Setting up LangSmith tracing in LangChain - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the LangSmith tracer.

LangChain

from langchain.tracing import [1]

Drag options to blanks, or click blank then click option'

ALangSmithTracer

BTracer

CLangTracer

DSmithTracer

Attempts:

3 left

💡 Hint

Common Mistakes

Importing a non-existent class like 'LangTracer' or 'SmithTracer'.

Using a generic name like 'Tracer' which is not the correct class.

The correct import is LangSmithTracer from langchain.tracing.

2fill in blank

medium

Complete the code to enable LangSmith tracing in LangChain.

LangChain

import [1]

[1].tracing_enabled = True

Drag options to blanks, or click blank then click option'

Atracing

Blangsmith

CLangSmithTracer

Dlangchain

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to set tracing on langsmith or tracing modules.

Using the tracer class name instead of the module name.

You enable tracing by setting tracing_enabled to True on the langchain module.

3fill in blank

hard

Fix the error in initializing the LangSmith tracer with the API key.

LangChain

tracer = LangSmithTracer(api_key=[1])

Drag options to blanks, or click blank then click option'

ANone

B'YOUR_API_KEY'

Capi_key

DYOUR_API_KEY

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the API key without quotes causing a NameError.

Passing None or a wrong variable name.

The API key must be passed as a string, so it needs quotes around it.

4fill in blank

hard

Fill both blanks to set the tracer and enable tracing in LangChain.

LangChain

import [1]
from langchain.tracing import [2]

[1].tracer = [2](api_key='YOUR_API_KEY')
[1].tracing_enabled = True

Drag options to blanks, or click blank then click option'

Alangchain

BLangSmithTracer

Ctracing

DTracer

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up module and class names.

Forgetting to enable tracing after setting the tracer.

You import langchain and LangSmithTracer, then set the tracer and enable tracing.

5fill in blank

hard

Fill all three blanks to create a LangChain client with LangSmith tracing enabled.

LangChain

import [1]
from langchain.tracing import [2]

[1].tracer = [2](api_key='YOUR_API_KEY')
[1].tracing_enabled = True
client = [1].Client()

Drag options to blanks, or click blank then click option'

Alangchain

BLangSmithTracer

CLangChainTracer

DTracer

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong tracer class names like LangChainTracer.

Not enabling tracing before creating the client.

You import langchain and LangSmithTracer, set the tracer and enable tracing on langchain, then create a client from langchain.Client().

Practice

1. What is the main purpose of setting up LangSmith tracing in a LangChain application?

easy

A. To encrypt data passed between LangChain components

B. To speed up the execution of LangChain components

C. To automatically fix errors in your LangChain code

D. To monitor and visualize the steps of your LangChain workflows

Solution

1. Step 1: Understand LangSmith tracing purpose

   LangSmith tracing is designed to help watch and understand the steps your LangChain app takes.

2. Step 2: Identify the correct purpose

   It does not speed up execution, fix errors automatically, or encrypt data, but helps monitor and visualize workflows.

3. Final Answer:

   To monitor and visualize the steps of your LangChain workflows -> Option D

4. Quick Check:

   Tracing = Monitoring steps [OK]

Hint: Tracing means watching steps clearly in LangChain [OK]

Common Mistakes:

• Thinking tracing speeds up code
• Assuming tracing fixes bugs automatically
• Confusing tracing with data encryption

2. Which of the following is the correct way to create a LangChainTracer for LangSmith tracing?

easy

A. tracer = LangChainTracer()

B. tracer = createTracer()

C. tracer = new LangSmithTracer()

D. tracer = LangSmith.createTracer()

Solution

1. Step 1: Recall LangChainTracer creation syntax

   The LangChainTracer is created by calling its constructor directly: LangChainTracer()

2. Step 2: Check options for correct syntax

   Options B, C, and D use incorrect function or class names or syntax not used in LangChain.

3. Final Answer:

   tracer = LangChainTracer() -> Option A

4. Quick Check:

   Constructor call = LangChainTracer() [OK]

Hint: Use LangChainTracer() constructor to create tracer [OK]

Common Mistakes:

• Using wrong class names like LangSmithTracer
• Calling non-existent functions like createTracer()
• Using 'new' keyword which is not Python syntax

3. Given the code snippet below, what will be the effect of passing the tracer to the LLM?

from langchain.chat_models import ChatOpenAI
from langchain.callbacks import LangChainTracer

tracer = LangChainTracer()
llm = ChatOpenAI(callbacks=[tracer])
response = llm.chat([{'role': 'user', 'content': 'Hello!'}])

medium

A. The LLM will log its steps to LangSmith for tracing

B. The LLM will run without any tracing or logging

C. The code will raise a syntax error due to wrong callback usage

D. The LLM will ignore the tracer and produce no output

Solution

1. Step 1: Understand passing tracer as callback

   Passing LangChainTracer in callbacks enables tracing of LLM steps.

2. Step 2: Analyze code behavior

   The LLM will send its internal steps to LangSmith via the tracer, enabling monitoring.

3. Final Answer:

   The LLM will log its steps to LangSmith for tracing -> Option A

4. Quick Check:

   Callbacks with tracer = tracing enabled [OK]

Hint: Callbacks=[tracer] enables LangSmith tracing [OK]

Common Mistakes:

• Assuming no tracing happens without explicit start call
• Thinking callbacks cause syntax errors here
• Believing tracer disables output

4. Identify the error in this LangSmith tracing setup code:

from langchain.chat_models import ChatOpenAI
from langchain.callbacks import LangChainTracer

tracer = LangChainTracer
llm = ChatOpenAI(callbacks=[tracer])

medium

A. LangChainTracer is not imported correctly

B. LangChainTracer is assigned without parentheses, missing instantiation

C. Callbacks list should be empty for tracing

D. ChatOpenAI does not accept callbacks parameter

Solution

1. Step 1: Check LangChainTracer assignment

   tracer = LangChainTracer misses parentheses, so tracer is a class, not an instance.

2. Step 2: Analyze usage in callbacks

   Passing callbacks=[tracer] passes the class instead of an instance, causing a runtime error when callbacks are used.

3. Final Answer:

   LangChainTracer is assigned without parentheses, missing instantiation -> Option B

4. Quick Check:

   Instantiate with () to create tracer object [OK]

Hint: Always instantiate classes with () before use [OK]

Common Mistakes:

• Assigning class instead of instance
• Calling instance as function
• Ignoring callbacks parameter usage

5. You want to trace both an LLM and a chain in LangChain using LangSmith. Which setup correctly enables tracing for both components?

hard

A. llm = ChatOpenAI()
chain = SomeChain(llm=llm)
tracer = LangChainTracer()
tracer.start()

B. tracer = LangChainTracer
llm = ChatOpenAI(callbacks=tracer)
chain = SomeChain(llm=llm, callbacks=tracer)

C. tracer = LangChainTracer()
llm = ChatOpenAI(callbacks=[tracer])
chain = SomeChain(llm=llm, callbacks=[tracer])

D. tracer = LangChainTracer()
llm = ChatOpenAI()
chain = SomeChain(llm=llm)

Solution

1. Step 1: Instantiate LangChainTracer correctly

   Use tracer = LangChainTracer() to create the tracer instance.

2. Step 2: Pass tracer in callbacks for both LLM and chain

   Both components accept callbacks as a list; passing [tracer] enables tracing on both.

3. Step 3: Evaluate options

   tracer = LangChainTracer() llm = ChatOpenAI(callbacks=[tracer]) chain = SomeChain(llm=llm, callbacks=[tracer]) correctly instantiates tracer and passes it as a list to both components. Others miss instantiation, use wrong types, or omit callbacks.

4. Final Answer:

   tracer = LangChainTracer() llm = ChatOpenAI(callbacks=[tracer]) chain = SomeChain(llm=llm, callbacks=[tracer]) -> Option C

5. Quick Check:

   Instantiate tracer and pass as list to callbacks [OK]

Hint: Instantiate tracer and pass as list to all callbacks [OK]

Common Mistakes:

• Not instantiating tracer with ()
• Passing tracer directly instead of in a list
• Forgetting to add callbacks to chain