Auth & Payments
Authentication, authorization, billing, payment processing, and security.
30 topics
What this section covers
Most AI projects die somewhere between "it works on my machine" and "someone paid me for it." This section is the reference for the two features that close that gap: knowing who the user is, and taking their money without losing their trust. You'll find focused pages on Stripe (including the customer portal integration) and Polar for subscription billing, Clerk for managed auth and billing in one, Supabase Auth for the self-hosted-friendly path, and Login with Google for the single most-requested social provider. Deeper pages on authentication, authorization, and general application security cover the patterns you need when rolling your own — or reviewing something an AI built for you and flagged as "probably fine." It's aimed at developers who are about to put a paywall on their AI-powered product and do not want to explain a data leak to their first ten customers.
Accounting & Bookkeeping Software: QuickBooks, Xero, FreshBooks, Wave, Sage, Zoho Books, Bench, Pilot
If you're running a SaaS in 2026, you'll need accounting software for: bookkeeping (transactions categorized + reconciled), tax-prep (annual filings), financ...
Auth Providers for SaaS
Picking an auth provider in 2026 is a different decision than it was in 2023. Clerk has matured into the indie / mid-market default. Better Auth has emerged ...
Authentication
Authentication is the process of verifying a user's identity, ensuring they are who they claim to be. In web applications, authentication systems manage user...
Better Auth
Better Auth is the framework-agnostic, TypeScript-first auth library that took over maintenance of Auth.js / NextAuth in late 2025. Self-hosted, plugin-driven, and the strongest default for new Next.js apps in 2026.
Cap Table & Equity Management Tools: Carta, Pulley, AngelList Stack, Capboard, Shareworks, Ledgy, Equiteo
If you've raised any money or issued any equity (founder shares, advisor grants, employee options) in 2026, you need a cap table tool. Spreadsheets work for ...
Clerk Billing for B2C SaaS - Vibe Code Tool Implementation Guide
> **Warning**: This feature is currently in Beta. The low-level JavaScript APIs exposed via `Clerk.billing` are experimental and may undergo breaking changes...
Contract Lifecycle Management (CLM) Platforms: Ironclad, DocuSign CLM, Juro, LinkSquares, Conga, ContractWorks, Concord, Agiloft
If you're a B2B SaaS in 2026 dealing with NDAs, MSAs, order forms, vendor contracts, and renewal negotiations at any volume, this is the consolidated compari...
CPQ & Quote-to-Cash Tools: Salesforce CPQ, DealHub, PandaDoc, GetAccept, Conga, Apttus, Subskribe, Tabs, Maxio
If you're a B2B SaaS at $10M+ ARR with sales-led GTM and complex pricing — multi-product bundles, custom pricing, multi-year contracts, expansion math — you ...
E-Signature & Document Signing Tools: DocuSign, Dropbox Sign, PandaDoc, Anvil, SignNow, Adobe Sign, Documenso
If you're closing B2B deals, hiring contractors, or running any contract-bound business in 2026, you need e-signature. This is the consolidated comparison. M...
Financial Data & Open Banking APIs: Plaid, Yodlee, Finicity, MX, TrueLayer, Tink, GoCardless, Stripe Financial Connections
If you're building a SaaS in 2026 that needs to read bank account data, verify income, automate ACH transfers, pull transaction histories, or move money betw...
Fraud Detection & Anti-Abuse Providers: Sift, Castle, Stripe Radar, Forter, Signifyd, Riskified, Kount, Sardine
If you process payments, run a marketplace, or have valuable user actions in your SaaS in 2026, you face fraud at scale. The threats are concrete: stolen-car...
Healthcare HIPAA-Compliant Stack & Tools: AWS HIPAA, Google Cloud Healthcare, TrueVault, Datica, Aptible, Paubox, Redox, Postmark, Twilio Healthcare, Doxy.me
If you're building healthcare software in the US in 2026 — telehealth, patient-facing apps, payer/provider tools, RCM, clinical AI, mental health platforms, ...
HR & Payroll Tools: Gusto, Rippling, Deel, Justworks, Paychex, ADP, TriNet
If you're hiring employees in 2026, you need payroll software. Running payroll manually is illegal in practice (tax filing alone is a multi-jurisdiction nigh...
Identity Verification & KYC Tools: Persona, Stripe Identity, Veriff, Onfido, Jumio, Plaid Identity, Trulioo, Sumsub
If you're building a SaaS in 2026 that needs to verify user identity — KYC for financial services, age verification, fraud prevention, vendor onboarding, mar...
Payment Integration
Payment integration refers to the process of connecting your application with payment processing services to enable financial transactions such as subscripti...
Payment Providers for SaaS: Stripe, Paddle, Lemon Squeezy, Polar, Chargebee, RevenueCat
If you're building a SaaS, marketplace, or app and trying to decide who processes your payments, this is the consolidated decision guide. Pick wrong here and...
Performance Management & Employee Engagement Tools: Lattice, 15Five, Culture Amp, Leapsome, WorkBoard, Officevibe, Small Improvements, Reflektive
If you're scaling a B2B SaaS past 30-50 employees in 2026, you'll hit performance management. The naive shape: annual reviews via Google Doc; CEO writes "goo...
Polar
Polar is a monetization platform built for developers and open-source maintainers. It provides tools for accepting payments, managing subscriptions, and sell...
Recruiting & ATS Platforms: Greenhouse, Ashby, Lever, Workable, Gem, Recruitee, Pinpoint, Rippling Recruiting, BambooHR Hiring
If you're a B2B SaaS at any stage from seed through Series C and you've hired more than 5-10 people, you'll hit the moment where Notion docs + email threads ...
Security
Web application security is the practice of protecting websites and online services from various security threats and vulnerabilities. Effective security mea...
Setting Up Google Authentication with Supabase in Next.js
Offical documentation: https://supabase.com/docs/guides/auth/social-login/auth-google
Startup Banking & Corporate Spend Platforms: Mercury, Brex, Ramp, Bluevine, Relay, Airbase, Spendesk
If you're forming a startup in 2026 and trying to figure out where to bank, what corporate card to issue, and how to manage employee spend, this is the conso...
Stripe Customer Portal
Add a Stripe Customer Portal so users can manage subscriptions and billing themselves. Covers configuration, session creation, and redirect handling.
Stripe Integration Guide for Next.js/Supabase Applications
Integrate Stripe subscriptions into your Next.js and Supabase app. Covers products, prices, webhooks, billing portal, and checkout session setup.
Stripe Usage-Based Billing
Implement usage-based (metered) billing with Stripe. Meters, meter events, pricing models, proration, and common pitfalls for SaaS and AI products.
Subscription Analytics Platforms: ChartMogul, Baremetrics, Paddle Retain, Maxio, Stripe Sigma, Equals
If you're running a SaaS in 2026 and trying to figure out your real ARR, MRR movement, churn cohorts, NRR, and LTV, this is the consolidated comparison. Subs...
Subscription Billing Providers: Stripe Billing, Lago, Orb, Metronome, Chargebee, Recurly, Maxio, Paddle Billing, Hyperline
If you're building a SaaS in 2026 and trying to pick a billing system, this is the consolidated comparison. Subscription billing is the line item that looks ...
Supabase Auth
Supabase Auth is a complete authentication system built on top of Postgres — it stores users directly in your database, integrates natively with Row Level Se...
Tax Compliance Tools: Stripe Tax, TaxJar, Avalara, Anrok, Sphere, Quaderno, Paddle, Lemon Squeezy
If you're building a SaaS in 2026 and trying to pick a tax-compliance tool, this is the consolidated comparison. Tax is the line item founders skip until a s...
Vendor Management & SaaS Procurement Platforms: Vendr, Tropic, Sastrify, Spendbase, Cledara, Coupa, SAP Ariba, Workday, Zip
If you're a B2B SaaS company at $5M+ ARR, you have a SaaS-spend problem you didn't know about. Marketing has 30 tools; engineering has 40; sales has 25; peop...