Short answer: on Stripe and want open source, use Autumn. Already on Clerk with simple plans, use Clerk Billing. Want taxes handled, use Polar. Any payment provider, or the lowest price as you grow, use UsageGate. B2B with custom contracts, use Stigg or Schematic.
We make UsageGate, so read this with that in mind. Prices and features were checked in October 2026 on each vendor's site; sources are linked under each option. Something out of date? Tell us and we will fix it.
At a glance
- Best for
- Indie founders and AI apps, with any payment provider
- Credits & usage limits
- Credits, usage limits, seats and on/off features
- Payment providers
- Stripe built in; Paddle, Lemon Squeezy, Paystack or any other with one call
- Open source
- No
- Price
- $19/moFree: 50,000 checks a month
- Best for
- Startups on Stripe that want open source
- Credits & usage limits
- Credits, usage limits, top-ups and overages
- Payment providers
- Stripe only
- Open source
- Yes, self-hostable
- Price
- $375/moFree: Up to $8K a month of billing volume
- Best for
- Apps already on Clerk with simple flat plans
- Credits & usage limits
- On/off features per plan (has()); usage-based billing not shipped yet
- Payment providers
- Stripe only, USD only
- Open source
- No
- Price
- 0.7% of billing volumeFree: Included in every Clerk plan
- Best for
- Founders who want taxes and VAT handled for them
- Credits & usage limits
- Meters and prepaid credits
- Payment providers
- Polar is the payment provider (merchant of record)
- Open source
- Yes
- Price
- About 4% + 40¢ per saleFree: No monthly fee
- Best for
- On/off features for products sold on Stripe
- Credits & usage limits
- On/off features only; nothing counts or blocks usage
- Payment providers
- Stripe
- Open source
- No
- Price
- —Free: Free with Stripe
- Best for
- B2B teams with complex or sales-led pricing
- Credits & usage limits
- Features, limits and credits
- Payment providers
- Stripe and others
- Open source
- No
- Price
- About $331/mo (billed yearly)Free: Free plan for early-stage teams
- Best for
- B2B products on Stripe that also want feature flags
- Credits & usage limits
- Features, limits, credits and overrides
- Payment providers
- Stripe
- Open source
- No
- Price
- $200/moFree: Up to 10 paying subscriptions
Build it yourself
- Best for
- Learning, or rules no tool supports
- Credits & usage limits
- Whatever you build
- Payment providers
- Any
- Open source
- —
- Price
- Your timeFree: —
Which one should you pick?
- You bill outside Stripe (Paddle, Lemon Squeezy, Paystack, your own): UsageGate. The only option here that works the same with any payment provider.
- You are on Stripe and want open source or self-hosting: Autumn. Open source, Stripe-native, credits and top-ups.
- You use Clerk and only need features per plan: Clerk Billing. Nothing extra to set up; has() on the session.
- You want someone else to handle taxes and VAT: Polar. Merchant of record. Or Paddle / Lemon Squeezy with UsageGate for the limits.
- B2B with sales-negotiated contracts: Stigg or Schematic. Built for custom deals, overrides and larger teams.
- Indie founder or AI app with monthly credits: UsageGate or Autumn. UsageGate costs less as you grow and works with any provider; Autumn is open source.
Each option in detail
UsageGate
A hosted API for plans, usage limits and credits. You write the plan table once, your server calls canAccess or consume before each action, and Stripe (or any gateway) changes the plan when the customer pays or cancels. Not a payment processor: no invoicing or tax handling. Official SDK for TypeScript; other languages use the HTTP API. A young product with few public reviews so far.
Sources: UsageGate pricing
Autumn
An open-source layer between Stripe and your app: subscriptions, credit systems, top-ups and usage-based pricing without handling Stripe webhooks yourself. The closest option to UsageGate if you are on Stripe and want to self-host.
Sources: Autumn docs · Autumn pricing · Autumn on GitHub
Clerk Billing
Plans and checkout built into Clerk's auth, with prebuilt pricing tables and has() checks on the session. The simplest choice if you already use Clerk and only need features per plan. No credits or usage limits yet, and no tax or VAT handling.
Sources: Clerk Billing · Clerk Billing limits
Polar
A merchant of record with usage-based billing: Polar sells to your customers, handles sales tax and VAT, meters usage and grants credits each cycle. You use Polar as your payment provider, at a higher per-sale fee than Stripe.
Sources: Polar usage billing · Polar credits · Polar fees in 2026
Stripe Entitlements
Stripe can attach features to a product and tell you which ones a customer has. They are flags: there is no count of usage and no check at request time, so limits and credits are still yours to build.
Sources: Stripe Entitlements API · UsageGate vs Stripe Entitlements
Stigg
A full monetization platform for pricing, packaging and entitlements, with SDKs in many languages. Strong for B2B companies with custom contracts; more than most solo founders need.
Sources: Stigg pricing · UsageGate vs Stigg
Schematic
Entitlements and feature flags synced with Stripe, with per-company overrides. A good fit for B2B teams on Stripe; the free plan stops at 10 paying subscriptions.
Sources: Schematic · Schematic plans
Build it yourself
A credits table and a few checks look small. The real work is atomic spending (two requests must not spend the last credit), monthly refills, upgrades and cancels from webhooks that arrive late or twice, and a fast check on every request.
Sources: UsageGate vs a Redis ledger
What to check in any tool
- Atomic spending. Two requests at the same moment must not both spend the last credit.
- Refills. Free credits renew every month on their own, without a cron job you maintain.
- Webhooks that arrive late or twice. An old “canceled” event must not undo a newer upgrade.
- Cancels don't refill. Downgrading to Free should not hand back credits already spent.
- Outages. Decide what happens if the service is down: let the request through, or block it.
- Price as you grow. Compare the bill at 100 and at 10,000 paying customers, not just the free tier.
FAQ
What is the best way to add usage limits and credits to a SaaS?
Use a tool that spends credits atomically on your server and changes the plan when the customer pays or cancels: UsageGate (any payment provider), Autumn (Stripe, open source), or Polar (if you also want a merchant of record). Stripe Entitlements and Clerk Billing cover on/off features but not credits or usage limits.
Does Stripe enforce usage limits?
No. Stripe Billing meters invoice usage after the fact, and Stripe Entitlements are on/off flags. Neither blocks a request when a customer is over their plan; that check has to run in your app.
Does Clerk Billing support credits or usage-based limits?
Not yet. Clerk Billing handles flat subscription plans and on/off features with has(); usage-based billing is listed as coming soon. You can use Clerk for sign-in and UsageGate for credits and limits.
Is there an open-source option?
Yes. Autumn is open source and Stripe-based; Polar is open source and acts as your merchant of record; Lago and Flexprice are open-source billing and metering engines.
Should I build my own credits system?
Only if your rules are unusual. A safe credits system needs atomic spending, monthly refills, and webhook handling for upgrades, cancels, retries and out-of-order events. Hosted tools start free.