siteforge-mcp

An MCP server that takes payment for a website and publishes it — but only after Stripe confirms the money arrived.

Standalone. No shared code, imports, or infrastructure with any other project.

Tools

Related MCP server: MCP Billing Gateway SDK

The one rule this server exists to enforce

publish_site is the paywall. The caller is a browser artifact — it can be edited by anyone with devtools, so it is never believed. The only thing it can send is a session_id, and the server asks Stripe directly whether that session is paid. There is no parameter that lets a caller assert payment.

Second-order protections:

• A paid session maps to exactly one Netlify site, recorded in that session's Stripe metadata. Republishing with the same session updates the same site, so one payment cannot mint unlimited sites. Metadata also means no database.

• No card number ever touches this server. Customers pay on Stripe's hosted page, which keeps the whole thing out of PCI scope.

• Secrets live only in this process's environment.

Site ownership

Sites are created under your umbrella Netlify team, then handed over. Each response includes a claim_url — a signed link that transfers the site into the customer's own Netlify account. You keep deploy access afterward, so paid edits still work, but their hosting is on their account. Set the OAuth vars below to enable it; without them claim_url is null and sites stay yours.

Setup

1. Stripe key — dashboard.stripe.com/apikeys. Start with sk_test_.

2. Netlify token — app.netlify.com/user/applications → personal access tokens.

3. Team slug — Netlify team settings → general. Use a team dedicated to customer sites, not your personal one.

4. OAuth app (for claiming) — app.netlify.com/user/applications → OAuth applications → Create new. No redirect URI needed for deploy-and-claim. Copy the client ID and secret.

Copy .env.example to .env for local runs. On Render, set the same keys under Environment. render.yaml is included — deploy from repo, free plan is fine.

pip install -r requirements.txt
python server.py            # serves on http://localhost:8000/mcp

Tests

pip install -r requirements-dev.txt
pytest -q                   # 66 tests, no network or credentials needed

Stripe and Netlify are both stubbed. Stripe responses are built with construct_from, so tests see the same object types a live call returns — that is what catches the version issue described below.

Verified

• Server boots; initialize, tools/list and tools/call answer correctly over streamable HTTP.

• publish_site refuses every non-paid payment status and never touches Netlify for one. It takes no argument through which a caller could assert payment — the artifact can only hand over a session_id.

• One paid session maps to one site: republishing redeploys the recorded site_id instead of creating a second site.

• Once a deploy succeeds the URL always comes back. No Stripe failure on the bookkeeping write afterward can turn a live, paid-for site into a failed call; it degrades to a warning field.

• Every Stripe and Netlify failure returns {ok, error, how_to_fix} rather than a raw exception, and Stripe's partially-masked API key is never echoed back.

• Misconfiguration names the missing variable.

• HTML fragments and oversized documents are rejected before Stripe is called.

• Claim link JWT signs and verifies with the expected client_id / session_id, and a broken OAuth secret yields claim_url: null instead of failing a publish.

Not yet verified

• A real payment moving unpaid → paid, and a real Netlify deploy. Both need live credentials. That is the first thing to run once this is on Render.

• Subscription (recurring=true) checkout has not been exercised end to end; the session is constructed correctly but no real subscription has been billed.

A note on the Stripe version

stripe-python 12 stopped making StripeObject a dict subclass. On 12+, session.metadata is not a mapping: .get() raises AttributeError, {**...} raises TypeError, and an empty one is truthy so or {} never falls back. Since this server keeps its payment→site mapping in Stripe metadata, every read goes through _stripe_dict(), which normalizes all of those shapes — plus absent and null fields — to a plain dict. It works on 11 and 12+ alike. Don't reach for session.metadata directly when adding code.

v1 scope

No refunds, no webhooks, no custom domains, no multi-page sites. Add them when a customer asks, not before.