Trace without setting environment variables

As mentioned in other guides, the following environment variables allow you to configure tracing enabled, the api endpoint, the api key, and the tracing project:

• LANGCHAIN_TRACING_V2
• LANGCHAIN_API_KEY
• LANGCHAIN_ENDPOINT
• LANGCHAIN_PROJECT

In some environments, it is not possible to set environment variables. In these cases, you can set the tracing configuration programmatically.

Recently changed behavior

Due to a number of asks for finer-grained control of tracing using the trace context manager, we changed the behavior of with trace to honor the LANGCHAIN_TRACING_V2 environment variable in version 0.1.95 of the Python SDK. You can find more details in the release notes. The recommended way to disable/enable tracing without setting environment variables is to use the with tracing_context context manager, as shown in the example below.

Python

The recommended way to do this in Python is to use the tracing_context context manager. This works for both code annotated with traceable and code within the trace context manager.

import openai
from langsmith import Client, tracing_context, traceable
from langsmith.wrappers import wrap_openai

langsmith_client = Client(
  api_key="YOUR_LANGSMITH_API_KEY",  # This can be retrieved from a secrets manager
  api_url="https://api.smith.langchain.com",  # Update appropriately for self-hosted installations or the EU region
)

client = wrap_openai(openai.Client())

@traceable(run_type="tool", name="Retrieve Context")
def my_tool(question: str) -> str:
  return "During this morning's meeting, we solved all world conflict."

@traceable
def chat_pipeline(question: str):
  context = my_tool(question)
  messages = [
      { "role": "system", "content": "You are a helpful assistant. Please respond to the user's request only based on the given context." },
      { "role": "user", "content": f"Question: {question}
Context: {context}"}
  ]
  chat_completion = client.chat.completions.create(
      model="gpt-4o-mini", messages=messages
  )
  return chat_completion.choices[0].message.content

# Can set to False to disable tracing here without changing code structure
with tracing_context(enabled=True):
  # Use langsmith_extra to pass in a custom client
  chat_pipeline("Can you summarize this morning's meetings?", langsmith_extra={"client": langsmith_client})

TypeScript

In TypeScript, you can pass in both the client and the tracingEnabled flag to the traceable decorator.

import { Client } from "langsmith";
import { traceable } from "langsmith/traceable";
import { wrapOpenAI } from "langsmith/wrappers";
import { OpenAI } from "openai";

const client = new Client({
    apiKey: "YOUR_API_KEY",  // This can be retrieved from a secrets manager
    apiUrl: "https://api.smith.langchain.com",  // Update appropriately for self-hosted installations or the EU region
});

const openai = wrapOpenAI(new OpenAI());

const tool = traceable((question: string) => {
    return "During this morning's meeting, we solved all world conflict.";
}, { name: "Retrieve Context", runType: "tool" });

const pipeline = traceable(
    async (question: string) => {
        const context = await tool(question);
        
        const completion = await openai.chat.completions.create({
            model: "gpt-4o-mini",
            messages: [
                { role: "system" as const, content: "You are a helpful assistant. Please respond to the user's request only based on the given context." },
                { role: "user" as const, content: `Question: ${question}\nContext: ${context}`}
            ]
        });
        
        return completion.choices[0].message.content;
    
    }, 
    { name: "Chat", client, tracingEnabled: true }
);

await pipeline("Can you summarize this morning's meetings?");