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Amazon Simple Queue Service
API Reference (API Version 2012-11-05)

SendMessage

Delivers a message to the specified queue.

Important

A message can include only XML, JSON, and unformatted text. The following Unicode characters are allowed:

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

Any characters not included in this list will be rejected. For more information, see the W3C specification for characters.

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

DelaySeconds

The length of time, in seconds, for which to delay a specific message. 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 applies.

Note

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

Type: Integer

Required: No

MessageAttribute
MessageAttribute.N.Name (key)
MessageAttribute.N.Value (value)

Each message attribute consists of a Name, Type, and Value. For more information, see Message Attribute Items and Validation in the Amazon SQS Developer Guide.

Type: String to MessageAttributeValue object map

Required: No

MessageBody

The message to send. The maximum string size is 256 KB.

Important

A message can include only XML, JSON, and unformatted text. The following Unicode characters are allowed:

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

Any characters not included in this list will be rejected. For more information, see the W3C specification for characters.

Type: String

Required: Yes

MessageDeduplicationId

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

The token used for deduplication of sent messages. If a message with a particular MessageDeduplicationId is sent successfully, any messages sent with the same MessageDeduplicationId are accepted successfully but aren't delivered during the 5-minute deduplication interval. For more information, see Exactly-Once Processing 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 recipient 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.

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 in the Amazon Simple Queue Service Developer Guide.

Type: String

Required: No

MessageGroupId

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

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 readers can process the queue, but the session data of each user is processed in a FIFO fashion.

  • You must associate a non-empty MessageGroupId with a message. If you don't provide a MessageGroupId, the action fails.

  • ReceiveMessage might return messages with multiple MessageGroupId values. For each MessageGroupId, the messages are sorted by time sent. The caller can't specify a MessageGroupId.

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

For best practices of using MessageGroupId, see Using the MessageGroupId Property in the Amazon Simple Queue Service Developer Guide.

Important

MessageGroupId is required for FIFO queues. You can't use it for Standard queues.

Type: String

Required: No

QueueUrl

The URL of the Amazon SQS queue to which a message is sent.

Queue URLs are case-sensitive.

Type: String

Required: Yes

Response Elements

The following elements are returned by the service.

MD5OfMessageAttributes

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.

Type: String

MD5OfMessageBody

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.

Type: String

MessageId

An attribute containing the MessageId of the message sent to the queue. For more information, see Queue and Message Identifiers in the Amazon SQS Developer Guide.

Type: String

SequenceNumber

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. SequenceNumber continues to increase for a particular MessageGroupId.

Type: String

Errors

For information about the errors that are common to all actions, see Common Errors.

AWS.SimpleQueueService.UnsupportedOperation

Error code 400. Unsupported operation.

HTTP Status Code: 400

InvalidMessageContents

The message contains characters outside the allowed set.

HTTP Status Code: 400

Example

The following example SendMessage request sends a message containing This is a test message to the queue. You must URL-encode the entire URL. However, in this example only the message body is URL-encoded to make the example easier to read. How you structure the AUTHPARAMS depends on how you are signing your API request. For information about AUTHPARAMS in Signature Version 4, see Examples of Signed Signature Version 4 Requests in the Amazon Web Services General Reference.

Sample Request

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http://sqs.us-east-2.amazonaws.com/123456789012/testQueue/ ?Action=SendMessage &MessageBody=This+is+a+test+message &MessageAttribute.1.Name=test_attribute_name_1 &MessageAttribute.1.Value.StringValue=test_attribute_value_1 &MessageAttribute.1.Value.DataType=String &MessageAttribute.2.Name=test_attribute_name_2 &MessageAttribute.2.Value.StringValue=test_attribute_value_2 &MessageAttribute.2.Value.DataType=String &Version=2012-11-05 &Expires=2014-05-05T22%3A52%3A43PST &AUTHPARAMS

Sample Response

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<SendMessageResponse> <SendMessageResult> <MD5OfMessageBody> fafb00f5732ab283681e124bf8747ed1 </MD5OfMessageBody> <MD5OfMessageAttributes> 3ae8f24a165a8cedc005670c81a27295 </MD5OfMessageAttributes> <MessageId> 5fea7756-0ea4-451a-a703-a558b933e274 </MessageId> </SendMessageResult> <ResponseMetadata> <RequestId> 27daac76-34dd-47df-bd01-1f6e873584a0 </RequestId> </ResponseMetadata> </SendMessageResponse>

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: