Pay-as-you-go billing and crypto are a natural fit. When you pay per API call, you want top-ups that settle fast and cost almost nothing in fees — which is exactly what USDT on Solana or Tron gives you. This explains why, and how funding works on Api18.dev.

Why crypto for an AI API#

  • No card on file. For adult/NSFW work, many developers don’t want a card tied to the account. USDT removes that requirement.
  • Fast settlement. Solana and Tron confirm in seconds, so your balance is usable almost immediately after you send.
  • Low fees. Network fees are a fraction of a cent, which matters when you’re topping up small amounts often.
  • Dollar-pegged. USDT tracks the US dollar, so your balance maps cleanly to the USD price of each call — no conversion guesswork.

How pay-per-call billing works#

Every request is priced in USD: image models per image, video models per second of output. The cost is charged when the job is accepted and reported back on the job as cost_usd. There is no subscription and no minimum, and failed jobs are refunded automatically, so you only ever pay for output you actually receive.

New accounts get $10 in welcome credit for the playground. The API itself runs on paid balance — top it up with USDT as below.

Topping up with USDT#

  1. Open Billing in the dashboard and choose the crypto option.
  2. Pick a network — Solana or Tron — and you’ll get a deposit address and QR code.
  3. Send USDT from your wallet on that network. (Make sure the network matches — USDT on Solana and USDT on Tron are different addresses.)
  4. After on-chain confirmation, your balance updates and you can call the API.
Always send on the network you selected. Sending USDT on the wrong network can result in lost funds — this is true of every crypto deposit, everywhere.

No card, minimal friction#

Combined with email-only signup, USDT means you can go from zero to generating without a card or identity check. More on that in No-KYC AI image API: sign up and pay with crypto.