Login and a money path — not another empty dashboard.
Auth.js credentials (swap OAuth later), middleware-gated /dashboard, POST /api/webhooks/polar with mock or HMAC verify. After order.paid, an entitlement flips so you see provisioning end-to-end.
~724 words · field guide
“We’ll add billing later” is how later becomes never and never becomes a spreadsheet.
ShipFast-shaped gaps
- Auth without billing.
- Billing without entitlements.
- Webhooks that trust the wind.
The shape of the solution
Harbor wires the dull path: session → gated app → Polar webhook → entitlement.
- Auth.js credentials
- Middleware gate
- Polar webhook
- Mock mode
- Entitlement flip
What's in the download
- Next/Auth shell
- webhook route
- README
- verify
What SaaS Auth + Polar Billing Shell (Harbor) is for (and what it isn’t)
SaaS Auth + Polar Billing Shell (Harbor) lives in the Auth.js · Polar lane. It’s a downloadable workshop folder — code you unzip, run in mock mode, and adapt — not a hosted product with seats, SLAs, or a customer success manager named Chad.
In plain terms: Harbor wires the dull path: session → gated app → Polar webhook → entitlement.
If you came here for a soft-focus brand story about ‘empowering data journeys,’ you’re in the wrong harbor. This is notes from people who got tired of rebuilding the same bridge on every engagement.
The Tuesday-afternoon version of the problem
These kits start on a Tuesday afternoon. Someone asks for a ‘thin wrapper’ or a ‘quick sync.’ Three weeks later you’re debugging pagination while Slack blinks like a smoke alarm.
For this one, the pain usually shows up as: (1) Auth without billing. (2) Billing without entitlements. (3) Webhooks that trust the wind.
“We’ll add billing later” is how later becomes never and never becomes a spreadsheet.
Money is a feature
Without entitlements, checkout is theater.
HMAC or mock
Verify signatures or admit you’re LARPing security.
How to evaluate it without vibes
Open the README. Copy .env.example. Run the verify script or mock path. You want a boring green signal that the contract works. Flashy demos that only run on the author’s laptop are how ‘kits’ earned a bad name.
Then read the modules like a colleague’s PR. If the structure looks reusable, keep going. If it feels like generated goo, close the tab — life’s short.
You’ll see pieces aimed at: Auth.js credentials; Middleware gate; Polar webhook; Mock mode; Entitlement flip.
A realistic first week (no hero montage)
Day 0: unzip, skim the license, run verify/mock. Day 1: point env vars at non-prod credentials if you have them. Day 2: hang it behind ADF, your app, or cron — depending on what this kit is — and watch one happy path.
Day 3 is when you stop treating it like a demo: logging, retries, secrets in a real secret store, and the inevitable ‘can we also support X?’ You own the code. Extend it. That’s the whole point of a workshop asset versus renting another logo.
If your process requires a design doc before a Dockerfile, paste the architecture from this page into the doc and skip inventing folklore from Slack threads.
Where the jokes stop
Humor is here so the page isn’t a funeral. It is not a substitute for signature checks, pagination, role gates, or private networks. If you smirked and skipped verify, that’s on both of us.
Checklist: secrets out of git, mock before prod, verify in CI if you can. The ZIP is the workshop. This page is the field notes.
Dark Lighthouse is a consulting alias with a product habit — reusable bridges because rewriting them from scratch was getting old.
Where it fits
SaaS Auth + Polar Billing Shell (Harbor) is aimed at data, platform, or SaaS engineers who recognize the pain bullets above and want a deployable starting point instead of a six-week inventing contest.
It won’t replace a fully managed sync, a white-glove marketplace app, or a promise that vendors never change APIs. Sharp tools, not frozen oceans.
Wrap-up
That’s the field notes for SaaS Auth + Polar Billing Shell (Harbor). Next step is the ZIP and the verify script — not another meeting. Questions: admin@darklighthousesolutions.com.
More bridges in the same style live on the kit guides index.
FAQ
Postgres?
In-memory first — drop DB when ready.
Pairs with?
ForgeChat + Billing Webhook Handler.
Download on Polar if you want the ZIP · All guides