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

{
  "txId": "6Uwh14rFrKG9XnKDYTWKc4",
  "amount": 0.001,
  "status": "New",
  "createdAt": "2025-06-23T14:52:43.000Z",
  "paidAmountCrypto": 0,
  "address": "bc1q...",
  "remainingTime": 3600,
  "expiration": 1750693963,
  "paymentLink": "bitcoin:bc1q...?amount=0.001"
}

​
Overview

The BTCPayServer integration allows API users to programmatically generate deposit addresses for multiple cryptocurrencies. When a user sends crypto to the generated address, their NanoGPT account balance is automatically credited with the equivalent value.

​
Supported Cryptocurrencies

  • BTC (Bitcoin)
  • LTC (Litecoin)
  • XMR (Monero)
  • DOGE (Dogecoin)
  • DASH (Dash)
  • BCH (Bitcoin Cash) - via PromptCash integration
  • BAN (Banano) - via Nanswap integration
  • KAS (Kaspa)

​
Authentication

All 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"

Create Crypto Deposit

Generate a deposit address for cryptocurrency deposits
​
ticker
string
required
Cryptocurrency ticker symbol. Supported values: btc, ltc, xmr, doge, dash, bch, ban, kas
​
amount
number
required
Amount of cryptocurrency to deposit. Must be between minimum and maximum limits.

​
Amount Limits

Each cryptocurrency has minimum and maximum deposit limits based on USD equivalent: Standard Limits (BTC, LTC, XMR, DOGE, DASH, BCH, BAN):
  • Minimum: $0.10 USD equivalent
  • Maximum: $500 USD equivalent
KAS Limits:
  • Minimum: $10 USD equivalent
  • Maximum: $500 USD equivalent
curl -X POST https://nano-gpt.com/api/transaction/create/btc \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"amount": 0.001}'

{
  "txId": "6Uwh14rFrKG9XnKDYTWKc4",
  "amount": 0.001,
  "status": "New",
  "createdAt": "2025-06-23T14:52:43.000Z",
  "paidAmountCrypto": 0,
  "address": "bc1q...",
  "remainingTime": 3600,
  "expiration": 1750693963,
  "paymentLink": "bitcoin:bc1q...?amount=0.001"
}

​
Response Fields

​
txId
string
Unique transaction identifier for tracking
​
amount
number
Requested deposit amount
​
status
string
Payment status (“New”, “Pending”, “Completed”, etc.)
​
createdAt
string
ISO timestamp of invoice creation
​
paidAmountCrypto
number
Amount paid so far (0 for new invoices)
​
address
string
Crypto deposit address to send payment to
​
remainingTime
number
Seconds until invoice expires
​
expiration
number
Unix timestamp of expiration
​
paymentLink
string
URI link for wallet apps
​
QRUrl
string
QR code URL for the payment address (if available)
​
amountCrypto
number
Amount in cryptocurrency (if available)
​
amountFiat
number
Equivalent USD value (if available)

Check Payment Limits

Get minimum and maximum deposit amounts for a cryptocurrency
​
ticker
string
required
Cryptocurrency ticker symbol
curl -H "x-api-key: YOUR_API_KEY" \
  https://nano-gpt.com/api/transaction/limits/btc

{
  "minimum": 0.00002,
  "maximum": 0.01,
  "fiatEquivalentMinimum": 0.10,
  "fiatEquivalentMaximum": 500.0
}

​
Error Handling

​
HTTP Status Codes

  • 200: Success
  • 400: Bad Request (invalid amount, unsupported ticker)
  • 401: Unauthorized (invalid or missing API key)
  • 429: Rate Limited
  • 500: Server Error (payment provider unavailable)

​
Common Errors

​
Rate Limits

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

​
Payment Flow

1

Create Invoice

Call /api/transaction/create/{ticker} with desired amount
2

Get Address

Extract address from response
3

Send Payment

User sends crypto to the provided address
4

Auto-Credit

Account balance automatically updated when payment confirms
KAS (Kaspa) Special Considerations:
  • Higher minimum deposit requirement (10USDvs10 USD vs 0.10 for other cryptos)
  • Deposits are automatically credited upon blockchain confirmation
  • 1-hour expiration time for payment invoices