Stripe usage-based billing vs Locus Pro for AI agents

What is the difference between Stripe usage-based billing and Locus Pro?

Stripe counts usage that happens somewhere else. Your product calls a provider, then sends Stripe a meter event, and Stripe prices it and invoices the customer. Locus Pro sits in the call itself: your server calls the API through Locus, names the customer with the X-Locus-End-User header, and Locus charges that customer's credit balance before it returns the result.

The table follows Stripe's documentation and the Locus Pro billing docs, checked November 10, 2026.

Can Stripe billing credits work as prepaid AI credits?

Partly. Stripe billing credits are prepaid or promotional amounts you give a customer through credit grants. They apply only to subscription items with metered prices that report through Meters, and only when an invoice finalizes. Stripe's docs say customers can exceed their balance during the cycle, so basic credits do not stop an agent mid-month.

For prepaid drawdown Stripe points new integrations to Metronome, which burns credits down in real time. Metronome's prepaid credits guide still leaves enforcement to you: it sends a webhook when a balance reaches zero so that your system can cut off access. Its threshold notifications are evaluated at least once every 3 minutes and fire within 5 minutes of the usage being ingested.

Locus Pro checks the customer's balance before it calls the provider. It holds the most the call can cost, captures the actual charge on success and releases the hold if the provider fails. A short balance returns HTTP 402 with the credits required and available, and nothing runs.

• A Stripe customer can hold up to 100 unused credit grants at a time.
• Credit grants never expire unless you set an expiry date.
• Stripe bars using billing credits as stored value or to pay other businesses.
• A credit note does not restore credits applied to an invoice; you issue a new grant.

• How prepaid credits work

Does Stripe meter LLM tokens and API calls for AI agents?

Stripe's billing for LLM tokens runs on Metronome and is in public preview for anyone with a Metronome account. Stripe syncs token prices for OpenAI, Anthropic and Google models, and you set your margin on top. Your integration sends usage events with the customer, model, token type and token count.

It bills tokens; it does not supply them. You still call each model provider with your own account and key. For search, scraping or enrichment calls, you add your own rates to the Metronome rate card and keep them current yourself.

Locus Pro covers both kinds of call from one balance. Model calls go through an OpenAI-compatible endpoint: Locus holds an amount sized from the prompt and max_tokens, then settles from the usage the provider reports. Search, data and enrichment calls are priced per call or by the response, and every charge carries the customer's ID.

How do you pay for Stripe usage-based billing and Locus Pro?

They charge for different things. Stripe charges for billing: a share of the volume you invoice, plus card processing on each payment. The API providers your agents call bill you separately, each on its own invoice. Locus Pro charges for the calls themselves: each call draws its catalog price from prepaid credits, and billing your customers comes with an Enterprise plan.

At high volume on one provider, such as Brave for search, calls can cost less with your own Brave account and API key. Locus Pro removes the provider accounts, the metering code and the reconciliation.

• Stripe's current rates
• Locus Pro plans

When is Stripe usage-based billing the better choice?

Choose Stripe when the usage you bill is not a third-party API call, or when Stripe already runs your invoicing.

• You bill your own product's usage, such as compute, storage, seats or tokens from models you host.
• Customers already get Stripe invoices and you want subscription and usage on one invoice.
• You sell enterprise contracts with commits, minimums or ramp schedules, which Metronome handles.
• You invoice in arrears against purchase orders instead of taking payment up front.
• You run a Stripe Connect platform: basic Meters supports Connect and Metronome does not.
• Your agents call only one or two providers, so an account and key for each is little extra work.

When is Locus Pro the better choice?

Choose Locus Pro when your customers' agents call paid third-party APIs and each customer should pay for their own calls.

Customer billing comes with Enterprise, $200 a month with $30 of credits included and up to 240 tool calls a minute. Enterprise Plus is $1,000 a month with $100 of credits and up to 1,200 calls a minute.

• Agents use several providers for search, scraping, enrichment, data or models, and you do not want an account, key and invoice for each.
• Each customer prepays, and their calls should stop at zero before the provider runs.
• You want your markup set for the whole workspace, one provider or one endpoint, with margin recorded per customer in a ledger.
• Agents need their own keys with allowed tools, a maximum per call and a run budget.
• You want signed webhooks for charges, low balances, top-ups and refunds without building them.

• Locus Pro for platforms
• Plans and prices
• Tool catalog and base prices

Can I use Stripe and Locus Pro together?

Yes, and many products should. Keep Stripe Billing for subscriptions and your own usage, and send third-party API calls through Locus Pro, so those calls need no meter events.

There are two ways to fund each customer. Bill them in Stripe as you do today, then move credits from your Locus pool to their balance; your markup returns to the pool as they spend. Or let them buy credits in the Locus balance widget or through a checkout link from your server; your margin on those credits pays out after a 30-day hold.

• Stripe usage-based billing explained
• Usage-based billing software compared