Credits, plans and limits explained

By Thomas Lovas Lokoy · Published 16 October 2026 · 5 min read

AI Orbit bills in credits, not in words or seats. This tutorial sets out exactly what a credit buys, what each plan includes, and what the code does to your balance at each point in a subscription's life. Every price and number here is the one on the pricing page and in the code on 16 October 2026; if the two ever disagree, the pricing page is the one you are buying under.

The unit

One credit is one article written with Sonnet. An article written with Opus costs three credits. That is the whole price list for generation. Length does not change the price: a 300-word Sonnet article and a 4,000-word Sonnet article both cost one credit. Keyword research, the cover image search, series planning and the keyword-brief preview are not charged separately.

The plan copy is generated from the same number the ledger uses. The line "250 credits a month — 250 Sonnet articles, or ~83 on Opus" is computed from the credit figure, so the quota you read cannot drift from the quota you are given.

Free

A new account receives 3 credits on sign-up. They never expire. On top of that, the Free tier can write one article per day that does not come out of that balance; the day's free article is use-it-or-lose-it and does not accumulate. No card is required.

Free limits: articles up to 800 words, Sonnet only, all five public personas, Markdown export. Funnel structure, internal links, cover images, keyword research, series, batch and rewrites are not included.

The paid plans

Each plan includes everything in the plan before it.

• Starter — $19 a month, 100 credits, articles up to 1,200 words. Adds funnel structure with an internal-link plan, a licensed cover image on every article, and a public page.
• Pro — $39 a month, 250 credits, articles up to 2,000 words. Adds live keyword research, series of up to 5 articles, rewrites, and Opus.
• Studio — $79 a month, 600 credits, articles up to 3,000 words. Adds batch runs of up to 5 topics at once, and email support.
• Agency — $149 a month, 1,500 credits, articles up to 4,000 words. Adds batch runs of up to 10 topics at once.

VAT is added in the EU. On Opus, 250 credits is about 83 articles, 600 is 200 and 1,500 is 500.

How the balance moves

The ledger is a single database function; every change is a row you could audit. These are the events that touch it:

• Subscription starts. When Stripe confirms the checkout, your balance is set to the plan's monthly credits and your tier is switched. The plan's Stripe price is matched to the plan by configuration, so an unknown price is logged and refused rather than guessed.
• Each monthly invoice is paid. The balance is set to the plan's monthly figure again. It is a reset, not a top-up: credits you did not use in the previous month do not carry over.
• You change plan. Plan changes happen in Stripe's billing portal, reached from "Manage or cancel subscription" in Settings. When the tier changes, the balance is set to the new plan's credits.
• A payment fails. While Stripe retries the card (the "past due" state), your plan and balance are left alone.
• You cancel. When the subscription ends, the account returns to Free-tier limits and the monthly allowance stops.
• A charge is refunded. The balance is set to zero and the account returns to Free.

Every one of these is idempotent on the Stripe event, so a webhook delivered twice applies once.

Two rules protect you on the way in. An account can hold one subscription at a time; if you already have one that has not ended, checkout refuses and points you to the billing portal instead of starting a second. And checkout is rate-limited to ten attempts an hour, a gate that fails closed: if the counter is unavailable, checkout is refused rather than allowed through.

When a credit is returned

The debit happens before the model is called, and the refund covers exactly what was debited:

• A generation that fails for any reason after the debit (model error, dropped connection, empty result, save failure) returns the credit, or the day's free article, immediately. The article is kept in the library marked Failed with the reason.
• A generation that is interrupted and makes no progress for 20 minutes is closed and refunded the next time its row is read.
• In a series or batch, each part is charged as it is written. If the run stops because the balance is exhausted, nothing further is charged; if it is interrupted, unstarted parts were never charged and the one in progress is refunded.
• The owner's admin tier is not charged at all; it exists so the product can be tested without distorting the ledger.

The debit and the refund are the two halves of one database function. Nothing in the web application re-implements the maths, which is why a failure cannot leave a half-charged state.

Every cap in the product

Besides the plan ceilings above:

• Length is clamped to between 300 words and your plan's ceiling, whatever the form sends.
• Topic 3 to 300 characters; niche or audience note up to 500; call to action up to 200.
• Rewrite source 200 to 60,000 characters.
• Series 3 to 5 parts. Batch 2 to 10 distinct topics, further limited by plan.
• Free tier one generation per rolling 24 hours in addition to the credit balance.
• Series starts, batch starts and keyword-brief previews five per hour per account.
• Checkout ten attempts per hour.

The generation gates deliberately fail open: if the counter that enforces them is unavailable, a paying user is not blocked from spending credits they own, because the ledger itself is the real gate. Only checkout fails closed.

Where to read your balance

The credit count sits in the header of every signed-in page, on the dashboard, on the "New article" page alongside your tier and word ceiling, and in Settings next to your email and tier. Settings also holds "Manage or cancel subscription", which opens Stripe's portal for invoices, card changes, plan changes and cancellation.

For what the credits are spent on, read how AI Orbit researches and writes an article; for how series and batch runs spend them part by part, read series, kinds and the public share link. If you are deciding whether any of this is worth paying for, the pricing page has the plans side by side and the Free tier needs no card.