LUNIUM
Lunium · PIX ↔ stablecoins API

Frequently asked questions

Updated August 31, 2026

Timing, limits, fees, refunds and receipts — what people ask before integrating.

What is Lunium?

Settlement infrastructure between crypto assets and PIX. A company integrates the API and can then offer crypto sales paid out to any PIX key (cash-out), crypto purchases paid by PIX (cash-in) and open payment verification. Venda Cripto is the consumer-facing version, operated by the same company.

Do I need to sign up to test?

No. POST /keys/sandbox returns a test key instantly, with no data required, and it runs the entire flow without moving money. A production key is also created with a single call (POST /keys).

How long does a sale (cash-out) take?

The quote is valid for 15 minutes; once the deposit is confirmed on Polygon, the PIX goes out in about 10 seconds (measured in production). On other networks the time depends on that blockchain's confirmations and is stated up front.

Which PIX keys can I pay out to?

Any key: CPF, CNPJ, phone, email or a random key — belonging to anyone. The API normalizes the format and confirms the account holder in the PIX directory before paying.

What about paying a QR code (copy-and-paste)?

Only with USDT or USDC on Polygon, through the br_code field. The amount and the payee come from the QR code itself. If the settlement provider rejects the charge, the crypto returns to the operation's refund address.

What are the fees?

For cash-out through the API, 0.20% to Lunium plus the settlement provider's fees (1% + R$ 0.17), already built into the quote: the amount in reais you see is what the key receives. For cash-in the fee is agreed per key. There is no monthly fee.

What are the limits?

Cash-out: from R$ 6.00 to R$ 250,000.00 per transaction, with no daily ceiling per API key. What closes the day is the recipient: R$ 100,000.00 per CPF/CNPJ of whoever receives the PIX, resetting at midnight (Brasília time) — when the PIX key is not a tax number (email, phone, random), that ceiling applies per key, and we never ask for the seller's CPF. The effective maximum of one operation is the lower of the two: for a recipient who has received nothing yet today, R$ 100,000.00. Cash-in: from R$ 1.00 to R$ 6,000.00 per charge; per payer's CPF/CNPJ, up to R$ 200.00 the money lands immediately and, from R$ 200.00 to R$ 6,000.00 a day, the QR code is still accepted, with the amount held for 24h before release — already on the first operation, with no history required. The per-key tier ladder (R$ 5,000 → R$ 25,000 → R$ 100,000 per day) applies to cash-in and payouts, never to the sale. Your key's current numbers are always at GET /keys/me.

What happens when something goes wrong?

Rejected key, reversed PIX, or a failure before sending: the crypto goes back to the refund_address given in the operation (or to the deposit's origin). When the funds were already with the settlement provider, the refund to the customer happens once that provider returns them to our custody, for the amount actually returned. The order ends in REFUNDED with the refund transaction hash.

Do I get a receipt?

Yes, in three forms: the official PIX identifier (E2E), a receipt page and a PDF — all of them in the API response and in the webhook. Anyone can check a payment at GET /v1/verificar/{e2e}, with no key.

I used the wrong network or address. Can it be recovered?

No. Blockchain transfers are irreversible, and a deposit on a network or asset different from the one quoted is held for manual handling. Always check the network before sending.

How do I track operations?

Through the API (GET /cash-outs/{id}), through a signed webhook, or through the Telegram agent, which reports every state change in your company's group and answers queries.

Who is the company behind Lunium?

ZANQUETA INTERMED LTDA, Brazilian company registry (CNPJ) 68.538.127/0001-00, headquartered in Americana, São Paulo. The same company operates Venda Cripto. Contact: contato@luniumpay.com.

Didn't find what you needed? Talk to us: contato@luniumpay.com · full documentation.

By use case

PIX to USDT APITake reais, deliver USDT to your customer’s wallet.USDT to PIX APISell stablecoin and pay any PIX key.PIX payout APIPay suppliers and users in reais, over the API.BRL ↔ USDT over APIBoth directions, with a quote and a receipt.Brazil on-ramp and off-rampCrypto in and out of Brazil, in one integration.PIX at checkout, stablecoin in treasuryCharge in PIX, hold in digital dollars.PIX and stablecoin for walletsGive your users a way in and out.Infrastructure under your brandThe whole rail running behind your product.

Talk to the people who built it

A sandbox key takes one call and no signup — if that's what you're after, start with the docs. This form is for the rest: volume pricing, a case the docs don't cover, or a question before you integrate.

Rather email us? contato@luniumpay.com