LangChain: Develop AI web-apps with JavaScript and LangChain from Udemy

What's inside

Learning objectives

Chat with anything - use ai to chat with books, videos, etc.
Supercharge your work - create autonomous ai agents that can "think" through complex tasks

Launch your product - display your ai projects for potential employers/customers to see
Troubleshoot anything - how to use ai tools beyond chatgpt to become the "10x developer"

Chat with anything - use ai to chat with books, videos, etc.
Supercharge your work - create autonomous ai agents that can "think" through complex tasks
Launch your product - display your ai projects for potential employers/customers to see
Troubleshoot anything - how to use ai tools beyond chatgpt to become the "10x developer"

Syllabus

Set up environment and start writing your first lines of LangChain!

1.1 • Developer Environment Setup

Note: Node Version

1.2 Cloning the Repository

(Optional) Downloading the Course Materials Manually

1.3 • Extensions to Make Life Easier

1.4 • Extensions to Make Life Easier (Cont.)

The most helpful resource here is the LangChain KapaAI.

You can ask your questions to an AI assistant that is trained on AI!

1.6 • API Keys Needed

This step is crucial so that we'll have API keys in the NodeJS runtime environment.

1.7 • Set API Usage Limits (Optional)

IMPORTANT: 1.8 Setting API Keys In Terminal

(OPTIONAL FOR WINDOWS USERS) Setting API keys in the Terminal

1.8 Course Resources

1.9 LangChain Quick Start Guide

NPM Issues (npm install, npm run dev)? – TRY THIS!

(Optional) NextJS/React/Tailwind Crash Course Part 1

(Optional) NextJS/React/Tailwind Crash Course Part 2

(Optional) NextJS/React/Tailwind Crash Course Part 3

(Optional) NextJS/React/Tailwind Crash Course Part 4

Memory (Project) + NextJS Intro

2.0 • Memory Demo

2.1 • Theory Intro

NOTE: To skip this section, simply copy the app/memory/page-finished.jsx

2.3 • Connecting the Frontend/Backend in NextJS

2.4 • Setting up the Backend

2.5 • Handling the Response in the Frontend

2.6 • Memory Summary

2.7 • Conclusion

Streaming (Project)

LangChain provides a streaming API that allows you to get words streamed back to you as they are generated. This is useful for chatbots, where you want to show the user what is being generated as it is being generated. You can find an example of how to use the streaming API in the LangChain documentation.

3.1 • Set up the Frontend

3.2 • Stream Responses from Backend

3.3 • Streaming Conclusion

PDF Chatbot (Project)

4.0 • PDF Chatbot Demo

4.1 • Set Up Pinecone

4.2 • Quick Review of Frontend

4.3 • Using PDFLoader (pdf-upload.js)

4.4 • Character Text Splitter (pdf-upload.js)

4.5 • How do Embeddings Work? (pdf-upload.js)

4.6 • Initialize Pinecone (pdf-query.js)

The VectorDBQAChain is a tool that allows you to interact with a vector store in an agentic manner. It is created by combining an LLM with a vector store, and can be used to answer questions about the data in the vector store. To use the VectorDBQAChain, you first need to create a vector store with your data, and then create the chain using the OpenAI LLM and the vector store. Once you have the chain, you can create a tool to use it, and then use the tool just like any other tool.

4.8 • Conclusion

Review

Lecture 40A (Optional): Namespaces in Pinecone Part 1

Lecture 40B (Optional): Namespaces in Pinecone Part 2

Lecture 40C (Optional): Namespaces in Pinecone Part 3: Upload

Lecture 40D (Optional): Namespaces in Pinecone Part 4: Query

Lecture 40E (Optional): Namespaces in Pinecone Part 5: Demo

YouTube Chatbot (Project)

5.0 • YouTube Chatbot Demo

5.1 • Frontend Setup

5.2 • YouTube Transcript API

ChatOpenAI is a chat model provided by LangChain. It allows you to get chat completions by passing one or more messages to the chat model. The response will also be a message. The types of messages currently supported in LangChain are AIChatMessage, HumanChatMessage, SystemChatMessage, and a generic ChatMessage. Most of the time, you'll just be dealing with HumanChatMessage, AIChatMessage, and SystemChatMessage. You can also use the streaming API to get words streamed back to you as they are generated. This is useful for chatbots, where you want to show the user what is being generated as it is being generated.

HNSWLib is an in-memory vector store that can be saved to a file and is only available on Node.js. It is used for similarity search and uses HNSWLib. You can create a new index from texts or a loader, save an index to a file and load it again, and filter documents.

5.5 • Handling Follow Up Questions to the Chain

5.6 • Conclusion

AI Content Generator (Project)

6.0 • AI Content Generator Demo

6.1 • Overview of Project

6.2 • Transcript API

6.3 • Video Metadata

6.4.1 • SerpAPI Tool

The Web Browser Tool allows an agent to visit a website and extract information. It has two modes of operation:

When called with only a URL, it produces a summary of the website contents.
When called with a URL and a description of what to find, it uses an in-memory Vector Store to find the most relevant snippets and summarize those.

To use the Web Browser Tool, you need to install the dependencies cheerio and axios. The tool can be used standalone or in an agent.

The "zero-shot-react-description" agent is a type of agent that can be used with text LLMs. It is a stateless wrapper around an agent prompt chain, such as MRKL, that formats tools into the prompt and parses responses obtained from the chat model. This agent is recommended for use with small tasks.

6.4.4 • Connecting it to the Handler

6.5.1 Summary

6.5.2 LLM Chain Prompt Template

6.6.1 Follow Up Questions

6.6.2 Conclusion

RoboHR (Project)

7.0 • RoboHR Demo

7.1 • High Level Overview

7.2 • File Overview

7.3 • Convert Resumes to Embeddings

7.4 • Resume Upload Section

The SummaryChain is a chain provided by LangChain that can be used to generate a summary of a given input text. To use it, you can import it from langchain/chains and create an instance of it. Once you have created the chain, you can call its call method with a text input to get a summary of the text.

7.8 • Upload to Pinecone (recommended)

7.8.1 Supabase Part 1: Uploading (alternative, if waitlisted on Pinecone)

7.8.2 Supabase Part 2: Querying (alternative, if waitlisted on Pinecone)

7.8.3 If you're enjoying, please consider leaving a review!

7.9 • Vector Database Question Answer Chain

7.10 • Conclusion

Deployment (Optional)

8.0 Upload to GitHub and Vercel

8.1 Fixing Deployment Issues

8.2 Summary

Good to know

Know what's good

, what to watch for

, and possible dealbreakers

Taught by Shawn Esquivel, an expert in the industry

Highly relevant to current industry practices

Examines cutting-edge tools and frameworks

In-demand skills

Offers hands-on learning

For skill development, suitable for beginners

Career center

Learners who complete LangChain: Develop AI web-apps with JavaScript and LangChain will develop knowledge and skills that may be useful to these careers:

AI Engineer

An AI Engineer is responsible for developing, deploying, and maintaining AI systems. They work on a variety of projects, from developing new algorithms to improving existing ones. This course can help you become an AI Engineer by providing you with the skills you need to develop and deploy AI systems. You will learn about the different types of AI algorithms, how to train and evaluate them, and how to deploy them in production. You will also learn about the ethical implications of AI and how to use AI responsibly.

See salaries and explore the career path for AI Engineer

Software Engineer

A Software Engineer is responsible for designing, developing, and maintaining software systems. They work on a variety of projects, from developing new features to fixing bugs. This course can help you become a Software Engineer by providing you with the skills you need to design, develop, and deploy software systems. You will learn about the different phases of the software development lifecycle, how to use different programming languages and tools, and how to test and debug software. You will also learn about the ethical implications of software development and how to develop software responsibly.

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Data Scientist

A Data Scientist is responsible for collecting, analyzing, and interpreting data. They work on a variety of projects, from developing new data analysis algorithms to improving existing ones. This course can help you become a Data Scientist by providing you with the skills you need to collect, analyze, and interpret data. You will learn about the different types of data analysis algorithms, how to use different data analysis tools, and how to communicate your findings to others. You will also learn about the ethical implications of data science and how to use data responsibly.

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AI Researcher

An AI Researcher is responsible for developing new AI algorithms and techniques. They work on a variety of projects, from developing new ways to train AI models to improving existing ones. This course can help you become an AI Researcher by providing you with the skills you need to develop new AI algorithms and techniques. You will learn about the different types of AI algorithms, how to train and evaluate them, and how to deploy them in production. You will also learn about the ethical implications of AI and how to use AI responsibly.

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Machine Learning Engineer

A Machine Learning Engineer is responsible for developing and deploying machine learning models. They work on a variety of projects, from developing new machine learning algorithms to improving existing ones. This course can help you become a Machine Learning Engineer by providing you with the skills you need to develop and deploy machine learning models. You will learn about the different types of machine learning algorithms, how to train and evaluate them, and how to deploy them in production. You will also learn about the ethical implications of machine learning and how to use machine learning responsibly.

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Mobile Developer

A Mobile Developer is responsible for developing and maintaining mobile apps. They work on a variety of projects, from developing new mobile apps to updating existing ones. This course can help you become a Mobile Developer by providing you with the skills you need to develop and maintain mobile apps. You will learn about the different mobile development languages and tools, how to design and develop mobile apps, and how to deploy mobile apps to the app store. You will also learn about the ethical implications of mobile development and how to develop mobile apps responsibly.

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Web Developer

A Web Developer is responsible for developing and maintaining websites. They work on a variety of projects, from developing new websites to updating existing ones. This course can help you become a Web Developer by providing you with the skills you need to develop and maintain websites. You will learn about the different web development languages and tools, how to design and develop websites, and how to deploy websites to the web. You will also learn about the ethical implications of web development and how to develop websites responsibly.

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Cloud Engineer

A Cloud Engineer is responsible for designing, developing, and maintaining cloud-based systems. They work on a variety of projects, from developing new cloud-based applications to improving existing ones. This course can help you become a Cloud Engineer by providing you with the skills you need to design, develop, and maintain cloud-based systems. You will learn about the different cloud computing platforms, how to use cloud computing tools, and how to deploy cloud-based systems. You will also learn about the ethical implications of cloud computing and how to use cloud computing responsibly.

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Data Analyst

A Data Analyst is responsible for collecting, analyzing, and interpreting data. They work on a variety of projects, from developing new data analysis techniques to improving existing ones. This course can help you become a Data Analyst by providing you with the skills you need to collect, analyze, and interpret data. You will learn about the different types of data analysis techniques, how to use different data analysis tools, and how to communicate your findings to others. You will also learn about the ethical implications of data analysis and how to use data responsibly.

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Product Manager

A Product Manager is responsible for developing and managing products. They work on a variety of projects, from developing new products to improving existing ones. This course can help you become a Product Manager by providing you with the skills you need to develop and manage products. You will learn about the different phases of the product development lifecycle, how to use different product management tools, and how to communicate with stakeholders. You will also learn about the ethical implications of product management and how to develop products responsibly.

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Business Analyst

A Business Analyst is responsible for analyzing business processes and identifying opportunities for improvement. They work on a variety of projects, from developing new business processes to improving existing ones. This course can help you become a Business Analyst by providing you with the skills you need to analyze business processes and identify opportunities for improvement. You will learn about the different types of business analysis techniques, how to use different business analysis tools, and how to communicate your findings to others. You will also learn about the ethical implications of business analysis and how to use business analysis responsibly.

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UX Designer

A UX Designer is responsible for designing the user experience for products and services. They work on a variety of projects, from designing new user interfaces to improving existing ones. This course can help you become a UX Designer by providing you with the skills you need to design user experiences. You will learn about the different principles of UX design, how to use different UX design tools, and how to communicate with stakeholders. You will also learn about the ethical implications of UX design and how to design user experiences responsibly.

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Technical Writer

A Technical Writer is responsible for writing and maintaining technical documentation. They work on a variety of projects, from writing new user manuals to updating existing ones. This course can help you become a Technical Writer by providing you with the skills you need to write and maintain technical documentation. You will learn about the different types of technical documentation, how to write clear and concise documentation, and how to use different documentation tools. You will also learn about the ethical implications of technical writing and how to write documentation responsibly.

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Project Manager

A Project Manager is responsible for planning, executing, and closing projects. They work on a variety of projects, from developing new products to improving existing ones. This course can help you become a Project Manager by providing you with the skills you need to plan, execute, and close projects. You will learn about the different phases of the project management lifecycle, how to use different project management tools, and how to communicate with stakeholders. You will also learn about the ethical implications of project management and how to manage projects responsibly.

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Information Architect

An Information Architect is responsible for organizing and structuring information. They work on a variety of projects, from designing new information architectures to improving existing ones. This course can help you become an Information Architect by providing you with the skills you need to organize and structure information. You will learn about the different principles of information architecture, how to use different information architecture tools, and how to communicate with stakeholders. You will also learn about the ethical implications of information architecture and how to design information architectures responsibly.

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