Locus product guide · Updated November 10, 2026

Usage-based billing software: Metronome, Orb, Lago, Stigg

Stripe Billing costs 0.7% of billing volume and now points new usage-based setups to Metronome, which Stripe bought in January 2026; Metronome Starter is 0.8% plus $0.04 per 1,000 events. Orb, which Adyen bought in July 2026, sells $6 credits that each cover $1,000 of billings, Kong's OpenMeter successor lists 0.4% plus $20 per million events, Stigg starts free, and Lago is open source. All of them meter and invoice your own product's usage. None supplies the APIs your agents call.

What are the main usage-based billing tools in 2026?

Six tools cover most AI and API billing setups. Three of them changed owners in the past 15 months. Prices checked November 10, 2026.

What are the main usage-based billing tools in 2026?
Tool	Owner and status	Published price	Notable limits
Stripe Billing (Meters API)	Stripe; basic usage billing, kept for existing integrations	0.7% of billing volume, with up to 100M meter events a month included	Credits apply only at invoice time; no real-time balance
Metronome	Part of Stripe since January 2026; Stripe's recommended usage platform	Starter: 0.8% of billing volume plus $0.04 per 1,000 events	No Stripe Connect support; Stripe Checkout needs custom work
Orb	Part of Adyen since July 2026	Business: $6 per credit; 1 credit covers $1,000 billed or 200,000 events	Commitments, NetSuite and revenue reports need Enterprise
Lago	Independent; open source under AGPLv3	Self-hosting is free; Cloud and Premium are priced on request	Tax, dunning and progressive billing are add-ons
OpenMeter	Bought by Kong in September 2025; the cloud is now Kong Konnect Metering & Billing	Konnect: 0.4% of billing volume plus $20 per million events	Open-source releases are beta and can include breaking changes
Stigg	Independent vendor	Build: free up to 5M events a month; Pro: $399 a month billed annually	Priced by managed entities and events, not billing volume

What does each tool cost for the same workload?

Take a product that bills $50,000 a month across 5 million usage events. The fee below is the billing tool's own charge from its public price list. Card processing comes on top, for example 2.9% plus 30 cents per card charge on Stripe Payments.

Volume discounts and contracts change these numbers. Stripe's pay-monthly plans start at $620 a month for up to $100,000 of billing volume. Orb, Metronome, Kong and Stigg all sell custom plans.

What does each tool cost for the same workload?
Tool	How the fee is worked out	Monthly fee
Stripe Billing	0.7% of $50,000; 5M events are inside the included 100M	$350
Metronome Starter	0.8% of $50,000 plus 5,000 × $0.04	$600
Orb Business	50 credits for billings plus 25 for events, at $6 each	$450
Kong Konnect (OpenMeter)	0.4% of $50,000 plus 5 × $20 for events, plus the $25 Plus base	$325
Stigg Build	Free up to 5M events and 10,000 managed entities	$0, then Pro at $399 to $499
Lago open source	No license fee; you run and maintain the servers	Your hosting cost

What changed for Metronome, Orb and OpenMeter?

Stripe completed its acquisition of Metronome on January 14, 2026. Stripe's docs now call Metronome its primary usage-based billing platform and the starting point for new integrations. Basic usage billing on the Meters API stays fully supported for existing integrations. It also works with Stripe Connect, Checkout and the Dashboard, which Metronome does not fully support.

Adyen closed its acquisition of Orb on July 1, 2026. It describes Orb as an enterprise billing platform and said at closing that it would begin integrating Orb's billing.

Kong announced its acquisition of OpenMeter on September 3, 2025. OpenMeter's pricing page now says OpenMeter Cloud is Kong Konnect Metering & Billing. The open-source project stays under the Apache 2.0 license, and its README says releases are beta and can include breaking changes.

Stripe usage-based billing explained

What does a billing engine leave to you?

A billing engine meters the events you send, applies your prices and produces invoices or balance updates. It does not supply the APIs or models your product calls. You still open an account with each provider, hold their keys, pay their bills and send a usage event for every call.

That gap matters for AI products. Your cost lives in provider invoices and your price lives in the billing engine. You reconcile the two to know your margin per customer, and every missed event is revenue you never bill.

When is Locus Pro the better fit?

Locus Pro Enterprise is billing and a paid tool catalog in one. Your customers' agents call search, scraping, enrichment, speech and model endpoints through Locus. Each customer has a balance, each call names the customer with X-Locus-End-User, and the customer pays the catalog base price plus your markup. Locus records the charge and your margin in a ledger grouped by customer, so there are no meter events to send and no provider invoices to match.

Customers top up their balance by card through Locus-hosted checkout or the embeddable balance widget. Or you sell credits your own way and allocate them from your pool.

Use a billing engine alone when you sell only your own product's usage, need seats, commits or enterprise contracts, or invoice in arrears. Many products use both: a billing engine for the subscription and Locus Pro for paid API calls.

How do I choose usage-based billing software?

Start from what you sell and where your data has to live.

Already on Stripe Meters with simple pay-as-you-go pricing: stay on Stripe Billing.
New usage pricing with prepaid drawdown, commits or rates by model, and you use Stripe: Metronome.
You want to test pricing changes on real customer data before launch: Orb, which includes simulations and plan versions on Business.
Billing data must stay on your own infrastructure: Lago or OpenMeter self-hosted, or Stigg BYOC from $40,000 a year.
Entitlements and per-agent credit budgets enforced in real time: Stigg.
You already run Kong API gateways: Kong Konnect Metering & Billing.
Your customers' agents need third-party paid APIs billed per customer: Locus Pro Enterprise.

Frequently asked questions

Is Metronome part of Stripe?

Yes. Stripe completed the acquisition on January 14, 2026. Metronome still publishes its own plans, and Stripe recommends it for new usage-based billing integrations.

Is Orb still an independent company?

No. Adyen closed its acquisition of Orb on July 1, 2026, and said it would begin integrating Orb's billing. Orb's pricing page still lists its own plans.

Is OpenMeter still open source?

Yes. The OpenMeter repository remains under the Apache 2.0 license after Kong bought the company. The hosted service is now Kong Konnect Metering & Billing.

Which usage-based billing tool is cheapest at low volume?

Stigg's Build plan is free up to 5 million events a month, and Lago is free to self-host if you run the servers. Among hosted tools priced on billing volume, Stripe Billing at 0.7% with no monthly fee is cheapest for small products. Kong's 0.4% plus a $25 base wins above about $8,300 a month of billings, before event fees.

Can I use Locus Pro with Stripe Billing?

Yes. Keep your subscription in Stripe Billing and run paid API calls through Locus Pro. Locus charges each customer balance per call, so those calls need no Stripe meter events.

Implementation references

Use these first-party references for current request contracts and account requirements. Tool availability, prices, and negotiated terms can change.

Sources

Third-party details were checked on November 10, 2026. Vendors change pricing and features often, so confirm on their site before you decide.