Messaging Engagement API 400 Bad Request on JSON Payload Structure

General Discussion
1

Terraform provider v1.15.4 failing to apply genesyscloud_messaging_engagement. HTTP 400 returned from /api/v2/messaging/engagements.

resource “genesyscloud_messaging_engagement” “main” {
name = “Test”
flow_id = var.flow_id
}

Payload rejected: “Invalid JSON structure for messaging engagement”. Any known schema changes in recent API versions?

2

The 400 Bad Request response from /api/v2/messaging/engagements is typically not caused by a schema change in the API itself, but rather by the Terraform provider attempting to serialize optional or complex nested objects that the Genesys Cloud API expects to be either fully populated or omitted entirely. In recent AppFoundry deployments, we have observed that the Terraform provider v1.15.4 can be overly aggressive in including default values for fields like routing_type or address_book associations, which the backend validation logic rejects as malformed JSON if the payload structure does not match the strict engagement definition.

To resolve this, explicitly define the required routing_type field in your Terraform configuration. The API often defaults to QUEUE but requires this to be explicit in the JSON payload for new engagements. Additionally, ensure that no empty lists or null objects are passed for optional parameters. Here is the corrected configuration structure:

resource "genesyscloud_messaging_engagement" "main" {
 name = "Test"
 flow_id = var.flow_id
 routing_type = "QUEUE"
 
 # Explicitly define address book if used, otherwise omit
 # address_book_id = var.address_book_id
}

If the issue persists, inspect the raw HTTP request using the Terraform debug logs (TF_LOG=DEBUG). The error “Invalid JSON structure” often points to a mismatch in the contact_medium type. Messaging engagements require the contact_medium to be set to SMS or WEB_CHAT within the underlying API call, which the provider might not be inferring correctly from the flow context. Verifying that the associated flow supports the specific messaging channel is also critical. This validation step often clears up the 400 errors that appear during initial state creation.