Deposits (Crypto + Fiat)

Overview

NanoGPT supports multiple deposit methods (crypto, stablecoins, and cards). This page documents the public endpoints you can use to:

Create a deposit payment intent
Check deposit limits
Track deposit status (polling or SSE)

Deposits are credited automatically after payment confirmation.

Supported Payment Methods

Limits vary by method and can change. Use GET /api/transaction/limits/{ticker} for the authoritative min/max.

Crypto (invoice / address)

Ticker	Name	Provider
`BTC`	Bitcoin	BTCPay
`BTC-LN`	Bitcoin Lightning	BTCPay
`LTC`	Litecoin	BTCPay
`LTC-MWEB`	Litecoin MWEB	BTCPay
`XMR`	Monero	BTCPay
`DOGE`	Dogecoin	BTCPay
`DASH`	Dash	BTCPay
`ZEC`	Zcash	BTCPay
`BCH`	Bitcoin Cash	Prompt.Cash
`BAN`	Banano	Nanswap (legacy)
`KAS`	Kaspa	Nanswap
`TON`	Toncoin	Nanswap
`NEAR`	NEAR Protocol	Nanswap
`EGLD`	MultiversX	Nanswap
`VVV`	VVV	Nanswap
`ZANO`	Zano	Zano proxy
`FUSD`	Freedom Dollar	Zano proxy

Stablecoins and multi-chain (Daimo Pay)

These methods settle as USDC and can be paid from multiple chains/wallets.

Ticker	Name
`USDC`	USD Coin
`USDT`	Tether
`ETH`	Ethereum
`SOL`	Solana

Fiat (card)

Ticker	Name	Provider
`USD`	US Dollar	Stripe
`EUR`	Euro	Stripe
`GBP`	British Pound	Stripe

Nano (direct deposit)

Nano deposits use a direct-send flow to your assigned Nano deposit address (no invoice creation). See: Check Balance and Receive Nano.

Authentication

All /api/transaction/* endpoints require API key authentication using one of these methods:

# Method 1: Authorization header
curl -H "Authorization: Bearer YOUR_API_KEY"

# Method 2: x-api-key header  
curl -H "x-api-key: YOUR_API_KEY"

Endpoint Summary

Pick the endpoint based on the payment method:

Crypto invoice / swap deposits: POST /api/transaction/create/{ticker}
Daimo Pay (multi-chain): POST /api/transaction/create/daimo/{ticker}
Card (Stripe): POST /api/transaction/create/usd
Limits: GET /api/transaction/limits/{ticker}
Status polling: GET /api/transaction/status/{ticker}/{txId}
Status SSE: GET /api/transaction/status/events?ticker={ticker}&txId={txId}
Nano (XNO): send to nanoDepositAddress (from Check Balance); optionally call Receive Nano

Create Crypto Deposit

Create an invoice / pay-in address for supported crypto tickers

string

required

Ticker symbol. Examples: btc, btc-ln, ltc, zec, bch, kas, vvv, zano, fusd

number

required

Amount of cryptocurrency to deposit. Must be between minimum and maximum limits.

curl -X POST https://nano-gpt.com/api/transaction/create/btc \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"amount": 0.001}'

const response = await fetch('https://nano-gpt.com/api/transaction/create/btc', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ amount: 0.001 })
});

const deposit = await response.json();
console.log('Send BTC to:', deposit.address);

// BTC-LN has lower minimum ($0.10)
const lnResponse = await fetch('https://nano-gpt.com/api/transaction/create/btc-ln', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ amount: 0.00001 })
});

const lnDeposit = await lnResponse.json();
console.log('Lightning invoice:', lnDeposit.paymentLink);

{
  "txId": "abc123",
  "address": "bc1q...",
  "amount": 0.001,
  "status": "New",
  "paymentLink": "bitcoin:bc1q...?amount=0.001",
  "createdAt": "2026-01-19T12:00:00.000Z",
  "expiresAt": "2026-01-19T13:00:00.000Z"
}

Response Fields

string

Unique transaction identifier for tracking

string

Deposit address for sending crypto

number

Requested deposit amount

string

Payment status. Common values include: New, Pending, Processing, Paid, Completed, Expired, Failed

string

URI for wallet apps (e.g., bitcoin:address)

string

ISO timestamp of creation

string

ISO timestamp when address expires

Check Payment Limits

Get minimum and maximum deposit amounts for a payment method

string

required

Payment method ticker symbol (for example: btc, btc-ln, zec, usdc, sol, usd)

curl https://nano-gpt.com/api/transaction/limits/kas \
  -H "Authorization: Bearer YOUR_API_KEY"

const limitsResponse = await fetch('https://nano-gpt.com/api/transaction/limits/btc', {
  headers: { 'Authorization': 'Bearer YOUR_API_KEY' }
});
const limits = await limitsResponse.json();

// Validate amount before creating deposit
if (amount < limits.minimum) {
  throw new Error(`Minimum deposit is ${limits.minimum} BTC`);
}

{
  "minimum": 10.5,
  "maximum": 5250,
  "fiatEquivalentMinimum": 1,
  "fiatEquivalentMaximum": 500,
  "timestamp": 1705669200
}

Create Daimo Payment

Create a multi-chain payment (USDC/USDT/ETH/SOL) via Daimo Pay

string

required

Daimo payment ticker. Common values: usdc, usdt, eth, sol

number

required

Amount to pay. This is typically treated as a USD/USDC amount (for example, 10 for about $10).

curl -X POST https://nano-gpt.com/api/transaction/create/daimo/usdc \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"amount": 10}'

{
  "paymentId": "encrypted_payment_id"
}

Create Card Deposit (Stripe)

Create a Stripe Checkout session for card deposits

number

required

Amount in the selected fiat currency (for example, 10).

curl -X POST https://nano-gpt.com/api/transaction/create/usd \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"amount": 10}'

{
  "paymentLink": "https://checkout.stripe.com/c/pay/cs_test_..."
}

Status Tracking

Most deposit methods can be tracked by polling a status endpoint:

GET /api/transaction/status/{ticker}/{txId}

Some methods use provider-specific IDs (for example Stripe session IDs). The create response usually returns the correct txId value to use. Example:

curl "https://nano-gpt.com/api/transaction/status/btc/abc123" \
  -H "Authorization: Bearer YOUR_API_KEY"

Real-time status (SSE)

Instead of polling, you can subscribe to Server-Sent Events:

GET /api/transaction/status/events?ticker={ticker}&txId={txId}

Example:

curl -N "https://nano-gpt.com/api/transaction/status/events?ticker=btc&txId=abc123" \
  -H "Authorization: Bearer YOUR_API_KEY"

The server may also return an x-poll-after header on status responses to indicate a recommended retry interval (seconds).

Transaction Lifecycle

Status values can vary slightly by payment method, but a typical lifecycle looks like:

Status	Meaning
`New` / `Pending`	Deposit created, awaiting payment
`Processing`	Payment detected and being confirmed/processed
`Paid`	Payment confirmed, crediting pending
`Completed`	Balance credited
`Expired`	Payment window expired (some providers can still credit late payments)
`Failed`	Provider error or processing failure

Notes:

BTC deposits can take longer to reach Completed due to on-chain settlement/confirmations.
Some providers may accept payment after an invoice expires; in those cases the deposit can still complete.

Payment Providers

NanoGPT uses different providers per ticker:

BTCPay: BTC, BTC-LN, LTC, LTC-MWEB, XMR, DOGE, DASH, ZEC
Prompt.Cash: BCH
Nanswap: BAN, KAS, TON, NEAR, EGLD, VVV
Zano proxy: ZANO, FUSD
Daimo Pay: USDC, USDT, ETH, SOL (multi-chain payments settling as USDC)
Stripe: card deposits (USD/EUR/GBP)
Native Nano: XNO direct deposits to your nanoDepositAddress

Pricing Endpoints

These endpoints are commonly used by deposit flows and checkout UIs:

GET /api/get-nano-price (NANO/USD pricing)
GET /api/get-fiat-prices (fiat FX rates)

Example:

curl "https://nano-gpt.com/api/get-nano-price"
curl "https://nano-gpt.com/api/get-fiat-prices"

Example responses:

// GET /api/get-nano-price
{
  "pair": "NANOUSD",
  "latestPrice": 1.23
}

// GET /api/get-fiat-prices
{
  "usdTo": {
    "USD": 1,
    "EUR": 0.92,
    "GBP": 0.79
  },
  "currencies": {
    "USD": "United States Dollar",
    "EUR": "Euro",
    "GBP": "British Pound"
  }
}

Bonuses and Discounts

BTC-LN: Lightning deposits may include a bonus on the credited amount (if enabled).
XNO: Paying with Nano balance may include a usage discount (if enabled).
USDC via Daimo: USDC stablecoin deposits typically credit close to $1 per 1 USDC.

Error Handling

HTTP Status Codes

Code	Description
200	Success
400	Invalid amount, unsupported ticker, or below/above limits
401	Authentication failure
429	Rate limited
500	Provider unavailable or internal error

Common Error Messages

Amount Validation Errors

"No amount specified" - Missing amount in request body
"Invalid amount. Must be a positive number." - Amount validation failed
"Minimum amount is X" - Below minimum threshold
"Maximum amount is X" - Above maximum threshold

Provider Errors

"Unsupported ticker" - Ticker not supported
"This payment method is currently not available" - Provider temporarily unavailable

Rate Limits

10 requests per 10 minutes per IP address or API key
Rate limit applies to all deposit creation endpoints

Payment Flow

Create Invoice

Call /api/transaction/create/{ticker} with desired amount

Get Address

Extract address from response

Send Payment

User sends crypto to the provided address

Auto-Credit

Account balance automatically updated when payment confirms

Get Started

Endpoint Examples

API Reference

Miscellaneous

Partner

Integrations

Overview

Supported Payment Methods

Crypto (invoice / address)

Stablecoins and multi-chain (Daimo Pay)

Fiat (card)

Nano (direct deposit)

Authentication

Endpoint Summary

Create Crypto Deposit

Response Fields

Check Payment Limits

Create Daimo Payment

Create Card Deposit (Stripe)

Status Tracking

Real-time status (SSE)

Transaction Lifecycle

Payment Providers

Pricing Endpoints

Bonuses and Discounts

Error Handling

HTTP Status Codes

Common Error Messages

Rate Limits

Payment Flow

​Overview

​Supported Payment Methods

​Crypto (invoice / address)

​Stablecoins and multi-chain (Daimo Pay)

​Fiat (card)

​Nano (direct deposit)

​Authentication

​Endpoint Summary

Create Crypto Deposit

​Response Fields

Check Payment Limits

Create Daimo Payment

Create Card Deposit (Stripe)

​Status Tracking

​Real-time status (SSE)

​Transaction Lifecycle

​Payment Providers

​Pricing Endpoints

​Bonuses and Discounts

​Error Handling

​HTTP Status Codes

​Common Error Messages

​Rate Limits

​Payment Flow

Overview

Supported Payment Methods

Crypto (invoice / address)

Stablecoins and multi-chain (Daimo Pay)

Fiat (card)

Nano (direct deposit)

Authentication

Endpoint Summary

Response Fields

Status Tracking

Real-time status (SSE)

Transaction Lifecycle

Payment Providers

Pricing Endpoints

Bonuses and Discounts

Error Handling

HTTP Status Codes

Common Error Messages

Rate Limits

Payment Flow