Parameter Extractor Node Costs Not Visible in Langfuse

[lyestarzalt]

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Dify version

0.15.3

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

1. Create a workflow with a Parameter Extractor node

2. Configure Langfuse integration
3. Run the workflow
4. Check Langfuse dashboard for cost information
5. LLM node costs are visible, but Parameter Extractor costs are not shown

✔️ Expected Behavior

Langfuse should display cost information for Parameter Extractor nodes.

❌ Actual Behavior

Cost information is only visible for LLM nodes in Langfuse, but not for Parameter Extractor nodes.

[dosubot]

Hey @lyestarzalt, I'm here to help you with any bugs, questions, or contributions you have for Langgenius' Dify project. Let's tackle this issue together!

The issue you're experiencing, where cost information for Parameter Extractor nodes is not visible in Langfuse, might be related to how the metadata is being sent. According to the Dify codebase, the metadata from the Parameter Extractor node does include cost information, such as total tokens, total price, and currency ^[1].

Here are a few things you might want to check:

1. Ensure Metadata is Sent Correctly: Verify that the metadata containing cost information is being correctly sent from the Parameter Extractor node. The relevant metadata keys are NodeRunMetadataKey.TOTAL_TOKENS, NodeRunMetadataKey.TOTAL_PRICE, and NodeRunMetadataKey.CURRENCY.

2. Langfuse Configuration: Double-check the Langfuse configuration to ensure that it is set up to display cost information for all node types, not just LLM nodes.

3. Logging and Error Handling: Look for any logging or error messages in the Dify logs that might indicate issues with sending or processing the cost data for Parameter Extractor nodes.

If these checks do not resolve the issue, it might be helpful to review the specific implementation details in your setup or consult any additional documentation or support resources available for Dify and Langfuse.

To continue talking to Dosu, mention @dosu.

---

^{Help Dosu learn! Give it feedback: Great Response | Irrelevant Answer | Incorrect Sources | Too Verbose | Hallucination | Bug Report | Other}

[lyestarzalt]

From Langfuse

LLM node:

id	name	model	startTime	totalTokens	inputPrice	outputPrice	calculatedInputCost	calculatedOutputCost
654--ef6	llm	gpt-4	2025-02-24T12:54:35.332Z	25	0.00003	0.00006	0.00069	0.00612 (LLM Node)
5f894395-..	llm	gpt-4	2025-02-24T12:54:23.262Z	25	0.00003	0.00006	0.00069	0.00612 (LLM Node)

Parameter Extractor Node:

id	name	model	startTime	totalTokens	inputPrice	outputPrice	calculatedInputCost	calculatedOutputCost
b186f4..c669780	llm	null	2025-02-24T12:52:21.666Z	658	null	null	null	null (Parameter Extractor)
61d6..3dd11	llm	null	2025-02-24T12:51:10.435Z	655	null	null	null	null (Parameter Extractor)
2320..0e5736	llm	null	2025-02-24T12:50:27.542Z	633	null	null	null	null (Parameter Extractor)

From Dify

The Parameter Extractor trace JSON shows:

{
  "usage": {
    "prompt_tokens": 623,
    "prompt_unit_price": "0.03",
    "prompt_price_unit": "0.001",
    "prompt_price": "0.0186900",
    "completion_tokens": 8, 
    "completion_unit_price": "0.06",
    "completion_price_unit": "0.001",
    "completion_price": "0.0004800",
    "total_tokens": 631,
    "total_price": "0.0191700",
    "currency": "USD",
    "latency": 1.4745679500047117
  }
}

In Dify trace logs, Parameter Extractor nodes correctly calculate and track token usage and costs, but these values aren't properly transmitted to Langfuse's cost tracking fields, while LLM nodes successfully populate these same fields.