Custom Property Not Working via API

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1

I’ve created a single-send email, used {{ custom.tracking_number }} in a raw HTML block, published it, and sent a POST to /email/public/v1/singleEmail/send with that custom property, and I still get MISSING_TEMPLATE_PROPERTIES.

Defining it like so:

body = {
“emailId”: 189265578342,
“message”: {
“to”: “jdevogel@arborwear.com”,
“customProperties”: {
“tracking_number”: “449044304137821”
}
}
}

2

Try using a known working default property (like {{ contact.firstname }}) in the email temporarily, and send the same request using a contact with a known firstname. If that works, the issue might be with the customProperties.

3

Your customProperties is in the wrong location in the JSON payload. You currently have it put in the “message” key while it should be at the root:

I formatted your payload to make it easier to see::

{
 "emailId": 189265578342,
 "message": {
 "to": "jdevogel@arborwear.com",
 "customProperties": {
 "tracking_number": "449044304137821"
 }
 }
}

Move custom properties outside of message and into the top level of the payload:

{
 "emailId": 189265578342,
 "message": {
 "to": "jdevogel@arborwear.com"
 },
 "customProperties": {
 "tracking_number": "449044304137821"
 }
}

Sample payload from docs:

{
 "emailId": 4126643121,
 "message": {
 "to": "jdoe@hubspot.com"
 "sendId": "6"
 },
 "customProperties": {
 "purchaseUrl": "https://example.com/link-to-product",
 "productName": "vanilla"
 }
}
4

I figured this out. Default properties worked fine. The documentation was either wrong or inconsistent.

Had to send as a list of objects rather than a dictionary.

This does not work (dictionary - as per docs):
“customProperties”: {
“tracking_number”: tracking_number
}

This does work (list of objects):
“customProperties”: [
{
“name”: “tracking_number”,
“value”: tracking_number
}
]