Skip to main content
This page covers the common errors you might encounter when sending requests to the APIs.
This is usually caused by the selected modules in the journey builder not having the needed credentials. In this case, you encounter a 201 status code that returns an empty collection of tasks. This happens even when you have modules in the journey builder. The response looks like this:
{
    "status": "Completed",
    "instanceId": "Qs7Zj2p4LMWT3V8Ndu9k6BRa",
    "tasks": []
}
To confirm this, send a POST request to the /journey/state/fetch endpoint. You will receive a response showing the GET_CREDENTIALS_ERRORcode.To resolve this, contact your GBG GO account manager to update the credentials for your modules.
When you call the /journey/state/fetch endpoint and receive a “COMPLETED” status (rather than a credentials error), this means that the journey has been successfully finished. All tasks associated with this journey instance have been completed, and no further action is required.
If you are a new user who attempts to log in to GBG GO with valid credentials but is immediately logged out, this might be because your organization hasn’t been created in the system yet. The account exists, but without an associated organization the system cannot direct you to your dashboard. As a result, the system automatically logs you out.To resolve this, contact your GBG GO account manager for help troubleshooting the issue.
In adaptive mode, the Facematch Verification module requires both face images to be submitted in the API payload. Submitting only one image causes the task to fail.

​
Symptom

When you run a journey in adaptive mode and reach the facematch verification task, the submit task data request returns a system error. The same journey completes successfully when executed in prefill mode.

​
Cause

The Facematch Verification module compares two face images against each other to produce a match decision. The module needs both images available before it can run:
  • face1Image is the selfie image captured during the journey.
  • face2Image is the anchor (reference) image that the selfie is compared against.
In prefill mode, both images are supplied up front in context.subject when the journey starts, so the platform has everything it needs for facematch verification. In adaptive mode, task data is collected progressively as the journey executes. You’re responsible for submitting both images together when the facematch verification task is presented.If only one of face1Image or face2Image is submitted, then the Facematch Verification module cannot perform the comparison and the task returns an error.

​
Resolution

When the Facematch Verification task is reached, submit face1Image (selfie) and face2Image (anchor) together in the API payload:
JSON
{
  "intent": "Complete",
  "instanceId": "<instanceId>",
  "taskId": "<taskId>",
  "data": {
    "context": {
      "subject": {
        "biometrics": [
          {
            "face1Image": "<base64-encoded string>",
            "face2Image": "<base64-encoded string>"
          }
        ]
      }
    }
  }
}

​
Why this differs from prefill

Prefill journeys front-load all subject data when the journey starts, so modules that depend on multiple inputs receive them before any task runs. Adaptive journeys collect data task-by-task, which means modules with multi-input dependencies, such as facematch verification must receive all required inputs in the API payload for that task.If a task errors in adaptive mode but works in prefill, check the module’s reference page for the inputs that task expects.
The Webhook module is a variant, so when the webhook fires, the journey technically hasn’t completed yet. Calling /journey/state/fetch immediately after receiving the webhook can return a state that doesn’t yet reflect journey completion.To handle this:
  • Implement a short delay before calling /journey/state/fetch after receiving the webhook.
  • Implement a retry mechanism on your /journey/state/fetch call to handle cases where the state isn’t yet finalised.

​
Symptom

You start a journey that contains a Webhook module in prefill mode. Your webhook endpoint receives a POST as part of the journey execution, before the instanceId is returned to your system. Because this is the first time your system has seen this instanceId, it isn’t tracking it, so the webhook gets dropped and you can’t act on it or fetch the results.

​
Cause

In prefill mode, the /journey/start call is synchronous by default. The call only returns its response, including the instanceId, after every module in the journey has finished processing.The Webhook module runs inside the journey, as the last module before the journey completes. Its payload includes the instanceId:
JSON
{
  "webhookCreatedAt": "2026-05-08T14:04:16.479398891Z",
  "deliveryId": "5ac674f6e2be56490a6d626c01ca9b228c99a37465e9e67c8ca21ae07b28e294",
  "instanceId": "PiLMes-cSuYR8aHYgtVco07_",
  "message": "Customer verification completed"
}
The webhook fires before the synchronous /journey/start call returns, so your application receives the webhook before it has the instanceId from the API response. The instanceId is in both places, but the webhook arrives first, so your system has nothing to match it against.

​
Resolution

Run journeys that contain a Webhook module in asynchronous mode. Add "async": true to the config object in the request context when you call /journey/start:
cURL
curl --request POST \
  --url https://eu.platform.go.gbgplc.com/captain/api/journey/start \
  --header 'Authorization: Bearer your_access_token' \
  --header 'Content-Type: application/json' \
  --data '{
    "resourceId": "your-journey-resourceID@2z5wz848",
    "context": {
      "config": { "async": true },
      "subject": {
        "identity": {
          "firstName": "Jane",
          "lastNames": ["Doe"],
          "dateOfBirth": "1992-10-01"
        },
        "documents": [],
        "biometrics": []
      }
    }
  }'
In asynchronous mode, /journey/start returns the instanceId immediately and the journey processes in the background. Store the instanceId, then match the webhook against it when it arrives and call /journey/state/fetch to retrieve the result:
  1. Call /journey/start with "config": { "async": true } and store the returned instanceId.
  2. When the webhook arrives, look up the stored instanceId from the payload.
  3. Call /journey/state/fetch for that instanceId to retrieve the final state. If the state isn’t finalised yet, apply the short delay or retry described in “Webhook fires before the journey completes” above.

​
Why this differs from synchronous prefill

Synchronous prefill suits callers that want a single blocking request that returns the full result, with no webhook involved. When you add a Webhook module, the webhook fires from inside the journey before the synchronous response returns, so you receive the completion signal before the instanceId. Asynchronous mode gives you the instanceId up front, so the webhook becomes a signal you can act on. It also avoids client-side timeouts on long-running prefill journeys.For all execution modes, see Step 2: Start a journey and How to use and configure a Webhook module.

​
Symptom

You submit a full street address in the PEPs and Sanctions request, but the screening results only appear to consider the subject’s name, date of birth, and country. This leads to more false positive matches than expected, particularly in ongoing monitoring (OGM).

​
Cause

The PEPs and Sanctions screening service only uses country and city (locality) when matching an address.It does not use street-level detail. This is by design, the service compares submitted details against watchlist records, which themselves typically only hold country and city-level address data.You can see this in the available hit types. The most granular address-based match codes are Full name, DOB, city and country matched and Full name, city and country matched.There is no match type that includes street name or building number.For details, see the PEPs and Sanctions module reference.The input payload reflects this, the currentAddress object only accepts locality and country:
JSON
{
  "context": {
    "subject": {
      "identity": {
        "firstName": "<string>",
        "lastNames": ["<string>"],
        "dateOfBirth": "<YYYY-MM-DD>",
        "currentAddress": {
          "locality": "<string>",
          "country": "<ISO 3166-1 alpha-3 country code>"
        }
      }
    }
  }
}

​
Resolution

To improve match accuracy and reduce false positives, always populate both currentAddress.locality (city or town) and currentAddress.country when they are available.Providing the city in addition to the country gives the screening service more identity elements to match against, which narrows results and lowers the false positive rate. Street-level fields are not used and do not need to be sent.