Clients can publish messages by making requests to the REST API using the HTTP 1.0 or 1.1 protocols. For the authentication and port mappings used by HTTP requests, see Protocols, port mappings, and authentication.


HTTPS doesn't support a clientId value like MQTT does. clientId is available when using MQTT, but it's not available when using HTTPS.

HTTPS message URL

Devices and clients publish their messages by making POST requests to a client-specific endpoint and a topic-specific URL:

  • IoT_data_endpoint is the AWS IoT device data endpoint. You can find the endpoint in the AWS IoT console on the thing's details page or on the client by using the AWS CLI command:

    aws iot describe-endpoint --endpoint-type iot:Data-ATS

    The endpoint should look something like this:

  • url_encoded_topic_name is the full topic name of the message being sent.

HTTPS message code examples

These are some examples of how to send an HTTPS message to AWS IoT.

Python (port 8443)
import requests import argparse # define command-line parameters parser = argparse.ArgumentParser(description="Send messages through an HTTPS connection.") parser.add_argument('--endpoint', required=True, help="Your AWS IoT data custom endpoint, not including a port. " + "Ex: \"\"") parser.add_argument('--cert', required=True, help="File path to your client certificate, in PEM format.") parser.add_argument('--key', required=True, help="File path to your private key, in PEM format.") parser.add_argument('--topic', required=True, default="test/topic", help="Topic to publish messages to.") parser.add_argument('--message', default="Hello World!", help="Message to publish. " + "Specify empty string to publish nothing.") # parse and load command-line parameter values args = parser.parse_args() # create and format values for HTTPS request publish_url = 'https://' + args.endpoint + ':8443/topics/' + args.topic + '?qos=1' publish_msg = args.message.encode('utf-8') # make request publish = requests.request('POST', publish_url, data=publish_msg, cert=[args.cert, args.key]) # print results print("Response status: ", str(publish.status_code)) if publish.status_code == 200: print("Response body:", publish.text)
Python (port 443)
import requests import http.client import json import ssl ssl_context = ssl.SSLContext(protocol=ssl.PROTOCOL_TLS_CLIENT) ssl_context.minimum_version = ssl.TLSVersion.TLSv1_2 # note the use of ALPN ssl_context.set_alpn_protocols(["x-amzn-http-ca"]) ssl_context.load_verify_locations(cafile="./<root_certificate>") # update the certificate and the AWS endpoint ssl_context.load_cert_chain("./<certificate_in_PEM_Format>", "<private_key_in_PEM_format>") connection = http.client.HTTPSConnection('<the ats IoT endpoint>', 443, context=ssl_context) message = {'data': 'Hello, I'm using TLS Client authentication!'} json_data = json.dumps(message) connection.request('POST', '/topics/device%2Fmessage?qos=1', json_data) # make request response = connection.getresponse() # print results print(

You can use curl from a client or device to send a message to AWS IoT.

To use curl to send a message from an AWS IoT client device
  1. Check the curl version.

    1. On your client, run this command at a command prompt.

      curl --help

      In the help text, look for the TLS options. You should see the --tlsv1.2 option.

    2. If you see the --tlsv1.2 option, continue.

    3. If you don't see the --tlsv1.2 option or you get a command not found error, you might need to update or install curl on your client or install openssl before you continue.

  2. Install the certificates on your client.

    Copy the certificate files that you created when you registered your client (thing) in the AWS IoT console. Make sure you have these three certificate files on your client before you continue.

    • The CA certificate file (Amazon-root-CA-1.pem in this example).

    • The client's certificate file (device.pem.crt in this example).

    • The client's private key file (private.pem.key in this example).

  3. Create the curl command line, replacing the replaceable values for those of your account and system.

    curl --tlsv1.2 \ --cacert Amazon-root-CA-1.pem \ --cert device.pem.crt \ --key private.pem.key \ --request POST \ --data "{ \"message\": \"Hello, world\" }" \ "https://IoT_data_endpoint:8443/topics/topic?qos=1"

    Use TLS 1.2 (SSL).

    --cacert Amazon-root-CA-1.pem

    The file name and path, if necessary, of the CA certificate to verify the peer.

    --cert device.pem.crt

    The client's certificate file name and path, if necessary.

    --key private.pem.key

    The client's private key file name and path, if necessary.

    --request POST

    The type of HTTP request (in this case, POST).

    --data "{ \"message\": \"Hello, world\" }"

    The HTTP POST data you want to publish. In this case, it's a JSON string, with the internal quotation marks escaped with the backslash character (\).


    The URL of your client's AWS IoT device data endpoint, followed by the HTTPS port, :8443, which is then followed by the keyword, /topics/ and the topic name, topic, in this case. Specify the Quality of Service as the query parameter, ?qos=1.

  4. Open the MQTT test client in the AWS IoT console.

    Follow the instructions in View MQTT messages with the AWS IoT MQTT client and configure the console to subscribe to messages with the topic name of topic used in your curl command, or use the wildcard topic filter of #.

  5. Test the command.

    While monitoring the topic in the test client of the AWS IoT console, go to your client and issue the curl command line that you created in step 3. You should see your client's messages in the console.