Flux RouterDocumentation

The Free plan

What you get at sign-up: a $1 monthly credit and a default key made for you. What Free covers, and what happens when you reach the cap.

Every new FluxRouter account starts on the Free plan. It exists so you can connect your agent and see real routing before you pay for anything, and it stops at its cap rather than ever billing you.

What you get when you sign up

  • A default key, made for you. Your account has a working sk- key from the start, so you can go straight to connecting your agent. Your keys are at /home/keys, where you can make more.
  • A $1 credit every month, spent against live routing in the Fast lane.
  • A monthly token allowance of 100,000 tokens, counted across every key on the account.

Whichever runs out first, the credit or the token allowance, pauses requests until the next month.

What does Free cover?

  • The flux-fast and flux-auto model ids. On Free, flux-auto stays within the Fast lane rather than reaching for larger models. Naming a specific model, or the Standard and Reasoning lanes, needs a paid plan.
  • flux-auto bills at the Standard rate, or the Fast rate when it sends your request to the Fast lane and a Fast model answers. To be sure of the Fast rate on every request, and the most out of your credit, send flux-fast. See How billing works.
  • A lower rate limit than the paid plans.
  • Community and docs support.

Abilities that need a paid, cleared plan, such as images and transcription, answer with a clear "needs a paid plan" message instead of running, whether you call the API or the Flux tools server.

What happens at the cap?

Free stops rather than charging you:

  • When the monthly credit is used, requests are refused with HTTP 402 and the code free_tier_exhausted.
  • When the token allowance is used, requests are refused with HTTP 429 and "state": "free_cap_reached" in the error body.

Both clear at the start of the next month. There is no overage and nothing to pay. See the error reference.

How far does the credit go?

It depends on the size of your prompts and replies, since you are metered by tokens. In practice the token allowance is usually reached first. It is enough to wire up your agent, confirm the base URL change works, and read real routing decisions and costs on each response before you choose a plan. See Receipts.

Moving to a paid plan

Pick a plan at /home/billing or on the pricing page. Pay As You Go has no monthly fee and meters usage directly; Builder adds an included monthly credit. Your key does not change. See Plans.