POST /api/v2/flows/executions returns 400 despite valid JSON payload

NICE CXone API & Integrations
1

Having some config trouble here… I am using Node.js v18 to trigger an Architect flow via POST /api/v2/flows/executions. The documentation states: “The request body must be a JSON object containing the flow ID and optional parameters.” My payload is {"flowId": "abc-123", "parameters": {"key": "val"}}. Yet, I receive a 400 Bad Request. Why does the API reject this standard structure?

2

It depends, but generally your payload structure is missing the required routingData object that Genesys Cloud expects for flow execution. The API strictly requires this wrapper for participant details.

  • Check the routingData schema in the API docs
  • Verify participantId is correctly set
  • Ensure language matches your flow settings
3

{
“flowId”: “abc-123”,
“routingData”: {
“from”: {
“id”: “user-id-or-phone”
},
“to”: {
“id”: “target-queue-id”
},
“language”: “en-us”
},
“parameters”: {
“key”: “val”
}
}

The suggestion above is correct. You are hitting a 400 because `routingData` is mandatory for voice/chat flows. But here is the catch.

*If you are triggering this from a serverless Lambda via EventBridge, do not hardcode the `from` ID.*

If you inject a static user ID, Genesys Cloud will attempt to match that identity against existing active participants. If a collision occurs, or if the user is not in a "Ready" state, the execution fails silently or throws a 409.

Instead, generate a unique `participantId` in your Node.js handler using `crypto.randomUUID()` and pass that into `routingData.from.id`. This ensures the flow execution is treated as a new, distinct session. Also, verify your OAuth token has the `flow:execution:write` scope. Missing scopes often masquerade as 400 errors in the SDK logs.
4

The problem here is the missing routingData wrapper. The API rejects minimal payloads because it needs participant context for the flow execution engine. Use this Python snippet to construct the correct payload structure before posting.

payload = {
 "flowId": "abc-123",
 "routingData": {"from": {"id": "caller-id"}, "to": {"id": "queue-id"}, "language": "en-us"},
 "parameters": {"key": "val"}
}

Ensure your OAuth token has the flow:execute scope or you will get 403s instead.

5

This seems like a standard payload structure issue, but the real headache in Python notebooks is handling the token expiration during the actual POST request. The suggestion above correctly identifies the routingData requirement, but I often see 400s persist because the from and to objects are malformed or missing required nested fields like address for SMS/Chat flows.

In my exploratory analytics workflows, I wrap the API call in a requests session to ensure the Bearer token is fresh. Using the PureCloudPlatformClientV2 SDK directly can be cumbersome for ad-hoc flow triggering because it expects full model objects. A raw requests.post gives more control over the JSON serialization.

Here is the robust pattern I use in Jupyter cells:

import requests
from purecloud_platform_client_v2 import PureCloudPlatformClientV2

client = PureCloudPlatformClientV2()
client.set_access_token('your_valid_token') # Ensure this is valid
token = client.configuration.access_token

headers = {
 'Authorization': f'Bearer {token}',
 'Content-Type': 'application/json'
}

# Critical: 'from' must have 'id' and potentially 'name' or 'address' depending on media type
payload = {
 "flowId": "abc-123",
 "routingData": {
 "from": {
 "id": "caller-user-id",
 "name": "Caller Name",
 "address": "+1234567890" # Required for Voice/SMS
 },
 "to": {
 "id": "target-queue-id",
 "name": "Support Queue"
 },
 "language": "en-us"
 },
 "parameters": {
 "key": "val"
 }
}

response = requests.post(
 'https://api.mypurecloud.com/api/v2/flows/executions',
 headers=headers,
 json=payload
)

print(response.status_code)
print(response.json())

If you omit the address field in routingData.from for a voice flow, the engine rejects it with a 400, even if the JSON syntax is perfect.

Warning: Do not hardcode the from.id if you are simulating multiple users for testing. The flow engine logs these IDs, and mixing test identities with production user IDs can corrupt your analytics data in the GET /api/v2/analytics/flows/summary endpoints. Always use distinct test user IDs.