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

# Get Payin by External ID

> Fetch a payin by externalId.

### Params

<ParamField path="externalId" type="string" required>
  Client reference id.
</ParamField>

### Response

Returns a payin object.

### Error Responses

<ResponseExample>
  ```json 404 theme={null}
  {
    "success": false,
    "error": "Not Found"
  }
  ```
</ResponseExample>