Set Participant Data action dropping custom vars in IVR

Architect & Flows
1

Has anyone figured out why the Set Participant Data action seems to silently drop variables when passing through an IVR flow?

i’m building a screen pop extension that relies on custom data pushed from the IVR. The logic is straightforward. I have a prompt that collects a reference number, then a Set Participant Data action that assigns inputs.referenceNumber to a custom variable custRef.

the problem is the variable never shows up in the interaction.participantData object when the call transfers to an agent. I’ve checked the Data Mapping carefully. The key is custRef and the value is the input from the previous block.

i’ve tried logging the event payload on the client side using the GC Embeddable Framework. The event fires, but the custom data section is empty.

{
 "type": "interaction",
 "participantData": {}
}

i’m not seeing any errors in the Architect logs either. The flow executes without warnings. Is there a specific scope issue with IVR participants? Or do i need to use a different action like Update Interaction to persist this data before transfer? The docs are vague on whether IVR participants support custom data keys natively. it feels like a bug or a limitation i’m missing. i’ve spent two days debugging this. any help would be appreciated.

2

Make sure you’re actually reading the data back correctly in the extension. The Set Participant Data action doesn’t drop vars, but the way you fetch them often does.

  • check the exact key name. Architect is case-sensitive. if you set custRef in the IVR, you must read custRef in the SDK. try logging participant.customAttributes to see the raw payload.
  • use the getParticipantData method from the platformClient, not the interaction summary. the summary endpoint often strips custom data for performance.
const data = await platformClient.ConversationsApi.getParticipantData(
conversationId, 
participantId
);
console.log(data.customAttributes);
  • verify the variable scope. if you’re setting it on the interaction level but trying to read it from the participant, it won’t show up. ensure the “Apply To” setting in the Set Participant Data action is “Participant”.
  • check for null values. if inputs.referenceNumber is empty or null, Genesys might skip setting the attribute entirely. add a condition to ensure the input has a value before setting the data.
  • look at the API logs. use the purecloud:debug logger or check the Genesys Cloud API logs for the specific interaction. you’ll see exactly what was sent and what was stored.

it’s usually a scope issue or a case mismatch. i’ve seen this a dozen times. the data is there, just not where you’re looking.

3

If I remember correctly… mate, you’re probably hitting the IVR scope limit. custom attrs set in IVR often don’t persist to the agent wrap-up unless you push them via the transfer endpoint. try hitting /api/v2/interactions/instances/{id} with a PATCH body like {"customAttributes": {"custRef": "{inputs.referenceNumber}"}} instead of relying on the Architect action.

4

The official documentation states the Set Participant Data action is strictly for internal flow state, not for persisting data to the interaction object for downstream API consumption. you’re seeing a silent drop because Architect doesn’t map those local variables to the customAttributes field on the interaction instance automatically. it’s a common trap.

i ran this exact scenario in my Postman test suite last week. the 404 or empty object response you’re likely getting from the Web Messaging extension isn’t a bug, it’s expected behavior. the IVR context is ephemeral. once the call transfers or ends, that local variable scope dies.

you need to explicitly write to the interaction object. stop using the Set Participant Data block for this. use a Set Interaction Data action instead. or better yet, hit the API directly if you need granular control. here is the curl command that actually works:

curl -X PATCH "https://{{environment}}.mypurecloud.com/api/v2/interactions/instances/{{interactionId}}" \
 -H "Authorization: Bearer {{accessToken}}" \
 -H "Content-Type: application/json" \
 -d '{
 "customAttributes": {
 "custRef": "{{inputs.referenceNumber}}"
 }
 }'

make sure your inputs.referenceNumber is cleaned up. if it has special characters, the JSON payload will fail silently or throw a 400. i always add a regex check in a pre-request script to strip non-alphanumeric chars before the API call.

Warning: if you’re doing this in a high-volume IVR, hitting the API for every caller can spike your request count. consider batching if possible, but for screen pops, real-time is usually worth the overhead.

the extension will then see custRef in the participant’s custom attributes when it fetches the interaction details. just verify you’re using the correct OAuth scope interaction:read in your client credentials. don’t use call:read if you’re dealing with web messaging interactions, they are separate entities in the backend.

i’ve seen teams waste days debugging this. it’s always the scope or the action type. check your environment variables in Postman. ensure the interactionId is being passed correctly from the transfer event. if it’s null, the PATCH fails.