> ## Documentation Index
> Fetch the complete documentation index at: https://koreai.mintlify.app/llms.txt
> Use this file to discover all available pages before exploring further.
# Test and Debug External NLU
[Back to External NLU Integrations](/ai-for-service/integrations/overview#external-nlu)
Use these tools to validate that your External NLU adapter is working correctly and to understand intent detection behavior.
***
## Test in Talk to Bot
After completing [Adapter Configuration](/ai-for-service/integrations/external-nlu/external-nlu-adapters#adapter-configuration) and [enabling the Dialogflow API](/ai-for-service/integrations/external-nlu/dialogflow-engine#enable-the-dialogflow-api):
1. Open your app and click **Test**.
2. Enter a user utterance that matches an intent configured in Dialogflow Essentials.
3. In the **Debug Log** panel, confirm the message: **intent identified using External NLU is initiated**.
***
## Debug Log
The Debug Log shows whether intent was detected by External NLU before the **Intent node initiated** entry. If the API call fails, an error response appears in the log.
* Intent detected by the external NLU engine is always marked as a **Definitive Match**.
* If intent is not detected by External NLU, this is also tracked in the Debug Log.
* Hover over the information icon to view the **K-Traceid** and **X-Traceid** for each interaction. K-Traceid tracks and debugs platform activities; X-Traceid is a unique per-message identifier included in platform logs.
* Under **Session Context & Variables**, inspect intent and entity variables in detail.
***
## Utterance Testing
[Utterance Testing](/ai-for-service/automation/testing/testing-your-bot-with-nlp) provides NLP Analysis for individual utterances. When intent is detected by an external engine, the utterance is not sent to the Platform NLP engine, and the **Matched Intents** and **Fields/Entities** tables are not shown.
* **Intent detected by external engine:**
* Click **View Response** to see the raw API response from the external NLU engine (available whether or not intent was detected).
* **Intent not detected by external engine** — Platform NLU acts as fallback. NLP analysis shows results from all three Platform engines plus ranking and resolver. See [Ranking and Resolver](/ai-for-service/automation/natural-language/training/ranking-and-resolver).
* **Intent detected but not mappable** — Platform NLU acts as fallback. NLP analysis displays a message with the API response containing detected intents and parameters.
***
## Batch Testing
Test results (TP, FP, TN, FN) are based on the combined outcome of External NLU and Platform NLU:
| Result | Condition |
| ------ | ------------------------------------------------ |
| TP | Expected intent detected by either engine |
| FP | Wrong intent identified by the net result |
| TN | No intent detected by any engine (none expected) |
| FN | No intent expected, but some intent was detected |
External NLU scores are not included in comparisons — there is no common scoring baseline across engines.
In the **Matched Intent Score** column of the downloaded CSV, intents detected by External NLU appear as `ExtNLU` (no score) instead of ML, FM, or KG scores.
If External NLU returns multiple intents, thresholds are evaluated for all of them before concluding the test result.
See [Batch Testing](/ai-for-service/automation/testing/regression-testing/batch-testing) for more details.
***
## Health and Monitoring
Go to **Test Cases > Detailed Analysis** to see intents and entities identified by External NLU (displayed without scores). The Traits engine operates independently of external NLU.
When external NLU is enabled, some Health and Monitoring recommendations may not apply — recommendations are based on training data in the Platform, not the external engine.
See [Health and Monitoring](/ai-for-service/automation/testing/regression-testing/health-and-monitoring/virtual-assistants-health-and-monitoring) for more details.
***
## NLP Insights
NLP Insights captures intent identified and not-identified utterances with their NLP analysis. Failed External NLU API call details appear in the debug logs of NLP Insights.
See [NLP Insights](/ai-for-service/analytics/automation/nlp-insights) for more details.
***
## Conversation Behavior
| Behavior | Details |
| --------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Intent triggering | When an intent is detected by the external engine, the corresponding Kore.ai task is triggered based on name mapping (case-insensitive). |
| Detection quality | Depends on training and capabilities of the external engine. |
| Fallback | If external NLU fails to detect an entity, Platform NLP engine is used as fallback. |
| Entity ordering | Define entity nodes in the same sequence on both the platform and the external engine. |
| Interruption handling | Only one behavior is supported: **Switch to a new task without notification and discard the current task**. See [Interruption Management Settings](/ai-for-service/automation/intelligence/conversation-management/manage-interruptions). |
| API failure | If External NLU API returns an error or is unreachable, a fallback intent activates with the response: **Error in continuing the conversation due to incorrect bot definition**. See [Standard Responses](/ai-for-service/automation/intelligence/conversation-management/standard-responses). |
The platform handles all other conversation behaviors, including:
* Re-prompts, error prompts, message responses, widgets
* Channel support and channel-specific customizations
* Authorization for service calls, alerts, small talk
* Language detection, sentiment analysis, traits identification
* Sub-intent and follow-up intent scanning decisions
* Interruption handling, entity/intent priority settings
* PII masking/redaction
* Dialog task node execution, context object construction
* Response messages, fulfillment, and logical flows
Response messages and fulfillment data from the external engine are ignored.
Intent and entity mapping uses case-insensitive name comparison between the two platforms.
***
## Follow-up and Sub-Intent Identification
* When all required parameters are available in context, follow-up intent scope activates on External NLU. Once active, utterances are sent to External NLU for intent identification.
* When sub-intent scope is active on the Platform, utterances are sent to External NLU for intent detection along with the parent intent context.