genai_extract_user_prompt

This page explains how to use the genai_extract_user_prompt function in APL.

The genai_extract_user_prompt function extracts the user’s prompt from a GenAI messages array. It returns the content of the last message with the ‘user’ role, which typically contains the user’s question or request to the AI.

You can use this function to analyze user queries, understand common question patterns, perform sentiment analysis on user inputs, or track user behavior and needs.

For users of other query languages

If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.

Splunk SPL users

In Splunk SPL, you would need to filter messages by user role and extract the last one.

Splunk example

| eval user_msgs=mvfilter(match(role, "user"))
| eval user_prompt=mvindex(user_msgs, -1)

ANSI SQL users

In ANSI SQL, you would unnest the array, filter by user role, and select the last message.

SQL example

SELECT 
  conversation_id,
  content as user_prompt
FROM (
  SELECT *, ROW_NUMBER() OVER (PARTITION BY conversation_id ORDER BY msg_index DESC) as rn
  FROM conversations
  CROSS JOIN UNNEST(messages) WITH OFFSET AS msg_index
  WHERE role = 'user'
) WHERE rn = 1

Usage

Syntax

genai_extract_user_prompt(messages)

Parameters

• messages (dynamic, required): An array of message objects from a GenAI conversation. Each message typically contains role and content fields.

Returns

Returns a string containing the content of the last user message in the conversation, or an empty string if no user message is found.

Use case examples

Log analysis

Extract user prompts to analyze common questions and understand what users are asking your AI application.

Query

['sample-http-logs']
| where uri contains '/api/chat'
| extend user_query = genai_extract_user_prompt(todynamic(request_body)['messages'])
| where isnotempty(user_query)
| summarize query_count = count() by user_query
| top 10 by query_count

Run in Playground

Output

user_query	query_count
How do I reset my password?	456
What are your business hours?	342
How can I track my order?	298

This query identifies the most common user questions, helping you understand user needs and improve responses.

List of related functions

• genai_extract_assistant_response: Extracts the assistant’s response. Use this to analyze AI responses along with user prompts.
• genai_extract_system_prompt: Extracts the system prompt. Use this to understand the AI’s configuration when analyzing user queries.
• genai_get_content_by_role: Gets content by any role. Use this for more flexible extraction when you need other specific roles.
• genai_concat_contents: Concatenates all messages. Use this when you need the full conversation instead of just the user prompt.
• genai_estimate_tokens: Estimates token count. Combine with user prompt extraction to analyze prompt sizes.