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

# Get Claim Signature

> How to retrieve a signature required for claiming boost incentives

The Boost API provides two methods to get a signature for claiming boost incentives:

1. Use a transaction hash via the [GET /signatures endpoint](/v2/api-reference/boost/generate-a-claim-signature-that-can-be-used-to-submit-a-claim)
2. Check recent transactions for an address via the [GET /transactions endpoint](/v2/api-reference/rewardkit/try-to-get-claim-signature-without-known-transaction)

<Note>
  In order to produce a valid signature, the transaction must meet the boost's requirements and the transaction must occur after the boost was created.
</Note>

## Fetching Signature by Transaction Hash

If you know the specific transaction that completed the boost's required action, you can fetch the signature directly:

```typescript theme={null}
const params = new URLSearchParams({
  txHash: '0x2dfc8f4f24b1a3a7ee73ea13b8a20a63fe7457d1c96b95178d3ea4126b6bf5ad',
  boostId: '8453:0x378632819f39c74c4f56b1429e760739c5fb51b7:12'
});

const response = await fetch(
  `https://api-v2.boost.xyz/signatures?${params.toString()}`
);
const { signature, claimant, incentiveId } = await response.json();
```

### Required Parameters for /signatures

* `txHash`: The transaction hash that completed the boost's required action
* `boostId`: The ID of the boost (format: `chainId:boostNumber`)
* `claimData`: (Optional) Additional data required for variable incentive types

### Response

```typescript theme={null}
{
    "signature": "0x...",   // Signature for verification
    "claimant": "0x...",    // Address eligible to claim
    "incentiveId": 0        // ID of the claimable incentive
}
```

<Tip>
  For complete API details including all available parameters and response fields, see the [API Reference](/v2/api-reference/boost/generate-a-claim-signature-that-can-be-used-to-submit-a-claim).
</Tip>

## Fetching Signature by Address

If you want to check whether a wallet has completed the boost requirements, you can scan recent transactions:

```typescript theme={null}
const params = new URLSearchParams({
  address: '0x1234...',
  boostId: '8453:0x378632819f39c74c4f56b1429e760739c5fb51b7:12'
});

const response = await fetch(
  `https://api-v2.boost.xyz/transactions?${params.toString()}`
);
const { signature, claimant, incentiveId } = await response.json();
```

<Tip>
  For complete API details, see the [GET /transactions reference](/v2/api-reference/rewardkit/try-to-get-claim-signature-without-known-transaction).
</Tip>

## Using the Signature

Once you have the signature from either endpoint, you can use it with the following SDK methods to claim your boost:

* [BoostCore.claimIncentive](/v2/boost-sdk/boost-core/claim-incentive#claimincentive) - Claim for the transaction sender
* [BoostCore.claimIncentiveFor](/v2/boost-sdk/boost-core/claim-incentive#claimincentivefor) - Claim on behalf of another address

<Frame>
  <Card title="Complete Claim Example" href="/v2/boost-sdk/examples/claim-example" icon="arrow-right" horizontal>
    See our SDK documentation for a complete example of claiming a boost with the returned signature.
  </Card>
</Frame>