> For the complete documentation index, see [llms.txt](https://docs.ltonetwork.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ltonetwork.com/protocol/public/transactions/sponsor.md).

# Sponsorship

{% hint style="danger" %}
You should only sponsor an account you trust, and/or have a legally binding agreement with. A sponsored account holder can easily drain your account through spam transactions. If the account holder is running a node, he/she can claim part of the spend tokens as mining reward. **Limit the amount of tokens on the sponsoring account**, adding funds when necessary.
{% endhint %}

{% hint style="success" %}
See [transaction fees with sponsored accounts](/protocol/public/transactions.md#transaction-fees) for more info.
{% endhint %}

### JSON

```javascript
{
  "type": 18,
  "version": 3,
  "id": "HtxiY9x8aVBDfPvEUifYZuBEDge5TCDDAtqRGBW8HDef",
  "sender": "3NBcx7AQqDopBj3WfwCVARNYuZyt1L9xEVM",
  "senderKeyType": "ed25519",
  "senderPublicKey": "7gghhSwKRvshZwwh6sG97mzo1qoFtHEQK7iM4vGcnEt7",
  "recipient": "3N9ChkxWXqgdWLLErWFrSwjqARB6NtYsvZh",
  "timestamp": 1610410901000,
  "fee": 500000000,
  "proofs": [
    "QKef6R8LrMBupBF9Ry8zjFTu3mexC55J6XNofDDQEcJnZJsRjZPnAk6Yn2eiHkqqd2uSjB2r58fC8QVLaVegQEz"
  ],
  "height": 1225821
}
```

{% hint style="info" %}

* `id` and `height` should be omitted when broadcasting. These fields are set by the node.
* Binary strings are base58 encoded.
* `timestamp` is in microseconds since epoch.
* `fee` includes 8 digits, so `LTO * 10^8`
  {% endhint %}

### Binary schema

The binary data structure of the unsigned transaction.

{% tabs %}
{% tab title="V3 (current)" %}

| # |      Field Name     |            Type           | Length   |
| - | :-----------------: | :-----------------------: | -------- |
| 1 |   Transaction type  | Byte (constant, value=18) | 1        |
| 2 |       Version       |  Byte (constant, value=3) | 1        |
| 3 |      Network id     |            Byte           | 1        |
| 4 |      Timestamp      |            Long           | 8        |
| 5 |  Sender's key type  |       KeyType (Byte)      | 1        |
| 6 | Sender's public key |  PublicKey (Array\[Byte]) | 32 \| 33 |
| 7 |         Fee         |            Long           | 8        |
| 8 |      Recipient      |   Address (Array\[Byte])  | 26       |

{% hint style="info" %}

* Network id can be obtained by taking the 2nd byte from the sender address.
* Each [key type](/protocol/accounts.md#key-types) has a numeric id in addition to the reference from the JSON.
* Integers (short, int, long) have a big endian byte order.
  {% endhint %}
  {% endtab %}

{% tab title="V1" %}

| # |      Field Name     |            Type           | Length |
| - | :-----------------: | :-----------------------: | ------ |
| 1 |   Transaction type  | Byte (constant, value=18) | 1      |
| 2 |       Version       |  Byte (constant, value=1) | 1      |
| 3 |      Network id     |            Byte           | 1      |
| 4 | Sender's public key |  PublicKey (Array\[Byte]) | 32     |
| 5 |      Recipient      |   Address (Array\[Byte])  | 26     |
| 6 |         Fee         |            Long           | 8      |
| 7 |      Timestamp      |            Long           | 8      |

{% hint style="info" %}

* Network id can be obtained by taking the 2nd byte from the sender or recipient address.
* Integers (short, int, long) have a big endian byte order.
  {% endhint %}
  {% endtab %}
  {% endtabs %}