Assigning name for multiple generation observations

[gadirajupavantiwari]

Describe your question

I am having many generation observation names as response, I want to assign names for them, how to do
I am using context manager, I have many generation observation steps in my code repo, where and how I have to update

Langfuse Cloud or Self-Hosted?

Langfuse Cloud

If Self-Hosted

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If Langfuse Cloud

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SDK and integration versions

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Pre-Submission Checklist

• I have checked for existing issues/discussions and consulted Langfuse AI.

[inkeep-ai-assistant[bot]]

You can assign custom names to generation observations using the name parameter when creating them with the context manager.

Using the Context Manager

When using start_as_current_observation(), pass the name parameter directly:

from langfuse import get_client

langfuse = get_client()

with langfuse.start_as_current_observation(as_type="span", name="outer-process") as outer_span:
    
    with langfuse.start_as_current_observation(as_type="generation", name="llm-step-1") as gen1:
        # gen1 is active, child of outer_span
        gen1.update(output="LLM 1 output")
    
    with langfuse.start_as_current_observation(as_type="generation", name="llm-step-2") as gen2:
        # gen2 is active, child of outer_span
        gen2.update(output="LLM 2 output")

(1)

Each generation observation gets its own descriptive name ("llm-step-1", "llm-step-2", etc.).

For Nested Generations

You can also create generations as children of other spans:

with outer_span.start_as_current_observation(name="intermediate-step") as mid_span:
    
    with mid_span.start_as_current_observation(as_type="generation", name="llm-step-2") as gen2:
        gen2.update(output="LLM 2 output")

(1)

Using the @observe Decorator

If you're using the decorator approach, set the name directly in the decorator:

from langfuse import observe

@observe(name="llm-call", as_type="generation")
async def my_async_llm_call(prompt_text):
    return "LLM response"

(1)

For each generation step in your code, simply add the name parameter with a descriptive string when creating the observation. This will replace the default "response" name with your custom name in the Langfuse UI.

📚 Sources:

1. Instrumentation

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