Been wrestling with data actions again - feels like half my time is spent debugging these. Architect flow’s trying to POST to a webhook, expecting JSON, but the API keeps returning a 400 with “Invalid JSON payload” and the body shows {"error":"Unexpected token u in JSON at position 0"}. PureCloudPlatformClientV2 is serializing the data fine on our end - we’ve tested the output independently, and it looks perfect. One gotcha is that the data action itself isn’t doing anything particularly complex; it’s just passing a variable value from the flow to a simple HTTP POST endpoint.
The webhook’s endpoint is /api/v2/zoom/integrations/my-endpoint, and we’re using v2 of the SDK. Not 100% sure but I’m suspecting a mismatch somewhere between what Architect is actually sending and what the SDK expects for serialization - maybe a type coercion issue or something. The flow variable is definitely a string, though. It’s frustrating because the initial data action setup seems correct and we’ve had similar setups working for months.
Okay - this one’s a bit annoying, we’ve hit this pattern a couple of times. It almost always comes down to stringification quirks, especially with the v2 SDK. Here’s a few things to check.
Data Type Mismatch: The “undefined” suggests something isn’t being serialized correctly. Double-check the data types you’re passing into JSON.stringify(). Sometimes, numbers can get interpreted as strings, and vice versa, which can throw off the webhook’s parser.
Empty Values: The error points to position 0, which is odd. It suggests the very first character is wrong. A common issue is unintentionally passing empty values or null at the beginning of the object. Try logging the object immediately before the JSON.stringify() call to see the exact structure.
SDK Version: YMMV, but we had an issue a while back where a specific SDK version had a bug with complex object serialization. I don’t have the exact version offhand, unfortunately.
Workaround (Temporary): As a quick test - and just a hunch - try wrapping the object in an array before stringifying.
This adds a leading bracket, which might bypass whatever’s choking the webhook parser. Not ideal, obviously, but it’ll help isolate the problem.
Webhook Logging: Is the webhook logging the entire request, including headers? A missing Content-Type header can cause issues. Make sure the webhook is expecting application/json.
Let me know if you’ve already checked those - happy to dig deeper if needed.
That’s a good point about stringification - it’s not the data types themselves, though. PureCloudPlatformClientV2 is adding a leading “undefined” to the JSON string before it even gets to the webhook; it’s like it’s trying to serialize the object’s prototype or something. We’re on Zoom Contact Center, and the data action’s ‘override content type’ option is definitely set to ‘application/json’ - double-checked that five times. It only happens when the data action has a condition attached.