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Starter Tutorial

Make sure you have installed LlamaIndex.TS and have an OpenAI key. If you haven't, check out the installation guide.

From scratch(node.js + TypeScript):​

In a new folder:

npm init
npm install -D typescript @types/node

Create the file example.ts. This code will load some example data, create a document, index it (which creates embeddings using OpenAI), and then creates query engine to answer questions about the data.

import fs from "node:fs/promises";

import {
  Document,
  MetadataMode,
  NodeWithScore,
  VectorStoreIndex,
} from "llamaindex";

async function main() {
  // Load essay from abramov.txt in Node
  const path = "node_modules/llamaindex/examples/abramov.txt";

  const essay = await fs.readFile(path, "utf-8");

  // Create Document object with essay
  const document = new Document({ text: essay, id_: path });

  // Split text and create embeddings. Store them in a VectorStoreIndex
  const index = await VectorStoreIndex.fromDocuments([document]);

  // Query the index
  const queryEngine = index.asQueryEngine();
  const { response, sourceNodes } = await queryEngine.query({
    query: "What did the author do in college?",
  });

  // Output response with sources
  console.log(response);

  if (sourceNodes) {
    sourceNodes.forEach((source: NodeWithScore, index: number) => {
      console.log(
        `\n${index}: Score: ${source.score} - ${source.node.getContent(MetadataMode.NONE).substring(0, 50)}...\n`,
      );
    });
  }
}

main().catch(console.error);

Create a tsconfig.json file in the same folder:

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "esnext",
    "moduleResolution": "bundler",
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "strict": true,
    "skipLibCheck": true,
    "lib": ["ES2022"],
    "types": ["node"],
    "outDir": "./lib",
    "tsBuildInfoFile": "./lib/.tsbuildinfo",
    "incremental": true,
    "composite": true
  },
  "ts-node": {
    "files": true,
    "compilerOptions": {
      "module": "commonjs"
    }
  },
  "include": ["./**/*.ts"]
}

Now you can run the code with

npx tsx example.ts

Also, you can clone our examples and try them out:

npx degit run-llama/LlamaIndexTS/examples my-new-project
cd my-new-project
npm install
npx tsx ./vectorIndex.ts

From scratch (Next.js + TypeScript):​

You just need one command to create a new Next.js project:

npx create-llama@latest