⚡ Larz

New in 1.1 — TOTP 2FA, social login (Google/GitHub), file uploads, a marketplace payout ledger, four more payment providers (Square, Razorpay, Mollie, Coinbase Commerce), and a first-class test client. See the changelog.

The money-native web framework.

pip install larz

Larz is a small, from-scratch, dependency-free Python web framework where payments, paywalls, subscriptions, trials, and usage-metering are first-class primitives — not something you bolt on with three libraries and a weekend.

Flask makes routes easy. Django makes data easy. Larz makes getting paid easy.

from larz import Larz
import larz.money as money

app = Larz(secret="change-me")
money.enable(app)                          # payments on. Zero keys in dev.

@app.paid("$9/mo", trial_days=7)           # subscription with a free trial
@app.get("/pro/report")
def report(req):
    return "<h1>Pro report for %s</h1>" % req.subject

@app.metered("$0.02/call")                 # per-call billing from prepaid credit
@app.post("/api/summarize")
def summarize(req):
    return {"summary": run(req.json()["text"])}

app.run()

A request to /pro/report from someone who hasn't paid is automatically sent through checkout (or given their free trial); when they come back, they're served. A request to /api/summarize with no credit gets a clean 402. You never write if user.is_paid.

Batteries included — all pure stdlib

Why

Every other framework treats money as an afterthought — the thing you wire up last, badly, copy-pasted from a payments tutorial. But for indie hackers, solopreneurs, and anyone shipping a product to make a living, monetization isn't the afterthought — it's the point. Larz puts it in the core.

Use it for

• Paid / metered APIs — AI wrappers, data APIs (@app.metered per call)
• Content paywalls — reports, courses, paid newsletters (@app.paid)
• Digital products — one-off unlocks and downloads
• Micro-SaaS — a free tier + a Pro plan with a trial (@app.plan)

Design principles

• Zero dependencies. Pure Python standard library — sqlite3, urllib, wsgiref. Runs anywhere python3 runs, including constrained boxes and phones.
• Provider-agnostic. The framework never hard-codes a processor. Implement create_checkout + parse_webhook and any processor drops in.
• Portable by default. No modern-SQLite assumptions, no C extensions.

Run the demos (no API keys)

python3 examples/paid_app.py     # the essentials: paid + metered routes
python3 examples/saas_app.py     # a full mini-SaaS: plans, trials, credits,
                                 # templates, ORM, dashboard, security

Then open http://127.0.0.1:8000/ and click through. Visit /larz/admin?token=admin123 on the SaaS demo to see the revenue dashboard.

Test

python3 tests/test_core.py       # 15 — routing, sessions, paywall, metering
python3 tests/test_features.py   # 43 — money, providers, templating, security
python3 tests/test_v1.py         # 52 — ORM, auth, API, admin, ops, billing

110 checks, no pytest required.

Scaffold a new app

python3 -m larz new myapp
cd myapp && python3 -m larz run

Status

v1.0.0 — real and tested, but not yet production-hardened (WSGI dev server, in-memory rate limiting, MockProvider is dev-only). Roadmap: ASGI/async core, production server recipe, dunning/renewal reminders, richer analytics, a hosted docs site at larzos.com/larz.

License

MIT.