larz 0.2.0

The money-native web framework — payments, paywalls and metering as first-class primitives. Zero dependencies.

⚡ Larz

The money-native web framework.

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

Area	What you get
Money	@app.paid · @app.metered · @app.plan · subscriptions & renewals · free trials · coupons · credit packs · built-in /larz/pricing, /larz/credits, and a /larz/admin revenue dashboard (MRR, sales, usage)
Providers	MockProvider (keyless dev) · StripeProvider · GemVaultProvider · DodoProvider · CryptoProvider — all via stdlib urllib, no SDKs. Add your own in ~40 lines.
Core	WSGI engine · typed routing (/u/<id:int>/<slug>) · signed-cookie sessions · blueprints · static files · debug error pages
Templating	A real {{ }} / {% for %} / {% if %} engine with autoescaping
Models	A tiny active-record ORM over sqlite (Model / Field, queries, ordering)
Security	Rate limiting · bot / invalid-traffic filter · CSRF · CORS
SEO	Auto sitemap.xml + robots.txt · OpenGraph/Twitter meta_tags() · IndexNow ping
CLI	larz new · larz run · larz routes

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 checks
python3 tests/test_features.py   # 32 checks — money, templating, models, security

47 checks, no pytest required.

Scaffold a new app

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

Status

v0.2.0 — 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.