What free covers on an open-source AI agent platform

Three meanings of free, one test

Free on a platform can be a grant, a cap, or software you host. The three behave differently in month two, and that difference decides whether a small team can plan around $0.

Dust gives a free seat 500 credits, once. Its pricing page calls the allowance lifetime, so the seat does not refill when the credits are spent (Dust pricing). CrewAI's free plan resets to 50 workflow executions a month, a ceiling that comes back but never grows (CrewAI pricing). n8n sells a 14-day cloud trial and points the free route at the Community Edition, which runs on a server you own (n8n pricing). Kortix renews 500 credits every month with no card, and its software carries no plan fee when you self-host it.

One question sorts the four: if nobody changes anything, what does month two cost? A one-time grant runs out. A monthly cap resets to the same number, whatever the team did last month. Software you run has no allowance to exhaust; the bill moves to the computers and the model keys.

The meter a free plan hides

Kortix does not count executions. Credits pay for the agent computer: the cloud computer that runs an agent's code, browser and file edits. The rate is published: 1 credit is $0.01, and the default computer, 2 vCPU with 4 GB of memory and 20 GB of disk, spends about 11 credits an hour. One credit is about five minutes of machine time (Kortix pricing, checked October 2026).

Billing runs per second, and a stopped computer costs nothing. A session that waits overnight does not bill overnight.

That rate turns the free grant into hours. Five hundred credits buy about 45 hours on one default computer. Take a five-person team that runs three agents for 40 minutes each on a working day. The team uses two hours of computer time a day, 44 hours across 22 working days, or 484 credits. It fits, with 16 credits to spare. Add a two-hour nightly job on the same 22 days and the month reaches 88 hours, 968 credits, and about $4.70 past the grant. Headcount never entered the arithmetic; the hours the computers ran did.

What the free plan keeps at zero

Self-hosting is the route with no allowance at all. Self-host is free, and Kortix charges nothing for the software; the compute comes from the sandbox provider you configure and the model calls go to the keys you connect.

On the managed cloud, three costs stay off the bill. Members are free, sharing one credit pool, so an eight-person team pays the same as a two-person one. A stopped computer costs nothing. And the 500 credits renew each month without a card, on one project. Unused monthly credits roll over one month, so a quiet month is not wasted.

Two model paths that keep the model bill at zero

Model calls are a second meter, and Kortix leaves the choice of who fills it to the project. With your own key, model usage goes straight to your provider. The first $1,000 a month passes through Kortix with no fee; past that, Kortix adds 5%, paid from credits. Connect a ChatGPT subscription you already pay for, and the agents use it for model calls with no credits spent. Choose Kortix's managed models, and each call costs the provider's base price plus a 5.5% platform fee, paid from credits.

The ChatGPT path spends no credits at all. Kortix's managed models draw on the same 500 credits as the computer, so a team that picks them reaches the end of its allowance sooner. Model choice is the one lever here that changes the bill without changing what the agents do.

Where a $0 setup breaks, and what follows

The break arrives when a session stays on. An agent left running around the clock uses about 730 hours a month, or 8,030 credits, about $80 at the published rate. The free grant covers 45 of those hours, roughly 6% of the month.

Two moves follow. A team whose work comes in bursts can buy credits: paid plans start at $50 a month for 5,000 credits, and a top-up covers a one-off overshoot without a plan change. A team that keeps computers running for hours at a time, or several at once, should price self-hosting against the credit bill. Self-host is free, the compute moves to the sandbox provider, and the model keys stay yours. The pricing page puts the paid tiers and the self-hosted route side by side.