookup_batch(ips)          # order-preserving
    origin = await ipregistry.lookup_origin()             # the server's own IP
    asn = await ipregistry.client.lookup_asn(400923)      # raw client escape hatch

Migrating from ipregistry-python

Existing ipregistry client code keeps working — this package layers FastAPI wiring on top:

• replace manual client creation with ipregistry_lifespan / add_ipregistry;
• replace per-endpoint lookups of the request IP with IpInfoDep;
• move country/threat checks into block_countries / block_threats dependencies;
• configuration moves to IPREGISTRY_* environment variables.

Other resources

• Ipregistry documentation
• Ipregistry Python client
• API status

License

Apache-2.0 © Ipregistry