{"id":21012632,"url":"https://github.com/developersdigest/get_started_with_langchain_in_nodejs","last_synced_at":"2025-07-12T14:35:27.725Z","repository":{"id":157638152,"uuid":"630502263","full_name":"developersdigest/Get_Started_with_LangChain_in_Nodejs","owner":"developersdigest","description":null,"archived":false,"fork":false,"pushed_at":"2024-09-25T20:54:46.000Z","size":15,"stargazers_count":44,"open_issues_count":1,"forks_count":14,"subscribers_count":3,"default_branch":"main","last_synced_at":"2025-05-15T04:33:26.853Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":null,"language":"JavaScript","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/developersdigest.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2023-04-20T14:16:36.000Z","updated_at":"2024-11-04T00:18:37.000Z","dependencies_parsed_at":null,"dependency_job_id":"2eded3da-8311-4171-a0a2-1f9a6cee95de","html_url":"https://github.com/developersdigest/Get_Started_with_LangChain_in_Nodejs","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/developersdigest/Get_Started_with_LangChain_in_Nodejs","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/developersdigest%2FGet_Started_with_LangChain_in_Nodejs","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/developersdigest%2FGet_Started_with_LangChain_in_Nodejs/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/developersdigest%2FGet_Started_with_LangChain_in_Nodejs/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/developersdigest%2FGet_Started_with_LangChain_in_Nodejs/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/developersdigest","download_url":"https://codeload.github.com/developersdigest/Get_Started_with_LangChain_in_Nodejs/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/developersdigest%2FGet_Started_with_LangChain_in_Nodejs/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":265004063,"owners_count":23696347,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-11-19T09:37:57.932Z","updated_at":"2025-07-12T14:35:27.719Z","avatar_url":"https://github.com/developersdigest.png","language":"JavaScript","readme":"\n# Retrieval-based QA System with Embeddings using LangChain\n\nThis project implements a retrieval-based question answering (QA) system using embeddings and the LangChain library. The system processes a text file, creates a vector store, and uses it to answer questions based on the content.\n\n## Contents\n\nThe project consists of the following key files:\n\n- `index.js`: The main JavaScript file containing the core logic\n- `.env`: Environment file for storing API keys\n- `package.json` and `package-lock.json`: Node.js project configuration files\n- `readme.md`: Project documentation\n\n## How it Works\n\n1. **Setup and Initialization**:\n   - The code imports necessary modules from LangChain and other libraries.\n   - It loads environment variables, including the OpenAI API key.\n\n2. **Vector Store Creation**:\n   - If a vector store doesn't exist, the system:\n     - Reads the input text file\n     - Splits the text into chunks\n     - Creates embeddings using OpenAI's model\n     - Stores these embeddings in a vector store (HNSWLib)\n\n3. **Question Answering**:\n   - The system uses a RetrievalQAChain, which combines:\n     - The OpenAI language model\n     - The vector store as a retriever\n\n4. **Query Processing**:\n   - When given a question, the system:\n     - Retrieves relevant information from the vector store\n     - Uses the language model to generate an answer based on the retrieved context\n\n## Usage\n\nTo use this system:\n\n1. Ensure you have the required dependencies installed (see `package.json`).\n2. Set up your OpenAI API key in the `.env` file.\n3. Prepare your input text file (default name: \"The_Creative_Act\").\n4. Run the `index.js` script, which will:\n   - Create or load the vector store\n   - Process the specified question\n   - Output the answer\n\n## Input and Output\n\n### Input:\n- A text file containing the corpus of information\n- A question string defined in the `index.js` file\n\n### Output:\n- The system logs the answer to the console\n\n## Dependencies\n\nThe project relies on several npm packages, including:\n- `langchain`: For the core QA and embedding functionality\n- `hnswlib-node`: For efficient similarity search\n- `dotenv`: For managing environment variables\n\n## Notes\n\n- The system uses OpenAI's API, so ensure you have proper authentication set up.\n- The vector store is saved locally, allowing for faster subsequent runs.\n- This implementation is designed for Node.js environments.\n","funding_links":[],"categories":[],"sub_categories":[],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdevelopersdigest%2Fget_started_with_langchain_in_nodejs","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fdevelopersdigest%2Fget_started_with_langchain_in_nodejs","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdevelopersdigest%2Fget_started_with_langchain_in_nodejs/lists"}