
Before diving into my RAG (Retrieval-Augmented Generation) project, I decided to explore LangSmith. The project I’m about to undertake has the potential to become increasingly complex as it progresses. With complex code, errors can often arise, and addressing these issues can be challenging. This is where LangSmith comes in as a helpful tool.
LangSmith is a service specifically designed to troubleshoot and debug problems, particularly when the output of your code differs from expectations. It excels at pinpointing where issues occur, making it an ideal solution for debugging complex scenarios.
By using LangSmith, I believe I’ll be able to streamline the development process for my RAG project. With this tool in hand, I plan to proceed with confidence and manage the project more efficiently.
LangSmith?
LangSmith, as part of the LangChain ecosystem, is a versatile platform designed to support the development, testing, evaluation, and monitoring of large language model (LLM) applications. Its key features include the following:
Development and Debugging
- LangSmith provides detailed insights into the execution process of RAG (Retrieval-Augmented Generation), allowing users to track and examine code inputs and outputs for efficient debugging.
Testing and Evaluation
- The platform enables thorough testing by analyzing results for various inputs across different models. It also supports automated testing for seamless model evaluation.
Monitoring and Logging
- Keep track of application performance and logs in real-time for better oversight.
Dataset Management
Performance Optimization
Collaboration Tools
Version Control
Cost Tracking
Security and Compliance
Seamless Integration
Start Guide LangSmith 1: A Step-by-Step Guide
Step 1: Sign Up on the LangSmith Website
Visit the LangSmith website and complete the registration process. Once signed in, you’ll be able to access the platform’s features and tools.
https://www.langchain.com/langsmith
Step 2: Generate an API Key
To analyze and manage individual project workflows, you’ll need a unique API Key to distinguish your activities. Follow these steps to create and secure your API Key:
- Click on “Invitations” in the dashboard.
- Select “Create API Key”.
- Finalize by clicking “Create API Key”.



Important Notes About Your API Key
- Store your API Key securely and avoid sharing or exposing it to others.
- The API Key is essential for integrating and utilizing LangSmith’s features within your project.
Next Steps
With your API Key set up, you’re ready to start leveraging LangSmith for your projects. In future posts, I’ll walk you through how to apply LangSmith specifically in a RAG (Retrieval-Augmented Generation) project, including debugging, testing, and optimization processes.
Stay tuned to explore how LangSmith can transform your workflow and make managing LLM applications more efficient!
Start Guide LangSmith 2: Using LangChain Hub
In the previous post, we explored the basic usage of LangSmith. Now, let’s dive into one of its convenient features:
LangChain HUB(https://smith.langchain.com/hub)
What is LangChain Hub?
When working with large language models (LLMs), one of the most commonly discussed terms is Prompt. A well-designed prompt is key to obtaining high-quality results from an LLM, which is why prompt engineering is so important.
However, writing prompts manually for every test case in an LLM project can be incredibly inefficient. To address this, LangSmith provides LangChain Hub, a repository where you can explore and test prompts created by other users. With LangChain Hub, you can easily access and incorporate prompts into your projects, saving time and effort.
How to Use LangChain Hub
- Click on “Prompts” in the dashboard.
- Click on the LangChain Hub option to access the repository.

LangChain Hub provides a variety of pre-designed prompts, which you can seamlessly pull into your project. Here’s how to use it:
from langchain import hub
# Replace "LangChain Hub Title" with the title of the prompt you want to use
prompt = hub.pull("LangChain Hub Title")
Tips for Using LangChain Hub
- If you’re unsure how to use a specific prompt, select the prompt from the LangChain Hub interface and scroll down to find the relevant code snippet. This will provide clear guidance on how to implement it in your project.
- Experiment with different prompts to identify the ones that deliver the best results for your specific use case.

Next Steps
Starting in the next post, we’ll apply LangSmith and LangChain Hub as we dive into a practical RAG Project. Stay tuned for detailed insights and step-by-step guidance!