spartanauth on SpartanAuth Blog

SpartanAuth is live

Wed, 22 Jul 2026 00:20:00 -0600

For a long time this blog was me writing about auth while the product was still finding its legs. That chapter is over.

SpartanAuth is live. Not a slide deck. Not a private prototype I only demo on good days. It is running in real applications — including several of my own — and other people are shipping with it too.

The point of SpartanAuth was never “another identity platform with a 40-page pricing grid.” It was simpler: give developers a path to solid auth without turning the front door of their app into a multi-month side quest. The login widget was always part of that bet. Drop it in, brand it, and let users sign in without you hand-rolling every edge case.

Here is what that looks like in the wild.

Real apps, real front doors

Same widget family. Different products. Different brands.

Lagom Supply CRM — password login and reset, styled for the product.

Book Club — password auth plus Continue with Google.

SpartanAuth's own dashboard login — the dogfooding never stops.

I care about this more than feature checklists. A login screen is the handshake before anyone trusts your app. If it feels bolted on, everything downstream feels a little worse. If it feels native, people stop thinking about auth and start using the product.

Live

Running in real deployed applications

Branded

Same widget, different product skins

Mine + others

Apps I run, and apps other people are shipping

If you last checked in during the early prototype posts, the surface area has grown up.

The login widget, backed by SpartanAuth, currently supports:

OAuth2 / social sign-in — Google, Apple, GitHub, and generic OIDC
Self sign-up
Password reset
MFA via email
Passkeys

OAuth paths: Google, Apple, GitHub, generic OIDC

Passkeys

Modern passwordless when you want it

Email MFA

A second factor without SIM-swap theater

That mix matters. Some apps want “Continue with Google” on day one. Some need boring email + password with a reset flow that does not shame the user. Some are ready for passkeys. A few want all of the above without maintaining four half-finished auth codepaths.

I am still opinionated about SMS OTP — I wrote about why I will not pretend it is a strong factor — but I am not opinionated about whether your users should start on OAuth, passwords, or passkeys. The widget is there to make the good options easy to offer.

One more from the wild

Screenshots are useful. This one needed motion — another live SpartanAuth integration, with a background animation I thought was too pretty not to include.

Sorry — your browser does not support embedded video.

Another live SpartanAuth integration — mostly here because the background animation is gorgeous.

If you have ever integrated auth the hard way, you know the invisible work: redirects, error states, “forgot password” loops, MFA handoffs, provider quirks. The goal here is that most of that complexity lives behind a small embed and a service that already knows how to do it.

Docs, skills, MCP, and shipping with AI

Something I did not fully expect when I started: people are not only reading docs — they are pointing coding agents at them.

The docs live at docs.spartanauth.com. Alongside the usual reference material, there are skills and guidance meant to help humans and AI assistants wire SpartanAuth up without inventing a snowflake architecture every time.

Next up is an MCP server integration. That matters once an agent is past “read the docs” and into actually building. Instead of only generating code that hopes it matches your tenant setup, an agent will be able to apply SpartanAuth settings and manage Sectors as it implements — configure the thing it is integrating, not just describe it. It is not available yet, but it is on the way.

That is a big deal in 2026. A lot of apps are getting scaffolded at unnatural speed. Auth is still one of the places where “move fast” turns into “accidentally store passwords wrong” or “ship a login page that only works on the author’s laptop.” If good docs, skills, and (soon) MCP tools make the secure, boring path the default path for an agent, I will take that win every day of the week.

Docs + skills

Available now for humans and agents

MCP

Coming soon — apply settings and manage Sectors

What I want you to do with this

If you have been waiting for SpartanAuth to feel real: it is.

Browse the product: spartanauth.com
Read / point your agent at the docs: docs.spartanauth.com
If you want updates as more ships, get on the list

I will keep writing here the way I have been — practical notes, honest boundaries, fewer buzzwords than the category usually deserves. The difference is that now the screenshots are not mockups. They are front doors on software people already use.

Login Widget

Thu, 26 May 2022 23:24:13 -0600

When I started SpartanAuth, I had a simple obsession: authentication should be easy to do correctly. Complexity is where security bugs and abandoned sign-ins both hide. Today I want to talk about the login widget.

TLDR: usability, branding, and making the secure path the easy path.

Businesses lose real money when people cannot sign in. “About a third of online purchases are abandoned at checkout because consumers cannot remember their passwords,” from a study conducted jointly by MasterCard and the University of Oxford (source). That is a big reason I care about helping apps move away from relying on passwords.

~⅓

Of online purchases abandoned at checkout over forgotten passwords

MasterCard / University of Oxford

Replacing passwords with stronger authentication can be expensive, complicated, error-prone, and hard to use. SpartanAuth exposes an API so you can build your own login page — but I also wanted a complete path that is kind to both end users and the developers wiring it up.

User experience matters. So does branding. A login screen is often the front door of a product; it should feel like your app, not a generic detour.

So I built a login widget with the factors SpartanAuth supports, configurable enough to match your look and feel.

Choosing a tech

Shipping third-party UI into someone’s app is a trust exercise. I wanted the widget stack to be reliable, fast, and small. Frontend framework debates aside, the last decade of competition has been great for bundle size and performance — and I wanted those gains.

I set three criteria. The technology had to:

be simple to implement in any web environment
have a minimal bundle size when delivered to the end user
be a leader in performance

Simple

Drop into any web environment

Small

Minimal bundle for end users

Fast

Performance as a first-class goal

My first prototype was in Vue. Reactive UI is lovely, and the prototype was decent — but Vue is not ideal when you are shipping a single custom element. They even say explicitly that “it is not ideal to use Vue if you are shipping a single custom element”. So I kept looking.

At the suggestion of my friend Christopher Bradshaw, I found SolidJS. This blog post is still one of the clearest write-ups I have seen on compilers, bundle size, and performance. Reactive programming on top was icing.

Solid checked the boxes: near-vanilla JS performance, a bias toward less client JS, TypeScript support, and a tiny final bundle. And yes — it could ship as something developers drop in easily.

Solid has a library aimed at custom elements: Solid Element.

Results

The early Solid prototype was promising. A custom login page could look like this:

<script type="module" crossorigin src="/assets/index.2157afe0.js"></script>

and

<spartan-login start-mode="webAuthn" locale="en" redirect="/app.html"></spartan-login>

2 lines

To embed a full login experience

~17 KB

Gzipped bundle in the early Solid prototype

Bundle size was already reasonable, with room to improve:

index.668c492a.js            44.63 KiB / gzip: 16.70 KiB

That build included i18n, and the multi-locale result looked like this:

Four copies of the login widget each with a different language.

Customization started simple and powerful: pass CSS through a styles attribute and it applies. More knobs can come later; full CSS control is already a lot.

Login widget with the button stylized to match with a background of trees.

This matters to me: the login widget library is open source. You should be able to inspect what you embed. SpartanAuth the service is a product I am building and running for real apps — including several of my own — but I want the client piece developers drop into a page to be transparent.

Open widget

Inspect what you embed — the login library is open source

Next steps

The widget began as a focused prototype and grows as the backend gains features. If you want to follow along, use the RSS feed or the newsletter below. And if you are building something that needs auth, I would love for you to try SpartanAuth.

What this blog is

Tue, 10 May 2022 21:10:40 -0600

I’m Mason Payne, and this is my blog about building SpartanAuth.

I started these posts while getting the product off the ground. The short version of where things stand now: SpartanAuth is a real auth service I use in several of my own applications. I’m still writing here when I learn something worth sharing — passwords, passkeys, login UX, and the tradeoffs you hit when auth has to work for real users.

Auth notes

Passwords, passkeys, MFA, login UX

Real product

SpartanAuth in apps I actually run

One clarification up front: SpartanAuth itself is not open source. The login widget library is, and I’m proud of that. The core product is how I’m building a sustainable business through Masonite Studios while still giving developers something solid to plug in.

Core

Not open source — the business product

Widget

Open source — inspect what you embed

If you want the product, head to spartanauth.com. If you want the thinking behind it, stick around.

spartanauth on SpartanAuth Blog

SpartanAuth is live

Real apps, real front doors

Lagom Supply CRM — password login and reset, styled for the product.

Book Club — password auth plus Continue with Google.

SpartanAuth's own dashboard login — the dogfooding never stops.

What the widget can do today

One more from the wild

Docs, skills, MCP, and shipping with AI

What I want you to do with this

Login Widget

Why build a widget?

Choosing a tech

Results

Four copies of the login widget each with a different language.

Login widget with the button stylized to match with a background of trees.

Why the widget is open source

Next steps

What this blog is