# gettxoutproof

Returns a hex-encoded proof that “txid” was included in a block.

NOTE: By default this function only works sometimes. This is when there is an unspent output in the utxo for this transaction. To make it always work, you need to maintain a transaction index, using the -txindex command line option or specify the block in which the transaction is included manually (by blockhash).

This method will use `10` [Compute Units](https://docs.validationcloud.io/v1/about/billing).

***

## **Reference:** [**Here**](https://developer.bitcoin.org/reference/rpc/gettxoutproof.html)

## **Parameters**

**`txids`** - json array, required

The txids to filter

```json
[
  "txid",    (string) A transaction hash
  ...
]
```

**`blockhash`** - string, optional

If specified, looks for txid in the block with this hash

## Returns

| Name | Type   | Description                                                    |
| ---- | ------ | -------------------------------------------------------------- |
| str  | string | A string that is a serialized, hex-encoded data for the proof. |