:doc:`Queue <index>` / Action / send_messages

*************
send_messages
*************



.. py:method:: SQS.Queue.send_messages(**kwargs)

  

  You can use ``SendMessageBatch`` to send up to 10 messages to the specified queue by assigning either identical or different values to each message (or by not assigning values at all). This is a batch version of ``SendMessage.`` For a FIFO queue, multiple messages within a single batch are enqueued in the order they are sent.

   

  The result of sending each message is reported individually in the response. Because the batch request can result in a combination of successful and unsuccessful actions, you should check for batch errors even when the call returns an HTTP status code of ``200``.

   

  The maximum allowed individual message size and the maximum total payload size (the sum of the individual lengths of all of the batched messages) are both 1 MiB 1,048,576 bytes.

   

  .. warning::

     

    A message can include only XML, JSON, and unformatted text. The following Unicode characters are allowed. For more information, see the `W3C specification for characters <http://www.w3.org/TR/REC-xml/#charsets>`__.

     

    ``#x9`` | ``#xA`` | ``#xD`` | ``#x20`` to ``#xD7FF`` | ``#xE000`` to ``#xFFFD`` | ``#x10000`` to ``#x10FFFF``

     

    If a message contains characters outside the allowed set, Amazon SQS rejects the message and returns an InvalidMessageContents error. Ensure that your message body includes only valid characters to avoid this exception.

     

   

  If you don't specify the ``DelaySeconds`` parameter for an entry, Amazon SQS uses the default value for the queue.

  

  See also: `AWS API Documentation <https://docs.aws.amazon.com/goto/WebAPI/sqs-2012-11-05/SendMessageBatch>`_  


  **Request Syntax**
  ::

    response = queue.send_messages(
        Entries=[
            {
                'Id': 'string',
                'MessageBody': 'string',
                'DelaySeconds': 123,
                'MessageAttributes': {
                    'string': {
                        'StringValue': 'string',
                        'BinaryValue': b'bytes',
                        'StringListValues': [
                            'string',
                        ],
                        'BinaryListValues': [
                            b'bytes',
                        ],
                        'DataType': 'string'
                    }
                },
                'MessageSystemAttributes': {
                    'string': {
                        'StringValue': 'string',
                        'BinaryValue': b'bytes',
                        'StringListValues': [
                            'string',
                        ],
                        'BinaryListValues': [
                            b'bytes',
                        ],
                        'DataType': 'string'
                    }
                },
                'MessageDeduplicationId': 'string',
                'MessageGroupId': 'string'
            },
        ]
    )
    
  :type Entries: list
  :param Entries: **[REQUIRED]** 

    A list of ``SendMessageBatchRequestEntry`` items.

    

  
    - *(dict) --* 

      Contains the details of a single Amazon SQS message along with an ``Id``.

      

    
      - **Id** *(string) --* **[REQUIRED]** 

        An identifier for a message in this batch used to communicate the result.

         

        .. note::

          

          The ``Id``s of a batch request need to be unique within a request.

           

          This identifier can have up to 80 characters. The following characters are accepted: alphanumeric characters, hyphens(-), and underscores (_).

          

        

      
      - **MessageBody** *(string) --* **[REQUIRED]** 

        The body of the message.

        

      
      - **DelaySeconds** *(integer) --* 

        The length of time, in seconds, for which a specific message is delayed. Valid values: 0 to 900. Maximum: 15 minutes. Messages with a positive ``DelaySeconds`` value become available for processing after the delay period is finished. If you don't specify a value, the default value for the queue is applied.

         

        .. note::

          

          When you set ``FifoQueue``, you can't set ``DelaySeconds`` per message. You can set this parameter only on a queue level.

          

        

      
      - **MessageAttributes** *(dict) --* 

        Each message attribute consists of a ``Name``, ``Type``, and ``Value``. For more information, see `Amazon SQS message attributes <https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-message-metadata.html#sqs-message-attributes>`__ in the *Amazon SQS Developer Guide*.

        

      
        - *(string) --* 

        
          - *(dict) --* 

            The user-specified message attribute value. For string data types, the ``Value`` attribute has the same restrictions on the content as the message body. For more information, see ``SendMessage.``

             

            ``Name``, ``type``, ``value`` and the message body must not be empty or null. All parts of the message attribute, including ``Name``, ``Type``, and ``Value``, are part of the message size restriction (1 MiB or 1,048,576 bytes).

            

          
            - **StringValue** *(string) --* 

              Strings are Unicode with UTF-8 binary encoding. For a list of code values, see `ASCII Printable Characters <http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters>`__.

              

            
            - **BinaryValue** *(bytes) --* 

              Binary type attributes can store any binary data, such as compressed data, encrypted data, or images.

              

            
            - **StringListValues** *(list) --* 

              Not implemented. Reserved for future use.

              

            
              - *(string) --* 

              
          
            - **BinaryListValues** *(list) --* 

              Not implemented. Reserved for future use.

              

            
              - *(bytes) --* 

              
          
            - **DataType** *(string) --* **[REQUIRED]** 

              Amazon SQS supports the following logical data types: ``String``, ``Number``, and ``Binary``. For the ``Number`` data type, you must use ``StringValue``.

               

              You can also append custom labels. For more information, see `Amazon SQS Message Attributes <https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-message-metadata.html#sqs-message-attributes>`__ in the *Amazon SQS Developer Guide*.

              

            
          
    
  
      - **MessageSystemAttributes** *(dict) --* 

        The message system attribute to send Each message system attribute consists of a ``Name``, ``Type``, and ``Value``.

         

        .. warning::

           

          
          * Currently, the only supported message system attribute is ``AWSTraceHeader``. Its type must be ``String`` and its value must be a correctly formatted X-Ray trace header string.
           
          * The size of a message system attribute doesn't count towards the total size of a message.
          

          

        

      
        - *(string) --* 

        
          - *(dict) --* 

            The user-specified message system attribute value. For string data types, the ``Value`` attribute has the same restrictions on the content as the message body. For more information, see ``SendMessage.``

             

            ``Name``, ``type``, ``value`` and the message body must not be empty or null.

            

          
            - **StringValue** *(string) --* 

              Strings are Unicode with UTF-8 binary encoding. For a list of code values, see `ASCII Printable Characters <http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters>`__.

              

            
            - **BinaryValue** *(bytes) --* 

              Binary type attributes can store any binary data, such as compressed data, encrypted data, or images.

              

            
            - **StringListValues** *(list) --* 

              Not implemented. Reserved for future use.

              

            
              - *(string) --* 

              
          
            - **BinaryListValues** *(list) --* 

              Not implemented. Reserved for future use.

              

            
              - *(bytes) --* 

              
          
            - **DataType** *(string) --* **[REQUIRED]** 

              Amazon SQS supports the following logical data types: ``String``, ``Number``, and ``Binary``. For the ``Number`` data type, you must use ``StringValue``.

               

              You can also append custom labels. For more information, see `Amazon SQS Message Attributes <https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-message-metadata.html#sqs-message-attributes>`__ in the *Amazon SQS Developer Guide*.

              

            
          
    
  
      - **MessageDeduplicationId** *(string) --* 

        This parameter applies only to FIFO (first-in-first-out) queues.

         

        The token used for deduplication of messages within a 5-minute minimum deduplication interval. If a message with a particular ``MessageDeduplicationId`` is sent successfully, subsequent messages with the same ``MessageDeduplicationId`` are accepted successfully but aren't delivered. For more information, see `Exactly-once processing <https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/FIFO-queues-exactly-once-processing.html>`__ in the *Amazon SQS Developer Guide*.

         

        
        * Every message must have a unique ``MessageDeduplicationId``, 

          
          * You may provide a ``MessageDeduplicationId`` explicitly.
           
          * If you aren't able to provide a ``MessageDeduplicationId`` and you enable ``ContentBasedDeduplication`` for your queue, Amazon SQS uses a SHA-256 hash to generate the ``MessageDeduplicationId`` using the body of the message (but not the attributes of the message).
           
          * If you don't provide a ``MessageDeduplicationId`` and the queue doesn't have ``ContentBasedDeduplication`` set, the action fails with an error.
           
          * If the queue has ``ContentBasedDeduplication`` set, your ``MessageDeduplicationId`` overrides the generated one.
          

        
         
        * When ``ContentBasedDeduplication`` is in effect, messages with identical content sent within the deduplication interval are treated as duplicates and only one copy of the message is delivered.
         
        * If you send one message with ``ContentBasedDeduplication`` enabled and then another message with a ``MessageDeduplicationId`` that is the same as the one generated for the first ``MessageDeduplicationId``, the two messages are treated as duplicates and only one copy of the message is delivered.
        

         

        .. note::

          

          The ``MessageDeduplicationId`` is available to the consumer of the message (this can be useful for troubleshooting delivery issues).

           

          If a message is sent successfully but the acknowledgement is lost and the message is resent with the same ``MessageDeduplicationId`` after the deduplication interval, Amazon SQS can't detect duplicate messages.

           

          Amazon SQS continues to keep track of the message deduplication ID even after the message is received and deleted.

          

         

        The length of ``MessageDeduplicationId`` is 128 characters. ``MessageDeduplicationId`` can contain alphanumeric characters ( ``a-z``, ``A-Z``, ``0-9``) and punctuation ( ``!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~``).

         

        For best practices of using ``MessageDeduplicationId``, see `Using the MessageDeduplicationId Property <https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/using-messagededuplicationid-property.html>`__ in the *Amazon SQS Developer Guide*.

        

      
      - **MessageGroupId** *(string) --* 

        ``MessageGroupId`` is an attribute used in Amazon SQS FIFO (First-In-First-Out) and standard queues. In FIFO queues, ``MessageGroupId`` organizes messages into distinct groups. Messages within the same message group are always processed one at a time, in strict order, ensuring that no two messages from the same group are processed simultaneously. In standard queues, using ``MessageGroupId`` enables fair queues. It is used to identify the tenant a message belongs to, helping maintain consistent message dwell time across all tenants during noisy neighbor events. Unlike FIFO queues, messages with the same ``MessageGroupId`` can be processed in parallel, maintaining the high throughput of standard queues.

         

        
        * **FIFO queues:** ``MessageGroupId`` acts as the tag that specifies that a message belongs to a specific message group. Messages that belong to the same message group are processed in a FIFO manner (however, messages in different message groups might be processed out of order). To interleave multiple ordered streams within a single queue, use ``MessageGroupId`` values (for example, session data for multiple users). In this scenario, multiple consumers can process the queue, but the session data of each user is processed in a FIFO fashion. If you do not provide a ``MessageGroupId`` when sending a message to a FIFO queue, the action fails. ``ReceiveMessage`` might return messages with multiple ``MessageGroupId`` values. For each ``MessageGroupId``, the messages are sorted by time sent.
         
        * **Standard queues:**Use ``MessageGroupId`` in standard queues to enable fair queues. The ``MessageGroupId`` identifies the tenant a message belongs to. A tenant can be any entity that shares a queue with others, such as your customer, a client application, or a request type. When one tenant sends a disproportionately large volume of messages or has messages that require longer processing time, fair queues ensure other tenants' messages maintain low dwell time. This preserves quality of service for all tenants while maintaining the scalability and throughput of standard queues. We recommend that you include a ``MessageGroupId`` in all messages when using fair queues.
        

         

        The length of ``MessageGroupId`` is 128 characters. Valid values: alphanumeric characters and punctuation ``(!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~)``.

         

        For best practices of using ``MessageGroupId``, see `Using the MessageGroupId Property <https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/using-messagegroupid-property.html>`__ in the *Amazon SQS Developer Guide*.

        

      
    

  
  :rtype: dict
  :returns: 
    
    **Response Syntax**

    
    ::

      {
          'Successful': [
              {
                  'Id': 'string',
                  'MessageId': 'string',
                  'MD5OfMessageBody': 'string',
                  'MD5OfMessageAttributes': 'string',
                  'MD5OfMessageSystemAttributes': 'string',
                  'SequenceNumber': 'string'
              },
          ],
          'Failed': [
              {
                  'Id': 'string',
                  'SenderFault': True|False,
                  'Code': 'string',
                  'Message': 'string'
              },
          ]
      }
      
    **Response Structure**

    

    - *(dict) --* 

      For each message in the batch, the response contains a ``SendMessageBatchResultEntry`` tag if the message succeeds or a ``BatchResultErrorEntry`` tag if the message fails.

      
      

      - **Successful** *(list) --* 

        A list of ``SendMessageBatchResultEntry`` items.

        
        

        - *(dict) --* 

          Encloses a ``MessageId`` for a successfully-enqueued message in a ``SendMessageBatch.``

          
          

          - **Id** *(string) --* 

            An identifier for the message in this batch.

            
          

          - **MessageId** *(string) --* 

            An identifier for the message.

            
          

          - **MD5OfMessageBody** *(string) --* 

            An MD5 digest of the non-URL-encoded message body string. You can use this attribute to verify that Amazon SQS received the message correctly. Amazon SQS URL-decodes the message before creating the MD5 digest. For information about MD5, see `RFC1321 <https://www.ietf.org/rfc/rfc1321.txt>`__.

            
          

          - **MD5OfMessageAttributes** *(string) --* 

            An MD5 digest of the non-URL-encoded message attribute string. You can use this attribute to verify that Amazon SQS received the message correctly. Amazon SQS URL-decodes the message before creating the MD5 digest. For information about MD5, see `RFC1321 <https://www.ietf.org/rfc/rfc1321.txt>`__.

            
          

          - **MD5OfMessageSystemAttributes** *(string) --* 

            An MD5 digest of the non-URL-encoded message system attribute string. You can use this attribute to verify that Amazon SQS received the message correctly. Amazon SQS URL-decodes the message before creating the MD5 digest. For information about MD5, see `RFC1321 <https://www.ietf.org/rfc/rfc1321.txt>`__.

            
          

          - **SequenceNumber** *(string) --* 

            This parameter applies only to FIFO (first-in-first-out) queues.

             

            The large, non-consecutive number that Amazon SQS assigns to each message.

             

            The length of ``SequenceNumber`` is 128 bits. As ``SequenceNumber`` continues to increase for a particular ``MessageGroupId``.

            
      
    
      

      - **Failed** *(list) --* 

        A list of ``BatchResultErrorEntry`` items with error details about each message that can't be enqueued.

        
        

        - *(dict) --* 

          Gives a detailed description of the result of an action on each entry in the request.

          
          

          - **Id** *(string) --* 

            The ``Id`` of an entry in a batch request.

            
          

          - **SenderFault** *(boolean) --* 

            Specifies whether the error happened due to the caller of the batch API action.

            
          

          - **Code** *(string) --* 

            An error code representing why the action failed on this entry.

            
          

          - **Message** *(string) --* 

            A message explaining why the action failed on this entry.

            
      
    
  