<p>Gets an Amazon Kinesis shard iterator. A shard iterator expires 5 minutes after it is returned to the requester.</p> <note> <p>When invoking this API, it is recommended you use the <code>StreamARN</code> input parameter rather than the <code>StreamName</code> input parameter.</p> </note> <p>A shard iterator specifies the shard position from which to start reading data records sequentially. The position is specified using the sequence number of a data record in a shard. A sequence number is the identifier associated with every record ingested in the stream, and is assigned when a record is put into the stream. Each stream has one or more shards.</p> <p>You must specify the shard iterator type. For example, you can set the <code>ShardIteratorType</code> parameter to read exactly from the position denoted by a specific sequence number by using the <code>AT_SEQUENCE_NUMBER</code> shard iterator type. Alternatively, the parameter can read right after the sequence number by using the <code>AFTER_SEQUENCE_NUMBER</code> shard iterator type, using sequence numbers returned by earlier calls to <a>PutRecord</a>, <a>PutRecords</a>, <a>GetRecords</a>, or <a>DescribeStream</a>. In the request, you can specify the shard iterator type <code>AT_TIMESTAMP</code> to read records from an arbitrary point in time, <code>TRIM_HORIZON</code> to cause <code>ShardIterator</code> to point to the last untrimmed record in the shard in the system (the oldest data record in the shard), or <code>LATEST</code> so that you always read the most recent data in the shard. </p> <p>When you read repeatedly from a stream, use a <a>GetShardIterator</a> request to get the first shard iterator for use in your first <a>GetRecords</a> request and for subsequent reads use the shard iterator returned by the <a>GetRecords</a> request in <code>NextShardIterator</code>. A new shard iterator is returned by every <a>GetRecords</a> request in <code>NextShardIterator</code>, which you use in the <code>ShardIterator</code> parameter of the next <a>GetRecords</a> request. </p> <p>If a <a>GetShardIterator</a> request is made too often, you receive a <code>ProvisionedThroughputExceededException</code>. For more information about throughput limits, see <a>GetRecords</a>, and <a href="https://docs.aws.amazon.com/kinesis/latest/dev/service-sizes-and-limits.html">Streams Limits</a> in the <i>Amazon Kinesis Data Streams Developer Guide</i>.</p> <p>If the shard is closed, <a>GetShardIterator</a> returns a valid iterator for the last sequence number of the shard. A shard can be closed as a result of using <a>SplitShard</a> or <a>MergeShards</a>.</p> <p> <a>GetShardIterator</a> has a limit of five transactions per second per account per open shard.</p>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}