Paying for an AI API in crypto: USDT, USDC, BTC, ETH or SOL to a prepaid balance
How a crypto top-up works here: the console quotes an amount, you send it, the balance credits in USD, and every request bills per token from it. What is stored, what is not, and what a dollar buys today.
A crypto payment here buys the same thing a card payment buys: a USD balance on your account, from which every request draws at the per-token price on the model page. There is no crypto plan, no separate price list and no markup for paying this way. This post walks through the top-up, what the account stores afterwards, and what a dollar of balance buys on the flagship models today.
- Coins
- USDT · USDC · BTC · ETH · SOL
- Also
- Card · Apple Pay · PayPal
- Smallest top-up
- $10
- Models on the key
- 469
01The top-up, step by step
- Open an account with an email address at the console. That is the whole sign-up; nothing else is asked for.
- Press Top up, pick an amount (from $10; the preset tiers are $10, $25, $50, $100, $250, $500) and choose the coin: USDT, USDC, BTC, ETH, SOL.
- The checkout shows the networks it accepts for that coin, an address and the exact amount to send. Send that amount on the network you selected.
- When the payment confirms on its network, the balance credits in USD. Create a key on the keys page; it is shown once.
02What it costs to pay this way
You pay the network fee for the transfer; the amount credited is the amount received, and the checkout shows the exact total before you send. There is no percentage added for crypto and no difference in the per-token price afterwards: the balance is the same USD credit a card top-up produces.
03What the account stores
For a crypto top-up: the amount, the method and the transaction hash. For a card top-up: the amount, the method and the processor's reference; card numbers never reach RelaySwitch. For every request: a usage record with the request id, the model, the token counts and the charge. The ledger of balance changes. The email address.
Not stored: request and response bodies. Prompts and completions pass through and are not written anywhere or used for training. The privacy page is the full list.
04What a dollar buys today
Prices are per million tokens, input and output separately, read from the live catalog. The last column is one chat turn of 2,000 input and 500 output tokens.
| Model | In / M | Out / M | One turn | Turns per $10 |
|---|---|---|---|---|
| Claude Opus 5.5 | $2.80 | $10.00 | $0.0106 | 943 |
| GPT-5.5 | $1.80 | $9.00 | $0.0081 | 1,234 |
| DeepSeek V4 Pro 0423 | $0.792 | $2.376 | $0.0028 | 3,607 |
| Grok 4.7 | $0.60 | $1.80 | $0.0021 | 4,761 |
| GLM 5.3 | $0.3276 | $1.0296 | $0.0012 | 8,547 |
| Kimi K3 | $0.90 | $4.50 | $0.0041 | 2,469 |
469 models from 47 developers are on the key; the Models page lists them all.
05Then the first request
The endpoint is OpenAI-compatible. Any SDK that takes a base URL works unchanged; the model id is any row of the Models page.
curl https://api.relayswitch.io/v1/chat/completions \ -H "Authorization: Bearer $RELAYSWITCH_KEY" \ -H "Content-Type: application/json" \ -d '{"model": "claude-opus-5-5", "messages": [{"role": "user", "content": "Hello"}]}'When the balance runs out, requests answer 402 until the next top-up. Nothing is charged automatically, nothing accrues, and credit does not expire.
Top up in crypto, call every model
USDT, USDC, BTC, ETH or SOL. No KYC.