> ## Documentation Index
> Fetch the complete documentation index at: https://docs.saturn-pay.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Fund via Lightning

> Create a Lightning invoice to fund wallet

Creates a Lightning Network invoice that, when paid, will credit your wallet with the specified amount of satoshis.

## Request

<ParamField body="amountSats" type="number" required>
  Amount in satoshis to add to wallet
</ParamField>

## Response

<ResponseField name="paymentRequest" type="string">
  Lightning invoice (BOLT11 format). Pay this with any Lightning wallet.
</ResponseField>

<ResponseField name="paymentHash" type="string">
  Payment hash for tracking
</ResponseField>

<ResponseField name="amountSats" type="number">
  Invoice amount in satoshis
</ResponseField>

<ResponseField name="expiresAt" type="string">
  ISO 8601 timestamp when invoice expires
</ResponseField>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST https://api.saturn-pay.com/v1/wallet/fund \
    -H "Authorization: Bearer sk_agt_..." \
    -H "Content-Type: application/json" \
    -d '{
      "amountSats": 10000
    }'
  ```

  ```typescript Node.js theme={null}
  const response = await fetch('https://api.saturn-pay.com/v1/wallet/fund', {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer sk_agt_...',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({ amountSats: 10000 })
  });

  const invoice = await response.json();
  console.log('Pay this invoice:', invoice.paymentRequest);
  ```

  ```python Python theme={null}
  import requests

  response = requests.post(
      'https://api.saturn-pay.com/v1/wallet/fund',
      headers={'Authorization': 'Bearer sk_agt_...'},
      json={'amountSats': 10000}
  )

  invoice = response.json()
  print('Pay this invoice:', invoice['paymentRequest'])
  ```
</RequestExample>

<ResponseExample>
  ```json 200 OK theme={null}
  {
    "paymentRequest": "lnbc100u1p3h9j2xpp5...",
    "paymentHash": "abc123def456...",
    "amountSats": 10000,
    "expiresAt": "2024-01-20T16:00:00Z"
  }
  ```
</ResponseExample>

## Notes

* Invoice expires after 1 hour
* Credits are added instantly when payment is received
* No minimum amount
* No fees charged by Saturn (you pay Lightning routing fees)