AWS IoT Core additional metering details

MQTT CONNECT	Metered as the size of the message including Will topic size and Will message payload. If using MQTT5, the message is also metered on any additional string and binary variable-header properties and Will properties, such as user properties.
MQTT PUBACK (received from device)	If using MQTT5, metered based on the size of the message including user properties. Otherwise, metered as a single 5 KB message.
MQTT SUBSCRIBE	Metered on the size of the topic submitted in the Subscribe message, plus the size of any user properties sent (if using MQTT5).
MQTT PUBLISH (received from device)	Metered on the size of the payload and topic in bytes. If using MQTT5, the size of the user properties, response topic, correlation data, and content type are also included in the payload size metered.
MQTT PUBLISH (sent by service)	Metered on the size of the payload and topic in bytes. If using MQTT5, the size of the user properties, response topic, correlation data, and content type are also included in the payload size metered.
MQTT RETAINED	Metered on the size of the payload and topic in bytes. If using MQTT5, the size of the user properties, response topic, correlation data, and content type are also included in the payload size metered.  For MQTT inbound messages published with the RETAIN flag, your account would be metered for inbound MQTT PUBLISH and for MQTT RETAINED

HTTP Request and Response Metering

Requests	Metered on the number of 5 KB messages needed to encode the body section of the HTTP request. If using the HTTP publish message API, the size of the user properties, response topic, correlation data, and content type are also included in the payload size metered.
Responses	Metered on the number of 5 KB messages needed to encode the body section of the HTTP response

LoRaWAN Metering

LoRaWAN.Uplink	Metered on the number of messages (sent by device)
LoRaWAN.Downlink	Metered on the number of messages (sent by service)
LoRaWAN.Join	Metered on the number of messages (sent by device)
LoRaWAN.UplinkACK	Metered on the number of messages (sent by service)
LoRaWAN.DownlinkACK	Metered on the number of messages (sent by device)

Sidewalk Metering

Sidewalk.Uplink	Metered on the number of messages (sent by device)
Sidewalk.Downlink	Metered on the number of messages (sent by service)

Note: Messages sent by Amazon Sidewalk devices that use the Amazon Sidewalk Integration feature to connect to AWS IoT Core are metered using LoRaWAN messaging pricing levels.

Registry

Rules engine has the following pricing dimensions:

1. Rules triggered for every IoT rule evaluation 
2. Rule actions executed to redirect data to other services or to call select in-line functions described below.

An IoT rule can invoke up to 10 IoT rule actions. In your AWS bill, the cost of IoT rule action can include the following: 1/ cost of routing data to an external service (such as Amazon S3, Amazon Kinesis, Amazon SNS), and/or 2/ cost of calling the following external functions within an IoT rule: get_thing_shadow(), aws_lambda(), get_dynamodb(), get_registry_data(). Arithmetic and logical SQL functions in IoT rule are not metered as actions. get_secret() external function call is also not metered as an IoT rule action.

An IoT rule action that sends a message to a resource inside a customer's Amazon Virtual Private Cloud (VPC) will be counted as 2 IoT rule actions. This additional action does not count towards the 10 actions per rule limit. VPC is supported for the following rule action(s): Apache Kafka action.

A rule that is triggered will always meter, at minimum, one rule and one action. For example, if your IoT rule is evaluated, but no IoT rule action is invoked, then you pay for 1 IoT rule and 1 IoT rule action.

Rules that process a message generated by AWS IoT Core are metered as a single rule, regardless of message size. For example, a 7 KB Device Shadow document may publish a /delta or /documents message that is quite large; however any rules initiated by such an update will be metered as if the message were 5 KB.

Protobuf-to-JSON Decode: Decoding a Protocol Buffer (Protobuf) message to JavaScript Object Notation (JSON) format using decode() function in Rules Engine will be metered as 1 Action. Rules Engine will charge for decode actions within a Rule, and the decode actions can be optimized by caching the descriptor file. When you decode a Protobuf message using Rules Engine, you will be charged for 1 Rule Triggered + 1 Rule Action (for sending the data to a downstream AWS service) + 1 Protobuf-to-JSON Decode. However, you will not be charged in 5kB increments for decoding Protobuf messages to JSON. You will charged for 1 Decode (Action) upto the maximum Protobuf payload size of 128kB.

Standard EC2 data transfer rates listed here under “Data transfer” apply to the following rules actions(s): HTTP action.